Birth Control Pills and Cancer Risk

Birth control pills (BCPs) are a type of contraception. Contraception is a way to prevent pregnancy. BCPs are a medication that contains hormones that prevent you from getting pregnant. BCPs contain man-made forms of estrogen and progestin or just progestin. They were first introduced in the 1960s, but over the years many changes have been made to how they are made. This continuing evolution makes it hard to apply the results of previous studies looking at cancer risk to today’s BCP preparations. There have been more recent studies that can provide some guidance on BCPs and cancer risks and benefits.

Breast Cancer

The link between BCPs and breast cancer is not straightforward, but some recent studies have found:

• An increase in breast cancer risk for women who use BCPs (estimated to be between 7-30% in different studies). The increase in risk is greatest in women over 40 years of age.
• Breast cancer risk is higher when BCPs are used for longer periods of time.
• The risks of breast cancer went down after a woman stops taking BCPs.
• 10 years after stopping BCPs, there was no increased risk of breast cancer over women who had never used BCPs.

Cervical Cancer

Women who take BCPs for 5 years or more have a higher risk of cervical cancer and this risk increases as BCPs are used for longer periods of time. As with breast cancer, the risk goes back down, over time, after BCPs are stopped.

Endometrial Cancer

The risk of endometrial cancer is lower among women who have taken BCPs. Some studies estimate the risk to be 30% lower and that number increases as BCPs are used for longer periods of time. This lower risk lasted for many years after stopping BCPs.

Ovarian Cancer

The risk of ovarian cancer is about 30-50% lower in women who have taken BCPs. The risk continues to decrease the longer a woman takes BCPs. This lower risk is still seen up to 30 years after stopping BCPs.

Colorectal Cancer

The risk of colorectal cancer is 15-20% lower in women who have taken BCPs.

What can I do with all this information?

Discuss the risks and benefits of any medication you are taking with your healthcare provider. In the case of BCPs, it is important for your provider to consider your personal and family history before prescribing BCPs. If you are at an increased risk of cancer, you may consider other options for birth control. These risks include:

• Your family history.
• Genetic mutations.
• Other health concerns (such as blood clots).

Non-hormonal birth control options do not have an effect on your cancer risk. Your provider should inform you of all your options.

If you took BCPs in the past talk to your provider about cancer screening tests for breast and cervical cancers that are recommended for you based on your age.

Resources for more information

American Cancer Society: Birth Control & Cancer: Which Methods Raise, Lower Risk

BreastCancer.org: Do Hormonal Contraceptives Increase Breast Cancer Risk?

National Cancer Institute (NCI): Oral Contraceptives and Cancer Risk