If you use birth control, you might be wondering whether it affects your risk of getting cancer. Research shows that some forms of birth control can raise your odds of getting certain kinds of cancers. But birth control can also play a role in lowering your risk of some cancers. Here’s what you should know.
Oral Contraceptives and Cancer
Oral contraceptives (also known as birth control pills) may slightly increase your risk of getting breast and cervical cancers. And the longer you use birth control pills, the higher your risk of both cancers tends to be. (Your risk usually decreases over time after you stop using the pills.)
Your risk also rises if you use birth control pills after age 40. One reason: Estrogen and progesterone are two hormones that play a role in the development of certain types of cancer. Oral contraceptives contain human-made versions of estrogen and progesterone, so researchers think they may increase the risk of cervical and breast cancers.
On the flip side, research shows that using birth control pills at any point in your life is linked to a 30% drop in your risk of endometrial cancer. It also lowers your risk of colon cancer by 15% to 20%, and your risk of ovarian cancer by as much as 50%.
Experts don’t know yet exactly why this is. A few theories include:
- The hormones in birth control pills may make it harder for endometrial cells to multiply, which drops your risk of endometrial cancer.
- Birth control pills stop ovulation. This reduces the amount of naturally occurring hormones flowing through your body, reducing your ovarian cancer risk.
- Most birth control pills contain estrogen, which may help reduce the amount of bile acid in the bloodstream, lowering colorectal cancer risk.
According to a University of Colorado study of several thousand women, using any intrauterine device (IUD) decreases your risk of ovarian cancer by as much as 32%. A Finnish study found that hormone-containing IUDs reduced the risk of endometrial, ovarian, pancreatic, and lung cancers. And a study from Columbia University found that women who used copper IUDs (IUDs with no hormones) have a lower risk of cervical cancer than those who use an IUD that releases levonorgestrel, a synthetic form of progesterone.
Some research suggests that using an IUD that contains levonorgestrel increases the risk of breast cancer. But other research suggests there’s no link. That’s why some experts say it’s still too soon to say whether IUDs that contain hormones increase the risk of breast cancer.
If you’re at an increased risk for breast cancer because of a family history or because you have gene mutations such as BRCA1 or BRCA2, your doctor may recommend using an IUD that doesn’t contain hormones.
The Birth Control Shot
The birth control shot contains progestin, a human-made form of progesterone. Experts aren’t clear on how it affects cancer risk. But some research suggests it may slightly raise your risk of breast cancer. One study from the Fred Hutchinson Cancer Research Center found that it may double the risk of breast cancer in women ages 20 to 44.
Condoms are a barrier method, meaning they prevent pregnancy by keeping sperm from entering the vaginal canal and potentially fertilizing an egg. They don’t increase or decrease the risk of most cancers. That’s because they don't add hormones or other chemicals to your body.
But some research shows that condoms may help reduce the spread of the human papilloma virus (HPV), which can cause cervical cancer. Because of that, condoms help reduce women’s risk of developing cervical cancer, according to a Danish review of eight studies.
Keep in mind that your health history, habits, and genes all have an impact on cancer risks. If you’re concerned your form of birth control may increase your cancer risk, talk to your gynecologist, urologist, or family doctor.