Otago researcher focusing on targeted therapies to treat triple negative breast cancer

An Otago researcher who spent 10 years based at the Translational Genomics Research Institute in Arizona, USA, is now bringing her knowledge of treating triple negative breast cancer (TNBC) patients to New Zealand. 

Breast cancer researcher and Otago University Senior Lecturer, Dr Heather Cunliffe, believes the best way of ensuring patients receive the most effective treatment is by defining the individual biology of their tumours. “When it comes to treating triple negative breast cancer, because there are several distinct subtypes of the disease you need to look at what’s happening in each tumour before making a treatment plan. There’s overwhelming evidence that by decoding the tumour’s DNA the underlying biology will be revealed. This enables the oncologist to select which treatment strategies will be most effective at fighting that particular patient’s cancer. It’s precision diagnosis – taking the guesswork out of treatment.” 

Around 10-20% of breast cancers diagnosed in New Zealand will be triple negative breast cancers. Unlike other breast cancers that use estrogen, progesterone or HER2 pathways to grow, TNBC doesn’t possess any of these three targets for shutting down the cancer, hence the name “triple negative”. Patients with TNBC are currently limited to receiving chemotherapy as their only treatment option. “Triple negative patients typically have a good response to chemotherapy but unfortunately their cancer often comes back quickly and comes back metastatic,” says Dr Cunliffe. 

However, recent research that Dr Cunliffe has undertaken in collaboration with the Mayo Clinic in the US has discovered that the androgen (testosterone) receptor typically found over-expressed in prostate cancer was also being over-expressed in approximately 20% of women with TNBC. “Our findings suggest the same drugs (used for prostate cancer) would also be effective in patients with the androgen-receptor positive subtype of TNBC,” says Dr Cunliffe.  

Other treatment options for women with triple negative breast cancer include PARP inhibitors which are new medicines (currently only available in clinical trials) that inhibit repair of DNA in cancer cells - these are most effective for women who carry the BRCA gene mutation – and a medicine called everolimus (Afinitor) which targets a specific cancer growth mechanism present in several types of breast cancer. Everolimus is currently available, but unfunded, in New Zealand.

BCAC Chair, Libby Burgess welcomes more research into triple negative breast cancer. “Finding effective strategies to combat the multiple sub-types of TNBC is a key priority in breast cancer research.  It’s also a complex and challenging task and it’s great to know we have a New Zealand scientist based in Otago focusing her research on this critical area”.

5th May, 2015

 

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