Oct 5 2008
New research, funded in part by the Canadian Cancer Society, shows that men suffering from prostate cancer are up to 2 1/2 times more at risk of dying from the disease if they are overweight or obese. The men who participated in the study had been weighed prior to being diagnosed with prostate cancer.
Dr. Michael Pollak, senior author of the study, published online in The Lancet Oncology, says the research team was surprised by these strong findings. "Previous studies have suggested a relationship between prostate cancer progression and being overweight," he says. "This study strongly confirms those earlier findings and in fact points to a leading culprit which appears to be an excess secretion of insulin in these patients." Excess production of insulin - or hyperinsulinemia - is one of the many metabolic changes that occur in overweight and obese people.
Heather Chappell, Senior Manager of Cancer Control Policy with the Canadian Cancer Society says: "This study emphasizes the value of reaching out to the Canadian public about the importance of maintaining a healthy body weight. We need to work to identify barriers that keep Canadians from eating as well as possible, and being as physically active as possible. It appears that having a healthy body weight can help you survive a prostate cancer diagnosis in the future."
"Being healthy is not simply up to the individual," she says. "In addition, we need healthy public policies that will help Canadians to make easy, affordable and healthy choices."
"Men living in affluent societies are facing two epidemics - obesity and prostate cancer," says Dr. Pollak of McGill University. "This research provides further impetus for men to avoid becoming overweight by improved physical activity and diet."
"Up until now, oncologists and researchers felt that the only hormones relevant to prostate cancer were the male hormones known as androgens. These results suggest that the insulin family may also be involved in the disease," he says.
The study looked at 2,546 men diagnosed with prostate cancer during a long-term follow-up sub-study - part of the Physicians Health Study involving more than 22,000 doctors.
This research was co-funded by the Canadian Cancer Society and the U.S. National Institutes of Health.
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