Kuo YJ, et al. - In this nationwide population-based cohort study, authors used the data of males 50 years or older with both type 2 diabetes mellitus (T2DM) and benign prostate hyperplasia (BPH) diagnosed between 1997 and 2007 to assess the impact of metformin on prostate cancer risk in men with BPH. There were 2,906 patients in the metformin cohort and 2,906 in the nonmetformin cohort. After controlling for age, traditional Chinese medicine (TCM) use, prostate-specific antigen, and Charlson comorbidity index, they noted metformin cohort had an adjusted hazard ratio (aHR) of 0.69 for prostate cancer when compared to the nonmetformin cohort. An association of both metformin medication and TCM use with a decreased risk of prostate cancer for men with BPH and diabetes was seen.