BRCA1 and ovarian cancer: In particular, risk-reducing bilateral oophorectomy also confers protection against ovarian cancer, a strategy relevant to BRCA1/2 carriers and other women with hereditary breast/ovarian cancer; oophorectomy has side-effects for premenopausal women, such as loss of fertility and sudden onset of menopause; and tamoxifen has been shown to be associated with an increased risk of endometrial cancer, deep vein thrombosis and pulmonary embolus.