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

Kim, Tae Jin; Lee, In Jae; Song, Byeong Do; Lee, Sang Chul; Hong, Sung Kyu; Byun, Seok Soo; Lee, Sang Eun; Oh, Jong Jin

Abstract

PURPOSE
To investigate the percentage of pathologic tumor volume (pTPV) among patients who underwent radical prostatectomy (RP).
MATERIALS AND METHODS
We reviewed 3,080 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 pTPV (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. pTPV was evaluated by Multivariate Cox proportional hazard analysis for predicting BCR. Subgroup analyses were performed according to preoperative risk.
RESULTS
The median prostate-specific antigen (PSA) was 7.87 ng/mL, and pTPV was 10%. Among a total of 2,964 patients, T2LV had 1,473 (49.7%), T2HV was 598 (20.2%), T3LV with 199 (6.7%), and T3HV was 694 (23.4%). When comparing T2HV and T3LV, Gleason score and positive surgical margin rate was higher in T3LV. During a 50-month follow-up, BCR-free survival rate was higher in the T2HV group (p<0.001). pTPV 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 pTPV was significant in the high risk group.
CONCLUSIONS
pTPV 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.