Hormonal Contraception and Breast Cancer Risk

Investigators from the University of Copenhagen, Denmark, and the University of Aberdeen, UK, conducted a population-based prospective cohort study to assess the association between contemporary hormonal contraception (HC) use and breast cancer in women. For the study, the investigators used data from the Danish Hormone Registry Study, which includes information from multiple linked databases. Study participants were women, 15 to 49 years old, living in Denmark on January 1, 1995, and those who turned 15 years old through 2011. The specific type (oral, patch, vaginal ring, implant, injection, or intrauterine system) of HC, and doses of estrogen and progestins, were recorded for study participants. For all women using HC, the length of use was measured and, for …