Oral Contraceptives Increase Risk of Triple-Negative Breast Cancer

Taking birth control pills is an easy, convenient and effective means of preventing pregnancy. Aside from the obvious benefit, oral contraceptives improve bone density and decrease the risk of ovarian and endometrial cancers. Although most studies have not found an overall increased risk of breast cancer from current low-dose birth control pills, young women who take the Pill may be at greater risk for a particularly aggressive and hard-to-treat breast cancer.

When researchers at Fred Hutchinson Cancer Center reviewed nearly 900 cases of breast cancer to determine what causes tumors in young women, they were surprised to discover that women 40 and under who used birth control pills for a year or more were 4.2 times more likely to develop triple-negative breast cancer than women of the same age who didn't use oral contraceptives. The population-based study looked at a variety of risk factors, including weight, use of tobacco and alcohol, reproductive and family history, and whether the women breastfed their children. Starting oral contraceptives at an early age and using them longer further increased risk. Women who used the Pill between ages 41-45 had no increased risk.

Although rare, triple-negative breast cancer is aggressive and very difficult to treat, and the prognosis is generally poor. Women diagnosed with these tumors are usually younger, African American or have a genetic predisposition to breast cancer.

While this single study adds precautionary information for young women, more research is needed to show exactly how oral contraceptives may increase breast cancer risk in women of this age. If you're thinking of using oral contraceptives, weigh all the risks and benefits and speak to your doctor about how your risk for breast cancer might be affected.