WASHINGTON, D.C.—Obesity is associated with a decreased risk of low-grade and increased risk of high-grade prostate cancer (PCa), according to study data presented at the American Urological Association 2011 annual meeting.
The study, by researchers at Duke University Medical Center in Durham, N.C., looked at 6,524 men enrolled in the four-year REDUCE (Reduction by Dutasteride of Prostate Cancer Events) study funded by GlaxoSmithKline, which tested dutasteride 0.5 mg daily for PCa risk reduction in men with a PSA level of 2.5-10 ng/mL and negative prostate biopsy. The men had at least one on-study prostate biopsy.
Overall, 1,762 men (27%) were normal weight (body mass index [BMI] below 25 kg/m2), 3,429 (53%) were overweight (BMI 25-29.9), and 1,333 (20%) were obese (BMI 30 or greater). After adjusting for age and prostate volume, both overweight and obesity were associated with lower PSA levels. Obesity was associated with a 21% decreased risk of low-grade PCa (Gleason score below 7) and a 28% increased risk of high-grade PCa (Gleason score of 7 or higher). The results were comparable for men on dutasteride or placebo.
The researchers, led by Stephen Freedland, MD, Associate Professor of Surgery (Urology) and Pathology in the Duke Prostate Center, concluded that the associations observed in the study cannot be explained simply by differential biopsy rates due to differences in PSA levels as all men had equal access to biopsies. Dr. Freedland suggested that these findings provide further support to a biological link between obesity and aggressive prostate cancer.