PSA and obesity among men with localized prostate cancer: results of the ANDROCAN study.

PURPOSE: PSA is known to be lowered in obese patients. There is a lack of data regarding patients with prostate cancer. Our objective was to prospectively assess the relationship PSA concentration, PSA mass and BMI in a cohort of patients with localized prostate cancer. METHODS: A prospective, multicenter cohort study was conducted including patients undergoing radical prostatectomy. Clinical and biological data were collected for each patient before surgery. RESULTS: A total of 1343 patients were analyzed. Mean age was 64.0 years. Mean weight was 82.2 kg and mean BMI was 26.8 kg/m2. Mean PSA concentration was 8.7 ng/mL and mean PSA mass 29.3 ng. On univariate analysis, an association was found between PSA mass and either BMI, weight and waist circumference. No association was found between PSA concentration and each weight parameters. On multivariate analysis, obesity was not an independent predictor of PSA concentration (p = 0.73). Independent predictors of PSA concentration were cardiovascular disease (negative association, p = 0.034), predominant Gleason 4 (positive association, p < 0.001) and pT3a (positive association, p < 0.001). BMI was an independent predictor of PSA mass (positive association, p = 0.009). PSA mass was negatively associated with TT (p = 0.015) and cardiovascular disease (p = 0.003), and positively associated with BT (p = 0.032), Gleason grade ≥ 4 + 3 (p < 0.001) and pT3a (p < 0.001). CONCLUSION: In this prospective study of patients with localized prostate cancer, higher BMI was associated with higher PSA mass but not with higher PSA concentration. Screening obese patients with a specific PSA method does not appear to be critical.