Women who carry BRCA1 or 2 mutations and who had mastectomies or salpingo-oophorectomies were found to have a decreased risk of developing breast or ovarian cancer, researchers report in the Journal of the American Medical Association. The researchers, led by the University of Pennsylvania School of Medicine's Timothy Rebbeck followed 2,482 women with BRCA1 or BRCA2 mutations, some of whom then had mastectomies or salpingo-oophorectomies.