Treatment could treat one in five breast cancers, study finds

Research by the Wellcome Trust Sanger Institute has found that one in five breast cancer patients could benefit from existing PARP inhibitor treatments.

Drugs called PARP inhibitors have been designed to specifically treat tumours with faulty BRCA1 and BRCA2 genes in breast and ovarian cancers. However, the study has discovered that a greater number of breast cancers are genetically similar to rarer cases with faulty BRCA1 or BRCA2 genes.

Published in Nature Medicine, the study opens up the possibility of up to 20 per cent of women being treated with PARP inhibitors and comes as breast cancer is recorded as the most common cancer in the UK, affecting nearly 55,000 women a year.

Dr Serena Nik-Zainal, lead author from the Wellcome Trust Sanger Institute, commented: “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."