The authors of a related comment note that the results from retrospective studies have suggested metformin might decrease the risk of cancer and mortality in patients with diabetes; this has led to investigations into the potential anticancer activity of metformin.
The results of this study were negative; the comment however points out that it was very ‘ambitious’, being powered to detect a 50% increase in survival for one of the most lethal and aggressive of all malignancies. The trial was underpowered to detect any small, but possibly still clinically significant, benefits of metformin. They say that despite these negative findings, ‘attempts to repurpose metformin for treating cancer should not be abandoned’. There are a number of studies currently investigating metformin in various stages and types of cancer and the results of these are awaited.