Drugs Help Prevent Breast Cancer but Pose Risks Too

THURSDAY, Sept. 17, 2009 (Health.com) — Women at high risk of breast cancer can often lower that risk by taking medication, including drugs like tamoxifen or the osteoporosis drug raloxifene (Evista).

Now, a new analysis suggests that women and their doctors need to weigh the dangers of the drugs’ side effects—which can include blood clots, cataracts, and cancer of the uterine lining—against the benefits of breast cancer prevention.

The analysis, funded by the U.S. Department of Health and Human Service’s Agency for Healthcare Research and Quality, was published in the September 15 issue of Annals of Internal Medicine.

However, the bigger problem may be that not enough women who are candidates for the drugs are actually taking them. About 2% of U.S. women are at high risk for breast cancer, but many don’t take tamoxifen or raloxifene, according to Christy Russell, MD, an American Cancer Society spokesperson who chairs the organization’s breast cancer advisory committee.

“That’s extremely unfortunate, because we have 200,000 new cases of invasive breast cancer every year and we could potentially reduce that number by half using drugs that are already approved by the [Food and Drug Administration] for this specific purpose,” she says. Dr. Russell says the drugs are underused due to a lack of education among both patients and physicians as to their safety and effectiveness.

“As a culture, it’s a very hard sell to convince us to take drugs for a disease we don’t already have,” she adds.