Clinical impact of prostate biopsy undergrading in an academic and community setting

To evaluate whether the rate of Gleason score (GS) upgrade on final pathology, the rate of positive surgical margins (PSM) and the rate of biochemical recurrence (BCR) after radical prostatectomy (RP) were different if prostate biopsy (PB) was graded by community pathologists (CP) as compared to specialized uro-pathologists (UP).

A consecutive series of patients undergoing RP in our institution between 2005 and 2013 were retrospectively reviewed. Any GS higher or lower in RP specimen as compared to PB GS was defined as GS upgrade or downgrade, respectively. Additionally, stratification for the new ISUP 2014 grading system was performed. Predictors of GS upgrade and PSMs and prognostic parameters for BCR were assessed by stepwise logistic regression models and by multivariable Cox regression analyses, respectively.

A total of 786 patients were available for analysis, and median follow-up was 36 months (1-101 months). A GS upgrade was found in 345 patients (43.9 %) and a GS downgrade in 91 patients (11.6 %). Discordance between PB GS and RP GS was significantly more frequent when grading had been performed by a CP (50.5 % upgrade, 9.0 % downgrade) than by a UP (33.1 % upgrade, 15.7 % downgrade, p < 0.001). CP evaluation was an independent predictor for GS upgrade (odds ratio [OR] 1.91, p < 0.001) and for PSMs (OR 1.69, p = 0.003), as well as an independent predictor of BCR (hazard ratio [HR] 1.65, p = 0.028).

Pathologic evaluation of PBs by a dedicated UP should be recommended to reduce the rate of biopsy undergrading, PSM and BCR after RP.