Raloxifene turned out not to have any effect on heart disease mortality risk, but it did reduce the risk of invasive breast cancer by 44 percent, which translates into 1.2 women per 1,000 treated for one year who were spared the agony of a breast cancer diagnosis.
The new analysis looked more specifically at raloxifene's effect on breast cancer and found a 55 percent lower incidence of invasive ER-positive tumors, but no effect on noninvasive breast cancer or invasive ER-negative breast cancer.
According to the study authors, these findings are consistent with results from other trials involving women without heart disease. This trial and others found an increased risk of blood clots and fatal strokes among women taking raloxifene, indicating that women need to weigh the risks and benefits of the drug.
Another question is how long to take raloxifene for breast cancer prevention, although the authors speculated that up to eight years might be safe and effective.
"We're learning more about this class of drugs, what works and what doesn't work," Jordan said. "[Raloxifene] is good for osteoporosis, no good for coronary heart disease, but breast cancer is inhibited."
The U.S. National Cancer Institute has more on SERMs and how they work.
SOURCE: V. Craig Jordan, Ph.D., vice president and research director, medical science, Fox Chase Cancer Center, Philadelphia; Jay Brooks, M.D., chairman, hematology/oncology, Ochsner Health System, Baton Rouge, La.; June 10, 2008, Journal of the National Cancer Institute, online
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