Obesity boosts prostate cancer mortality

Obese men diagnosed with prostate cancer are more than twice as likely to die of the disease than their leaner peers, a new study shows.

They also have more than triple the risk that the cancer will spread beyond their prostate gland, Dr. Alan R. Kristal of Fred Hutchinson Cancer Research Center in Seattle and colleagues found.

"These results provide yet one more important reason for men to adopt healthful patterns of diet and physical activity to achieve and maintain a normal weight," Kristal and his team conclude in the medical journal Cancer.

A number of studies have linked excess weight with more advanced prostate cancer, Kristal and his team note, but evidence for the effect of obesity on actual outcome from the disease has been unclear. To investigate, they looked at 752 men who had been diagnosed with prostate cancer between 1993 and 1996 and followed for an average of 9.5 years.

Men who were obese in the year before they were diagnosed with prostate cancer, meaning their body mass index (BMI) was 30 or higher, were 2.6 times more likely to have died of the disease, the researchers found. They were also at 3.6 times greater risk of disease metastasis.

The data also suggested that the effect of obesity on mortality risk was stronger among men with more aggressive disease.

A clinical trial would be needed to determine if weight loss could actually help treat prostate cancer, Kristal and colleagues add.