MONTREAL — Diabetic men are more likely than healthy men to develop pancreatic and liver cancer, indicates a study that suggests a potentially fatal complication linked to the insulin deficiency.

University of Montreal researchers found diabetic men were three times more likely to develop liver cancer and twice as likely to develop pancreatic cancer compared with healthy subjects.

The sobering findings add to well-documented complications from diabetes such as heart disease, blindness and kidney damage.

Dr. Marie-Claude Rousseau's study, based on data compiled from cancer patients and healthy subjects in the 1980s, was presented at the recent Frontiers in Cancer Research Prevention meeting in Seattle.

The findings are consistent with those in a U.S. study and another in Europe which highlight the potentially fatal effects of diabetes and its link to cancer.

"I think what it means, even for everybody, is there is possibly another consequence to being diabetic," Rousseau said in an interview.

"And I think this should just give more weight to the message that we should try and prevent diabetes, period."

Dr. Gary Lewis, a leading Canadian diabetes expert, called the study "interesting" but also flawed because either liver or pancreatic cancer was reported in only a minority of the 3,288 cancer subjects.

Of the 34 with liver cancer, eight had diabetes. Of the 92 with pancreatic cancer, 15 had diabetes.

Overall, 311 of the cancer subjects had diabetes.

Lewis, who works at the University Health Network and Mount Sinai Hospital in Toronto, said it's possible the cancers could have caused the diabetes - not the other way around.

"People get sick from cancers and any physical stress to the body can bring out diabetes," said Lewis, the Canada Research Chair in Diabetes at the university.

"Just because you can show a relationship doesn't mean that diabetes causes cancers."

Rousseau, a 35-year-old disease specialist, stopped short of saying diabetes can cause cancer.

"I'm always reluctant to make any definitive pronouncements about causality," she said.

"However, our results strongly suggest a link between diabetes and liver cancer."

Although the link between diabetes and certain cancers is already established, Rousseau and her colleagues factored in demographic and lifestyle factors they said were unavailable in previous studies.

The University of Montreal team analysed the medical history of the 3,288 patients who were interviewed just after being diagnosed with cancer in the 1980s.

The cancer patients and a control group of more than 500 cancer-free men were asked a number of questions, including whether they suffered from diabetes.

Subjects were asked whether they smoked and for how long. They were also weighed and checked for obesity.

"When we're comparing the cancer patients and the (others), the difference that we're seeing is really a difference that comes from diabetes and not from other factors," said Rousseau.

Researchers said that given the adult age of the subjects, they likely had type 2 diabetes, which is acquired later in life.

The Montreal study is consistent with the results of a large U.S. study that suggested diabetes was linked to higher mortality rates from cancer of the colon and pancreas for men and women, liver and bladder cancer for men only, and breast cancer for women.

The U.S. researchers examined more than 467,000 men and 588,000 women beginning in 1982.

They were followed up for 16 years and the results were published in the American Journal of Epidemiology.

Some facts about diabetes:

• Type 1 diabetes occurs when the pancreas no longer produces insulin, a substance that uses sugar for energy.
• Type 2 diabetes occurs when the pancreas does not produce enough insulin or when the body does not effectively use the insulin that is produced.
• Signs and symptoms of diabetes include:
• Unusual thirst
• Frequent urination
• Weight change (gain or loss)
• Extreme fatigue or lack of energy
• Blurred vision
• Frequent or recurring infections
• Cuts and bruises that are slow to heal
• Tingling or numbness in the hands or feet
• Trouble getting or maintaining an erection
• If left untreated or improperly managed, diabetes can result in a variety of complications, including:
• Heart disease
• Kidney disease
• Eye disease
• Problems with erection (impotence)
• Nerve damage

Prevention measures include a healthy meal plan, weight control, physical activity and stress reduction.