tag:theconversation.com,2011:/au/topics/mammography-1196/articlesMammography – The Conversation2023-08-01T23:47:58Ztag:theconversation.com,2011:article/2108002023-08-01T23:47:58Z2023-08-01T23:47:58ZAI can help detect breast cancer. But we don’t yet know if it can improve survival rates<figure><img src="https://images.theconversation.com/files/540591/original/file-20230801-37936-vo7733.jpg?ixlib=rb-1.1.0&rect=22%2C99%2C5089%2C2774&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hospital-radiology-room-beautiful-multiethnic-woman-1942278181">Shutterstock</a></span></figcaption></figure><p>Around <a href="https://nbcf.org.au/about-breast-cancer/breast-cancer-stats/#:%7E:text=Breast%20cancer%20is%20the%20most,breast%20cancer%20in%20their%20lifetime.">one in seven Australian women</a> will be diagnosed with breast cancer in their life, with 20,000 new breast cancers diagnosed each year. </p>
<p><a href="https://www.cancer.org.au/mammogram">Mammograms</a> are a key detection tool for early-stage breast cancer and involve placing the breast tissue between two plates and then doing an x-ray. </p>
<p>Scans from mammograms are usually analysed by two doctors. But a Swedish study, published today in the <a href="https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(23)00298-X/fulltext">Lancet</a>, found using artificial intelligence (AI) to help analyse the scans detected 20% more cancers and reduced the workload by 44%.</p>
<p>However there is a risk it could detect small cancers in women that would never cause harm, resulting in unnecessary treatment. </p>
<h2>How are breast cancers currently detected?</h2>
<p>Breast screening using mammography was introduced in Australia <a href="https://www.health.gov.au/our-work/breastscreen-australia-program">more than 30 years ago</a> to detect cancers earlier, allowing more effective and often less invasive treatments. Free mammograms <a href="https://www.health.gov.au/our-work/breastscreen-australia-program/having-a-breast-screen/who-should-have-a-breast-screen">are available</a> to women over the age of 40 and are recommended for all women aged 50-74. </p>
<p>Currently, a mammogram is studied (or “read”) by two doctors (called radiologists) who decide whether the mammogram looks normal or not. If any abnormality is seen, the woman is referred for further tests to a <a href="https://www.health.gov.au/our-work/breastscreen-australia-program/having-a-breast-screen/book-your-free-breastscreen-mammogram-appointment#state-and-territory-contacts">BreastScreen assessment clinic</a>. These tests may include more mammograms, ultrasounds, needle biopsies and sometimes surgery.</p>
<p>Most of those referred are cleared of cancer, but around one in ten are <a href="https://www.aihw.gov.au/reports/cancer-screening/breastscreen-australia-monitoring-report-2022/summary">eventually diagnosed with a breast cancer</a>. </p>
<p>This reading and assessment requires a lot of expertise and time, and is performed by an ageing and diminishing workforce who are retiring and leaving the profession. Coupled with a <a href="https://treasury.gov.au/sites/default/files/2021-06/p2021_182464.pdf">growing population</a> eligible for screening, this adds up to a perfect test bed for an AI solution.</p>
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Read more:
<a href="https://theconversation.com/biopsies-confirm-a-breast-cancer-diagnosis-after-an-abnormal-mammogram-but-structural-racism-may-lead-to-lengthy-delays-185824">Biopsies confirm a breast cancer diagnosis after an abnormal mammogram – but structural racism may lead to lengthy delays</a>
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<h2>What did the researchers test?</h2>
<p>The Swedish study followed 80,000 women aged 40–80 attending a screening program in one area of Sweden. </p>
<p>The researchers set out to test whether AI could better direct a radiologist’s attention to a suspicious, but often very subtle, abnormal area on a mammogram, using a commercially available AI-supported mammogram reading system.</p>
<p>They also looked at whether using AI could replace one of the two radiologists who normally read the mammogram. This would make the process more efficient.</p>
<p>The study was randomised so half of the women received normal screening protocols and the other half the AI-assisted protocol. </p>
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<img alt="African-Australian woman has a mammogram" src="https://images.theconversation.com/files/540594/original/file-20230801-16682-nsicg8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/540594/original/file-20230801-16682-nsicg8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/540594/original/file-20230801-16682-nsicg8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/540594/original/file-20230801-16682-nsicg8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/540594/original/file-20230801-16682-nsicg8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/540594/original/file-20230801-16682-nsicg8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/540594/original/file-20230801-16682-nsicg8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Mammograms aim to detect breast cancers early.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/SMxzEaidR20">National Cancer Institute</a></span>
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<h2>So what did they find?</h2>
<p>The early findings are very encouraging. In those in whom AI was used, if the AI suggested a suspicious area, the mammogram was still read by two radiologists. But if the AI did not see a suspicious area then only one “live” radiologist read the mammogram. </p>
<p>This saved nearly six months of radiologists’ time. There were 36,886 fewer screenings read by radiologists in the AI supported group (46,345 vs 83,231), resulting in a 44% reduction in the radiologists’ screening workload. </p>
<p>Using the AI software to direct the radiologist attention to abnormal areas also seemed to improve the accuracy of their reading. The AI-assisted reading meant slightly more women were referred for further assessment (2.2% versus 2%) and of those assessed from the AI group, more cancers were seen. </p>
<p>In total, 244 women (28%) from the AI-supported group were found to have cancer, compared to 203 women (25%) in the standard double reading without AI. </p>
<p>Overall, the AI program picked up one extra cancer for each 1,000 women screened (six per 1,000 vs five per 1,000).</p>
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Read more:
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<h2>Risk of overdiagnosis</h2>
<p>But just detecting more cancers is not necessarily a good thing if the cancers found are tiny, non-aggressive tumours that may never grow to harm the woman. </p>
<p>Of course what we really want to know is can any new test improve survival from cancer – and make the burden of treatment easier. </p>
<p>“Interval cancers” are faster-growing aggressive cancers that turn up between mammograms. Studies often use the detection of interval cancers as a surrogate for improving cancer survival. But it’s unclear if AI can detect more of these interval cancers. </p>
<p>Until we understand more about these extra cancers the AI detects, these remain open questions.</p>
<p>So, despite the positive signals from this study, we are still <a href="https://www.breastscreen.org.au/news/using-ai-to-improve-breast-screening/">not ready to use it</a> in our screening programs without more mature data form this and other work, including data that currently is being collected in Australia.</p>
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Read more:
<a href="https://theconversation.com/29-000-cancers-overdiagnosed-in-australia-in-a-single-year-127791">29,000 cancers overdiagnosed in Australia in a single year</a>
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<p><em>Correction: this article originally said 20,000 new breast cancers were diagnosed in Australia each week, rather than each year.</em></p><img src="https://counter.theconversation.com/content/210800/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christobel Saunders does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Mammograms are usually analysed by two doctors. But a new study found using one doctor with AI assistance detected 20% more cancers and reduced the workload by 44%.Christobel Saunders, James Stewart Chair Of Surgery, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2019512023-04-07T12:16:57Z2023-04-07T12:16:57ZThe FDA’s rule change requiring providers to inform women about breast density could lead to a flurry of questions<figure><img src="https://images.theconversation.com/files/519672/original/file-20230405-1759-sbi3a7.jpg?ixlib=rb-1.1.0&rect=107%2C71%2C7832%2C5225&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Breast density is one of the factors that can influence whether people should pursue supplemental screening. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/female-doctor-talking-to-her-patient-and-adjusting-royalty-free-image/1221770065?phrase=mammogram&adppopup=true">andresr/E+ via Getty Images</a></span></figcaption></figure><p><em>The U.S. Food and Drug Administration <a href="https://public-inspection.federalregister.gov/2023-04550.pdf">finalized a regulation</a> in early March 2023 that updates mammography reporting requirements. The new regulation goes into effect on Sept. 10, 2024, and will require that all women receive information about breast density following a mammogram. It will also require they be told in their mammogram report that dense breast tissue can mask cancer and make cancer more difficult to detect.</em></p>
<p><em>The Conversation asked <a href="https://www.rad.pitt.edu/profile-detail.html?profileID=311">Dr. Wendie A. Berg</a>, professor of radiology at the University of Pittsburgh School of Medicine, to explain how the rule change could affect screening recommendations as well as the way people interpret their results.</em></p>
<h2>What is breast density and why does it matter?</h2>
<p>All breasts are made up of a mix of fat, milk glands and ducts. The glands are supported by fibrous tissue and ligaments, collectively called “fibroglandular tissue.” The more fibroglandular tissue a woman has, the “denser” her breast tissue. </p>
<p>When a woman has a mammogram, the radiologist reviewing it will describe her breast density using one of four categories: A) fatty, B) scattered tissue, C) heterogeneously dense or D) extremely dense. Categories C and D are considered “dense” whereas categories A and B are “not dense.” </p>
<p>Dense breasts are <a href="https://doi.org/10.1093/jnci/dju255">normal and common</a>. Over 50% of women have dense breasts before menopause, as do about 40% of women in their 50s and 30% of women in their 60s. Breasts can become less dense after menopause, but a woman with extremely dense breasts will likely continue to have dense breasts all her life.</p>
<p>Breast density matters for two reasons. Most importantly, dense breast tissue can hide cancer on a mammogram. About 40% of breast cancers will go unseen on mammography in the densest breasts, labeled “extremely dense breasts,” and about <a href="https://doi.org/10.7326/m14-1465">25% will go undetected in heterogeneously dense breasts</a>. </p>
<p>Secondly, dense tissue also increases the risk of developing breast cancer, with about <a href="https://doi.org/10.1158/1055-9965.epi-06-0034">fourfold the risk of breast cancer in extremely dense breasts</a> compared with fatty breasts, and about <a href="https://doi.org/10.1016/j.breast.2022.09.007">twofold the risk compared to breasts with scattered tissue</a>.</p>
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<a href="https://images.theconversation.com/files/519670/original/file-20230405-24-mpiqoo.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Mammography comparison of cancer easily seen in a a fatty ('not dense') breast on the left and hard to see in a 'dense' breast on the right." src="https://images.theconversation.com/files/519670/original/file-20230405-24-mpiqoo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/519670/original/file-20230405-24-mpiqoo.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/519670/original/file-20230405-24-mpiqoo.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/519670/original/file-20230405-24-mpiqoo.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/519670/original/file-20230405-24-mpiqoo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/519670/original/file-20230405-24-mpiqoo.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/519670/original/file-20230405-24-mpiqoo.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Dense breasts not only make cancer harder to spot, they also increase the risk of developing cancer.</span>
<span class="attribution"><span class="source">DenseBreast-info.org and Dr. Wendie Berg</span></span>
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<h2>What does the FDA ruling entail?</h2>
<p>Until now, <a href="https://densebreast-info.org/legislative-information/state-legislation-map/">38 states plus Washington, D.C.</a>, have had varying laws about what to tell women about breast density. This has resulted in inconsistent levels of information being provided to U.S. women depending on where they live. </p>
<p>Beginning in September 2024, the <a href="https://public-inspection.federalregister.gov/2023-04550.pdf">FDA’s final rule</a> creates a uniform national standard requiring that all women be informed in the mammogram results letter that their breasts are either “dense” or “not dense.” They will be told that dense tissue can hide cancer on a mammogram and that it also raises the risk of developing breast cancer.</p>
<p>The new regulations require that the specific density category be included in all mammography reports that go to the referring health care provider. Some states require the specific density category also be included in the patient results letter, and this information can be included, but must be separate from the language required by the FDA. The FDA notification cannot be altered in any way.</p>
<p>The FDA requirement also includes this sentence in the letter to women with “dense” breasts: “In some people with dense tissue, other imaging tests in addition to a mammogram may help find cancers.” Such “supplemental screening” deserves discussion.</p>
<h2>How might this affect how patients respond to mammogram results?</h2>
<p>Without some guidance on what to do about it, there is the potential for this information to cause some confusion and worry. </p>
<p>3D mammograms, also known as tomosynthesis, are becoming standard and are slightly <a href="https://doi.org/10.1148/radiol.221571">better at detecting cancer, with fewer callbacks</a> for extra testing for findings that turn out not to be cancer. Women with dense breasts should make sure to have routine screening with a 3D mammogram.</p>
<p>Deciding whether to pursue supplemental screening beyond an annual mammogram starting at age 40 depends on several considerations. These include breast density and other risk factors, potential benefits, downsides – such as additional testing for findings that turn out not to be cancer – insurance coverage and costs. </p>
<p>By age 30, <a href="https://doi.org/10.1016/j.jacr.2017.11.034">all women should discuss their risk factors</a> with their health care provider and consider genetic testing, if appropriate. This is because women considered to be “high risk” should start screening earlier and have MRI screening in addition to mammography, regardless of breast density. </p>
<p><img src="https://cdn.theconversation.com/static_files/files/2615/BIRADS_Cancer_%281%29.gif?1680793880">
</p><figure><figcaption><span class="caption">Breast density is described as one of four categories in the mammogram report. The denser the breast, the harder the cancer is to see on a mammogram.</span></figcaption></figure><p></p>
<p>Here is a list of some of the factors that would make a woman “high risk,” and good candidates for yearly screening with MRI up to ages 70 to 75, depending on overall health.</p>
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<li><p>Women with disease-causing genetic variants, such as BRCA1 or BRCA2, or who have a mother, sister or daughter with a disease-causing variant, should start having yearly <a href="https://doi.org/10.3322/canjclin.57.2.75">screening with MRI by age 25-30</a>, and add mammography screening once they turn 30. </p></li>
