Gleason Grade Group Concordance between Systematic Template Combining Magnetic Resonance Imaging Fusion Targeted Biopsy and Radical Prostatectomy Specimens: A Comparison of Transperineal and Transrectal Approaches

Abstract

Objective: To evaluate the Gleason grade (GG) discrepancy between biopsy (Bx) techniques (transperineal [TP] /transrectal [TR] approaches or multiparametric magnetic resonance imaging [mpMRI] targeted biopsy [TBx] / standard template biopsies [SBx]) and radical prostatectomy (RP) specimens.

Patients and methods: We identified 310 prostate cancer (PCa) patients who underwent RP following either TP TBx combining SBx (20-core) (n = 105) or TR TBx combining SBx (12-core) (n = 205) from September 2019 to February 2021. The Bx GG was based on the core with the highest GG and clinically significant PCa (csPCa) was defined as grade group 2 or greater prostate adenocarcinoma.

Results: TP combined TBx and SBx (CBx) showed a better GG concordance (63.8% vs 57.1%) than the TR approach, but did not reach a statistical significance. TBx demonstrated a significantly higher csPCa detection than SBx in all patients including both approaches (70.2% vs 63.9%, P < .001). TR TBx showed a significantly higher concordance than TR SBx (52.2% vs 41.5%, P = .0.002) while TP TBx did not differ from TP SBx. TP CBx showed the highest Kappa coefficient (κ =0.48) followed by TR CBx (κ = 0.39). Thirty-eight of 69 (55.1%) cases with a GG1 diagnosis in CBx were upgraded to csPCa in RP. TR approach showed a trend of 2.8-fold risk to upgrade to RP csPCa than TP approach (P = .0.065).

Conclusion: The combination of SBx and TBx led to a better pathological concordance and lower upgrading rate for both TP and TR approaches to RP. With more SBx cores, TP CBx showed a better performance than TR CBx.