Well Research

Birth Control Pills Raise Breast Cancer Risk Slightly, But Don’t Panic

January 16, 2018
a birth control blister package with one pill left, over a pink background
© Leandro Crespi / Stocksy United
Quick Read

The risk is actually pretty small

  • A new study found a slightly increased risk of breast cancer in women who use all kinds of hormonal birth control compared to those who didn’t use hormonal birth control.
  • Experts hoped lower doses of estrogen in modern birth control pills would lower that risk.
  • Hormonal birth control may also lower your risk of ovarian cancer and endometrial cancer.
  • Talk with your doctor about your priorities before trashing your pills.

After the recent news broke that hormonal birth control is still linked to breast cancer, many women who rely on the pill were left wondering about their risk—and their options. 

For those who use it to suppress heavy periods, keep their skin clear, ease endometriosis, or do any number of things not limited to preventing pregnancy, the “just use a condom” alternative recommended by some experts wasn’t a helpful alternative.

Like many health news items that have worked people up in the past, the Danish study that discovered the link is not so black and white.

Understanding the history of birth control, how breast cancer risk compares to other risks, and how to make a decision that works best for you may help ease your mind, says Sarah Prager, M.D., director of the UW Medicine Family Planning Division.

Birth control has come a long way

When birth control pills were invented in the 1960s, they contained large doses of estrogen that came with tons of side effects—including an increased risk for breast cancer—and made many women feel pretty miserable, explains Prager.

Over the years, pharmaceutical companies lowered the estrogen doses and started combining estrogen with newer forms of progestin, the synthetic progesterone hormone found in birth control.

Experts hoped the lower doses of estrogen would lower the risk of breast cancer from hormonal contraception, but, as this new research makes clear, that hasn’t happened.

Interestingly, the Danish study found that all hormonal birth control—not just birth control pills—increased breast cancer risk.

“We haven’t made birth control zero risk and I don’t think we ever will or that that’s a reasonable expectation,” says Prager. “But it is incredibly low risk.”

Putting the breast cancer stats in perspective

Hearing that birth control can increase your risk of cancer is scary. But the risk demonstrated by this study is actually pretty small, says Prager. To be exact: The researchers found 13 additional breast cancer diagnoses out of every 100,000 women using hormonal birth control compared to those who didn’t use hormonal birth control. This increased risk translates into only one additional case for every 7,690 women using contraceptives for one year.

“Just to put it in another perspective: Let’s say every single woman who used hormonal birth control stopped using birth control at all. That would mean many more millions of pregnancies that are potentially unplanned or unwanted,” says Prager. “Pregnancy comes with a much more significant risk than does contraception.”

In Denmark, where this research was done, the maternal mortality rate was 4.2 per 100,000 live births in 2015, according to data from the Institute for Health Metrics and Evaluation. In other words, for every 100,000 babies born, four moms died. (It’s worth noting: The maternal mortality rate in the U.S. in 2015 was 26.4 per 100,000 live births, the highest in the developed world.)

You may be thinking: Four is a smaller number than 13, so what’s the point?

One important thing that this most recent study does not reveal is if any of the women who were diagnosed with breast cancer after taking hormonal birth control died of it, says Prager.

In fact, other research has shown that women who have used hormonal birth control have similar mortality rates from breast cancer compared with women who have never used hormonal birth control, says Prager.

“Even if there is this small increased number of women who will have a diagnosis of breast cancer, it does not appear to have a negative impact on survival,” she says.

Birth control protects against cancer, too

While there may be a slightly increased risk of breast cancer diagnosis for women who use hormonal birth control, there is evidence that it can have protective benefits, too. Research shows that women who use hormonal birth have an overall survival benefit from all causes of mortality, including ovarian cancer. 

“Ovarian cancer is much more difficult to diagnose and much more likely to kill somebody and kill somebody quickly than is breast cancer,” says Prager.

Women who use hormonal birth control are also at a lower risk for endometrial cancer, research shows. The protective benefit appears to increase over time and lasts several years after a woman stops using hormonal birth control.

Weigh your options

Choosing a birth control method that’s right for you is personal. It requires you to analyze your priorities and assign some value to them, says Prager. 

Avoiding any increased risk for breast cancer might be the most important thing to you. Or you may find that avoiding heavy, painful periods, keeping your skin clear, reducing the risk of ovarian cancer or avoiding unplanned pregnancy is the highest priority for your everyday well-being.

All of these are perfectly acceptable decisions, and going through the process of figuring out your priorities is important, says Prager.

“There are a lot of different ways to value risk and it’s a really personal decision for a woman to value what is important to her about a contraceptive,” she says. “Starting from the framework of identifying what’s most important to each individual woman allows for better contraceptive counseling, regardless of what may be motivating her.”