Breast cancer drug reduces the risk of recurrence by 42 percent

A targeted breast cancer treatment reduces the risk of BRCA-related cancer returning or spreading after chemotherapy.

The PARP-inhibitor olaparib (Lynparza) inhibits a cancer cell's ability to repair damage to their DNA by trapping the PARP protein, causing further DNA damage and cell death. The drug is the first in its class and has already been approved for a range of advanced PARP-dependent cancers, including certain types of ovarian, breast, pancreatic and prostate cancer.

Dr Sue Friedman, executive director of Facing Our Risk of Cancer Empowered (FORCE) and member of the OlympiA trial steering committee, said: 'While there have been great strides in the early treatment of breast cancer, the fear of cancer returning is still at the forefront of patients' minds. New targeted treatment approaches are needed in the adjuvant setting that can help keep cancer and that fear at bay.'

The OlympiA stage III multicentre clinical trial in patients with BRCA-mutated high-risk early-stage breast cancer was coordinated by several funders, including the US National Cancer Institute and the Institute of Cancer Research, London. Results were published in the New England Journal of Medicine.

Over 1800 patients with germline BRCA-mutated high-risk, HER2-negative early breast cancer completed local treatment and standard chemotherapy before being given either olaparib or a placebo tablet.

After three years 85.9 percent of patients who received olaparib showed no signs of the cancer returning, compared to 77.1 percent of patients in the placebo group. The trial also showed that 87.5 percent of patients receiving olaparib remained free of metastasis, compared to 80.4 percent in the placebo group.

BRCA1 and BRCA2 mutations are found in about 5 percent of breast cancer patients and can lead to problems in the cell's DNA repair mechanisms. This makes the cell's DNA more unstable and likely to accumulate more mutations that can lead to cancer, but also renders the cells more susceptible to drugs like olaparib.

'We are thrilled that our global academic and industry partnership in OlympiA has been able to help identify a possible new treatment option for patients with early-stage breast cancer and who have inherited mutations in their BRCA1 or BRCA2 genes. Patients with early-stage breast cancer who have inherited BRCA mutations are typically diagnosed at a younger age compared to those without such a mutation' said Professor Andrew Tutt, chair of the OlympiA trial steering committee and professor of oncology at the Institute of Cancer Research, London and King's College London.

He added: 'Olaparib has the potential to be used as a follow-on to all the standard initial breast cancer treatments to reduce the rate of life-threatening recurrence and cancer spread for many patients identified through genetic testing to have mutations in these genes.'