<li><p>Women who received radiation therapy to the chest for prior cancer – usually Hodgkin lymphoma – before age 30 should start MRI screening eight years after treatment – but not before age 25 – and add mammography by the time they’re 30. </p></li>
<li><p>Women with an estimated lifetime risk of breast cancer of at least 20% should have annual MRIs, in addition to mammography. The most accurate estimates are from the <a href="https://ibis.ikonopedia.com/">Tyrer-Cuzick or IBIS model</a> and include weight, height, breast density, family history, biopsy history and other risk factors. AI-based processing of mammograms alone may be even <a href="https://doi.org/10.1200/jco.21.01337">more accurate than risk models</a> at predicting who will develop breast cancer in the next one to five years.</p></li>
<li><p>Annual MRI screenings are also recommended for women <a href="https://doi.org/10.1016/j.jacr.2017.11.034">diagnosed with breast cancer prior to age 50 or women with dense breasts</a>.</p></li>
<li><p>The European Society of Breast Imaging recommends that <a href="https://doi.org/10.1007/s00330-022-08617-6">women with extremely dense breasts</a> add MRI screening every 2 to 4 years from age 50 to 70 (with mammograms every 2 years).</p></li>
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<p>Women with dense breasts, especially if they also have other risk factors such as family history of breast cancer or prior atypical biopsy, should consider adding screening MRI to their annual mammogram. But MRI requires lying in the tunnel of the magnet, which can be <a href="https://doi.org/10.1148/radiol.2541090953">difficult for women with claustrophobia</a>. It also requires intravenous contrast injection. Cancers become more visible with contrast because they have more and leakier blood vessels than normal tissue. </p>
<p>For women who cannot tolerate or access MRI, adding ultrasound to mammography can be considered, but <a href="https://densebreast-info.org/screening-technologies/cancer-detection-by-screening-method/">MRI finds more cancers than ultrasound</a>. <a href="https://doi.org/10.1016/j.ejrad.2022.110513">Contrast-enhanced mammography</a> is being evaluated as an alternative to MRI.</p>
<h2>Will insurance cover additional screening tests?</h2>
<p>Currently 15 states plus D.C. have <a href="https://densebreast-info.org/legislative-information/state-legislation-map/">laws requiring insurance coverage</a> for supplemental breast cancer screening, but only New York, Connecticut and Illinois require such coverage without copays. </p>
<p>A federal insurance bill, the <a href="https://densebreast-info.org/legislative-information/find-it-early-act/#">Find It Early Act</a>, is being reintroduced by two U.S. representatives. This measure would ensure all health insurance plans cover screening and diagnostic breast imaging with no out-of-pocket costs. </p>
<p>This would include supplemental screening for women with dense breasts or at a higher risk for breast cancer, in accordance with National Comprehensive Cancer Network guidelines and the <a href="https://doi.org/10.1016/j.jacr.2021.09.002">American College of Radiology’s Appropriateness Criteria</a>.</p><img src="https://counter.theconversation.com/content/201951/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wendie A. Berg receives funding from the Breast Cancer Research Foundation and Pennsylvania Breast Cancer Coalition. She is voluntary Chief Scientific Advisor to <a href="http://www.DenseBreast-info.org">www.DenseBreast-info.org</a>. </span></em></p>Dense breast tissue is common and normal, but it can make cancer more difficult to detect. FDA requirements going into effect in September 2024 will dictate that patients be better informed about it.Wendie A. Berg, Professor of Radiology, School of Medicine, University of PittsburghLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1221262019-09-18T20:37:08Z2019-09-18T20:37:08ZFor routine breast screening, you may not need a 3D mammogram<figure><img src="https://images.theconversation.com/files/292746/original/file-20190917-19083-1kzbsly.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4992%2C3318&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">3D mammograms may be useful in investigating abnormalities, but as a means of routine screening, they may do more harm than good.</span> <span class="attribution"><span class="source">From shutterstock.com</span></span></figcaption></figure><p>Victorian Minister for Health Jenny Mikakos recently announced <a href="https://www.jennymikakos.com.au/media-releases/cutting-edge-3d-breast-cancer-imaging-to-save-lives/">six new 3D breast screening machines</a> would be rolled out across the state. </p>
<p>These will be used to assess women recalled for further investigation when a standard 2D screening mammogram picks up something that wasn’t anticipated. </p>
<p>Offering this sophisticated technology within the public system is designed to help women with breast cancer receive an accurate diagnosis in a timely manner, in turn ensuring they can start appropriate treatment as early as possible. </p>
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Read more:
<a href="https://theconversation.com/what-causes-breast-cancer-in-women-what-we-know-dont-know-and-suspect-86314">What causes breast cancer in women? What we know, don't know and suspect</a>
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<p>But there’s a distinction to be made here. While this funding will provide 3D mammography machines to be used for further assessment when there may be a problem, many 3D mammography machines are already operating throughout the private system, offered to women as a means for routine screening. </p>
<p>Newer medical technology is often assumed to be better than traditional technology. But when we’re talking about mammography for routine breast screening, this may not be the case.</p>
<p>While <a href="https://jamanetwork.com/journals/jamaoncology/article-abstract/2726028">evidence shows</a> 3D mammograms detect more cases of breast cancer than the 2D version, many of the additional cancers detected may not go on to cause harm. In these cases, their detection will only lead to anxiety and unnecessary treatment. </p>
<h2>What is a mammogram?</h2>
<p>A mammogram is an x-ray of the breasts that can be used to investigate breast symptoms such as lumps and pain. It can also be used for screening, to pick up early breast cancer in healthy women who have no symptoms.</p>
<p>In Australia, the <a href="http://www.cancerscreening.gov.au/internet/screening/publishing.nsf/Content/breast-screening-1">BreastScreen program</a> invites women aged 50 to 74 for a free screening mammogram every two years. All women over 40 are welcome to attend if they choose to.</p>
<p>The BreastScreen program offers conventional 2D digital mammograms. During this standard mammogram, compression is applied to the breast, and two images are taken of each breast using a small dose of radiation. </p>
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Read more:
<a href="https://theconversation.com/women-should-be-told-about-their-breast-density-when-they-have-a-mammogram-66125">Women should be told about their breast density when they have a mammogram</a>
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<h2>What does a 3D mammogram do differently?</h2>
<p>3D mammography, also called <a href="https://www.insideradiology.com.au/breast-tomosynthesis/">breast tomosynthesis</a>, has been introduced over the last decade. </p>
<p>It’s not currently used for screening as part of the BreastScreen program, but it is available in many private radiology practices around the country.</p>
<p>A 3D mammogram applies the same compression to the breast as a 2D test, but takes multiple images, like thin “slices”. </p>
<p>The radiologist can scroll through the collection of images on a computer screen to get a 3D picture of the breast, which can be examined layer by layer, one millimetre at a time. This aims to see through layers of normal breast tissue to find hidden cancer.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/2ODcyRysCjg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Source: Breast Imaging Victoria.</span></figcaption>
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<p><a href="https://jamanetwork.com/journals/jamaoncology/article-abstract/2726028">Research</a> has shown 3D mammograms are able to pick up some cancers not seen on conventional 2D mammograms. The cancer detection rate of 3D mammography was around 1.4 times higher than for 2D mammography. </p>
<p>The additional cancers detected by 3D mammograms were small and had not spread to the lymph glands; these are early cancers expected to have better survival rates.</p>
<p>Cancer can be difficult to see in lumpy or dense glandular breast tissue, which is typically seen in women before menopause. 3D mammography appears to be <a href="https://academic.oup.com/jnci/article/110/9/942/5068658">particularly good</a> at detecting cancer in women with dense breast tissue, which may partially account for the increase in detection. </p>
<h2>The possibility of overdiagnosis and overtreatment</h2>
<p>Some cancers are indolent or slow growing and will never cause clinical symptoms. These cancers can be difficult to distinguish from aggressive cancers detected early. So when they’re found by a screening mammogram, they may be treated with surgery and radiotherapy, causing harm without improving survival.</p>
<p>When we’re talking about breast screening, we’ll often mention the recall rate. That’s the number of women asked to return for further testing, and possibly treatment, when an initial screening shows up something abnormal. </p>
<p>The recall rate is important because, we know for 2D mammography, <a href="https://www.aihw.gov.au/getmedia/c28cd408-de89-454f-9dd0-ee99e9163567/aihw-can-116.pdf.aspx?inline=true">around 80-90% of women recalled</a> for assessment do not have cancer. </p>
<p>In these cases, being recalled can lead to anxiety, risks and pain associated with biopsy and surgery, and costs for unnecessary procedures.</p>
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<img alt="" src="https://images.theconversation.com/files/292904/original/file-20190918-149001-1nkaz3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/292904/original/file-20190918-149001-1nkaz3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/292904/original/file-20190918-149001-1nkaz3l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/292904/original/file-20190918-149001-1nkaz3l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/292904/original/file-20190918-149001-1nkaz3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/292904/original/file-20190918-149001-1nkaz3l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/292904/original/file-20190918-149001-1nkaz3l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">While a 3D mammogram might pick up more cancers, it could necessitate treatment for cancers not destined to cause harm.</span>
<span class="attribution"><span class="source">From shutterstock.com</span></span>
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<p>Earlier <a href="https://jamanetwork.com/journals/jamaoncology/article-abstract/2726028">research</a> found the recall rate was lower for 3D mammography than 2D mammography, so there were fewer false positive studies or false alarms that added extra tests, biopsies and anxiety. </p>
<p>But new <a href="https://onlinelibrary.wiley.com/doi/abs/10.5694/mja2.50320">Australian research</a>, published in the Medical Journal of Australia, has drawn this into question. This study included more than 10,000 women attending a BreastScreen centre in Victoria for routine screening. Some were invited to have a 3D mammogram, while others had a conventional 2D mammogram.</p>
<p>Again, the cancer detection rate was around 1.5 times higher for 3D mammography. However, the recall rate was actually higher for 3D mammography compared to 2D – so more women were asked to return for further work-up (mammogram, ultrasound and/or a biopsy).</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/three-questions-to-ask-about-calls-to-widen-breast-cancer-screening-82894">Three questions to ask about calls to widen breast cancer screening</a>
</strong>
</em>
</p>
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<h2>Should I have a 3D mammogram?</h2>
<p>Public health experts are currently debating the issue of <a href="https://www.nejm.org/doi/10.1056/NEJMoa1600249?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dwww.ncbi.nlm.nih.gov">overdiagnosis in breast screening</a>. The extent of overdiagnosis in screening is not agreed upon, but it is accepted that it exists to some extent. </p>
<p>In the 3D mammography studies, including the latest Australian study, a higher proportion of cancers in the 3D groups were very small invasive or “in situ” malignancies less likely to cause harm than more aggressive cancers. This means many of the additional cancers detected by 3D mammograms could be “over-diagnosed” cancers that cause women to undergo gruelling cancer treatments without real benefit.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/treating-stage-0-breast-cancer-doesnt-always-save-womens-lives-so-should-we-screen-for-it-46624">Treating 'stage 0' breast cancer doesn't always save women's lives so should we screen for it?</a>
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<p>It’s unlikely BreastScreen will introduce routine 3D mammography screening in the short term based on the current evidence.</p>
<p>But should you have a 3D mammogram through a private radiology practice? Perhaps, if you have dense breast tissue or you are starting screening in your 30s or 40s due to a family history of breast cancer. </p>
<p>For older women, there may not be additional benefits of 3D mammography over 2D. All women should consider the balance of potential benefits (early detection) and potential harms (overdiagnosis, overtreatment and anxiety) before deciding on a 3D versus a 2D screening mammogram.</p><img src="https://counter.theconversation.com/content/122126/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Meagan Brennan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>3D mammography is becoming more widely available, but is it superior to the traditional 2D technology for breast cancer detection? The answer isn’t clear-cut.Meagan Brennan, Clinical A/Prof Breast Physician, Westmead Breast Cancer Institute, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1154872019-04-30T08:33:19Z2019-04-30T08:33:19ZBreast cancer diagnosis by AI now as good as human experts<figure><img src="https://images.theconversation.com/files/271193/original/file-20190426-194612-x1u4yl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Could a machine do better?</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Breast cancer is the most common cancer in the UK. It accounts for <a href="https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/breast-cancer#heading-Zero">15% of all new cases</a> in the country, and about one in eight women will be diagnosed with it during their lifetime. In the NHS, breast cancer screening routinely includes a mammogram, which is essentially an X-ray of the breast. </p>
<p>But the future of this early test is at risk as the number of specialists able to read them <a href="https://www.rcr.ac.uk/system/files/publication/field_publication_files/bfcr185_cr_census_2017">declines</a>. While this skills shortfall can’t be made up immediately, promising advances in artificial intelligence may be able to help.</p>
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<p>Interpreting a mammogram is a complex process normally performed by specially trained radiologists and radiographers. Their skills are vital to the early detection and diagnosis of this cancer. They visually scrutinise batches of mammograms in a session for signs of breast cancer. </p>
<p>But these signs are often ambiguous or hard to see. <a href="https://www.cancer.gov/types/breast/mammograms-fact-sheet">False negative rates</a> – where cancers are incorrectly diagnosed or missed – are between 20 and 30% for mammography. These are either errors in perception or errors in interpretation, and can be attributed to the sensitivity or specificity of the reader.</p>
<p>It is widely believed that the key to developing the expertise needed to interpret mammograms is rigorous training, extensive practice and experience. And while researchers like myself are looking into training strategies and perceptual learning modules which can expedite the transition from novice reader to expert, others have been investigating how AI could be used to speed up diagnosis and improve its accuracy. </p>
