Study Suggests Role of Bilateral Oophorectomy in Preventing Premenopausal Breast Cancer in BRCA2- but Not BRCA1-Mutation Carriers
Bilateral oophorectomy was associated with prevention of premenopausal breast cancer in BRCA2- but not BRCA1-mutation carriers, according to a study reported by Kotsopoulos et al in the Journal of the National Cancer Institute.
The study included 3,722 women with BRCA mutations in a prospective cohort from 78 centers in 12 countries. The women had no history of cancer, had both breasts intact, and had data on oophorectomy status. Overall, 1,552 women had undergone oophorectomy and 2,170 had not; BRCA1 mutation was present in 77% and 83%; and BRCA2 mutation was present in 23% and 17% (10 and 18 subjects had both mutations or missing data).
Risk of Breast Cancer
Over a mean follow-up of 5.6 years, 350 new breast cancers were diagnosed. Overall, oophorectomy was not associated with breast cancer risk among women with a BRCA1 or BRCA2 mutation vs no oophorectomy; the age-adjusted hazard ratio (HR) was 0.96 (P = .76) among BRCA1 carriers and 0.65 (P = .14) among BRCA2 carriers. In an analysis stratified by BRCA mutation status and age at diagnosis, oophorectomy was associated with a significantly reduced risk of breast cancer in BRCA2 carriers diagnosed at age < 50 years (age-adjusted HR = 0.18, P = .007) but not among BRCA1 carriers diagnosed at < 50 years (age-adjusted HR = 0.79, P = .51).
The investigators concluded: “Findings from this large prospective study support a role of oophorectomy for the prevention of premenopausal breast cancer in BRCA2, but not BRCA1 mutation carriers. These findings warrant further evaluation.”
The study was supported by the National Cancer Institute and Canadian Cancer Society Research Institute.
Steven A. Narod, MD, FRCPC, of the Women’s College Research Institute, Women’s College Hospital, Toronto, Ontario, Canada, is the corresponding author of the Journal of the National Cancer Institute article.
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