(HealthDay News) — Among women with mutations in BRCA1 or BRCA2, oophorectomy reduces the risk of developing ovarian, fallopian tube, or peritoneal cancer by 80% and reduces the risk of death by 77%, with greater BRCA1 benefit seen with earlier removal, according to a study published online Feb. 24 in the Journal of Clinical Oncology.
Amy P.M. Finch, PhD, from the University of Toronto, and colleagues examined the association between prophylactic oophorectomy and mortality in 5,783 women with mutations in BRCA1 or BRCA2. Of these, 2,270 did not have an oophorectomy, 2,123 had an oophorectomy at baseline, and 1,390 had an oophorectomy during follow-up.
During an average follow-up period of 5.6 years, the researchers found that 186 women were diagnosed with ovarian, fallopian tube, or peritoneal cancer, and 68 deaths were noted.
Women who underwent a bilateral oophorectomy had a significantly lower risk of developing any of these cancers (hazard ratio [HR], 0.20). Among those with no cancer at baseline, those who underwent oophorectomy also had a significantly lower risk of all-cause mortality until 70 years of age (HR, 0.23).
The researchers noted that the prevalence of occult cancers rose sharply among BRCA1 carriers starting at 40 years of age, while no association was found for BRCA2, supporting “the recommendation for a BRCA1 mutation carrier to undergo oophorectomy at age 35 years.”
“Preventive oophorectomy was associated with an 80% reduction in the risk of ovarian, fallopian tube, or peritoneal cancer in BRCA1 or BRCA2 carriers and a 77% reduction in all-cause mortality,” Finch and colleagues concluded.