It’s no surprise that the hormonal contraceptives of yesteryear have had wonky and sometimes negative effects on our bodies. But a study released December 6 says even newer versions of said contraceptives place women at increased risk for developing breast cancer compared to those using non-hormonal methods of birth control.
The study, published by The New England Journal of Medicine and funded by the Novo Nordisk Foundation, is the first to examine the risks associated with modern-day formulations of hormonal contraceptive methods. Researchers have been following the entire of-age female population (more specifically, the 1.8 million who are of childbearing age) of Denmark for more than a decade, drawing necessary data from national prescription and cancer registries. What they ultimately found is the more hormonal birth control a woman uses, the more at risk for cancer she may be.
Women all over the world have been using birth control pills for decades. They’ve evolved immensely, and the category of hormonal contraceptives has grown to include intrauterine devices (IUD) and implants. The New York Times reports that nearly 10 million American women use oral contraceptives, with 1.5 million of them consuming for reasons other than birth control (think acne regulation, menstruation stabilization, and experts even say they can be helpful in reducing ovarian, endometrial, and possibly colorectal cancers that may surface in later stages of life—ironic, huh?).
What surprised researchers the most was the conclusion that increased risk was not just found among those taking oral pills (which are known to release estrogen or estrogen-progestin combinations), but was also found affect those using any type of implant that contains progestin only. Older generations of pills have been shown to increase the risk of breast cancer, but everyone just assumed that those kinks had been worked out with the newer formulas. Unfortunately, that doesn't appear to be the case.
“This is an important study because we had no idea how the modern day pills compared to the old-fashioned pills in terms of breast cancer risk, and we didn’t know anything about IUDs,” says Dr. Marissa Weiss, an oncologist and the founder of breastcancer.org. “Gynecologists just assumed that a lower dose of hormone meant a lower risk of cancer. But the same elevated risk is there … It’s small but it’s measurable, and if you add up all the millions of women taking the pill, it is a significant public health concern.”
If you’re thinking about discontinuing use, you should consult your doctors first because the study also showed the risk to still be high regardless of discontinued use if you’ve been taking the contraceptive for five or more years.
Risk intensity is shown to vary with age (along with other variables that unfortunately were not tested, like physical activity, breastfeeding, and alcohol consumption). The Times notes the probability of a 20-year-old woman developing breast cancer in the next 10 years is .06 percent, and the probability for a woman older than 40 is 1.45 percent.
There are plenty of other options for women who want to stop putting themselves at risk, as Dr. Weiss points out. “It’s not like you don’t have a choice,” she said. “Why not pursue another option.”