Birth control methods that use one hormone or a combination of two can all raise breast cancer risk by similar amounts, research suggests.
Studies have suggested for decades that birth control pills containing both estrogen and progestogen — synthetic versions of female hormones — may slightly elevate one's risk of breast cancer. But less research has focused on the risk associated with progestogen-only contraceptives like intrauterine devices or the so-called mini pill. A study published Tuesday in the journal PLOS Medicine found that the risk of developing breast cancer is similar across all of these options, whether they rely on one hormone or two. The relative risk of being diagnosed with breast cancer was 20% to 30% higher among women who use or recently used birth control pills with a two-hormone combination, progestogen-only pills or hormonal IUDs compared to women who did not. As of 2019, 14% of U.S. women ages 15 to 49 took oral contraceptive pills, and around 10% used long-acting reversible contraceptives such as IUDs or birth control implants, according to the Centers for Disease Control and Prevention. "I really don't want women to be seeing this and thinking, 'Oh, no, I've got to come off the progestogen-only pill,'" said Gillian Reeves, who co-authored the new study and directs the Cancer Epidemiology Unit at the University of Oxford. "There is this increased risk whatever you use in terms of hormonal contraceptives," she added. "These newer types that hadn't been so well studied, what it does look like is that they are certainly no worse." The findings are based on an analysis of prescription records from women under age 50 in the U.K. Nearly 9,500 of those women were diagnosed with breast cancer between 1996 and 2017, while more than 18,000 were not. The researchers combined the results of their analysis with…