The effect of pathologic T-stage and Gleason score on cancer-specific survival for specimen-confined high-risk prostate cancer.

Abstract

114 Background: High-risk prostate cancer (HRPC) is a challenging disease and the role of surgery is often considered in the context of a multimodal approach. The indication for adjuvant therapy after surgery for HRPC patients who have specimen-confined disease (R0, pN0, <pT3b) is still difficult. The current study aims to analyze postoperative pathological features which help to predict CSS in specimen-confined HRPC and thus may aid in the decision to administer adjuvant EBRT or ADT. Methods: From a multi-institutional retrospective cohort of 5876 HRPC patients treated by radical prostatectomy and pelvic lymph node dissection, 1391 patients with specimen-confined disease were selected. Following surgery, adjuvant EBRT and/or ADT were delivered according to institutional protocols. Patients were subdivided into four groups according to pT stage (pT≥3 and pT<3) and final Gleason score (GS≥8 and GS<8). Kaplan-Meier plots with log-rank tests and a Cox proportional hazards model were applied to study CSS. All significance levels were set at 0.05. MedCalc was used for all statistical analyses. Results: Median age was 65 years (43-84). Of all patients, 346 (24.9%) had GS≥8 and 794 (57.1%) had pT≥3 at definitive histopathology. Patients were classified into COMBO groups: C1 (478; 34.4%; GS<8,pT<3), C2 (567; 40.8%; GS<8, pT≥3), C3 (119; 8.6%; GS≥8, pT<3), C4 (227; 16.3%; GS≥8, pT≥3). Adjuvant EBRT and ADT, respectively, were delivered in C1 2%/2%, C2 15%/22%, C3 3%/10%, C4 18%/25%. Kaplan Meier plots demonstrated statistically different 10-yr CSS between groups: C1 97.4%, C2 95.2%, C3 89.9% and C4 84.4% (p<0.0001). COMBO groups were also compared using a Cox model and results are shown in the Table. Conclusions: COMBO groups demonstrated to be able to subdivide specimen-confined HRPC into 4 demarcated groups with significantly different CSS. This subdivision could be considered an easy-to-use tool which can help for counseling patients for adjuvant treatment strategies. [Table: see text]