Stoer NC, Botteri E, Thoresen GH, et al. - A drug-wide association study was performed to assess any relationships between prescription drugs and risk of cancer. Researchers assessed the relationship between prescribed drugs, categorized according to the anatomical therapeutic chemical (ATC) classification system, and the risk of the 15 most common cancer types, overall and by histology. They applied stratified Cox regression, adjusted for other drug use, comorbidity, county, and parity, and explored dose-response trends. As per the outcomes, 145 associations were observed among 1,230 drug–cancer combinations on the ATC2-level and 77 of 8,130 on the ATC4-level. This research verified previously reported relationships and generated new hypotheses on possible carcinogenic or chemopreventive effects of prescription drugs. Outcomes from this type of explorative approach need to be confirmed in customized epidemiologic and preclinical studies.