The osteoporosis drug Evista is better than Tamoxifen in preventing breast cancer in high risk post-menopausal women, new research has suggested. Researchers said that both drugs reduce the risk of cancer by 50 percent. But the results of a 19,000-woman trial show that Eli Lilly and Co's Evista, known generically as raloxifene has fewer side effects. This fact could prompt clinicians to replace Tamoxifen with Evista in the future.
Raloxifene was found to cause less of blood clots, cataracts and uterine cancer than tamoxifen in the trial. "It is clear that raloxifene is the winner of this trial," said lead researcher Dr. Norman Wolmark, a researcher at the University of Pittsburgh Medical Center. Tamoxifen is sold as a generic drug and is widely used to prevent breast cancer, but Lilly said it would seek U.S. Food and Drug Administration approval to market Evista for this purpose. "Tamoxifen will remain the drug of choice for reducing breast cancer risk in pre-menopausal women," Vogel said. However, Raloxifene was found to cause more pre-cancerous lesions, which has puzzled doctors. "For now it will be very important for women with an increased risk of breast cancer to make an informed decision with the advice of their physician," the group said. "It is also important to note that while both drugs can prevent many breast cancers, neither has been shown to reduce the risk of death due to the disease." Of the 9,745 women in the raloxifene group, 167 developed invasive breast cancer, compared to 163 of 9,726 women in the tamoxifen group.