RESUMO
OBJECTIVE: To compare the effect of tibolone to conjugated estrogens with medroxyprogesterone-acetate (CEEâ+âMPA) on breast density, as a predictor for breast cancer risk, in women with a high risk of breast and ovarian cancer. METHODS: Women aged 30-50 (Nâ=â114) who had undergone risk-reducing salpingo-oophorectomy (RRSO) were randomized to tibolone or CEEâ+âMPA. RESULTS: Breast density decreased 46% after RRSO in untreated women, 39% after treatment with tibolone, and 17% after treatment with CEEâ+âMPA; the decrease in breast density after CEEâ+âMPA was significantly different compared with that of untreated women (Pâ=â0.017). CONCLUSIONS: A decline in breast density is seen after premenopausal RRSO despite the use of both CEEâ+âMPA or tibolone, although lower breast density is seen after tibolone use.