Drug's Breast-Cancer Benefits Make a Two-for-One Value

Medical research’s hunt for the perfect designer estrogen is getting hot. Ever since science has come to appreciate the good-news/bad-news equation associated with the natural female hormone -- it helps lower cholesterol and the risk of osteoporosis, but it may increase the risk of breast cancer -- researchers have been trying to come up with a better, synthetic substitute to help women in need of long-term hormone-replacement therapy after menopause. A new study published in Wednesday’s issue of the Journal of the American Medical Association suggests that scientists may have made a significant discovery about the properties of the osteoporosis drug raloxifene. In a study of more than 7,000 women, researchers found that postmenopausal women with osteoporosis who were treated with raloxifene for three years reduced their risk of breast cancer by 76 percent.

"This is the latest in a string of discoveries that indicate you can create chemicals that can act like estrogen in some parts of the body and as anti-estrogens in other parts of the body," says TIME medical columnist Christine Gorman. In the latest study, for example, the researchers found that raloxifene fits into the body’s estrogen receptors in such a way as to both increase bone density and block breast cancer. There are apparent side effects to raloxifene, however, such as an increased risk of blood clots. And there are also side effects to the other well-known estrogenlike drug, tamoxifen, which can increase the risk of uterine cancer. "A new study is now under way to compare the benefits and risks of the two drugs," says Gorman. The perfect designer estrogen has yet to be found, she notes, but researchers’ immense interest in the subject should provide women with an increasing set of options in the years ahead.