Guleria S, et al. - Researchers examined the relationship between use of fertility drugs and risk of breast cancer using a nationwide cohort of Danish women. The study cohort included women aged 20-44 years and living in Denmark between January 1, 1995, and December 31, 2011. The Danish Infertility Cohort and various Danish national registers were used to gather information on fertility status, use of fertility drugs, breast cancer, covariates, and vital status. They included approximately 1.33 million women. Of these participants, 7.3% were infertile, and breast cancer was diagnosed among 1.5% during a median follow-up of 20.9 years. Data yielded no convincing evidence supporting associations between use of fertility drugs and breast cancer after two decades of follow-up.