Two recent studies led by the Familial Breast Cancer Research Unit at Women’s College Research Institute (WCRI) have clarified the benefit of ovary removal and bilateral mastectomy in reducing the risk of mortality for women genetically predisposed to breast and ovarian cancer. The findings were presented at the 2014 Biannual Conference on Hereditary Breast and Ovarian Cancer, which was organized by the Familial Breast Cancer Research Unit and attended by more than 150 individuals, including patients.
One study found that women who carry a BRCA gene mutation and opt for a preventive oophorectomy, or ovary removal surgery, decrease their risk for ovarian or fallopian tube cancer by 80 per cent and have a 77 per cent lower risk of death from all causes than those who do not opt for surgery. The research was led by Dr. Amy Finch, a postdoctoral fellow working with Dr. Steven Narod, a Tier 1 Canada Research Chair in Breast Cancer at WCRI and director of the Familial Breast Cancer Research Unit.
“Our study was the first to look at the effects of oophorectomy on cancer risk and mortality, as well as the optimal age for this preventive surgery, among a large cohort of women over a nearly six-year follow-up period,” says Finch. “This study shows the clear benefit of oophorectomy on cancer risk and on mortality in women who carry a BRCA mutation, with the greatest benefit for women who choose to have the surgery close to age 35.”
The second study, led by Dr. Kelly Metcalfe, an adjunct scientist at WCRI, found that women with BRCA-related breast cancer who have a bilateral 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.
“Our study suggests a bilateral mastectomy is an effective first-line treatment for women with early-stage breast cancer who carry a BRCA mutation and that it reduces the risks of dying of breast cancer,” says Metcalfe. “Once diagnosed, women with these mutations have a 34 per cent chance of developing breast cancer in the opposite breast within 15 years; therefore, we need to think about treating the first breast cancer and preventing a second breast cancer. Our findings highlight the importance of providing genetic testing for BRCA at the time of breast cancer diagnosis.”
Although the findings support the benefit of oophorectomy and double mastectomy in preventing cancer and death in women with BRCA mutations, the researchers caution more research is necessary to confirm these findings and better understand the long-term effects of these surgeries, particularly oophorectomy.