For the t/t and prevention of Breast CaThe first SERM to reach the market was Tamoxifen which blocks the stimulative effect of estrogen on breast tissue and is used in breast cancer.Raloxifene is the second SERM to be approved by the FDA.Raloxifens has been approved for the t/t and prevention of osteoporosis in postmenopausal women.Raloxifens acts like estrogen on bone and helps to build and maintain bone density.Raloxifen has been shown in clinical trials to increase bone density in the spine and hip and to reduce the risk of spinal fractures in women with osteoporosis.While it acts like estrogen on bone, it blocks the action of estrogen on breast and uterus.This profile makes it very useful for the t/t of osteoporosis because Raloxifene provides the bone benefits of estrogen without increasing the risk for estrogen related breast and uterine cancers.Raloxifene in Breast cancerDue to its antiestrogenic effect on breast, Raloxifene has been shown to reduce the risk of invasive breast cancer in women who are taking it for osteoporosis.Raloxifene reduces the risk of breast cancer by 50-70% in both low risk and high risk postmenopausal women.The national cancer institute U.S.A. funded the STUDY OF TAMOXIFEN AND RALOXIFEN (STAR) a clinical trial comparing raloxifens with tamoxifen in preventing breast cancer, in postmenopausal women who are at increased risk of developing the disease.The study found that tamoxifen and Raloxifen are equally effective in reducing invasive breast cancer risk in postmenopausal women who are at increased risk of the disease.The study also found out that women who took raloxifen had fewer uterine cancer and fewer blood clots than women who took tamoxifen. However, Raloxifen did not decrease the risk of noninvasive breast Ca.On September 14 2007, the U.S. food and drus administration announced approval of raloxifens for reducing the risk of invasive breast cancer in postmenopausal women with osteoporosis and in postmenopausal women at high risk for invasive cancer.">