Understanding the link between birth control pills and potential reduced risk of certain cancers


Millions of women use birth control pills to prevent pregnancy and control health issues related to menstruation. But recent studies show that oral contraceptives containing the hormones estrogen and progestin (combined pills) may also greatly reduce your risk for ovarian and uterine (endometrial) cancers.

Taking birth control pills may sound like a win-win, but there are many other factors to consider, according to Aparna Sridhar, MD, a comprehensive women’s reproductive health provider at UCLA Health.

“When deciding on contraception, you and your physician really need to look at your personal and family health history,” Dr. Sridhar says. “Then weigh your preferences, the health benefits and the risks.” The key is to understand how the pill may alter your risk of different cancers. Then work with your physician to make the best decision about contraception for you.

How contraceptive pills affect your risk for cancer

Research shows that combined hormone pills can affect your risk of certain cancers, but their impact depends on the type of cancer risk and how long you use the pill. For some cancers, the influence stops when pill use ends. For others, the effects can last for years, even decades. Here’s what you need to know:

Ovarian cancer

A recent study confirms that the hormones in oral contraceptive pills can reduce the risk of ovarian cancer by up to 50%. The effects can last for decades even after you stop taking the pill.

This news is especially significant if you have a BRCA1/BRCA2 mutation, which raises the risk of ovarian cancer by more than 40%. “Experts agree,” Dr. Sridhar says, “that it is appropriate and acceptable for women with an increased risk of ovarian cancer to use oral contraceptives if indicated or even as cancer prevention.”

Endometrial (uterine) cancer

Hormonal oral contraceptives also reduce your risk of developing endometrial cancer. This type of cancer, which begins in the uterus, is the most common gynecological cancer in the United States.

If you used combined pills at any point, your chances of developing uterine cancer are 30% less than someone who never took the pill. The risk reduces further with continued use.

Breast cancer

With approximately 140 million women worldwide taking combined oral contraceptives, the connection between the pill and breast cancer is especially important. But researchers have yet to agree on the link between the two.

Some studies have found that the pill causes a slight increase in the risk of breast cancer that diminishes after you stop taking it. But the American College of Obstetricians and Gynecologists states that any increased risk is extremely minimal, even for women with a BRCA1/BRCA2 mutation or a family history of breast cancer.

“There have been conflicting reports in literature about how oral contraception affects breast cancer,” Dr. Sridhar says. “But the overall risk of breast cancer in those who use hormonal contraception is very low.” One thing experts do agree on is that the minimal increase in breast cancer risk is greatly outweighed by the reduction in ovarian and endometrial cancer risk.

Cervical cancer

If you use birth control pills, your probability of developing cervical cancer increases slightly. Your risk continues to grow the longer you take oral contraceptive pills. Even so, the risk does not rise enough to warrant additional cervical cancer screening.

The good news is that the increased risk does not continue after you stop using birth control and getting the HPV (human papillomavirus) vaccine protects against cervical cancer. Talk to your doctor about getting the recommended cervical cancer screening and HPV vaccine.

Colorectal cancer

Growing research shows that taking oral contraceptives may lower your risk of colorectal cancer. Some studies show use of the pill decreases colorectal cancer risk by 15% to 20%. But experts agree that there is not yet enough evidence to suggest taking birth control as a preventive measure for colon cancer.

How to determine if oral contraceptive pills are right for you

Even after you understand the cancer risks associated with birth control, Dr. Sridhar says, the best way to know if the pill is right for you is to discuss it with your physician.

“It’s really important to talk to your provider, go over your medical history, family history and prior hospitalizations,” Dr. Sridhar says. “There are many health considerations involved when taking oral contraceptives. You should work together with a clinician to find a birth control method that meets all your needs while also being a medically appropriate method for you.”

If you’re already taking birth control pills, speak with your doctor about how long you should be on them. “The duration of use for any birth control should be based on the need for contraception or non-contraceptive benefit,” Dr. Sridhar says. “Your doctor can help you decide whether or not to continue using the pill.”

To learn more about whether oral contraception is right for you, reach out to your obstetrician/gynecologist. If you’d like to understand your risk for cancer, talk to your primary care provider.