What you need to know
- A study of more than 2 million women “confirmed” that hormonal contraceptive use was associated with “an increased risk of breast cancer.”
- Pills containing only one hormone, specifically a form of progesterone called desogestrel, increased the risk of developing breast cancer.
- The study authors cautioned that because birth control pills have benefits, women should talk to their health care providers.
A large study of more than 2 million women “confirmed that an increased risk of breast cancer is associated with hormonal contraceptive use.” But researchers warn that the benefits of birth control pills may still outweigh the risks.
Researchers found that women who took birth control pills containing only one hormone, a type of progesterone called desogestrel, had a 21 percent increased risk of developing breast cancer, while women who took the combination pill had a 12 percent higher risk. “The finding that desogestrel may increase breast cancer risk more than other progestins is a novel finding that, to our knowledge, has not been previously reported,” the published study said. JAMA Oncology.
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“These results suggest that estrogens may attenuate the harmful effects of progestins,” the researchers wrote, given the lower risk of breast cancer with combination agents.
Minipills, or progestin-only pills, thicken cervical mucus (making it more difficult for sperm to travel to the uterus), preventing ovulation, thinning the uterine lining, and preventing a fertilized egg from implanting. cleveland clinic They explain that combination drugs that have the same effect also contain estrogen.
Minipills come in packs containing 28 “active” pills. Combination pills include three weeks of active pills and one week of inactive or placebo pills.
The researchers noted that while further research is needed, the “statistically significant” risks of taking hormonal contraceptives “must be considered in the broader context of their well-established benefits.”
“These benefits include prevention of unintended pregnancies associated with increased maternal morbidity and mortality, as well as protective effects against ovarian and endometrial cancer,” the study explains. “Collectively, these considerations highlight the importance of tailored contraceptive counseling that takes into account an individual’s risk profile and preferences.”
