Combining a new anti-cancer agent with chemotherapy has shown promise in the treatment of some of the most aggressive and difficult-to-treat forms of breast cancer, scientists have found.
Around 20% of breast cancers are known as ‘triple negative’ cancers, which test negative for oestrogen, progesterone and HER2 receptors, and are notoriously hard to tackle with regular anti-cancer treatments.
But researchers from the Walter and Eliza Hall Institute’s (WEHI) Stem Cells and Cancer division have found that a two-pronged attack featuring chemotherapy and an anti-cancer drug called ABT-737 is offering new hope for triple negative cancer patients.
Chemotherapy alone is not effective because of a protein called Bcl-2, which serves to help the cancer cells recover from treatment and live on.
But ABT-737 attacks Bcl-2 proteins, making the chemotherapy drugs more effective, according to early test results compiled by the WEHI team.
“ABT-737 targets proteins from the Bcl-2 family, which are found at high levels in up to 70 per cent of breast cancers,” said Professors Geoff Lindeman, one of the lead researchers.
“We have shown that breast tumours that have high levels of Bcl-2 respond well to treatment with ABT-737 when used in combination with a conventional chemotherapy drug.”
ABT-737 alone did not work on cancers with high levels of Bcl-2, nor on cancers that did not express Bcl-2.
“We have had a good result in pre-clinical models of disease, but we are still a way off this being used in humans,” Dr Lindeman, who is also an oncologist at The Royal Melbourne Hospital, said.
He said he hoped a clinical trial of the new anti-cancer drug could take place in the next few years.
The study was published in the journal Proceedings of the National Academy of Sciences USA.
The project was supported by the Victorian Breast Cancer Research Consortium through the Victorian Cancer Agency, the National Health and Medical Research Council, Australian Cancer Research Foundation and the National Breast Cancer Foundation. Breast cancer samples were provided with the support of the Victorian Cancer Biobank.