MONDAY, March 19 (HealthDay News) — Men who are obese when they’re diagnosed with prostate cancer are 2.6 times more likely to die of the disease than normal-weight men, new findings suggest.

The study, by researchers at the Fred Hutchinson Cancer Research Center in Seattle, included 752 recently diagnosed prostate cancer patients who were followed for about 10 years. Of the men in the study, 50 died of prostate cancer, and 64 died of other causes.

“I was very surprised by the findings. We found the prostate-cancer-specific mortality risk associated with obesity was similar regardless of treatment, disease grade or disease stage at the time of diagnosis,” senior author Alan Kristal, associate head of the Cancer Prevention Program in Hutchinson’s Public Health Sciences Division, said in a prepared statement.

“If a man is obese at the time of diagnosis, he faces a 2.6-fold greater risk of dying as compared to a normal-weight man with the same diagnostic profile, regardless of whether he has radical prostatectomy or radiation therapy, whether or not he gets androgen-deprivation therapy, whether he has low- or high-grade disease, and whether he has localized, regional or distant disease,” Kristal said.

The study also found that obese men with local or regional prostate cancer — disease that’s confined to the prostate or has spread to surrounding tissue — are 3.6 times more likely than normal-weight men to have their cancer spread to distant organs (metastatis).

It’s believed that both inflammation and steroid hormones are factors in the link between obesity and increased risk of prostate cancer metastasis and death, the researchers said.

“We are now beginning to appreciate that obesity is a massive inflammatory condition, and obesity also increases levels of serum estrogens and growth factors that can promote cancer growth,” Kristal said.

The study is published in the March 15 issue of Cancer magazine.