Metformin Also Helps Pancreatic Cancer Patients

April 12th, 2012
by Michael O'Leary

Dr. Donghui Li, of MD Anderson Cancer
Center

A new study shows that people with diabetes and pancreatic cancer may live longer if they take metformin. In fact, those prescribed metformin had a 32 percent lower risk for death compared to those who didn’t take metformin.

Whether taking metformin might prevent people with diabetes from developing pancreatic cancer, however, is unknown.
This is mostly because the relationship between diabetes and pancreatic cancer is unclear. While about 80 percent of those diagnosed with pancreatic cancer also have diabetes, researchers have been unable to determine if the diabetes causes the cancer, or whether the cancer causes the diabetes.

A 2003 review of multiple studies of the link between the two found that there is no simple answer to which is the cause and which is the result, and that neither theory excludes the possibility that pancreatic cancer is both caused by diabetes and causes diabetes. (Published site)


In the new study published in the March 31, 2012 Clincal Cancer Research researchers led by Dr. Donghui Li, of MD Anderson Cancer Center reviewed the medical records of 302 patients diagnosed with pancreatic cancer. The found that one year after diagnosis 63.9 percent of the patients prescribed metformin were still alive compared to 46.3 percent of the group that were not given metformin.

After two years the contrast was even clearer with 30.1 percent of the metformin group surviving while 15.4 percent of the non-metformin group survived. Putting it another way, the midpoint of the survival range for the metformin group was 15.2 months compared to 11.1 months for those not prescribed metformin.

This effect of reducing the risk of death in these patients held true for all stages of cancer except the most advanced stage, in which the cancer has spread throughout the body. The researchers found no benefit for the metformin patients with such advanced cancer.

In an editorial accompanying the research study in the same issue, Dr. Michael Pollack of McGill University, Montreal, wrote that although the studies reviewed show clinical, drug and biologic evidence pointing to a protective effect of metformin, the only way to  determine conclusively whether metformin might be used to treat or prevent pancreatic cancer in diabetes patients is by conducting studies that compare patients treated with metformin to patients treated without metformin.

“Clinical trials that simply use metformin at antidiabetic doses in unselected cancer patients may or may not reveal benefit,” he wrote, “so carefully designed preclinical and clinical studies are needed for rigorous investigation of important details.”