Carrying a BRCA mutation does not affect a young woman’s breast cancer prognosis, a study shows.
While the BRCA1 or BRCA2 genes are linked to a heightened risk of developing breast or ovarian cancers, a UK study that followed up 2733 young breast cancer patients for eight years found that overall survival rates were the same for women regardless of whether they carried a BRCA mutation
Published in Lancet Oncology, the prospective cohort study involved women aged 18-40 years with an initial diagnosis of breast cancer, of whom 12% carried a BRCA mutation. Most (89%) underwent chemotherapy, half had breast-conserving surgery and half had a mastectomy.
At two years, survival rates were 97% for BRCA carriers vs 96.6% for non-carriers and after five years they were 83.8% vs 85%. Survival rates remained similar regardless of whether mutations were in the BRCA1 or BRCA2 gene.
A subgroup analysis of 558 women with triple-negative breast cancer suggested that those with a BRCA mutation may initially have better overall survival than women not carrying the mutation (95% vs 91% at two years), but survival rates were similar at five and ten years after diagnosis.
The findings have important implications for young women with early breast cancer who are often offered double mastectomies soon after their diagnosis or chemotherapy treatment if they carry the BRCA mutation, the researchers said.
“Our findings suggest that this surgery does not have to be immediately undertaken along with the other treatment,” said study co-author Professor Diana Eccles (pictured), Professor of Cancer Genetics at University of Southampton.
“In the longer term, risk-reducing surgery should be discussed as an option for BRCA1 mutation carriers in particular, to minimise their future risk of developing a new breast or ovarian cancer. Decisions about timing of additional surgery to reduce future cancer risks should take into account patient prognosis after their first cancer, and their personal preferences.”
Women with triple-negative breast cancer and a BRCA mutation who choose to delay additional surgery for 1-2 years to recover from their initial treatment should be reassured that this is unlikely to affect their long-term survival, the researchers suggested. However, risk-reducing surgery will still likely be beneficial for BRCA mutation carriers to prevent another new breast or ovarian cancer from developing in the longer term.
However they cautioned that the results might not translate to older women with a BRCA mutation.