The impact of excess weight on prostate cancer has been studied extensively without consistent findings. Now, a prospective study in the February 15 Cancer shows clearly that obese men are more likely to die from prostate cancer than men of normal weight, though no more likely to actually develop the disease.

Dr. Margaret E. Wright from NCI's Division of Cancer Epidemiology and Genetics (DCEG) and colleagues said their finding confirms earlier reports of an obesity-prostate cancer mortality link, but is the first to show that weight gain after age 18 also increases the risk of dying from prostate cancer.

"This is a large study that shows a convincing dose-response association between obesity and adult weight gain and death from prostate cancer," said Dr. Wright. Nearly 287,000 male AARP members aged 50 to 71 years self-reported their height and weight at enrollment into the NIH-AARP Diet and Health Study, begun in 1995. During the next 5 to 6 years, 9,986 developed prostate cancer and 173 died of the disease.

Compared with men with a body-mass index (BMI) of less than 25 kg/m2, those who were overweight (BMI 25-29.9) had a 25 percent increased risk of death, mildly obese men (BMI 30-34.9) had a 46 percent higher risk, and severely obese men (BMI greater than 35) doubled their risk.

"The growing prevalence of obesity in Western countries is alarming, and reducing the risk of prostate cancer death is only one among many health reasons to maintain a healthy weight through diet and exercise," said Dr. Wright.