The studies found that for men diagnosed with prostate cancer, those who were obese were more likely to have an increased risk that the cancer was aggressive and likely to recur after surgery, the New York Times reported.

In the United States the disease tends to occur more in black men than in whites and is more aggressive and twice as likely to be fatal.

The two studies, conducted by the Naval Medical Center in San Diego, indicated blacks had higher rates of obesity than whites, and the researchers said that might explain the increased severity of prostate disease for blacks.

The two studies, published online and scheduled for the Feb. 1 issue of The Journal of Clinical Oncology, are the first to examine obesity's relation to the recurrence of prostate cancer after surgery.

"The message is probably more important in men who haven't yet developed prostate cancer," said Dr. Christopher L. Amling, author of both studies and an assistant professor in the urology department at the Naval Medical Center in San Diego.