Selective estrogen receptor modulators: a new category of therapeutic agents for extending the health of postmenopausal women

Selective estrogen receptor modulators (SERMs) may provide postmenopausal women with all the benefits of estrogen but not its risks. Tamoxifen is one of the best-known SERMs, and is used to treat breast cancer because it blocks the activity of estrogen in the breast. This is important because many breast tumors are stimulated by estrogen. Tamoxifen also prevents bone loss just as estrogen does and lowers cholesterol levels. However, it can cause proliferation of endometrial tissue, which could lead to endometrial cancer. A newer SERM called raloxifene does not cause endometrial proliferation.