Metformin Associated with Lower Cancer Risk

During the past decade, observational studies have suggested associations between cancer and type 2 diabetes (or insulin therapy). Although several plausible mechanisms exist (e.g., cancer cells express insulin receptors that when activated could promote cell proliferation in type 2 diabetic patients with hyperinsulinemia), the association remains controversial (CA Cancer J Clin 2010; 60:207). In some studies, metformin has been associated with decreased cancer risk.

In a population-based retrospective study, Dutch researchers recorded the incidence of cancer in 85,000 type 2 diabetic patients who initiated metformin or sulfonylurea monotherapy. During up to 10 years of follow-up, metformin users were less likely to receive cancer diagnoses …