Does a medication used to treat diabetes have anti-cancer potential?

This study looked at the anticancer effect of metformin (Glucophage), a drug commonly used to treat type 2 diabetes. The authors concluded that metformin in combination with current cancer therapies such as chemotherapy improved progression free survival in patients with advanced non-small-cell lung cancer.

Patients with advanced non-small-cell lung cancer (NSCLC) are commonly treated with a combination of chemotherapy and the targeted therapy bevacizumab (Avastin). Despite treatment, however, this type of advanced cancer is incurable and better treatments are needed.

Metformin (Glucophage) is a drug used to treat type 2 diabetes. Some studies have indicated that it has anticancer potential, as diabetes patients treated with metformin had a lower incidence of cancer than those treated with other drugs. It is possible that metformin combined with current cancer therapies may be effective in the treatment of advanced NSCLC.

This trial aimed to examine the benefit and safety of including metformin in cancer treatment. 25 patients with advanced NSCLC who had not received prior chemotherapy were included in the trial. Patients were then treated with chemotherapy followed by bevacizumab with or without metformin. 18 patients in group A had metformin in their treatment plan while the remaining patients in group B did not.

Progression free survival (PFS, time from beginning trial until disease progression) and overall survival (OS, time from beginning trial until death) were measured.

Average PFS for patients in group A was 9.6 months compared to 6.7 months in the control group. The 1 year PFS rate for patients in group A was 47%, compared to 15% in group B. OS at 1 year was 68% for patients in group A. Prior studies reported a 1-year OS of 51%. Average OS was 15.9 months for group A and 13.9 months for group B. This was not a significant difference.

Overall, the most common side effect was neutropenia (low level of white blood cells). There were no differences in incidences of side effects between each group.

The authors concluded that including metformin in cancer treatment is safe and has the potential to improve PFS for patients with advanced NSCLC.