<h2>Machine diagnosis</h2>
<p>As in countless other fields, the potential for AI algorithms to help with cancer diagnosis has not gone unrecognised. Along with breast cancer, researchers have been looking at how AI can improve the efficacy and efficiency of care for <a href="https://www.sciencedaily.com/releases/2019/03/190312195050.htm">lung</a>, <a href="https://physicsworld.com/a/ai-can-evaluate-treatment-response-for-brain-tumours/">brain</a> and <a href="https://www.eurekalert.org/pub_releases/2019-04/uoc--apa041619.php">prostate</a> cancer, in order to meet ever increasing diagnosis demands. Even Google is looking at how AI can be used to diagnose cancer. The search giant has trained an algorithm to <a href="https://ai.googleblog.com/2018/10/applying-deep-learning-to-metastatic.html">detect tumours which have metastasised</a>, with a 99% success rate.</p>
<p>For breast cancer, the focus so far has been on how AI can help diagnose the disease from mammograms. Every mammogram is read by two specialists, which can lead to potential delays in diagnosis if there is a shortfall in expertise. But researchers have been looking at introducing AI systems at the time of the screening. The idea is that it would support a specialist’s findings without waiting for the second opinion of another professional. This would reduce the waiting time and associated anxiety for the women who have been tested. </p>
<p>AI has already made substantial strides in cancer image recognition. In late 2018, researchers reported that one commercial system <a href="https://academic.oup.com/jnci/advance-article-abstract/doi/10.1093/jnci/djy222/5307077?redirectedFrom=fulltext">matched the accuracy</a> of over 28,000 interpretations of screening mammograms by 101 radiologists. This means it achieved a cancer detection accuracy <a href="https://physicsworld.com/a/artificial-intelligence-versus-101-radiologists/">comparable to an expert radiologist</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/271508/original/file-20190429-194600-lfu6am.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/271508/original/file-20190429-194600-lfu6am.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/271508/original/file-20190429-194600-lfu6am.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/271508/original/file-20190429-194600-lfu6am.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/271508/original/file-20190429-194600-lfu6am.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/271508/original/file-20190429-194600-lfu6am.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/271508/original/file-20190429-194600-lfu6am.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/271508/original/file-20190429-194600-lfu6am.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Humans need years of training, practice and experience to diagnose cancer from mammograms.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/medical-xray-mammogram-image-breast-1095605585?src=gHLDkqVT1WtS_rJpR1i7nQ-2-41">Mark_Kostich/Shutterstock</a></span>
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<p><a href="https://pubs.rsna.org/doi/10.1148/radiol.2018181371">In another study</a> led by the same researcher, radiologists using an AI system for support showed an improved rate of improved breast cancer detection – rising from 83% to 86%. This research also found that using an AI system reduced the amount of time radiologists spent analysing the images on screen. </p>
<h2>Fine tuning</h2>
<p>But while the potential of AI has been welcomed by some radiologists, it has brought suspicion from others. And though other researchers have also found that AI is <a href="https://ecronline.myesr.org/ecr2019/index.php?p=recorddetail&rid=4dc19e9a-ec20-422a-89e8-3c7c2e738424&t=browsesessions#ipp-record-88751544-6586-49b2-81c2-aefd93b79d35">just as good at detecting breast cancers</a> from mammograms as its human counterparts, this comes with the caveat that more fine tuning and software improvement is needed before it can be safely introduced into breast screening programmes. </p>
<p>Exciting as it may be to think that AI could be used to help detect such a prevalent cancer, specialist and public confidence needs to be taken into consideration before it can be introduced. Acceptance of the technology is vital so that patients and medical professionals know they are receiving the correct results.</p>
<p>As yet, there has been little research into the public perception of AI in breast cancer screening, but more general studies into AI and healthcare have found that <a href="https://www.pwc.co.uk/industries/healthcare/patient-voice-2017/artificial-intelligence-results.html">39% of people</a> are willing to engage with artificial intelligence/robotics for healthcare. This rises to 55% for the 18- to 24-year-old demographic.</p>
<p>The AI systems are still in the research phase, with no firm plans to use it to diagnose patients in the UK yet. But these promising results show there is a tremendous opportunity for the delivery of radiology healthcare services, and ultimately the potential to detect more patients with breast and other cancers.</p><img src="https://counter.theconversation.com/content/115487/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen Yule does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Artificial intelligence is being used to diagnose breast cancers from early mammogram tests.Helen Yule, PhD Researcher in Breast Radiology and Consultant Radiographer, Cardiff Metropolitan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/996602018-08-06T16:22:37Z2018-08-06T16:22:37ZThe risk of lung cancer for young breast cancer survivors<figure><img src="https://images.theconversation.com/files/230092/original/file-20180731-118933-18vkpnb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">New research shows the risk of lung cancer slowly increases five to 10 years after a breast radiation treatment; a form of brachytherapy developed in Canada is the safest treatment to reduce this risk.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Women who have been lucky enough to survive breast cancer may face increased risk of lung cancers, <a href="https://doi.org/10.1016/j.radonc.2018.05.032">according to a new study in <em>Radiotherapy and Oncology</em></a>. The study shows how this can be prevented — limiting the radiation dose to a lung, using a treatment which targets only a small part of the breast.</p>
<p>Breast cancer is the most frequently diagnosed cancer in women, with <a href="https://seer.cancer.gov/statfacts/html/breast.html">more than 266,000 new cases diagnosed in 2018 in the United States</a>. </p>
<p>Thanks to the widespread use of screening mammography, most women are now diagnosed at an early stage — meaning that the cancer has only grown in the breast and not spread under the armpit or to distant organs. These individuals have a good prognosis with <a href="https://seer.cancer.gov/statfacts/html/breast.html">only a 1.3 per cent risk of dying of cancer recurrence after five years</a>. </p>
<p>Treatment currently involves a limited breast surgery followed by multiple daily radiation treatments targeting the whole breast. However, despite being cautiously delivered, a small amount of radiation can spill into the lung. </p>
<p>Using a complex predictive model called the <a href="https://radiationcalculators.cancer.gov/radrat/about/">Biologic Effects of Ionizing Radiation (BEIR) VII</a>, and by testing multiple radiation techniques on a realistic model of a breast cancer patient, the study by PhD student <a href="https://www.researchgate.net/profile/Nienke_Hoekstra2">Nienke Hoekstra</a> shows that the risk of lung cancer slowly increases five to 10 years after a breast radiation treatment. It reaches three per cent of surviving patients after more than 30 years. </p>
<h2>A small part of the breast</h2>
<p>This risk of lung cancer is a real concern for young patients diagnosed with early stage breast cancers — for example, a ductal carcinoma in situ (DCIS), which is a form of non-invasive cancer and hence a very highly curable disease. These patients have the chance of living long enough to experience this scary treatment side-effect.</p>
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<img alt="" src="https://images.theconversation.com/files/230088/original/file-20180731-136667-1g3izme.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/230088/original/file-20180731-136667-1g3izme.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/230088/original/file-20180731-136667-1g3izme.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/230088/original/file-20180731-136667-1g3izme.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/230088/original/file-20180731-136667-1g3izme.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/230088/original/file-20180731-136667-1g3izme.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/230088/original/file-20180731-136667-1g3izme.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Robotic delivery of radiation from all angles around the breast is the focus of ongoing research at Erasmus University.</span>
<span class="attribution"><span class="license">Author provided</span></span>
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<p>The good news is that risk is not the same for all radiotherapy techniques. The study shows that a new form of radiotherapy for early-stage breast cancers — called accelerated partial breast irradiation (APBI) — dramatically reduces this risk. </p>
<p>APBI delivers the radiation treatment to only a small portion of the breast. It focuses on the cavity left after the surgery, where there is risk that cancer cells may remain. </p>
<p>There are multiple advantages to APBI, including the delivery of treatment in just five days. And the study found it results in much lower radiation exposure to body organs, including the lungs, than conventional treatments.</p>
<p>APBI is a technique on the rise. This study adds to the growing amount of evidence that it should be the preferred technique for women with very low-risk breast cancer. </p>
<p>But not all patients will benefit from APBI. Some need more complex and extensive radiotherapy to save their lives. Patients should be encouraged to discuss this with their radiation oncologist.</p>
<h2>Tiny radioactive seeds</h2>
<p>Among APBI techniques tested, <a href="https://doi.org/10.1016/S0140-6736(15)00471-7">“brachytherapy”</a> — a form of radiotherapy where radioactive material is implanted inside the surgical cavity — appears to be the safest. </p>
<p>A particular form of brachytherapy developed in Canada, called “permanent breast seed implant,” is the one with the lowest risk of secondary lung cancer. </p>
<p>This technique, which is also used to treat prostate cancer, <a href="http://www.dx.doi.org/10.1016/j.ijrobp.2015.07.2266">involves the permanent implantation of tiny radioactive seeds</a>, the size of a grain of rice, during a one-hour procedure performed under light sedation. Patients are discharged the same day. </p>
<p>The radiation emitted by the radioactive seeds is so weak that it is absorbed within a few millimetres and hence rarely reaches other organs. </p>
<p>The good news is that there is still lots of room for improvement — for example, using a robotic delivery of radiation from all angles around the breast to better avoid the lung. This is the focus of ongoing research.</p><img src="https://counter.theconversation.com/content/99660/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jean-Phillippe Pignol has received funding from Canadian Institute for Health Research (CIHR), Canadian Breast Cancer Foundation (CBCF), Canadian Breast Cancer Research Alliance (CBCRA), Canadian Cancer Society Research Institute (CCSRI), Natural Sciences and Engineering Research Council of Canada (NSERC), The Dutch Cancer Society (KWF), The Dutch High Tech Systemen en Materialen (HTSM). </span></em></p><p class="fine-print"><em><span>Nienke Hoekstra does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research reveals the risks of lung cancer after breast cancer radiotherapy and identifies the best treatment to reduce these risks.Jean-Philippe Pignol, Professor and Chair, Department of Radiation Oncology, Dalhousie UniversityNienke Hoekstra, PhD student in Radiotherapy, Erasmus MC, Netherlands, Dalhousie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/855172017-10-31T21:58:05Z2017-10-31T21:58:05ZRoutine mammograms do save lives: The science<p>A recent article published by The Conversation Canada stated routine mammographies do not save lives – and that <a href="https://theconversation.com/routine-mammograms-do-not-save-lives-the-research-is-clear-84110">the harms of screening outweigh the benefits</a>. </p>
<p>As researchers who have worked in the field of breast cancer detection for decades, we know that exactly the opposite is true — there’s overwhelming evidence that earlier detection of breast cancer by mammography screening, combined with modern therapy, reduces deaths from breast cancer markedly.</p>
<p>We believe that women should decide for themselves whether to participate in screening after they have all the facts. </p>
<p>Screening mammograms help save lives by detecting small breast cancers when they have not yet spread through the body (metastasized). Metastases are what make breast cancer a lethal disease. An additional benefit of earlier detection is that it often allows less toxic, gentler therapies to be used — less extensive surgery and the use of drugs that have fewer and less severe side effects than chemotherapy.</p>
<h2>Screening mammograms help save lives</h2>
<p>Debates on the wisdom of, and best age to begin, routine mammography screening have raged within both the medical literature and the media for many years. It is important, then, that recommendations and guidance for women are based upon a thorough review and presentation of the best evidence available.</p>
<p>The study referenced in the original article was based on screening performed in the early 1980s using obsolete technology. That study was <a href="http://pubs.rsna.org/doi/10.1148/radiology.189.3.8234686">heavily</a> <a href="http://www.ajronline.org/doi/10.2214/ajr.161.4.8372753">criticized</a> by <a href="http://www.mammographyed.com/Resources/15266/FileRepository/Canadian%20Research%20Feedback/Tarone_Advanced_Cancers_CNBSS_1994.pdf">multiple reviewers</a> because of the <a href="http://www.ajronline.org/doi/10.2214/ajr.161.4.8372752">poor quality of the images</a> and <a href="http://pubs.rsna.org/doi/10.1148/radiology.189.3.8234686">other flaws</a> in <a href="https://doi.org/10.1093/jnci/85.2.93">how the study was conducted</a>. This was the only study that failed to show a benefit of screening.</p>
<p>Multiple overviews of all of the <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)61611-0/fulltext">randomized trials of breast cancer screening</a> on the other hand — including one recently performed by <a href="http://www.nejm.org/doi/10.1056/NEJMsr1504363">The International Agency for Research on Cancer</a>, one by <a href="http://annals.org/aim/article/745247/screening-breast-cancer-update-u-s-preventive-services-task-force">a research team in the United States</a> and one <a href="https://www.cancer.org/content/dam/cancer-org/cancer-control/en/reports/complete-systematic-evidence-review-acs-breast-cancer-screening-guideline.pdf">produced for the American Cancer Society</a> — show a reduction in breast cancer deaths by about 20 per cent. The way randomized trials are analyzed tends to underestimate the benefit, so the real benefit for women who do get screened is likely to be higher.</p>
<p>A <a href="https://academic.oup.com/jnci/article-lookup/doi/10.1093/jnci/dju261">recent Canadian study</a>, published in 2014, reinforces these findings. Researchers compared breast cancer deaths across seven Canadian provincial screening programs and observed about 40 per cent fewer deaths in women screened, with benefits extending for screening between ages 40 and 79. For women in their 40s, the reduction in breast cancer deaths was 44 per cent. </p>
