Estrogen Level Determines Osteoporosis Drug's Breast Cancer Prevention Effectiveness in Postmenopausal Women SAN FRANCISCO, CA -- January 9, 2002 A common osteoporosis drug can reduce breast cancer in postmenopausal women with high estrogen levels, but produces no reduction in risk for women whose estrogen levels are very low, according to a University of California-San Francisco (UCSF) study. Researchers found that raloxifene administered to a selected population of women reduced their rate of breast cancer by 76 percent. The study was published in the January 9 issue of the Journal of the American Medical Association (JAMA). The authors studied 7290 postmenopausal women aged 80 or younger with osteoporosis and no history of breast cancer. Study participants were given either the recommended daily 60 mg dose, a 120 mg dose, or a placebo. Their blood was screened for estradiol - the most potent form of estrogen. Women with levels in the upper third of the range for the tested group were shown to be at high risk of breast cancer and benefit most from raloxifene at any dosage. According to the authors, previous studies have found that the risk of breast cancer rises with increases in a woman's estrogen level. In some breast cancers, proteins on the malignant cells have a receptor that locks to estrogen molecules. Drugs like raloxifene block the effect of estrogen in the breast. The authors therefore postulated that the success of drugs like raloxifene, called selective estrogen receptor modulators (SERMs), in preventing breast cancer is likely to depend on a woman's level of estrogen. With little or no circulating estrogen to feed breast cancer cells, a woman is already at reduced risk, without treatment with SERMs. JAMA 1/02 [01/09/2002; Doctor's Guide] Anticancer Res, 5-6/02 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.