Clinical use of selective estrogen receptor modulators.

The concept of selective estrogen receptor modulators (SERMs) is derived from the observation that tamoxifen, an effective adjuvant therapy of breast cancer that has an antiestrogenic effect on breast tissue, has estrogen-like effects on the skeleton and on plasma lipoproteins. Raloxifene is a SERM that has undergone extensive clinical investigation in the prevention and treatment of postmenopausal osteoporosis. It prevents bone loss at all skeletal sites, and in a large trial in osteoporotic women, the incidence of vertebral fractures was significantly decreased (relative risk 0.64) after up to 4 years of treatment with raloxifene 60 mg. The decrease of nonvertebral fractures did not reach the level of significance. Raloxifene decreased significantly the incidence of breast cancer (relative risk 0.28) and has no effect on the risk of endometrial cancer. SERMs are likely to play an important role in the management of postmenopausal women.