Associations of adiponectin and leptin with stage and grade of PSA-detected prostate cancer: The ProtecT study

Purpose: Obesity has been associated with an increased risk of advanced and fatal prostate cancer; adipokines may mediate this association. We examined associations of the adipokines leptin and adiponectin with the stage and grade of PSA-detected prostate cancer. Methods: We conducted a nested case-control study comparing 311 men with mainly locally advanced (≥T3, N1, or M1 cases) vs. 413 men with localized (T ≤2 & NX-0 & M0 controls) PSA-detected prostate cancer, recruited 2001-2009 from 9 UK regions to the ProtecT study. Associations of body mass index and adipokine levels with prostate cancer stage were determined by conditional logistic regression and with grade (Gleason score ≥7 vs. ≤6) by unconditional logistic regression. Results: Adiponectin was inversely associated with prostate cancer stage in overweight and obese men (OR 0.62; 95 % CI 0.42-0.90; p = 0.01), but not in normal weight men (OR 1.48; 0.77-2.82; p = 0.24) (p for interaction 0.007), or all men (OR 0.86; 0.66-1.11; p = 0.24). There was no compelling evidence of associations between leptin or leptin to adiponectin ratio and prostate cancer stage. No strong associations of adiponectin, leptin, or leptin:adiponectin ratio with grade were seen. Conclusions: This study provides some evidence that adiponectin levels may be associated with prostate cancer stage, dependent on the degree of adiposity of the man. Our results are consistent with adiponectin countering the adverse effects of obesity on prostate cancer progression.