The impact of estrogen replacement therapy and raloxifene on osteoporosis, cardiovascular disease, and gynecologic cancers

OBJECTIVE: To compare the clinical utility of estrogen replacement therapy (ERT) and raloxifene in osteoporosis and cardiovascular disease in postmenopausal women and to evaluate the contrasting adverse effects of these therapies. DATA SOURCES: A MEDLINE search was performed for January 1980 through September 1998 using the key terms raloxifene, estrogen, CVD, lipoproteins, and osteoporosis. STUDY SELECTION AND DATA EXTRACTION: All clinical studies assessing ERT and raloxifene in cardiovascular disease or osteoporosis were evaluated. DATA SYNTHESIS: ERT remains the standard for prevention and treatment of osteoporosis in women. Its use increases total bone mineral density (BMD) up to 12.1% and reduces hip fracture risk by 66-73%. It reduces low-density lipoprotein (LDL) cholesterol by 15-19% and increases high-density lipoprotein (HDL) cholesterol by 6-18%. Raloxifene, an alternative to ERT in the prevention of osteoporosis, increases total BMD by 2.2%. It reduces LDL by 6.2-14.1% and increases HDL by 1.5-5.7%. Preliminary data suggest that raloxifene has contrasting effects on gynecologic cancers compared with the increased risk posed by ERT. CONCLUSIONS: Clinical trials have illustrated greater effects on BMD with ERT than with raloxifene. Studies of significant duration assessing raloxifene and its fracture risk effects are lacking. ERT appears to have greater beneficial cardiovascular risk factor effects than raloxifene. Prospective, primary prevention studies evaluating overall cardiovascular risk reduction do not exist for either intervention. Raloxifene, while more costly, is an alternative that may have a lower associated risk of breast cancer compared with ERT.