Background: Obesity is frequently linked with tumors of the kidney, breast, colon, endometrium, and prostate cancer (PCa). However, data regarding the mechanism by which obesity is related to the prognosis of PCa are still controversial.

Aim: The purpose of this study was to examine a possible correlation between obesity and biochemical recurrence (BCR) in patients treated with Radical Prostatectomy (RP) for localized prostate cancer.

Patiens and Methods: From 2005 to 2014, 259 patients underwent RP and had BMI data available were enclosed in this study retrospectively. Patients were categorized with BMI into three groups: obese (BMI ≥ 30 kg/m2), overweight (BMI 25 to 30 kg/m2), and normal weight (BMI ≤ 25 kg/m2). Patients with a surgical treatment of prostatic disease, neoadjuvant therapy, positive surgical margin status after RP or incomplete clinical data were excluded from study. We tested the effect of BMI on the rate of pathological Gleason Score (GS), extracapsular extension (ECE), seminal vesicle invasion (SVI) and lymph node invasion (LNI) in univariate and multivariate analysis.

Results: Obese men were older at the time of the surgery, had significantly higher grade disease (p <0.002) and had higher stage disease, as 27.1% of obese men had pT3 disease compared with 10.2% normal weight men and 17.4% overweight men. Overall, the mean follow-up time was 52 months (range 12-98), during which 26.6% of patients developed BCR of disease. On multivariate analysis for identifying significant predictors of BCR, which included pathological variables (GS, ECE, SVI and LNI) preoperative serum PSA level (p <0.001), GS (p = 0.032) and BMI (p < 0.002) were found to be independent predictors of BCR.

Conclusions: Obese patients with localized PCa had worse pathologic outcomes, and had a greater predicted risk of BCR after RP compared with normal weight patients.