Do oral contraceptives cause breast cancer?

BY: Nancy Gottesman

For years, experts have debated whether oral contraceptives increase the risk of breast cancer. Some studies suggest they do; others do not. In a new Boston University study, researchers have found that women who had taken birth control pills for at least one year had a 50 percent increased risk for breast cancer compared to women who took the pill for less time or who had never taken it. The study also found that the risk was greatest in younger women (under age 50), whose underlying risk for breast cancer is otherwise low. In addition, the increased risk appears to dissipate about 10 years after a woman stops taking the pill.

So, should women stop using oral contraceptives? There’s no simple answer. Every method of contraception has risks and benefits, notes study leader Lynn Rosenberg, Sc.D., professor of epidemiology at Boston University School of Public Health. For instance, while birth control pills appear to increase the risk of breast cancer, they have been shown to be protective against ovarian cancer. “Each woman will have her own risk/benefit equation,” says Rosenberg. “Women at very high risk for breast cancer -- such as those with the BRCa1 gene -- might choose to avoid oral contraceptive use.” Bottom line: Talk to your doctor about your breast cancer risk and birth control options.