Metformin a Pancreatic Cancer Fighter for Diabetics

August 5, 2009
Bradley Schmidt

Diabetics on insulin or insulin secretagogues were 62 percent more likely to develop pancreatic cancer according to an M.D. Anderson Cancer Center study. “Insulin seems to have a growth-promoting effect in cancer," said lead author Donghui Li.

The oral anti-diabetic drug metformin has demonstrated a significant chemopreventative effect in diabetics according to researchers at the University of Texas M.D. Anderson Cancer Center.

The four year study of “973 patients with pancreatic adenocarcinoma (including 259 diabetic patients) and 863 controls (including 109 diabetic patients)” found that patients on a metformin regimen were 62 percent less likely to develop pancreatic cancer compared to those who were not taking it.

"This is the first epidemiological study of metformin in the cancer population, and it offers an exciting direction for future chemoprevention research for a disease greatly in need of both treatment and prevention strategies," said Donghui Li, Ph.D., professor in M. D. Anderson's Department of Gastrointestinal Medical Oncology.

Metformin’s protective effect remained significant for those patients who had diabetes for more than two years or those who never used insulin. Diabetics in the study on insulin or insulin secretagogues were nearly 5 and more than 2.5 times as likely to contract the disease, respectively, compared to non-users.

“Insulin seems to have a growth-promoting effect in cancer," said Li.

A paper published in the British Journal of Cancer by researchers at France’s Université de Bourgogne, indicates that though diagnostic procedures for pancreatic cancer have changed (ultrasonography and computed tomography are the major diagnostic tools), there have only been slight improvements in stage, cases resected for cure, and 5-year relative survival between the 1976-1980 and 2001-2005 periods: stage I—II diagnosis increased from 2.8% to 8.8%; cases resected for cure increased from 4.5 to 11.3%; the 5-year relative survival increased from 2.0 to 4.2%.

Such findings highlight the importance of metformin and other currently available preventative therapies.

"While further validation is needed, our findings show metformin's potential as a chemopreventive agent," said Li. "Currently, once pancreatic cancer is diagnosed, we have few successful therapeutic agents to offer our patients, so obviously, for those at greatest risk, a preventive mechanism such as metformin would be a welcome option."