One in five women with breast cancer could benefit from existing therapy
A new study emerging from the Wellcome Trust Sanger Institute has discovered that there are more cases of breast cancer linked to faulty BRCA1 or BRCA2 mutations than previously thought. The research found that even those who did not exhibit the gene still had ‘mutational signatures’ that were identical to those expressed in people with the culprit gene.
Between 1% and 5% of breast cancers are as a result of inherited BRCA1 or BRCA2 genes. With breast cancer the most common form of cancer in women and with roughly 1.7 million breast cancer sufferers worldwide, the research could change treatment for many people.
This is because there is a treatment used in those with BRCA1 and BRCA2 mutations; drugs called PARP inhibitors specifically target the action of an enzyme that allows cancer cells with faulty BRCA genes to survive. The action of the drugs means that there are relatively few side-effects compared with standard treatment.
In the UK, 55,000 women suffer from breast cancer and the researchers believe that there is a possibility of 20% of those sufferers benefiting from treatment by PARP inhibitors.
Dr Serena Nik-Zainal, lead author from the Wellcome Trust Sanger Institute, said upon the findings of her research: "In the past, clinical trials for PARP inhibitors have focused mainly on the 1 to 5 per cent of women with breast cancer. However, our study shows that there are many more people who have cancers that look like they have the same signatures and same weakness as patients with faulty BRCA1 and BRCA2 genes. We should explore if they could also benefit from PARP inhibitors. The results suggest that clinical trials now need to look at cancer patients who share the same genetic signature in their cancer. This could change how clinical trials are designed in the future."
The ability to analyse a person’s genome, as the trial did, opens up whole new methods of treatment and for shaping clinical trials, as mentioned by Nik-Zainal. This particular study looked 560 patients’ breast cancer genomes to scan for every potential mutation. The tool developed was a computer-based program called HRDetect.
There are already clinical trials underway to test the efficacy of PARP inhibitors of women with breast cancer but this study reveals that there is huge potential for a new avenue of treatment.