<p>Similar observations have been noted in <a href="https://doi.org/10.1016/j.ypmed.2011.07.005">British Columbia</a>, in <a href="http://onlinelibrary.wiley.com/doi/10.1002/cncr.28174/abstract;jsessionid=5146A956679BFC959041C6A09D77DEB9.f03t01">Norway</a>, <a href="http://www.ejcancer.com/article/S0959-8049(01)00382-3/fulltext">Florence</a> and <a href="https://www.nature.com/bjc/journal/v99/n3/full/6604532a.html">five regions of Italy</a> and <a href="http://journals.sagepub.com/doi/10.1258/jms.2012.012078">across Europe</a> — women who participate in mammography screening are less likely to die of breast cancer than those who do not.</p>
<h2>Mammograms detect possible cancers</h2>
<p>It is important for women to know that mammography screening doesn’t diagnose cancer. The pictures from a mammogram simply allow the radiologist to detect suspicious areas in the breast where cancer could be present. </p>
<p>As a result, it is likely that some cancers are over-detected by mammography — in that if they weren’t found they would possibly not have caused harm. This could be the case if a cancer that is growing slowly is detected, but the patient dies of other causes before the cancer becomes lethal. For example, if the woman dies in a car accident, or from a heart attack before the cancer kills her. </p>
<p>Here is an example based on real data from the <a href="http://www.bccancer.bc.ca/screening/Documents/SMP_Report-AnnualReport2016.pdf">British Columbia Screening Program</a>. In every 1,000 women age 55 who go for screening, 929 (or 93 per cent) of them will have a normal result. They will be asked to return in one or two years for the next exam. The other 71 women will be asked to return for additional imaging to evaluate abnormal areas. At this point, the level of suspicion for cancer is still very low. After the imaging, 59 of these women will be told that there is no evidence of cancer (this can be considered to be a false alarm). </p>
<p>For 12 women (1.2 per cent of those who were screened), suspicion will remain. They will have a biopsy, with local freezing, in which a small amount of tissue is removed with a needle and examined under a microscope. This is where the actual diagnosis takes place. About four of the original 1,000 women will be found to have breast cancer and will be offered treatment. One cancer will be missed in the screening.</p>
<p>These four cancers are real. Some will be highly aggressive and grow quickly while other may grow slowly, possibly not at all. The pathologist has some tools to distinguish between these two situations, and research continues to improve these tests. But this is not an exact science. </p>
<p>Most doctors and women opt for aggressive treatment because it is “better to be safe than sorry” and in some cases this results in over-treatment. While <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1206809#t=article">unreasonably high estimates of over-detection</a> have been made by <a href="http://www.bmj.com/content/348/bmj.g366">some</a> <a href="http://theoncologist.alphamedpress.org/content/19/2/103">researchers</a>, more careful analysis suggests that it is in the order of <a href="http://journals.sagepub.com/doi/10.1258/jms.2012.012082">one to 10 per cent</a> <a href="http://journals.sagepub.com/doi/full/10.1177/0969141315573978">of cancers</a>. </p>
<p>It does not makes any sense to throw away the lives saved by screening — to avoid over-treating a small number of cancers. A promising way to avoid over-treatment is to follow the lead of male prostate cancer treatment while we wait for the pathology tests to improve. This involves a discussion between patient and doctor of more conservative treatment of some cancers. <a href="http://www.ejcancer.com/article/S0959-8049(15)00697-8/fulltext">Clinical trials</a> are <a href="http://www.ejcancer.com/article/S0959-8049(15)00394-9/fulltext">now underway</a> to <a href="https://clinicaltrials.gov/ct2/show/NCT02926911">test these ideas</a>.</p>
<h2>False alarms and smoke detectors</h2>
<p>Recalls (false alarms) from screening for additional tests can cause anxiety. It is important, therefore, that women are informed of the possibility of false alarms before they choose to be screened. Women should be informed that only a small percentage of those recalled are subsequently diagnosed with cancer.</p>
<p>Most women will accept the risk of transient anxiety once they are aware of the potential mortality reduction by participating in screening. In one study, <a href="http://www.jacr.org/article/S1546-1440(16)30942-5/fulltext">women who attended public education sessions about screening reported decreased anxiety</a>. Patients and physicians should also advocate for faster diagnostic investigation to reduce the time to resolution of whether cancer is present, or not. </p>
<p>The false alarms from mammography are very similar to those from smoke detectors. You install a smoke detector to avoid damage and injury from a fire. For most people, there will never be a fire in the house (only about 12 per cent of women will develop breast cancer), so for those people who don’t, you could argue that the smoke detector is a waste of money. </p>
<p>It is also possible that a fire will start and the detector will not go off for some reason (the sensitivity of mammography is approximately 80 per cent) or that the fire grows so quickly that the alarm does not really help you (a fraction of cancers are too aggressive for screening to be useful). Alternatively, the fire might start in the fireplace, so it does not really matter that the alarm went off because the fire would not have hurt you (some cancers are indolent; these are the over-detected cancers). The alarm might sound in the middle of the night and wake you up, but there is no fire (as when mammograms raise false alarms). </p>
<p>The benefits, of course, are that the alarm could wake you up just in time and save your life. It could even wake you so quickly you can extinguish the fire before any real damage has been done to your house. The equivalents of all these situations occur with mammography screening.</p>
<h2>Radiologists opt for mammograms</h2>
<p>We know that large x-ray doses increase the risk of cancer. And, while there is no direct evidence, it is reasonable to be cautious and assume that the lower x-ray dose from mammograms can cause cancer. However, avoiding mammography due to fear of radiation is not a winning bet. </p>
<p><a href="http://pubs.rsna.org/doi/10.1148/radiol.10100655">We have analyzed</a> the risks and the benefits of screening every two years from ages 50 to 69. In a sample of 1,000 women the radiation from mammograms would hypothetically be responsible for 0.27 cancers and 0.04 cancer deaths. Mammograms, on the other hand, would prevent five deaths (125 times more than those lost) and save 105 years of life. </p>
<p>This is why breast radiologists, who are well-acquainted with the radiation dose in modern mammography, <a href="http://www.ajronline.org/doi/10.2214/AJR.14.13237">overwhelmingly have annual screening themselves</a> and recommend the same for their families, friends and patients.</p>
<p>We recognize both the benefits of mammography screening as well as its limitations or risks. It is far from perfect. But screening has the potential to <a href="http://www.statcan.gc.ca/pub/82-003-x/2015012/article/14294-eng.pdf">prevent 1,000 breast cancer deaths in Canadian women each year</a>. Women and their health-care providers need an accurate and balanced picture of these strengths and limitations so they can make an educated decision about participation in screening.</p><img src="https://counter.theconversation.com/content/85517/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paula Gordon is a radiologist in Vancouver. She reads screening mammograms and does diagnostic breast imaging and image-guided biopsies. She is a volunteer advisor to dense breast-info.org and densebreastscanada.ca.</span></em></p><p class="fine-print"><em><span>This article is based on work performed by Martin Yaffe that has in the past been funded by The Canadian Institutes for Health Research, The Canadian Cancer Society, The Canadian Breast Cancer Foundation the US National Cancer Institute and the US Department of Defense Breast Cancer Research Program. He has a research collaboration with GE Healthcare through his employer, He also owns shares in Volpara Health Technologies (NZ) which produces software for measurement of breast density. </span></em></p>The majority of research suggests the benefits of mammography screening greatly outweigh the harms for women over age 40.Paula Gordon, Clinical Professor in the Department of Radiology & Medical Director of the Sadie Diamond Breast Program at BC Women’s Hospital, University of British ColumbiaMartin Yaffe, Professor of Medical Biophysics and Medical Imaging and Senior Scientist at Sunnybrook Research Institute, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/841102017-10-01T23:09:50Z2017-10-01T23:09:50ZRoutine mammograms do not save lives: The research is clear<figure><img src="https://images.theconversation.com/files/188098/original/file-20170928-1483-g9qngk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A recent Canadian trial reports breast cancer over-diagnosis rates of up to 55 per cent, from routine screening mammograms.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>As breast cancer awareness month kicks off, all women should know something: there is no reliable evidence that routine mammograms for healthy women save lives.</p>
<p>There is good evidence that such mammograms can cause harm. </p>
<p>And yet there are 12 breast-screening programs in Canada, each offering routine mammography screening to well women. Most of them offer mammograms to women of 50 to 74 years of age every two to three years. These programs were set up based on evidence produced in the 1970s and 1980s — that detecting breast cancer early through a mammogram would save many lives. </p>
<p>The <a href="https://canadiantaskforce.ca/guidelines/published-guidelines/breast-cancer/">Canadian Task Force on Preventive Health Care</a> also still recommends that women aged 50 to 74 get regular mammography screening. They are updating their breast-screening recommendations this year; hopefully they’ll reflect the latest evidence.</p>
<p>I have been looking at breast-screening evidence for more than 20 years.</p>
<p>I was part of a small group of individuals who started the breast-screening program in Newfoundland and Labrador. My job was professional and public education, including recruitment of women. </p>
<p>Over time there was increasing evidence that mammography screening may not be as beneficial as once thought. As the daughter of a woman with pre-menopausal breast cancer, I was also interested in the evidence on breast self-examination and clinical breast examination in screening.</p>
<p>If you are a woman who is considering having (or continuing to have) routine mammography screening, here is some information you need to know.</p>
<h2>1. Screening mammograms do not reduce death from breast cancer</h2>
<p>There is no reliable evidence that having a screening mammogram reduces death by breast cancer on a population basis. The <a href="http://dx.doi.org/10.1002/14651858.CD001877.pub5">Cochrane Collaboration</a> reached this conclusion after taking a good look at the original randomized trials. A <a href="http://dx.doi.org/10.1136/bmj.g366">recent Canadian trial</a>, considered the best mammography trial, supported this finding for women aged 40 to 59. This is important evidence that needs careful consideration.</p>
<h2>2. Routine mammograms over-diagnose cancer</h2>
<p>The Cochrane Collaboration also reported on harms associated with mammography screening. The most important of these is over-diagnosis. That is, the diagnosis of breast cancers in healthy women that would never have become clinically detectable without screening or would have caused harm to the woman in any way.</p>
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<img alt="" src="https://images.theconversation.com/files/188091/original/file-20170928-1438-4wgiw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/188091/original/file-20170928-1438-4wgiw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/188091/original/file-20170928-1438-4wgiw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/188091/original/file-20170928-1438-4wgiw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/188091/original/file-20170928-1438-4wgiw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/188091/original/file-20170928-1438-4wgiw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/188091/original/file-20170928-1438-4wgiw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Woman receives a mammogram.</span>
<span class="attribution"><span class="source">(Wikimedia Commons/National Cancer Institute)</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>Estimates of over-diagnosis vary from 30 per cent in the Cochrane Collaboration 2013 report to 55 per cent in the <a href="http://dx.doi.org/10.1016/j.ypmed.2016.06.033">2016 update from the Canadian trial</a> and 54 per cent by the <a href="https://www.cancer.gov/types/breast/hp/breast-screening-pdq#link/_13_toc">United States National Cancer Institute</a>. </p>
<h2>3. Treatment for over-diagnosed cancer is harmful</h2>
<p>Women with over-diagnosed breast cancer receive the usual breast cancer treatments including lumpectomy, mastectomy, radiation and hormonal therapy. All treatment for over-diagnosed cancer is harmful. This means that, because of mammography screening, many women are diagnosed with a breast cancer that might never have become apparent, and they undergo unnecessary treatment.</p>
<h2>4. False positives and over-diagnosis cause anxiety</h2>
<p>Another harm associated with mammography screening is <a href="http://dx.doi.org/10.1136/bmj.g366">false positive findings</a> — when an abnormality is detected that might be breast cancer but, after further testing including more mammography, is found not to be. Having additional testing causes significant anxiety for some women, including the belief that they are at higher risk for breast cancer. </p>
<p>In addition to the significant anxiety some women feel because of a false positive finding, consider the experience of a woman who is over-diagnosed, receives cancer treatment and lives with a breast cancer diagnosis for the rest of her life — a diagnosis that might never have occurred without mammography screening.</p>
<h2>5. Radiation from screening can also kill</h2>
<p>Radiation associated with mammography screening, additional mammography for false positives and with radiation treatment for overdiagnosed breast cancer carries significant risk for women. </p>
<p>A study done for the United States Preventive Services Task Force estimated that radiation exposure from screening and diagnostic workup <a href="http://dx.doi.org/10.7326/M15-1241">causes 27 breast cancers and 4 deaths</a> for every 100,000 women aged 50 to 69 screened every two years.</p>
<h2>6. Screening directs resources away from treatment</h2>
<p>There are significant harms associated with mammography screening and no reliable evidence of benefit. It is time to discontinue routine mammograms for all healthy women of a particular age. Resources should be shifted toward surveillance of women at higher risk for breast cancer, diagnostic workup for women with a change in their breast that does not go away and for ensuring that women receive timely treatment for a confirmed invasive breast cancer. </p>
<p>Population-based mammography screening has opportunity costs for the health care system, not to mention the social, financial, interpersonal and emotional costs to women and their families.</p>
<h2>7. Public information is not balanced</h2>
<p>It’s important that women are told — in plain language — about the potential harms and benefits of mammography screening so they can make an informed decision about being screened or not. I was involved in a recent review of the websites of 12 breast screening programs in Canada. Our results (accepted for publication) show that no program is offering balanced information on their website to support an informed decision.</p>
