Ding DC, et al. - Using Taiwan's National Health Insurance Research Database, researchers investigated if there exists a link between the risk of developing thyroid cancer and infertility and the use of fertility drugs among Asian women in this large, retrospective cohort study. Using insurance claims data, they identified 13,356 women aged 20 to 49 years who were diagnosed with infertility from 2000 through 2013 and were defined as the infertile group. These were compared to fertile comparisons comprising 53,424 women without a history of infertility. An increased risk of developing thyroid cancer was evident in women with infertility. An attenuated incidence of thyroid cancer was observed among infertile women who had taken the fertility drug clomiphene vs those who were treated without the drug. However, an approximately 6-fold greater cancer incidence was reported in infertile women being treated with clomiphene vs that in fertile women taking the drug.