Abstract Quantification of biopsy Gleason pattern (GP) 4 contributes to risk assessment and supports clinical decision-making in Grade Group 2 (GG2) prostate cancer (PCa) patients. The optimal methodology for assessment of GP4 quantity is yet unclear. The objective of this study is to compare the mutual relation and performance of biopsy GP4 quantification methods to predict biochemical recurrence-free survival (BCRFS) after radical prostatectomy (RP). Ninety-four patients with biopsy GG2 PCa who underwent RP were included. We recorded overall GP4 percentage and cumulative GP4 length (mm) across all cores, as well as the maximum percentage and length within a single core. Quantification methods were compared using Spearman’s rank correlation and Cox proportional hazard regression for BCRFS. All biopsy GP4 quantification methods were mutually correlated (rho coefficients varying from 0.655 to 0.935; P 0.5) for predicting BCRFS once absolute GP4 length was known. Absolute GP4 length (mm) in biopsy GG2 PCa patients has better predictive value for post-operative BCRFS than GP4 percentage. GP3 volume does not add to prediction once GP4 volume is known.
Belisario et al. (Sat,) studied this question.