The drug raloxifene(Drug information on raloxifene) (Evista) significantly reduces the risk of invasive breast cancer in postmenopausal women, according to the results of a large-scale study involving the University of Pittsburgh Graduate School of Public Health (GSPH) and published in a recent issue of Breast Cancer Research and Treatment (65:125-134, 2001). The Multiple Outcomes of Raloxifene Evaluation (MORE) trial measured the effects of raloxifene, which has been approved by the US Food and Drug Administration for the prevention and treatment of osteoporosis, on breast cancer rates after 4 years of follow-up. The results confirm the study’s preliminary findings, which where initially published in the Journal of The American Medical Association (281:2189-2197, 1999).
"The MORE trial showed that raloxifene reduces the risk of invasive breast cancer by 72% in women who took this drug daily for 4 years," said Jane Cauley, DrPH, lead author of the study report and associate professor of epidemiology at the GSPH. "Specifically, raloxifene reduced the risk of estrogen-receptor-positive invasive breast cancer by 84%. This finding indicates that raloxifene is very effective at curbing the development of estrogen-fed breast tumors among older women with an average breast cancer risk."
MORE, a multicenter osteoporosis trial, involved 7,705 postmenopausal women, with an average age of 66.5 years and a history of osteoporosis. About 12% reported a family history of breast cancer. Participants were randomly assigned to receive 60 or 120 mg of raloxifene per day or a placebo. Neither investigators nor participants knew who received placebos and who received raloxifene.
After 4 years, 39 cases of breast cancer were confirmed among the 5,129 women assigned to either dose of raloxifene, compared with 28 cases among the 2,576 women assigned to the placebo. There were no significant differences in outcome between the group taking 60 mg of the drug and those taking 120 mg. Overall, raloxifene was well tolerated by participants.
Venous thromboembolism is a serious, although infrequently reported side effect of raloxifene. Other side effects associated with raloxifene include flu symptoms, hot flashes, leg cramps, endometrial cavity fluid and peripheral edema.
Longer-term effects of raloxifene on reducing the incidence of breast cancer in postmenopausal women will be evaluated in the Continuing Outcomes Relevant to Evista (CORE) trial.