Comparison of Localized High Volume Tumor and Locally Advanced Low Volume Tumor after Radical Prostatectomy According to Risk Classification

Abstract

Purpose: To investigate the relevance of the pathologic tumor volume (PTV) among patients who underwent radical prostatectomy (RP).

Materials and Methods: We reviewed 3080 patients who underwent RP between September 2003 and March 2015 and with a postoperative follow up for more than 1 year. The patient population was stratified into 4 disease risk groups according to tumor stage and PTV (T2 low volume -T2LV, T2 high volume – T2HV, T3 low volume – T3LV and T3 high volume – T3HV). Probability of biochemical recurrence (BCR)-free survival was determined using Kaplan-Meier curves. PTV was evaluated by Multivariate Cox proportional hazard analysis for predicting BCR. Subgroup analyses were performed according to preoperative risk.

Results: The median PSA was 7.87ng/ml, and PTV was 10%. Among a total of 2964 patients, T2LV had 1473(49%), T2HV was 598(20%), T3LV with 199(6%), and T3HV was 694(23%). When comparing T2HV and T3LV, Gleason score and positive surgical margin rate was higher in T3LV. During a 50 months follow-up, BCR free survival rate was higher in the T2HV group (p < 0.001). PTV was a significant factor to predict BCR in multivariate Cox analysis. In subgroup analyses, T2HV group had similar BCR free survival rates to T3LV group in the preoperative high risk group while PTV was significant in the high risk group.

Conclusion: PTV was a significant predictor of BCR among prostate cancer patients after RP, however T2HV had favorable BCR results. Among patients with a preoperative high PSA and Gleason score, T2HV had similar BCR results to T3LV.