<p>It’s time to change the conversation in Canada about how to reduce the significant illness and death associated with breast cancer. Population-based mammography screening is not the way. We need to continue to research better early detection methods, including breast self examination and clinical breast examination.</p><img src="https://counter.theconversation.com/content/84110/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Anne Kearney received funding from Government of Newfoundland and Labrador for a current project related to non-nursing duties (not-related). I have held other funding in the past but none that puts me in a conflict of interest.</span></em></p>October is breast cancer awareness month. Women should know there is no reliable evidence that routine mammograms reduce death from breast cancer, and there’s good evidence that they cause harm.Anne Kearney, Associate Professor of Nursing, Memorial University of NewfoundlandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/828942017-08-30T06:29:50Z2017-08-30T06:29:50ZThree questions to ask about calls to widen breast cancer screening<figure><img src="https://images.theconversation.com/files/183898/original/file-20170830-5012-ykfmzz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">More mammography, for instance, starting at a younger age or screening more often, isn't necessarily better.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/560294245?src=YLhWfkj2eWvoidSYttzpMQ-1-2&size=medium_jpg">from www.shutterstock.com</a></span></figcaption></figure><p>It’s easy to assume the earlier women are screened for breast cancer, the better. And a <a href="http://onlinelibrary.wiley.com/doi/10.1002/cncr.30842/abstract">recent US study</a>, which found screening women with mammography from the age of 40 saved the most lives, <a href="http://www.sbs.com.au/news/article/2017/08/21/us-study-revives-mammogram-debate">generated</a> <a href="http://www.smh.com.au/national/mammograms-from-age-40-would-save-more-lives-study-finds-20170821-gy0uqo.html">headlines</a> <a href="https://news.google.com/news/story/dU4hXdrjI3KNgFMfdLIBRKOKZeOTM?ned=au&hl=en-AU">around the world</a>. </p>
<p>We need to be cautious, however, when interpreting studies like this and the media reports they create. That’s because with screening, its benefits – less risk of dying of cancer – are clear, and are easily exaggerated. But the potential harms of screening are harder to recognise and readily overlooked.</p>
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Read more:
<a href="https://theconversation.com/when-talking-about-cancer-screening-survival-rates-mislead-30395">When talking about cancer screening, survival rates mislead</a>
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<p>The <a href="http://onlinelibrary.wiley.com/doi/10.1002/cncr.30842/abstract">recent US study</a> compared an intensive screening strategy (strategy a) of annual mammograms for women starting at age 40 all the way to 84 years of age, with two less-intensive screening strategies.</p>
<p>Strategy b) offered annual mammograms from 45-54 years, then every two years until age 79. Strategy c) offered mammograms every two years from 50-74, the <a href="http://cancerscreening.gov.au/internet/screening/publishing.nsf/Content/breast-screening-1">same screening policy we have in Australia</a>.</p>
<p>Strategy a) has become known in the media as “screening from age 40” but it is really screening more often, and until an older age (when breast cancer is more common), as well as starting earlier. It prevented the most deaths, according to the modelling. But at what “price”?</p>
<p>By screening longer and more often, the more intensive strategy a) required women to have three times as many mammograms. It caused three times as many false positives or false alarms (when women didn’t end up having a breast cancer despite an abnormal mammogram), as the least intensive strategy c). In a major omission, the authors did not address potential harms of overdiagnosis and overtreatment (more below).</p>
<p>So what questions do you need to consider when reading reports about studies like this?</p>
<h2>1. Who’s giving the advice?</h2>
<p>Three specialist radiologists and a medical physicist, all employed by departments of imaging or radiology, authored this study. Screening mammography in the US is big business. The total annual cost of screening mammography there was estimated to be <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4142190/">US$7.8 billion in 2010</a>.</p>
<p>So, why should we be concerned? Because previous research has found financial conflicts of interest <a href="http://www.nejm.org/doi/full/10.1056/NEJM199308193290812">increase the risk of bias</a>, and lead committees towards recommendations that are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5441061/">more favourable towards mammography screening</a>.</p>
<p>Non-financial conflicts of interest can also affect recommendations. Guideline panels with radiologist members are <a href="https://www.ncbi.nlm.nih.gov/pubmed/22498428">more likely to recommend screening for women from age 40 years</a> than recommendations issued by panels without radiologist members.</p>
<h2>2. What aren’t they telling me?</h2>
<p>A mammogram may seem harmless, but it can cause long-term problems that many people would never think of. An important one is finding harmless, idle or dormant cancers, a major factor in overdiagnosis.</p>
<p>Overdiagnosis is common not just in <a href="http://jamanetwork.com/journals/jama/fullarticle/1722196">breast cancer, but in screening for prostate, thyroid and lung cancer</a>.
How common? When a UK panel carried out an <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)61611-0/abstract">independent assessment</a> of the benefit and harms of screening mammography, it found the chance of a woman being overdiagnosed by screening was three times greater than the chance screening would save her from dying of breast cancer.</p>
<p>Even the chief medical officer of the American Cancer Society urges accepting <a href="http://annals.org/aim/article/2597574/accepting-existence-breast-cancer-overdiagnosis">overdiagnosis and overtreatment as harms</a> of breast cancer screening.</p>
<p>Yet the authors of this latest US study didn’t consider overdiagnosis and overtreatment when concluding annual screening from age 40-84 years is best.</p>
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Read more:
<a href="https://theconversation.com/five-commonly-over-diagnosed-conditions-and-what-we-can-do-about-them-82319">Five commonly over-diagnosed conditions and what we can do about them</a>
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<p>Overdiagnosis is important because it isn’t a good idea to have cancer treatments (surgery, radiotherapy and antihormone pills) for a harmless cancer (overtreatment).</p>
<p>Each of these treatments comes with risks of side-effects, as UK woman Elizabeth Dawson <a href="https://olot1.wordpress.com/2015/11/04/a-mammogram-may-break-your-bones/">describes in her blog</a>. Two and a half years after starting treatment she was still wondering whether the cancer that was found by screening was overdiagnosed or not, and whether she needed all, or even any, of the treatments she’d had. She hates that the drugs she’s still taking to prevent a recurrence make her bones frailer. She’s been told not to go out when it’s icy because she might fall and fracture, but she hates the idea of being housebound at 56 when she feels so well and active.</p>
<p>The US study did include false positives in its calculations, but may not have recognised fully the impact. Being recalled for an abnormal mammography is scary. But what is less well known is that even three years after being declared free of suspected cancer, women with false positives consistently report <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3601385">worse psychosocial outcomes</a>; they report feeling more dejected and more anxious, and report worse sleep and negative impacts on sexuality than women with normal mammograms.</p>
<p>Mammography uses radiation, so <a href="http://annals.org/aim/article/2480762/radiation-induced-breast-cancer-incidence-mortality-from-digital-mammography-screening">there’s a small chance</a> the screening process itself may induce cancers over time. But starting screening from 50 and screening every two years is estimated to reduce the number of induced cancers <a href="http://annals.org/aim/article/2480762/radiation-induced-breast-cancer-incidence-mortality-from-digital-mammography-screening">five-fold</a> compared to annual screening from age 40.</p>
<h2>3. What’s the health-care context?</h2>
<p>The US has a very different health-care context to Australia. In the US, mammography screening costs are paid by many different organisations. So debates over recommendations may <a href="http://www.stoptheguidelines.com/">have implications</a> for whether health plan organisations cover services or not. </p>
<p>In contrast, as part of our national cancer screening programs, <a href="http://cancerscreening.gov.au/internet/screening/publishing.nsf/Content/breast-screening-1">BreastScreen Australia</a> provides mammograms in a national, publicly funded program that offers high-quality screening to eligible women, for free.</p>
<p>The health-care context is also relevant when we consider an individual woman’s risk of breast cancer. This debate (about when to start screening and how often) is relevant to women at average risk of breast cancer. For women with a strong family history, or who know they carry a breast cancer genetic mutation, <a href="http://www.genetics.edu.au/individuals-and-families/cancer-in-the-family">screening more intensively offers greater benefits</a>.</p>
<h2>So which strategy really is best?</h2>
<p>The ultimate aim of screening is to reduce deaths from breast cancer. Yet, whichever screening strategy we use, screening is not 100% effective.</p>
<p>It probably reduces the risk of dying from breast cancer <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)61611-0/abstract">by about 20%</a>, at most <a href="http://journals.sagepub.com/doi/abs/10.1258/jms.2012.011127">by 40%</a>, and perhaps as little as only <a href="http://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1792915">a few percent</a>.</p>
<p>So we must balance this limited benefit with a clearer picture of harms like overdiagnosis and overtreatment to avoid tipping over into net harm.</p><img src="https://counter.theconversation.com/content/82894/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alexandra Barratt receives funding from NHMRC. She is a member of the Public Health Association of Australia, and of the Australasian Epidemiological Association. </span></em></p>Calls to routinely offer breast cancer screening to more women might sound like a good idea, but can harm. Here are three questions to ask when figuring out whether more screening really is better.Alexandra Barratt, Professor of Public Health, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/670472016-10-16T19:08:22Z2016-10-16T19:08:22ZBreast self-examination: should you really ‘pledge to check’?<figure><img src="https://images.theconversation.com/files/141708/original/image-20161014-3944-5bi62g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's normal for breasts to be a little bit lumpy.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-201864136/stock-photo-breast-cancer-self-check-healthy-lifestyle-concept.html?src=DFhSlgOWfekGxs2kfXaGOw-1-13">9nong/Shutterstock</a></span></figcaption></figure><p>Shopping at my local pharmacy last week, I was taken aback by a product on the counter: <a href="http://www.egopharm.com/qv-self-check-breast-cream/">“self check breast cream”</a>. Sorry, what? Breast self-examination cream? Is that even a thing?</p>
<p>Looking closer at the <a href="https://twitter.com/drgrinzi/status/784315845421912064">bright pink display</a>, I discovered a sales campaign in full swing, seemingly timed to coincide with <a href="https://canceraustralia.gov.au/healthy-living/campaigns-events/breast-cancer-awareness-month">“breast cancer awareness month”</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/141701/original/image-20161013-3985-1jw5kjm.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/141701/original/image-20161013-3985-1jw5kjm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/141701/original/image-20161013-3985-1jw5kjm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=250&fit=crop&dpr=1 600w, https://images.theconversation.com/files/141701/original/image-20161013-3985-1jw5kjm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=250&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/141701/original/image-20161013-3985-1jw5kjm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=250&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/141701/original/image-20161013-3985-1jw5kjm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=314&fit=crop&dpr=1 754w, https://images.theconversation.com/files/141701/original/image-20161013-3985-1jw5kjm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=314&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/141701/original/image-20161013-3985-1jw5kjm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=314&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://qvskincare.com.au/promotions/breast-cream/">QV Breast Cream screen shot.</a></span>
</figcaption>
</figure>
<p>Two dollars from each tube sold was going to <a href="http://www.mcgrathfoundation.com.au/">a breast cancer charity</a>, and there was a ready-to-use social media hashtag – #<a href="https://www.twitter.com/search?q=%23IPledgeToCheck">IPledgeToCheck</a>. In large font was the message “self checking your breasts is important”.</p>
<p>This is a fairly familiar message. But is it true? The evidence is surprisingly complicated.</p>
<h2>Breast cancer screening</h2>
<p>Breast cancer is a common and important disease. Affecting about one in eight women at some point in their lives, it is <a href="http://www.aihw.gov.au/publication-detail/?id=10737423008">the second most common</a> cause of cancer death in Australian women. I’ve seen it profoundly affect many people, including several of my general practice patients. Preventing this would be wonderful.</p>
<p>Cancer screening means looking for cancer in people without symptoms. An established (though <a href="https://theconversation.com/growing-uncertainty-about-breast-cancer-screening-15997">still controversial</a>) example is <a href="http://www.cancerscreening.gov.au/internet/screening/publishing.nsf/Content/breast-screening-1">mammography</a>: breast X-rays. Another less established method is breast self-examination.</p>
<p>At first glance, being offered a chance of finding cancer early sounds like a good thing. But it’s more complicated than that. Some screening tests, despite good intentions, fail to help, or even cause harm.</p>
<p>There are various ways screening can mislead us. Screen-detected cancers often show better survival rates than other cancers, but this doesn’t mean the screening is saving lives. </p>
<p>It can instead mean we’re just detecting the cancer earlier <a href="https://theconversation.com/when-talking-about-cancer-screening-survival-rates-mislead-30395">without changing its course</a>, or that the screening is picking up some so-called “cancers” that would <a href="https://theconversation.com/whats-in-a-name-why-we-need-to-reconsider-the-word-cancer-16606">never have caused symptoms</a> (this is called “overdiagnosis”). </p>
<p>Screening can also cause problems by raising false alarm – discovering a lump that resembles possible cancer, but after a worrisome round of tests turns out not to be.</p>
<p>To best measure the effect of a screening program, we need large “randomised controlled trials” of screening. These are studies in which people are randomly allocated to either screening or normal care, and followed over time to see what happens.</p>
<h2>The paradox of breast self-examination</h2>
<p>Two large trials of breast self-examination measured important outcomes such as harms and death. In these trials, study staff taught groups of women how to examine their own breasts in a careful, structured manner. Monthly self-examination was encouraged. </p>
<p>These women were followed up and compared to other women who had no training or encouragement in self-examination.</p>
<p>The results of these studies have been brought together and meta-analysed (mathematically combined) in order to summarise our best evidence on the effectiveness of self-examination. </p>
<p>The <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD003373/abstract">combined results</a> from nearly 400,000 women are disappointing: encouraging women to examine their own breasts does not prevent any deaths from breast cancer, but does cause false alarm and an increase in the need for biopsies (involving needles or surgical excision).</p>
