BRCA Carriers Morely Likely to Survive with Bilateral Mastectomy
Bilateral Mastectomy Cuts Mortality for BRCA-Related CA
(HealthDay News) — Women with BRCA-associated early-stage breast cancer who receive bilateral mastectomy are less likely to die from breast cancer than those who receive a unilateral mastectomy, according to research published Feb. 11 in BMJ.
Kelly Metcalfe, MD, of the University of Toronto, and colleagues performed a retrospective analysis of data for 390 women, carriers of the BRCA1 or BRCA2 mutations, who underwent unilateral mastectomy or bilateral mastectomy (n=181) as initial treatment for stage I or II breast cancer.
The researchers found that, at 20 years (median follow-up time, 14.3 years), the survival rate for women with hereditary breast cancer was 88% (95% confidence interval [CI], 83% to 93%) for those who had bilateral mastectomy and 66% (95% CI, 59% to 73%) for those who had unilateral mastectomy.
According to multivariable analysis, women with hereditary breast cancer who received a mastectomy of the contralateral breast were 48% less likely to die from breast cancer (hazard ratio [HR], 0.52; 95% CI, 0.29 to 0.93; P = 0.03).
According to propensity score-adjusted analysis of 79 matched pairs, bilateral mastectomy was not significantly associated with reduced risk of death from breast cancer (HR, 0.60; 95% CI, 0.34 to 1.06; P = 0.08).
"Based on these results, we predict that of 100 women treated with contralateral mastectomy, 87 will be alive at 20 years compared with 66 of 100 women treated with unilateral mastectomy," the researchers wrote.
"This study suggests that women who are positive for BRCA mutations and who are treated for stage I or II breast cancer with bilateral mastectomy are less likely to die from breast cancer than women who are treated with unilateral mastectomy. Given the small number of events in this cohort, further research is required to confirm these findings," they concluded.
"Given the worse prognosis of BRCA1/2 associated breast cancers, the absence of mammary tissue after a contralateral mastectomy should translate into a reduction of breast cancer related deaths," Karin B. Michels, ScD, PhD, of Harvard Medical School in Boston, MA, wrote in an accompanying editorial. "Nevertheless, larger studies tackling this issue are needed."
- Metcalfe K, Gershman S, Ghadirian P, et al. Contralateral mastectomy and survival after breast cancer in carriers of BRCA1 and BRCA2 mutations: retrospective analysis. BMJ. 2014;doi:10.1136/bmj.g226.
- Michels KB. Contralateral mastectomy for women with hereditary breast cancer. BMJ. 2014;doi:10.1136/bmj.g1379.