Gleason grade accuracy of transperineal and transrectal prostate biopsies in MRI-naïve patients.

Abstract

Accurate assessment of Gleason grade is essential to guiding prostate cancer management. Not all healthcare systems have universal access to prostate MRI. We investigated whether transperineal (TP) prostate biopsies provide more accurate Gleason grading than transrectal (TR) biopsies in MRI-naïve patients. Consecutive patients undergoing TP and TR systematic prostate needle biopsies from 2011 to 2018 were analysed. Patients who underwent radical prostatectomy (RP) within 180 days of biopsies were included. Patients undergoing MRI prior to biopsies were excluded. Pathological concordance, incidence of Gleason upgrading, and correlation coefficients among biopsies and RP Gleason grade were compared. A sub-analysis for concordance in anterior prostate tumours was conducted. 262 patients were included (112 TP; 150 TR), the median age was 63 years, and median time from biopsy to RP was 68 days. Concordance with RP histology for TP was 65% compared to 49% for TR (p = 0.011). Biopsy technique predicted RP concordance independent of the number of cores. Gleason upgrading occurred following 24% of TP versus 33% of TR biopsies. In anterior and apical tumours, upgrading occurred in 19% of TP biopsies and 38% of TR biopsies (p = 0.027). This study suggests TP approach to prostate biopsies result in improved histological grade accuracy in men whom MRI is not available, even after controlling for number of cores. TP approach also resulted in less upgrading for lesions in the anterior and apical prostate compared to TR.