<p>But here’s the apparent paradox: despite this lack of effectiveness of breast self-examination in these trials, most breast cancers are still discovered because women notice a change in their breasts.</p>
<p>Trying to put these seemingly contradictory facts together can be headache-inducing. How can this all be true? </p>
<p>It must be that significant breast cancers are likely to be detected spontaneously or accidentally by women in the course of normal life, even without self-examination. Adding structured, monthly self-examination sounds wise, even noble, but sadly our best evidence finds it is unhelpful and leads to false alarm.</p>
<p>Why the false alarm? Because it’s normal for breasts to be a little bit lumpy, as firmer glandular breast tissue sits suspended amongst looser fatty tissue. Picking the “signal” of cancer from the “noise” of normal lumpiness can be tricky.</p>
<h2>So what should we do?</h2>
<p>Authors of breast cancer guidelines have tried to resolve the apparent paradox. They recognise the ineffectiveness of formal regular self-examination, but they also don’t want women to completely ignore their own breasts. </p>
<p>As a sort of compromise, guidelines now talk about <a href="https://canceraustralia.gov.au/publications-and-resources/position-statements/early-detection-breast-cancer">breast awareness</a> – having some self-awareness of one’s breasts, and knowing the importance of presenting quickly to a doctor if a change is noted. </p>
<p>This is a prudent message, and it is one I share with my patients. But it’s still unclear exactly where the sweet spot lies between too much self-examination and too little awareness.</p>
<p>These evidence-based uncertainties and nuances are often lost in media messages about breast awareness, and they seem thoroughly lost in this moisturising cream’s marketing campaign. On <a href="https://twitter.com/egoeveryday/status/783891677668790273">Twitter</a> and <a href="https://www.youtube.com/watch?v=zbPkFZtvwgs">YouTube</a>, the manufacturer actually encourages women to perform <em>daily</em> self-checks, “by making it part of their every day skincare routine”.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"783891677668790273"}"></div></p>
<p>To be fair to the manufacturer, the “daily routine” phrase is echoed by <a href="https://canceraustralia.gov.au/affected-cancer/cancer-types/breast-cancer/awareness/what-can-you-do-find-breast-cancer-early/50-74-years-old">Cancer Australia</a>. But Cancer Australia seem more relaxed about the process, stating that no special technique is necessary and suggesting that a more casual awareness in the shower or in the mirror may suffice. </p>
<p>I haven’t found any evidence to show that using a moisturising cream is necessary or helpful in cancer detection. So it’s not at all clear that this cream will save anyone from bad cancer outcomes, and there’s a real possibility of causing false alarm. While sales help raise money for a worthwhile charity, it’d be more efficient to <a href="https://www.mcgrathfoundation.com.au/Donate.aspx">donate directly</a>.</p>
<p>Is it possible, behind all the pink-tinted pledge-gathering, that the main goal of this campaign is simply to sell moisturising cream?</p><img src="https://counter.theconversation.com/content/67047/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brett Montgomery is a general practitioner working academically and clinically. In his clinical work he sometimes treats people who have breast disease.</span></em></p>Women are told it’s important to self-check their breasts. But is this true?Brett Montgomery, Senior Lecturer in General Practice, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/466242015-08-26T19:45:14Z2015-08-26T19:45:14ZTreating ‘stage 0’ breast cancer doesn’t always save women’s lives so should we screen for it?<figure><img src="https://images.theconversation.com/files/92976/original/image-20150826-32480-j0rt1g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Women with DCIS or stage 0 breast cancer have the same chance of dying from breast cancer as the rest of the population – 3.3%.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-243901117/stock-photo-woman-in-s-about-to-undergoing-a-mammography-test.html?src=I7c8Kyu33z1Lv4w5zQVYOA-1-19">CristinaMuraca/Shutterstock</a></span></figcaption></figure><p>We’re told that “prevention is better than cure”; that finding symptoms of disease early will prevent the more serious consequences of that disease, particularly for cancer. </p>
<p>Women largely understand that a regular screening mammogram may decrease their chance of dying from the disease by allowing earlier detection and therefore less aggressive treatments. This is <a href="http://cancerscreening.gov.au/internet/screening/publishing.nsf/Content/programme-evaluation">largely true</a>: for every 1,000 women screened over a 25 year period, nine will not die from breast cancer because of that screening. But it does not give the entire picture.</p>
<p>For a minority of women diagnosed with the “pre-cancerous” lesion ductal carcinoma in situ, or DCIS, treatment doesn’t reduce their chance of getting or dying from breast cancer.</p>
<p>DCIS consists of abnormal cells in the breast ducts that rarely cause any symptom but are detectable on mammogram, often calcium deposits in the breast. This is also known as “stage 0” breast cancer. </p>
<p>Many of these indolent lesions are unlikely to ever cause a problem in a woman’s lifetime. So finding one can be said to be “over-diagnosis”. This detection will result in “overtreatment”, with surgery (lumpectomy or mastectomy, where the lump or breast is removed) and perhaps radiotherapy. </p>
<p>A <a href="http://canceraustralia.gov.au/publications-and-resources/position-statements/overdiagnosis-mammographic-screening">recent Australian analysis</a> concedes it is hard to put a definite figure on this, but it around eight women in every 100 screened over 25 years may have one of these “over-diagnosed” and “over-treated” lesions.</p>
<p>The real problem is that we currently have little ability to predict which of these DCIS lesions will either progress into an invasive cancer or predict the development of a future invasive cancer, with the potential to spread and impact on a woman’s life.</p>
<p>A study released last week in <a href="http://oncology.jamanetwork.com/article.aspx?articleid=2427491">JAMA Oncology</a> adds further data to this debate, but perhaps leads to more questions than answers. This study is a detailed examination of a huge North American registry database of outcomes of 100,000 women diagnosed with DCIS between 1988 and 2011 were studied. </p>
<p>The authors show that, overall, women diagnosed with DCIS have the same chance of dying of breast cancer than women with no breast problems: 3.3% after 20 years of follow up. </p>
<p>However, there were some important exceptions. Very young women (under 35) diagnosed with DCIS, women of African American ethnicity, and those with the more aggressive types of DCIS (larger, high-grade and non-hormone-dependent) had a higher risk of dying of breast cancer. </p>
<p>The researchers found treating DCIS did not save lives. Having a more radical surgery – mastectomy rather than lumpectomy – or adding radiotherapy to a lumpectomy overall did not decrease the chance of ultimately dying of breast cancer.</p>
<p>Interestingly, having a mastectomy or radiotherapy lowered the chance of getting an invasive cancer in the treated breast yet did not alter the chance of dying of breast cancer. This suggests that some DCIS lesions do have the ability to spread.</p>
<p>What can we conclude from this study? Well, it seems to confirm that there are at least two types of DCIS – and the more aggressive one <em>does</em> need to be treated.</p>
<p>But the majority of women with DCIS will not go on to get invasive cancer. So perhaps we need to consider DCIS more as a warning sign of potential future cancer risk. This opens the way for new research into less aggressive treatments for these types of DCIS, and how best to lower future cancer risk with drug treatments or even lifestyle changes such as weight loss and exercise.</p>
<p>Breast cancer screening undoubtedly <a href="http://cancerscreening.gov.au/internet/screening/publishing.nsf/Content/breastscreen-n-you-html">has benefits</a> but the size of these benefits is debated. A <a href="http://www.breast-cancer-research.com/content/17/1/63">recent review from the United Kindom</a> suggested perhaps only one out of 15 women diagnosed with cancer by mammographic screening will be helped: </p>
<ul>
<li>three will die of breast cancer anyway</li>
<li>eight will likely have survived even if not treated until symptomatic</li>
<li>three have cancers that would not have manifested or killed them anyway</li>
<li>one will avoid breast cancer death. </li>
</ul>
<p>The Australian breast screening program probably offers better odds than this, with more frequent screens, excellent equipment, staff and quality assurance, and good access to care for the majority of Australians. </p>
<p>Only further research can unravel exactly which DCIS is really a risk to health and needs aggressive treatment, which DCIS may be a marker of future cancer risk and how we can modify this risk, and perhaps which DCIS is an indolent condition which will never affect a woman in her lifetime.</p>
<p>When deciding whether or not to go for a mammographic screening test, getting balanced comprehensive information is important. Working out your individual cancer risk (via <a href="http://canceraustralia.gov.au/affected-cancer/cancer-types/breast-cancer/your-risk/calculate">calculators such as this</a>) and what you can do about it may help inform not only your screening choices but also your lifestyle choices which in turn can help prevent a number of diseases. </p>
<p>Understanding your individual risk also relies on emotions, anecdote and personal experience; this all feeds into decision-making. </p>
<p>However, choice does not solve the fundamental dilemma of screening: is it ethically acceptable to cause serious harm in some people in order to improve the prognosis of others?</p><img src="https://counter.theconversation.com/content/46624/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christobel Saunders does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We’re told that finding symptoms of disease early will prevent the more serious consequences. But for pre-cancerous lesions, also known as stage 0 breast cancer, the picture is much more complicated.Christobel Saunders, Professor of Surgical Oncology, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/317582014-10-22T09:36:40Z2014-10-22T09:36:40ZAwash in pink, but breast cancer awareness isn’t a cure<figure><img src="https://images.theconversation.com/files/59732/original/4q2c8bpd-1411415664.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Participants and guests at a Walk for Breast Cancer decked out in pink.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-104793701/stock-photo-czech-republic-prague-june-participants-and-guests-celebrate-after-the-final-ceremony-speeches.html?src=GskVD3-OuyGt-Go5wVFXQw-1-40">Breast cancer walk image via www.shutterstock.com</a></span></figcaption></figure><p>This month, we are inundated with pink. By wearing pink ribbons, purchasing pink products, and participating in walks and other collective activities, citizens try to raise awareness of the scourge of breast cancer, with the eventual goal of curing the disease. But three decades after October was established as Breast Cancer Awareness Month, we need to ask ourselves: has all our pink paraphernalia really helped improve health?</p>
<p>At best, the results are mixed. <a href="http://asr.sagepub.com/content/77/5/780.short">Studies show</a> these campaigns can put a particular disease on the map, which can be valuable for rare illnesses. The summer of 2014’s <a href="http://www.alsa.org/fight-als/ice-bucket-challenge.html">Ice Bucket Challenge</a> for amyotrophic lateral sclerosis is a perfect example. It raised the disease’s profile and the ALS Association generated <a href="http://www.alsa.org/news/archive/als-association-thankyou-video.html">US$100 million in donations</a> in a month. But dumping a bucket of ice over your head doesn’t teach you anything about the disease or how it affects those who suffer from it. Those who donated money had little sense of how their efforts might improve the health and lives of ALS patients, and a year on, the disease and its sufferers have been largely forgotten.</p>
<p>The longer history of breast cancer awareness efforts gives us a deeper understanding of the benefits and limits of these kinds of campaigns. Without a doubt, the past three decades have generated an enormous increase in public awareness of breast cancer. There have been thousands of consciousness-raising events across the world, and hundreds of targeted initiatives among government agencies, major corporations and nonprofit organizations, to the point that it’s not strange to see even <a href="http://www.nfl.com/pink">NFL players</a> decked out in pink during October. </p>
<p>Breast cancer research funding has grown considerably. In 1990 the US federal government spent <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.0141-9889.2004.00420.x/full">less than $100 million</a> on the disease. Now the government and top private foundations spend <a href="http://pinkribbonblues.org/resources/beyond-awareness-workbook/background/funding-for-research/">at least $1 billion</a> annually. And there has been a massive <a href="http://www.hrsa.gov/quality/toolbox/measures/breastcancer/">increase</a> in mammography screening. </p>
<p>But across the world, breast cancer rates have gone up right along with awareness. In the United States, a woman’s lifetime risk of breast cancer has gone from one in 20 in the 1960s to <a href="http://www.cancer.org/acs/groups/content/@research/documents/document/acspc-042725.pdf">one in eight</a> today. While part of this shift can be explained by increased access to mammography, researchers also point to long-term use of <a href="http://www.cancer.gov/cancertopics/factsheet/detection/probability-breast-cancer">hormone therapies</a> and <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1582-4934.2005.tb00350.x/abstract">lifestyle changes</a>. This year in the US, nearly <a href="http://www.cancer.org/research/cancerfactsstatistics/breast-cancer-facts-figures">a quarter of a million</a> women will be diagnosed with invasive breast cancer. Mammography <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1206809">does not seem to reduce</a> breast cancer mortality. </p>
<p>And while survival rates have improved for white women, women of color have not seen the same gains: today, black women are <a href="http://www.cdc.gov/vitalsigns/breastcancer/">40% more likely</a> to die of breast cancer than their white counterparts. Even women of color who are diagnosed early have more aggressive cancers. Low-income women also have <a href="http://www.biomedcentral.com/1471-2407/9/364">difficulty accessing</a> the expensive treatments that are improving survival rates for middle- and high-income women. </p>
<p>Also problematic is the fact that the breast cancer awareness movement’s enormous success has actually led women to overestimate their risk of getting the disease while underestimating their risks of contracting more common – but at least as deadly – conditions, including <a href="http://www.cdc.gov/heartdisease/facts.htm">heart disease</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/98346/original/image-20151014-879-xsmj7e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/98346/original/image-20151014-879-xsmj7e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/98346/original/image-20151014-879-xsmj7e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/98346/original/image-20151014-879-xsmj7e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/98346/original/image-20151014-879-xsmj7e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/98346/original/image-20151014-879-xsmj7e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/98346/original/image-20151014-879-xsmj7e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/98346/original/image-20151014-879-xsmj7e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It’s going to take more than a month’s supply of pink ribbons to find a cure.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/susangkomenforthecure/9623480056">Susan G Komen®</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>So while awareness efforts can focus significant public attention and help scientists raise funds for research, the impact on eradicating the disease itself is much less clear. </p>
