Does Body Mass Index Affect Preoperative Prostate Specific Antigen Velocity or Pathological Outcomes After Radical Prostatectomy?

Purpose: Several studies suggest that obesity may be associated with more aggressive prostate cancer. Similarly the rate of serum prostate specific antigen change is associated with adverse tumor features and prostate cancer specific mortality rates after radical prostatectomy and radiation therapy. We examined the associations among obesity, prostate specific antigen velocity and adverse tumor features in men treated with radical prostatectomy. Materials and Methods: A total of 587 men with documented preoperative height and weight measurements underwent radical prostatectomy. Prostate specific antigen velocity and other clinicopathological features were compared among men with a body mass index of less than 25, 25 to 29.9 and 30 or greater. Results: Although Gleason score and prostate volume were similar among groups, there was a significantly lower proportion with organ confined disease and fewer low volume tumors as body mass index increased. Of patients with a body mass index of 30 or greater 52% had a preoperative prostate specific antigen velocity of more than 2 ng/ml yearly compared to 34% with a body mass index of 25 to 29.9 and 26% with a body mass index of less than 25 (p = 0.04). Although on univariate analysis body mass index was associated with adverse clinical and pathological tumor features, on multivariate analysis with other preoperative variables body mass index did not add significant independent predictive information concerning pathological stage (OR 1.02, 95% CI 0.96-1.08). Conclusions: Obesity was significantly associated with several adverse pathological features. However, it did not provide independent predictive information concerning final pathological tumor stage. Nevertheless, obesity was significantly associated with increased preoperative prostate specific antigen velocity. Additional studies are needed to further clarify the links between body mass index, prostate specific antigen velocity and prostate cancer progression, and determine whether weight reduction could lead to improved outcomes.