Objective: To evaluate whether specific preoperative variables might better predict the concordance between biopsy and radical prostatectomy (RP) Gleason grade, and to assess the effect of the biopsy Gleason score (bGS) when controlling for the pathological GS (pGS) on clinical outcomes in patients undergoing RP.
Patients and methods: Between 1989 and 1998, 1088 men had RP at our institution, with a median follow-up of 56 months. To evaluate the independent effect of bGS within categories of pGS, we stratified the sample by pGS (three categories; <or=6, 7, 8-10). Within each stratum we constructed Kaplan-Meier plots of recurrence-free survival by bGS (in the same three categories), assessing the significance of the differences among the three curves by the log-rank test.
Results: Overall, only 41.1% of patients had exactly concordant findings between bGS and pGS; concordance rates did not differ significantly when stratified by preoperative variables. On multivariate analysis, a change in the pGS compared with the bGS had a significant, independent effect on recurrence rates, specifically a 15% change in risk for a one-unit change in GS (P = 0.021).
Conclusions: There was only modest agreement between the bGS and the pGS; the bGS continued to have independent prognostic influence after RP and assignment of the pGS.