24-hour test predicts breast cancer’s likely response to chemotherapy
A new test has been developed which can predict whether a breast cancer patient will respond to chemotherapy within 24-hours of starting treatment, thus sparing her unnecessary treatment and side effects, according to a study published in the medical journal Clinical Cancer Research. The test can also determine whether the woman can benefit from PARP-inhibitors, a promising new type of cancer treatment currently undergoing clinical trials.
The test was developed at the Breakthrough Breast Cancer Research Centre, at The Institute of Cancer Research (ICR), London, England. Researchers say the test will be able to determine which patients will likely benefit from anthracycline chemotherapy – a standard treatment for a significant number of the 46,000 people diagnosed with breast cancer in the UK annually.
The researchers examined RAD 51, one of the key proteins involved in DNA repair. The study, involving 68 patients, all of them with breast cancer, found that in some cases RAD51 did not work in cancer cells. They report that anthracycline is much more likely to have a beneficial effect in cases where RAD51 did not work on cancer cells.
A significant percentage of patients responded well, with their tumor completely disappearing from the breast. If the DNA repair process was working in the tumour, they would probably not respond to the treatment, with complete response being unlikely.
Patients who are likely to respond to PARP inhibitors could also be identified, Turner added. According to recent research, up to 30% of patients could be treated effectively with PARP inhibitors. PARP inhibitors are not yet licensed for use; they are still in clinical trials. This test could help speed up the development of PARP inhibitors and similar cancer medications.
Finding out in 24 hours, rather than the current 12 weeks to determine whether a woman has responded to chemotherapy, which typically is a combination of two or three drugs, will spare patients who will not respond nearly three months of wasted time and needless side effects, the researchers say.
“A marker of homologous recombination predicts pathological complete response to neoadjuvant chemotherapy in primary breast cancer”
Monika Karla Graeser, Afshan McCarthy, Christopher J Lor, Kay Savage, Margaret Hills, Janine Salter, Nick Orr, Marina Parton, Ian E Smith, Jorge Reis-Filho, Mitchell Dowsett, Alan Ashworth, and Nicholas Turner
Clinical Cancer Research Published OnlineFirst August 27, 2010; doi: 10.1158/1078-0432.CCR-10-1027
Source: Medical News Today