It possesses anticancer properties through a number of mechanisms including the activation of AMP-activated protein kinase, which inhibits the mTOR pathway that promotes cell proliferation.47 Observational studies show that metformin reduces the incidence of advanced CRA and CRC among diabetes patients.48 To date, there is only one RCT on metformin and chemoprevention of sporadic CRA that used endoscopy-confirmed CRA rates as outcome.49 Risk of CRA was significantly reduced among the metformin group. This evidence concerns the gene MTOR and diabetes mellitus.