Chang MS, Hartman RI, Xue J, et al. - Researchers performed a meta-analysis to explore the connection between metformin and skin cancer risk in patients with diabetes/prediabetes. A systematic literature search was conducted until March 23, 2020, to identify randomized controlled trials (RCTs) and observational studies of metformin that documented any event of squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and melanoma. Participants in the study were 8,541 patients. There was no statistically significant association between metformin and the risk of skin cancer in meta-analyses of both RCT and cohort studies, while suggestive evidence of modestly reduced risk of skin cancer among metformin users was found.