Why Consider Breast Cancer Chemoprevention?
There is fair evidence that treatment with tamoxifen can significantly reduce the risk for invasive estrogen-receptor-positive breast cancer in women at high risk for breast cancer and that the likelihood of benefit increases as the risk for breast cancer increases. The U.S. Preventive Services Task Force (UPSTF) found consistent but less abundant evidence for the benefit of raloxifene. The USPSTF found good evidence that tamoxifen and raloxifene increase the risk for thromboembolic events (for example, stroke, pulmonary embolism, and deep venous thrombosis) and symptomatic side effects (for example, hot flashes) and that tamoxifen, but not raloxifene, increases the risk for endometrial cancer. The USPSTF concluded that the balance of benefits and harms may be favorable for some high-risk women but will depend on breast cancer risk, risk for potential harms, and individual patient preferences.
U.S. Preventive Services Task Force, July 2002