Oh TK, Song IA., et al. - Among noncancer patients with chronic pain, researchers assessed the association between chronic opioid therapy and a greater risk of cancer. Using data from the National Health Insurance Service, they performed a population-based historical cohort study of the South Korean adult population. Individuals registered with a diagnostic code of M00–M99 (musculoskeletal system and connective tissue diseases) according to the International Classification of Diseases, 10th revision, in 2010 were included in the study. In total, 351,701 patients were examined in the study; 7.2% of them were chronic opioid users. Among non-cancer patients with chronic pain, chronic opioid therapy was correlated with an increased risk of cancer, and in chronic strong opioid users, this correlation was more evident. Unmeasured and possible confounders may have affected the outcomes, so this association should be assessed with caution.