Selective estrogen receptor modulation and reduction in risk of breast cancer, osteoporosis, and coronary heart disease

The recognition of selective estrogen receptor modulation in the laboratory has resulted in the development of two selective estrogen receptor modulat ors (SERMs), tamoxifen and raloxifene, for clinical application in healthy women. SERMs are antiestrogenic in the breast but estrogen-like in the bone s and reduce circulating cholesterol levels. SERMs also have different degr ees of estrogenicity in the uterus. Tamoxifen is used specifically to reduc e the incidence of breast cancer in premenopausal and postmenopausal women at risk for the disease. In contrast, raloxifene is used specifically to re duce the risk of osteoporosis in postmenopausal women at high risk for oste oporosis. The study of tamoxifen and raloxifene (STAR) trial is currently c omparing the ability of these SERMs to reduce breast cancer incidence in hi gh-risk postmenopausal women. There is intense interest in understanding th e molecular mechanism(s) of action of SERMs at target sites in a woman's bo dy. An understanding of the targeted actions of this novel drug group will potentially result in the introduction of new multifunctional medicines wit h applications as preventive agents or treatments of breast cancer and endo metrial cancer, coronary heart disease, and osteoporosis.