New research targets drug-resistant breast cancer
New Zealand researchers will soon use cutting-edge genetic technology to help control resistance to the latest drug for treating HER2-positive breast cancer that has spread to other parts of the body.
The new study, led by Dr Francis Hunter from the University of Auckland, was announced today through the Breast Cancer Research in New Zealand 2016 initiative, a joint partnership between the Health Research Council of New Zealand (HRC), Breast Cancer Cure, and The New Zealand Breast Cancer Foundation.
Each year more than 3000 New Zealanders are diagnosed with breast cancer and 600 will die from the condition. A quarter of these breast cancers are driven by increased amounts of a gene called HER2, which can be targeted with the drug trastuzumab, more commonly known as Herceptin.
“Herceptin markedly improves outcomes for HER2-positive breast cancer. Unfortunately, treatment resistance develops in many patients, leading to a very aggressive disease with poor prognosis,” says Dr Hunter.
In 2013 a new drug called trastuzumab emtansine (T-DM1) was approved for treating HER2-positive secondary breast cancer that has stopped responding to Herceptin. However, T-DM1 shrinks tumours in only half of patients and the reasons why the other patients are resistant to it remains unclear.
“We’re going to use a powerful genetic tool to identify genes that control – and thus predict – the sensitivity and resistance to T-DM1 in HER2-positive breast cancer. Our aim is to reduce the distressing uncertainty associated with treating this illness and to enable patients and their caregivers to make informed treatment decisions,” says Dr Hunter.
HRC Chief Executive Professor Kath McPherson says recurrent HER2- positive breast cancer is a major challenge in New Zealand, particularly as this type of breast cancer grows rapidly and is associated with a high risk of metastasis and relapse, with devastating impacts for the women concerned and their family/whānau.
“Developing a diagnostic tool that can predict how patients will likely respond to the drug T-DM1 – and advancing our understanding of why some people are resistant to it – would help improve the chances of survival for people with this aggressive type of breast cancer and allow more targeted and efficient use of expensive cancer medicines,” says Professor McPherson.