Factors predicting Gleason score 6 upgrading after radical prostatectomy

OBJECTIVES Prostate cancer Gleason score 6 is the most common score detected on prostatic biopsy. We analyzed the clinical parameters that predict the likelihood of Gleason score upgrading after radical prostatectomy. METHODS The study population consisted of 241 patients who underwent radical retropubic prostatectomy between Feb 2002 and Dec 2007 for Gleason score 6 adenocarcinoma. The influence of preoperative parameters on the probability of a Gleason score upgrading after surgery was evaluated using multivariate logistic regression and ROC curves. RESULTS Gleason score upgrade was found in 92 of 241 patients (38.2%). Multivariate logistic regression analysis showed that only percentage of cancer in dominant lobe and prostate weight were significant predictors for Gleason score upgrading (p = 0.043 and p = 0.006, respectively). ROC curves showed that prostate weight and PSA density were only two independent significant parameters for prediction of upgrade (AUC - 0.634, p <0.0001 and 0.604, p = 0.006, respectively). Gleason score upgrading was observed to be accompanied by significantly higher rates of extra prostatic extension (p <0.001) and seminal vesicle invasion (p = 0.002). CONCLUSIONS Almost forty percent of tumors graded Gleason 6 at biopsy are Gleason 7 at surgery. Upgraded tumors significantly associated with adverse pathological features. The probability of Gleason score upgrade can be predicted using prostate weight and PSA density as independent parameters.