Last week, the New England Journal of Medicine published a study finding that hormonal contraceptives increase the risk of breast cancer. It is among the first studies to specifically analyze the effect of newer, low-dosage methods of contraception. The study is both thorough and comprehensive, as it analyzes nearly 1.8 million women over a span of 17 years using Denmark’s comprehensive medical registry. The study has been covered by a number of mainstream media outlets including the New York Times, USA Today, Slate, NPR, and Time.
A significant body of public-health research finds that contraceptives with high doses of estrogen increase the risk of breast cancer. For instance, a 1996 meta-study in The Lancet analyzed data from 54 studies surveying 25 countries and found solid statistical evidence that both current and recent users of oral contraceptives were at an increased risk for breast cancer. Many public-health researchers believed that newer methods of contraception with lower doses of estrogen would eliminate these risks. In fact, a relatively small 2014 study of Seattle-area women arrived at this exact conclusion.
But this latest study — which analyzes a larger, more comprehensive dataset over a longer period of time — is among the first to provide statistical evidence showing that even low-dosage hormonal contraceptives increase the risk of breast cancer. The study also contains enough data to analyze the effects of various types of low-dosage contraceptives. It finds that long-term use of each of seven different types of low-dosage contraceptives significantly increases the risk of contracting breast cancer.
The media’s coverage of this study has been surprisingly accurate. Most outlets tend to downplay research finding that either abortion or contraception poses health risks. For instance, in 1997 the New England Journal of Medicine published study methodologically similar to this latest one, which also used data from Denmark’s health registry to analyze the abortion–breast cancer link. When covering that study, outlets claimed that induced abortion does not increase the likelihood of developing breast cancer, when in fact, the study found that abortions performed after 18 weeks gestation significantly increased the risk of breast cancer.
However, despite the fact that this new research reports that low-dosage contraceptives increase the risk of breast cancer, the increase in that risk is relatively slight, and the media have emphasized this finding in their coverage. Additionally, in the days after the study was released, many commentators were quick to tout the purported health benefits of oral contraceptives. That said, in an era of exceptionally politicized news coverage, it is heartening to see the mainstream media cover research on a potentially controversial public-health topic in a reasonable manner.