<p>Does that mean we should abandon such efforts? Absolutely not. But in the fight against a particular disease, we need to understand that awareness efforts are only initial steps down a very long road. The time has come for us to think about other steps we need to take. </p>
<p>We can begin by putting at least as much time and effort into understanding the social, health, economic, environmental and policy-related challenges faced by individuals at risk for and suffering from a particular disease. Then we should help them fight these battles. Imagine “national days of action” in which we work within communities to improve access to the local health infrastructure. Or we could direct fundraising to organizations that serve patients’ practical and emotional needs. In the case of breast cancer, these <a href="http://www.shanti.org/pages/shanti-model.html">organizations</a> provide help in getting to the grocery store, interacting with medical professionals and communicating the patient’s wishes, and providing home care. </p>
<p>If we continue to focus on increasing research funding, then we need to ask questions not only about the percentage of money actually spent on research as opposed to overhead, but also how to ensure that this research will benefit those suffering from the disease. Scholars have suggested, for example, that <a href="http://dx.doi.org/10.1016/j.envsci.2006.10.001">decisions about allocating research funding</a> be tied to the potential for improved health outcomes and the researchers’ track records in achieving them. At the moment, funding is doled out based primarily on scientific priorities that may or may not align with health and social priorities.</p>
<p>Others have argued that in order to ensure that findings turn into widely available new technologies rather than expensive innovations available only to a few, research efforts must be <a href="http://dx.doi.org/10.1016/j.amepre.2008.05.018">truly interdisciplinary</a>. So a breast cancer team could include not only biologists but also social scientists, public health and policy experts, and even patients. They would work together throughout the research process to produce outputs that are acceptable, useful and affordable to the populations most in need.</p>
<p>And we need to pressure research funding organizations and other policymakers to ensure that intellectual property agreements do not hinder access to important treatments, preventive or diagnostic measures. Until 2013, for example, genetic testing on genes linked to breast and ovarian cancer was extremely expensive in the United States due to a <a href="http://www.nytimes.com/2015/01/28/business/myriad-genetics-ending-patent-dispute-on-breast-cancer-risk-testing.html?_r=0">patent-based monopoly</a> held by biotechnology company Myriad Genetics. But public interest lawyers, civil society groups, and other citizens fought against the patent, and now the technology is <a href="http://bcconnections.org/resources/brca-test-providers/">cheaper and more widely available</a>. The competition that has emerged may produce more research and better testing too.</p>
<p>If we continue to focus our advocacy on disease awareness efforts, then we will only make limited progress toward our real goals. We must think strategically about generating the same kind of public engagement in all the other steps down the long road toward better health and cures.</p><img src="https://counter.theconversation.com/content/31758/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shobita Parthasarathy has received funding from the US National Science Foundation and the UK Wellcome Trust. She is on the Board of Directors for Breast Cancer Action.</span></em></p>Awareness efforts can focus public attention and help scientists raise funds for research. But the impact on eradicating the disease itself and helping patients today is much less clear.Shobita Parthasarathy, Associate Professor of Public Policy and Women's Studies, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/73962012-09-10T20:25:03Z2012-09-10T20:25:03ZOver-diagnosis and breast cancer screening: a case study<figure><img src="https://images.theconversation.com/files/15291/original/89ysp677-1347258264.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Women need to be made aware of over-diagnosis and given enough information to make up their own minds about screening.</span> <span class="attribution"><span class="source">Johan/Flickr</span></span></figcaption></figure><p><em>OVER-DIAGNOSIS EPIDEMIC – Today Robin Bell and Robert Burton examine breast cancer to evaluate the role of population-wide screening in over-diagnosis.</em></p>
<p>Since the national <a href="http://www.aihw.gov.au/WorkArea/DownloadAsset.aspx?id=6442454634">screening mammography program</a> (Breastscreen) began in Australia in 1991, <a href="http://www.aihw.gov.au/data">mortality from breast cancer</a> has declined by 28%. We wanted to know how much of this improvement was due to Breastscreen and how much was due to advances in breast cancer treatment.</p>
<p>This is an important question to ask in light of the recent passionate debate about the benefits and harms of mammographic screening in <a href="http://www.bmj.com/content/340/bmj.c3106?tab=responses">medical literature</a> as well as in the lay <a href="http://www.theage.com.au/national/behind-the-screen-20111103-1mxrh.html">press</a>. We published an <a href="http://www.ncbi.nlm.nih.gov/pubmed/21956213">analysis</a> that addressed this issue using three different approaches.</p>
<h2>Who avoids breast cancer death?</h2>
<p>We started by comparing the relative reductions in breast cancer-specific mortality between 1991 and 2007 (the latest data year available) in women across different age groups. We know women aged 50 to 69 years were invited to screen, so their uptake of mammographic screening should have been higher than other age groups. So if screening was important, this is where we would expect to see the most impact.</p>
<p>But what we found was that the greatest relative reduction in breast cancer mortality (44%) occurred in the youngest age group. These women (aged 40 to 49 years) are not invited for screening. In contrast, women aged 60 to 69 years, who <em>are</em> invited to screen, had the smallest relative reduction in mortality (19%). </p>
<p>Given that three times as many women aged 60 to 69 (about 60%) participated in Breastscreen (compared to 20% of women aged 40 to 49 years), our finding <em>is not consistent</em> with screening having a major impact on the reduction in breast cancer mortality since 1991.</p>
<h2>When was mortality reduced?</h2>
<p>We then considered <em>when</em> Breastscreen could have had an impact on breast cancer mortality between 1991 and 2007. </p>
<p>The proportion of invited women who attended for screening didn’t exceed 50% until 1996. And we know from randomised trials of screening that the impact of screening on mortality was not seen for four to six years after the commencement of the trials (they had an even higher level of <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(02)08020-0/fulltext">participation of 70% and more</a>). </p>
<p>So <a href="http://www.ncbi.nlm.nih.gov/pubmed/21956213">we compared the reductions</a> in mortality that occurred in two time periods – (1) between 1991 and 1999 when we wouldn’t have expected Breastscreen to have an impact and (2) between 2000 and 2007 when the impact of Breastscreen would’ve been expected. </p>
<p>For women invited for screening (50 to 69 years), most of the reduction in mortality that occurred between 1991 and 2007 took place prior 2000. The reduction was <em>before</em> the impact of screening could be expected. </p>
<p>Only about a third of the total 28% reduction in breast cancer mortality seen in this age-group over the full time period occurred after 1999 (9%). This finding is also inconsistent with mammographic screening having a major impact on the observed reduction in breast cancer mortality since 1991.</p>
<h2>Improved treatment</h2>
<p>Finally, we used a number of different data sources to estimate the likely impact on breast cancer mortality of changes in the use of <a href="http://www.cancer.gov/cancertopics/factsheet/Therapy/adjuvant-breast">adjuvant chemo</a> - and <a href="http://breastcancer.about.com/lw/Health-Medicine/Conditions-and-diseases/Endocrine-Treatments-for-Breast-Cancer.htm">endocrine therapy</a> over the same time period. We obtained published data from the Early Breast Cancer Trialists’ Collaborative Group (<a href="http://www.ncbi.nlm.nih.gov/pubmed/15894097">EBCTCG</a>) to provide the <a href="http://www.ncbi.nlm.nih.gov/pubmed/21802721">estimated impact</a> of regimens of chemo and endocrine therapy on women in different age groups with early breast cancer. </p>
<p>We used this data, together with data from a population-based <a href="http://onlinelibrary.wiley.com/doi/10.1002/cncr.20401/abstract">survey</a> of women treated for early breast cancer in Victoria in 1999, to calculate the impact the use of adjuvant chemo- and endocrine therapy could have had on breast cancer mortality in these women. We found that the adjuvant therapy Victorian women received in 1999 could have produced a mortality reduction of about 26% in women in the age group invited to screen. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/15283/original/38jdcdv4-1347257115.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/15283/original/38jdcdv4-1347257115.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/15283/original/38jdcdv4-1347257115.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/15283/original/38jdcdv4-1347257115.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/15283/original/38jdcdv4-1347257115.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/15283/original/38jdcdv4-1347257115.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/15283/original/38jdcdv4-1347257115.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Diagnosis comes with its own worries and stresses.</span>
<span class="attribution"><span class="source">Ronny-André Bendiksen</span></span>
</figcaption>
</figure>
<p>Indeed, improvements in the treatment of breast cancer could explain almost all of the reduction in breast cancer mortality that has occurred in women invited to screen since 1991.</p>
<p>We estimate mammographic screening is responsible for a minority of the reduction in breast cancer-specific mortality seen in Australia since 1991 and that advances in adjuvant therapies adequately explain the majority of the observed mortality reduction.</p>
<h2>Breast cancer and over-diagnosis</h2>
<p>A modest reduction in mortality as a result of mammographic screening would seem acceptable if it were not for the issue of over-diagnosis. Over-diagnosis is the diagnosis and treatment of breast cancer that would have never have made a woman ill in her lifetime – she would never have known about it if she had not been screened. </p>
<p>The extent of the problem of breast cancer over-diagnosis has been estimated in the <a href="http://www.ncbi.nlm.nih.gov/pubmed/21249649">Cochrane review of screening mammography</a> at 30%, based on the randomised trials. In Australia, based on increases in new case rates, over-diagnosis was estimated at 30% to 40% in the women aged 50 to 69 years invited to screen in New South Wales in <a href="https://www.mja.com.au/journal/2012/196/1/do-benefits-screening-mammography-outweigh-harms-overdiagnosis-and-unnecessary-0">2001 and 2002</a>. </p>
<p>Putting their estimates of the relative mortality reduction in breast cancer (15%) and over-diagnosis (30%) together to calculate the balance of benefits versus harms, <a href="http://www.ncbi.nlm.nih.gov/pubmed/21249649">the Cochrane review summarised</a>:</p>
<blockquote>
<p>“… for every 2000 women invited for screening throughout 10 years, one will have her life prolonged. In addition, 10 healthy women, who would not have been diagnosed if there had not been screening, will be diagnosed as breast cancer patients and will be treated unnecessarily.”</p>
</blockquote>
<p>Our estimate of the likely breast cancer-specific <a href="http://www.ncbi.nlm.nih.gov/pubmed/21956213">mortality reduction from screening</a> in women aged 50 to 69 years (9%) and the New South Wales estimates of 30% to 40% over-diagnosis <a href="http://www.ncbi.nlm.nih.gov/pubmed/19894130">in this age group are similar</a> to the Cochrane estimates. </p>
<p>Based on these Australian estimates and the incidence and mortality of breast cancer in women aged 50 to 69 years in 2007, we know that for every death from breast cancer prevented, 15 healthy women, who wouldn’t have been diagnosed if they hadn’t been screened, will be diagnosed as having invasive breast cancer and will be treated unnecessarily.</p>
<p>Although there’s considerable argument about the exact extent of over-diagnosis, most estimates find the balance of lives saved to cases over-diagnosed and treated unnecessarily unfavourable, with more women over-diagnosed than saved.</p>
<p>We believe that the decision to invite women for screening should be reviewed with the aim of ceasing the standard invitation for screening. As women aged 50 to 69 years have been invited for screening for 20 years now, a change in policy may take some time to work through. </p>
<p>In the meantime, women need to be made aware of the issue of over-diagnosis and the information provided to those invited for mammographic screening needs to be better balanced between benefits and harms so they can make up their own minds about whether to be screened.</p>
<p><em>Have you or someone you know been over-diagnosed? Share your story below or <a href="mailto:reema.rattan@theconversation.edu.au">email</a> the series editor.</em></p>
<p><em>This is part two of our series on over-diagnosis, click on the links below to read other articles:</em></p>
<p><em><strong>Part one:</strong> <a href="https://theconversation.com/preventing-over-diagnosis-how-to-stop-harming-the-healthy-8569">Preventing over-diagnosis: how to stop harming the healthy</a></em></p>
<p><em><strong>Part three:</strong> <a href="https://theconversation.com/the-perils-of-pre-diseases-forgetfulness-mild-cognitive-impairment-and-pre-dementia-8702">The perils of pre-diseases: forgetfulness, mild cognitive impairment and pre-dementia</a></em></p>
<p><em><strong>Part four:</strong> <a href="https://theconversation.com/how-genetic-testing-is-swelling-the-ranks-of-the-worried-well-9080">How genetic testing is swelling the ranks of the ‘worried well’</a></em></p>
<p><em><strong>Part five:</strong> <a href="https://theconversation.com/psa-screening-and-prostate-cancer-over-diagnosis-8568">PSA screening and prostate cancer over-diagnosis</a></em></p>
<p><em><strong>Part six:</strong> <a href="https://theconversation.com/over-diagnosis-the-view-from-inside-primary-care-8889">Over-diagnosis: the view from inside primary care</a></em></p>
<p><em><strong>Part seven:</strong> <a href="https://theconversation.com/moving-the-diagnostic-goalposts-medicalising-adhd-8675">Moving the diagnostic goalposts: medicalising ADHD</a></em></p>
<p><em><strong>Part eight:</strong> <a href="https://theconversation.com/the-ethics-of-over-diagnosis-risk-and-responsibility-in-medicine-9054">The ethics of over-diagnosis: risk and responsibility in medicine</a></em></p>
<p><em><strong>Part nine:</strong> <a href="https://theconversation.com/ending-over-diagnosis-how-to-help-without-harming-9633">Ending over-diagnosis: how to help without harming</a></em></p><img src="https://counter.theconversation.com/content/7396/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robin Bell receives funding from the Victorian Cancer Agency, the BUPA Health Foundation and the National Health and Medical Research Council of Australia.</span></em></p><p class="fine-print"><em><span>Robert Burton does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>OVER-DIAGNOSIS EPIDEMIC – Today Robin Bell and Robert Burton examine breast cancer to evaluate the role of population-wide screening in over-diagnosis. Since the national screening mammography program…Robin Bell, Professor & Deputy Director, Women's Health Program, School of Public Health and Preventive Medicine, Monash UniversityRobert Burton, Professor School of Public Health and Preventive Medicine, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/86022012-08-03T04:55:00Z2012-08-03T04:55:00ZUnderstanding risk statistics about breast cancer screening<figure><img src="https://images.theconversation.com/files/13797/original/6ccxk5v4-1343957168.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Basic statistical literacy is important for communicating and understanding medical risks</span> <span class="attribution"><span class="source">Janet Ramsden</span></span></figcaption></figure><p><a href="http://www.bmj.com/content/345/bmj.e5132">An article published</a> in the British Medical Journal <a href="http://www.bmj.com/">(BMJ)</a> today says a US charity “overstates the benefit of mammography and ignores harms altogether.” The charity’s questionable claim is that early detection is the key to surviving breast cancer and to support this, it cites a five-year survival rate of 98% when breast cancer is caught early, and 23% when it’s not. </p>
