Primary Gleason pattern in biopsy Gleason score 7 is predictive of adverse histopathological features and biochemical failure following radical prostatectomy

Abstract

Objective. The aim of this study was to analyse whether primary Gleason pattern in biopsy Gleason score (GS) 7 predicted adverse histopathological features and had an impact on the risk of biochemical failure in a consecutive series of patients undergoing radical prostatectomy (RP). Material and methods. Between 2006 and 2010, 441 patients with biopsy GS 7 underwent RP at Rigshospitalet, Copenhagen, Denmark. Favourable histopathological features were defined as pT2 margin-negative cancer, RP specimen GS ≤ 3+4 and no lymph-node metastasis. Adverse histopathological features were defined as advanced pT3/4 cancer or pT2 margin-positive cancer and/or RP specimen GS ≥ 4+3 and/or positive lymph nodes. Biochemical failure was defined as the first prostate-specific antigen (PSA) ≥ 0.2 ng/ml. Results. A total of 344 patients (78.0%) had GS 3+4 in biopsies, while 97 patients (22.0%) had GS 4+3. No difference in age, PSA, percentage of biopsies with cancer, clinical tumour stage or volume on transrectal ultrasonography was found. Primary Gleason pattern 4 was associated with worse pathological stage (p = 0.049). On multivariate analysis, primary Gleason pattern 4 (p < 0.0001), cT stage (p = 0.024), PSA (p < 0.0001) and age (p = 0.009) predicted adverse histopathological features. In univariate analysis, Gleason score 3+4 had a significantly lower biochemical failure rate compared with Gleason score 4+3 (p = 0.0035). PSA (p < 0.0001), primary Gleason pattern 4 (p = 0.001) and percentage of biopsies with cancer (p = 0.02) were independently associated with risk of biochemical failure. Conclusions. In biopsies with GS 7, a primary Gleason pattern 4 was associated with significantly elevated risk of adverse histopathological features and biochemical failure compared to pattern 3 in patients undergoing RP. This study underlines the heterogeneity of biopsy GS 7.