Prostate-Specific Antigen Density as a Powerful Predictor of Extracapsular Extension and Positive Surgical Margin in Radical Prostatectomy Patients with Prostate-Specific Antigen Levels of Less than 10 ng/ml

ABSTRACT

PURPOSE: To assess the ability of preoperative variables to predict extracapsular extension (ECE) and positive surgical margin (PSM) in radical prostatectomy patients with prostate-specific antigen (PSA) levels of less than 10 ng/ml. MATERIALS AND METHODS: From January 2008 to December 2009, 121 patients with prostate cancer with PSA levels lower than 10 ng/ml who underwent radical prostatectomy were enrolled in the study. The differences in clinical factors (age, PSA, PSA density [PSAD], digital rectal examination [DRE] positivity, positive magnetic resonance imaging [MRI], Gleason sum, positive core number, and positive biopsy core percentage) with ECE and the presence of positive margins were determined and their independent predictive significances were analyzed. RESULTS: The ECE-positive patients had higher PSA, PSAD, and MRI-positive percentages, and PSM patients had higher PSA, PSAD, MRI-positive percentages, Gleason sum, and positive biopsy core percentages for prostate cancer. In the multivariate analysis, PSAD and MRI positivity were the best independent predictors for ECE, and PSA and PSAD were the best independent predictors of PSM. By receiver operating characteristic curve analysis, PSAD had better discriminative area under the curve value than did PSA for ECE (0.765 vs 0.661) and PSM (0.780 vs 0.624). The best predictive PSAD value was 0.29 ng/ml/cc for ECE and 0.27 ng/ml/cc for PSM. CONCLUSIONS: PSAD has relevance to ECE (plus MRI findings) and PSM (plus PSA). PSAD might be a powerful predictor of ECE and PSM preoperatively in patients undergoing a radical prostatectomy with PSA levels of less than 10 ng/ml.