Birth Control Pill May Be Linked to Breast Cancer Risk: Study

The findings of a new study suggest that there may be a link between side effects of birth control pills and an increased risk of breast cancer, finding that women taking high-dose estrogen pills may be more likely to develop breast cancer. 

In a study published in the medical journal Cancer Research on August 1, researchers from the Fred Hutchinson Cancer Research Center in Seattle found that younger women who take certain classes of birth control pills have a higher rate of breast cancer.

Researchers looked at data on women ages 20 to 49 who were diagnosed with breast cancer from 1990 to 2009. The study found that women taking high-dose estrogen pills were about 50% more likely to be diagnosed with breast cancer compared to women taking other birth control pills.

They also found similar increases among women taking birth control pills with the progestin ethynodiol diacetate, which includes Continuin, Femulen and Metrodiol, as well as among women taking oral contraceptives with triphasic dosing with an average of 0.75 mg of norethindrone, such as Aygestin, Mocronor, Errin, Jolivette, and Heather.

“Our results suggest that recent use of contemporary oral contraceptives is associated with an increased breast cancer risk, which may vary by formulation,” the researchers concluded. “If confirmed, consideration of the breast cancer risk associated with different oral contraceptive types could impact discussions weighing recognized health benefits and potential risks.”

The researchers noted that the overall risks of breast cancer from taking birth control pills is still very low, translating to less than a one percent chance that younger women taking the Pill will develop breast cancer.

According to the American Cancer Society, less than one percent of women under the age of 40 will be diagnosed with breast cancer, and the increased risks indicated by the study would not raise that number considerably.