The ASAMET trial: a randomized, phase II, double-blind, placebo-controlled, multicenter, 2 × 2 factorial biomarker study of tertiary prevention with low-dose aspirin and metformin in stage I-III colorectal cancer patients.

Background: Epidemiological studies and cardiovascular prevention trials have shown that low-dose aspirin can reduce colorectal cancer (CRC) incidence and mortality, including inhibition of distant metastases. Metformin has also been associated with decreased colon adenoma recurrence in clinical trials and lower CRC incidence and mortality in epidemiological studies in diabetics. While both drugs have been tested as single agents, their combination has not been tested in cancer prevention trials.