<p>We’re not interested in judging the charity’s actions or intentions but would like discuss the importance of <a href="http://www.psychologicalscience.org/journals/pspi/pspi_8_2_article.pdf">statistical literacy in communicating medical risks</a>.</p>
<p>There are two critical claims in the argument presented by the experts in the BMJ report – that routine breast screening results in high false positive diagnoses and that five-year survival rates are biased. It’s necessary to understand them both to be able to judge whether the statistics quoted by the charity are misleading. </p>
<h2>False positive diagnoses</h2>
<p>What would you think if your routine mammogram came back positive? Most women would justifiably fear the worst. And what you probably won’t be considering is the high false positive rate of screening tests (9%) combined with the low probability of breast cancer in the female population (about 1%, but note that this is different to lifetime risk, which is about one in nine). This combination means a lot of false diagnoses.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/13771/original/372mmh5m-1343890618.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/13771/original/372mmh5m-1343890618.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=469&fit=crop&dpr=1 600w, https://images.theconversation.com/files/13771/original/372mmh5m-1343890618.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=469&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/13771/original/372mmh5m-1343890618.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=469&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/13771/original/372mmh5m-1343890618.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=589&fit=crop&dpr=1 754w, https://images.theconversation.com/files/13771/original/372mmh5m-1343890618.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=589&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/13771/original/372mmh5m-1343890618.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=589&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The probability that a woman who returns a positive mammogram actually has breast cancer. Factoring in the low probability of breast cancer and the high rate of false alarms, only one in ten women with a positive mammogram in this scenario will have breast cancer.</span>
<span class="attribution"><span class="source">Fidler and Wintle, adapted from Gigerenzer at al, 2008</span></span>
</figcaption>
</figure>
<p>It’s important to remember that we are talking here about the outcomes of widespread screening in the absence of well-defined risk factors – not the screening of women in specific high-risk groups, defined by factors associated with age, genetic predisposition, exposure and lifestyle. </p>
<p>The statistics would be different for high-risk groups because the base rate of the disease will be different (higher). In the case of routine screening, however, positive diagnoses need to be treated with caution, and serious action should not be taken on the results of a screening diagnosis alone.</p>
<h2>Five-year survival statistics</h2>
<p>Imagine a group of women all diagnosed with breast cancer at the same time. The proportion of those still alive after five years is called the five-year survival rate. It’s calculated by dividing the number of women diagnosed with breast cancer still alive after five years, by the total number of women diagnosed with breast cancer.</p>
<p>Now imagine a random group of women, not defined by breast cancer diagnosis. The proportion of those who die within a 12-month period of breast cancer is called the annual mortality rate. It’s calculated by dividing the number of women who die of breast cancer within a 12-month period, by the number of women in the random group. </p>
<p>It’s often claimed that the five-year survival rate gives an inflated, or overly optimistic, picture of survival compared to mortality rates. This optimistic picture of survival comes from two sources of bias.</p>
<h2>Lead-time bias</h2>
<p>The first of these sources is known as lead-time bias. Imagine a woman who is diagnosed with breast cancer at age 67. She dies three years later at age 70. The five-year survival rate in this case is 0% – she survived only three years, not five. </p>
<p>Now imagine this same woman was instead diagnosed with breast cancer as a result of routine screening at age 60. She still dies at 70, but because she has survived ten years (rather than three), the five-year survival rate is 100%. Although the mortality age is exactly the same, the five-year survival rate is dramatically different.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/13793/original/cbm2jj5k-1343956389.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/13793/original/cbm2jj5k-1343956389.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=408&fit=crop&dpr=1 600w, https://images.theconversation.com/files/13793/original/cbm2jj5k-1343956389.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=408&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/13793/original/cbm2jj5k-1343956389.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=408&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/13793/original/cbm2jj5k-1343956389.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=512&fit=crop&dpr=1 754w, https://images.theconversation.com/files/13793/original/cbm2jj5k-1343956389.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=512&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/13793/original/cbm2jj5k-1343956389.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=512&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The combination of the high false positive rate of screening tests combined with the low base rate of breast cancer in the female population means a lot of false alarms and diagnoses.</span>
<span class="attribution"><span class="source">U.S. Navy/Wikimedia Commons</span></span>
</figcaption>
</figure>
<h2>Over-diagnosis bias</h2>
<p>The other source of bias is called over-diagnosis. Over-diagnosis is not the same as false diagnosis, which we mentioned at the start of this piece. Rather, over-diagnosis refers to non-progressive cancers and “pseudo-disease”. </p>
<p>Pseudo-diseases are abnormalities that meet the technical definition of cancer, but are unlikely to ever cause symptoms, let alone death. Non-progressive cancers are unlikely to cause death within the five-year survival rate time frame. </p>
<p>How much over-diagnosis inflates the five-year survival rate depends on the type of cancer. For breast cancer, some estimates of pseudo-disease are as high as <a href="http://www.bmj.com/content/335/7623/731">one-in-four of all diagnoses</a> made by screening. For these women, a positive diagnosis may mean unnecessary chemotherapy, radiation or surgery.</p>
<h2>Alternative measures</h2>
<p><a href="http://www.psychologicalscience.org/journals/pspi/pspi_8_2_article.pdf">Critics</a> of the five-year survival rate make two recommendations. The first is to report absolute risks (the risk of developing a disease over a period of time) rather than relative risks (compares risk in two different groups of people). </p>
<p>The BMJ article reports the absolute risk of a woman in her 50s dying from breast cancer over the next ten years as being reduced from 0.53% to 0.46% with mammography – a difference of 0.07 percentage points. This compares with the 25% relative risk reduction that is often cited in support of screening.</p>
<p>The second recommendation is to report risks in “natural frequencies” – in real numbers, like ten out of 1,000 (as shown in our figure above) rather than percentages and probabilities. There’s good empirical evidence suggesting the presentation of absolute risks in natural frequencies is a much clearer way to communicate medical risks to doctors and patients alike. </p>
<p>Improved statistical literacy about breast cancer screening is vital because it means that people can make informed decisions about screening and seek a second opinion if a test comes back positive.</p><img src="https://counter.theconversation.com/content/8602/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fiona Margaret Fidler has previously received funding from the ARC.</span></em></p><p class="fine-print"><em><span>Bonnie Claire Wintle does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>An article published in the British Medical Journal (BMJ) today says a US charity “overstates the benefit of mammography and ignores harms altogether.” The charity’s questionable claim is that early detection…Fiona Fidler, Senior Research Fellow, The University of MelbourneBonnie Claire Wintle, PhD student, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/26892011-08-12T03:57:55Z2011-08-12T03:57:55ZBreast cancer screening – are women given all the facts?<figure><img src="https://images.theconversation.com/files/2858/original/aapone-20041014000012598198-mammography_machine-original.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Early detection means a better chance of successful treatment but are some women being treated unnecessarily?</span> <span class="attribution"><span class="source">AAP</span></span></figcaption></figure><p><a href="http://www.breastcanceraustralia.org/home.html">Breast cancer</a> is the most common cause of cancer-related death in Australian women. But experts disagree on the benefits of breast cancer screening programs, with some arguing that it’s unclear whether it does <a href="http://onlinelibrary.wiley.com/o/cochrane/clsysrev/articles/CD001877/frame.html">more harm than good</a>.</p>
<p>One in 11 women will be diagnosed with breast cancer before the age of 75. In Australia, as in many other developed countries, we have a screening program to detect breast cancer early because this offers the best chance of survival. </p>
<h2>Early detection programs</h2>
<p>The National Program for the Early Detection of Breast Cancer, now called BreastScreen Australia, was introduced in 1991. </p>
<p>The program encourages all women aged between 50 and 69 years without any signs or symptoms to have screening mammograms every two years. </p>
<p>Mammography uses X-ray to try to find early breast cancers before a lump can be felt. </p>
<p>The reason for screening asymptomatic women is that early detection in this age group is believed to offer a better chance of successful treatment and recovery.</p>
<p>Researchers from the <a href="http://www.bmj.com/content/338/bmj.b86.full">Nordic Cochrane Centre</a> and others are now questioning this reasoning. </p>
<p><a href="http://www.bmj.com/content/343/bmj.d4411.abstract">French researchers</a> for instance, have recently analysed data from breast cancer deaths registered in the <a href="http://www.who.int/healthinfo/morttables/en/index.html">World Health Organization mortality database</a>. </p>
<p>They compared three pairs of countries: Northern Ireland and the Republic of Ireland, the Netherlands and Belgium, and Sweden and Norway. </p>
<p>The country pairs are neighbours and similar in population structure, socioeconomic circumstances, quality of health-care services and access to treatment. </p>
<p>But they differ in the length of time they’ve had mammography screening programs. </p>
<p>In one half of each pair, the program has existed since around 1990, while the other country introduced it some years later.</p>
<p>The researchers found that between 1989 and 2006, trends in breast cancer mortality rates varied little between the pairs of countries.</p>
<p>They concluded that screening didn’t play a direct part in the reduction of breast cancer mortality.</p>
<p>How can this be explained, if early detection is supposed to lead to better detection, treatment and years of survival after diagnosis? </p>
<p>Well, some of the cancerous tumours detected through screening grow very slowly, or not at all. Indeed, some disappear if left untreated.</p>
<p>So some women receive a cancer diagnosis even though their tumours won’t necessarily lead to sickness or death. </p>
<p>These women experience needless anxiety and stress and are treated unnecessarily. </p>
<p>A systematic review of interventions <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001877.pub4/abstract;jsessionid=18D69F315F62E3D90AC518F2F1C54BF2.d03t03">published in the Cochrane Library</a> found that for every 2,000 women screened regularly for 10 years, one will avoid dying from breast cancer and have her life prolonged. </p>
<p>In addition, 10 healthy women, who wouldn’t have been diagnosed if they hadn’t participated in the screening program, will be diagnosed with breast cancer and treated unnecessarily. </p>
<p>These women have either a part or the whole of their breast removed, as well as often receiving radiotherapy and chemotherapy.</p>
<h2>So why do it?</h2>
<p>Unfortunately, medical science hasn’t yet discovered how to distinguish tumours that will lead to cancer from those that will disappear without treatment or cause no harm during the lifetime of a person. </p>
<p>But this isn’t explained to women when they are about to participate in breast cancer screening. The website of the <a href="http://www.health.gov.au/internet/screening/publishing.nsf/Content/faqs">BreastScreen Australia Program</a> notes a 25% fall in mortality since the introduction of mammography screening, but doesn’t mention the unnecessary pain and anguish that may be caused by the program. </p>
<p>Instead, a link to a <a href="http://canceraustralia.nbocc.org.au/our-organisation/position-statements/over-diagnosis-from-mammography-screening">National Breast and Ovarian Cancer Centre position statement</a> on over-diagnosis from mammography screening is provided. It is a technical statement and “not intended to be a decision-making aid for women considering screening”. </p>
<p>Women need to be given the existing evidence about benefits and harms of screening programs in a plain English statement and the opportunity to discuss the available evidence with their health-care provider. It is a necessary condition for informed consent. </p>
<p>After all, we expect to be provided with information about possible side effects of medical procedures and prescription drugs. So possible harms of screening procedures need to be disclosed as well.</p>
<p>The Nordic Cochrane Centre has developed a mammography screening leaflet that addresses the following questions:</p>
<ul>
<li><p>What are the benefits and harms of attending a screening program?</p></li>
<li><p>How many will benefit from being screened, and how many will be harmed?</p></li>
<li><p>What is the scientific evidence for this? </p></li>
</ul>
<p>The <a href="http://www.cochrane.dk/">leaflet</a> is available online in English and 12 other languages. BreastScreen Australia Program should either promote the use of this leaflet or develop its own. </p>
<p>Different people make different choices. Given all the information, some women may decide it’s reasonable for them to attend breast cancer screening with mammography. </p>
<p>Others may choose not to attend but all women need to know <em>all</em> the available facts to make an informed choice.</p><img src="https://counter.theconversation.com/content/2689/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Monika Merkes does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Breast cancer is the most common cause of cancer-related death in Australian women. But experts disagree on the benefits of breast cancer screening programs, with some arguing that it’s unclear whether…Monika Merkes, Honorary Associate, Australian Institute for Primary Care & Ageing, La Trobe UniversityLicensed as Creative Commons – attribution, no derivatives.