Study shows benefit of double mastectomy beyond preventing breast cancer to increasing longevity in women with breast cancer who have a BRCA1 or BRCA2 mutation
Women with BRCA-related breast cancer who have a double mastectomy are nearly 50 per cent less likely to die of breast cancer within 20 years of diagnosis compared to women who have a single mastectomy, according to a new study led by Women's College Hospital's Kelly Metcalfe.
The findings, published in the British Medical Journal, suggest a double mastectomy may be an effective first-line treatment for women with early-stage breast cancer who carry a BRCA1 or BRCA2 genetic mutation. The BRCA1/2 genes belong to a class of genes that typically act to protect individuals from acquiring cancer, yet women who inherit a mutated form of the genes have a high risk of developing breast and ovarian cancers.
"Women with a BRCA mutation have a 60 to 70 per cent chance of developing breast cancer in their lifetime, and once diagnosed, a further 34 per cent chance of developing breast cancer in the opposite breast within 15 years," said Kelly Metcalfe, an adjunct scientist at Women's College Research Institute and professor at the University of Toronto. "For these women, we need to think about treating the first breast cancer, but also about preventing a second breast cancer."
To compare the survival rates of women with BRCA-related breast cancers, researchers assessed the medical records of 390 women with stage one or two breast cancer and a BRCA1 or BRCA2 mutation. The women were required to have been initially treated with a single or double mastectomy. The researchers found: