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Metformin use associated with significant improvement in mortality among diabetic men with prostate cancer: study


Metformin, one of the most commonly used oral drugs to treat type 2 diabetes, may have an anti-cancer effect. According to a study published in the Journal of Clinical Oncology by researchers at the Institute for Clinical Evaluative Sciences (ICES) and the University Health Network (UHN), men with prostate cancer who were using metformin were almost 25 per cent less likely to die from their prostate cancer than men who were not taking metformin.

“Our study shows that cumulative use of metformin after a prostate cancer diagnosis is associated with a significant improvement in all-cause and prostate cancer-specific survival among older men with diabetes and prostate cancer. We have shown that for every additional 6 months of metformin treatment, there is a 24 per cent decrease in prostate cancer-specific mortality and a significant decrease in all-cause mortality that declines over time,” says Dr. David Urbach, author of the study, scientist at ICES, surgeon at Toronto General Hospital, University Health Network and Professor of Surgery, University of Toronto.

Prostate cancer is the most common cause of cancer affecting men in the western world, and is the second most common cause of cancer death among men.

The researchers studied 3,837 men aged 66 and older with newly diagnosed diabetes who subsequently developed prostate cancer and found:

  • The men with prostate cancer who were using metformin were almost 25 per cent less likely to die from their prostate cancer than men who were not taking metformin.
  • The men with prostate cancer who were using metformin were also less likely to die from any cause, although this benefit declined over the time that men were taking metformin.
  • These survival benefits were not seen with use of other diabetic drugs

“Our findings indicate that the use of metformin to improve survival among non-diabetic men with newly diagnosed prostate cancer should be investigated in a clinical trial,” adds Urbach.

Authors: Margel D, Urbach D, Lipscombe LL, Bell CM, Kulkarni G, Austin PC, Fleshner N.

The study “Metformin use and all-cause and prostate cancer–specific mortality among diabetic men,” was published today in the Journal of Clinical Oncology.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

University Health Network consists of Toronto General and Toronto Western Hospitals, the Princess Margaret Cancer Centre, and Toronto Rehabilitation Institute. The scope of research and complexity of cases at University Health Network has made it a national and international source for discovery, education and patient care. It has the largest hospital-based research program in Canada, with major research in cardiology, transplantation, neurosciences, oncology, surgical innovation, infectious diseases, genomic medicine and rehabilitation medicine. University Health Network is a research hospital affiliated with the University of Toronto. www.uhn.ca


  • Deborah Creatura
  • Communications, ICES
  • [email protected]
  • (o) 416-480-4780 or (c) 416-904-4547  
  • Jane Finlayson
  • Public Affairs, Princess Margaret Cancer Centre
  • [email protected]
  • (o) 416-946-2846  

Read the Journal Article