Background: Studies suggest obesity is associated with lower risk of prostate cancer (PC) but more aggressive cancers.
As obesity lowers PSA levels, these observations may be influenced by detection bias. We examined the association between obesity and risk of low- and high-grade PC in REDUCE, where biopsies were largely independent of PSA.
Methods: The REDUCE study tested dutasteride for PC risk reduction in men with a PSA of 2.5-10.0 ng/mL and a negative biopsy. Study participants included 6,729 men who underwent at least one on-study biopsy. The association between baseline body mass index (BMI < 25 kg/m2-normal weight; 25-29.9 kg/m2-overweight; ≥30 kg/m2-obese) and risk of high-grade (Gleason >7) or low-grade PC (Gleason < 7) vs. no PC was examined using multinomial logistic regression.
Results: Overall, 1,739 men (27%) were normal weight, 3,384 (53%) overweight, and 1,304 (20%) were obese. Obesity was associated with lower risk of low-grade PC in both univariable (OR 0.74, p=0.001) and multivariable analyses (OR 0.79, p=0.01). In univariable analysis, obesity was not associated with high-grade PC (OR 1.08, p=0.50). However, in multivariable analysis, obesity was associated with increased risk of high-grade PC (OR 1.28, p=0.042). The current analysis was not able to address how obesity may influence prostate cancer progression.
Conclusions: Obesity is associated with decreased risk of low-grade and increased risk of high-grade PC. These data provide further support to the hypothesis that obesity is associated with aggressive PC.
Impact: Obesity is linked with aggressive PC. Avoiding obesity may prevent the risk of developing high-grade PC.
Vidal AC, Howard LE, Moreira DM, Castro-Santamaria R, Andriole GL Jr, Freedland SJ. Are you the author?
Surgery, Duke University; Department of Biostatistics and Bioinformatics, Duke University School of Medicine; Urology, The Author Smith Institute for Urology; GlaxoSmithKline; Division of Urology, Washington University School of Medicine; Division of Urology, Department of Surgery, Duke University School of Medicine.
Reference: Cancer Epidemiol Biomarkers Prev. 2014 Sep 27. pii: cebp.0795.2014.