Could metformin be used to treat cancer?

This study investigated the relationship between the use of metformin (Glucophage) and prostate cancer mortality.

Metformin is a drug commonly used in the management of diabetes. Metformin works by suppressing glucose production in the liver and increasing the body's sensitivity to insulin. Recent studies have suggested that metformin may also affect the progression of certain cancers. In order to investigate whether metformin use affects the survival of prostate cancer patients, researchers investigated the outcome of patients diagnosed with both cancer and diabetes.

The study included 3,837 patients (men older than age 66 years) with diabetes, who were also diagnosed with prostate cancer. Of these, 1619 (42.2%) were receiving treatment with metformin.

Results showed that men who took metformin, and especially those receiving the drug for a longer period of time, experienced significantly improved survival compared to prostate cancer patients not receiving metformin. A reduced risk of 24% for cancer related mortality was seen in association with every 6 months of metformin use. Other commonly used diabetes medications were not shown to have the same benefit.

This study concluded that metformin use after cancer diagnosis, and duration of exposure, is associated with decreased mortality among diabetic men.

Further studies are needed to investigate whether metformin could also benefit non-diabetic prostate cancer patients. If proved beneficial, metformin may provide a new avenue of cancer therapy, used both to delay cancer progression and to reduce to risk of recurrence.

Consult with your physician regarding the use of metformin for the treatment of cancer in ongoing clinical trials.