Men's Health: Lose weight to improve prostate cancer survival odds

Here's some advice for obese men diagnosed with prostate cancer: Lose some weight -- your life could depend on it.

That's the message from researchers who found that obese men diagnosed with prostate cancer are more than twice as likely to die from the disease as their normal-weight counterparts.

The findings provide "the first good piece of evidence" that losing weight may reduce the risk of dying of prostate cancer, the study authors say. Until now, little had been known about whether lifestyle changes could affect survival after diagnosis and treatment.

"What was unclear was whether obesity increased the risk that you develop a bad form of prostate cancer or whether obesity increased the risk that after you were treated you would die of prostate cancer," says Alan Kristal, a study investigator and associate head of cancer prevention at the Fred Hutchinson Cancer Research Center in Seattle.

He and his colleagues followed 752 middle-aged men in the Seattle area who recently had been diagnosed with prostate cancer. Seventeen per cent of the men were classified as obese.

Over the next 10 years, obese men were 2.6 times more likely to die of prostate cancer, regardless of the type of treatment or the seriousness of the disease when it was diagnosed.

Among those men whose cancer was initially confined to the prostate, obesity was associated with 3.6-fold increased risk of the disease spreading to other parts of the body.

Kristal says the mechanism behind the link between obesity and death from prostate cancer is probably related to sex hormones, which can promote the growth of the tumour. "Obesity profoundly affects hormone levels in men, particularly estrogen levels. It increases them substantially."