Purpose: The added value of nontargeted systematic prostate biopsies when performed alongside magnetic resonance imaging targeted biopsies in men referred with a suspicion of prostate cancer is unclear. We aimed to determine the clinical utility of transperineal nontargeted systematic prostate biopsies, when performed alongside targeted systematic prostate biopsies, using pre-biopsy multiparametric magnetic resonance imaging.
Materials and methods: Consecutive patients referred with a suspicion of prostate cancer (April 2017 to October 2019) underwent pre-biopsy multiparametric magnetic resonance imaging. A transperineal biopsy was advised if multiparametric magnetic resonance imaging PI-RADS® (v.2.0) score was 4 or 5, and score 3 required a prostate specific antigen density 0.12 ng/ml or greater. Primary threshold for clinically significant prostate cancer was defined as any Gleason 3+4 or greater. Multivariable logistic regression analysis identified pre-biopsy predictors of clinically significant prostate cancer in nontargeted systematic prostate biopsies, regardless of targeted pathology (p <0.05, R, version 3.5.1).
Results: A total of 1,719 men underwent a pre-biopsy multiparametric magnetic resonance imaging, with 679 (39.5%) proceeding to combined targeted systematic prostate biopsies and nontargeted systematic prostate biopsies. In these men clinically significant prostate cancer was detected in 333 (49%) and 139 (20.5%) with targeted systematic prostate biopsies and nontargeted systematic prostate biopsies, respectively. In those men with clinically significant prostate cancer in targeted systematic prostate biopsies, clinically significant prostate cancer was also present in nontargeted systematic prostate biopsies in 117 (17.2%); Gleason 3+3 was present in 50 (7.4%). In 287 men without any cancer in the targeted systematic prostate biopsies, 13 (1.9%) had clinically significant prostate cancer in nontargeted systematic prostate biopsies. In addition 18/679 (2.7%) had Gleason 3+3 disease and no Gleason greater than 4+3 was detected. Predictors associated with clinically significant prostate cancer in nontargeted systematic prostate biopsies were prostate specific antigen 5 ng/ml or greater (OR 2.05, 95% CI 1.13-3.73, p=0.02), PI-RADS score 5 (OR 2.26, 95% CI 1.51-3.38, p <0.001) and prostate volume less than 50 cc (OR 2.47, 95% CI 1.57-3.87, p <0.001).
Conclusions: Detection of clinically significant prostate cancer in exclusively nontargeted transperineal systematic biopsies in a pre-biopsy multiparametric magnetic resonance imaging pathway was low (1.9%).
Keywords: biopsy; early diagnosis; multiparametric magnetic resonance imaging; prostate; prostatic neoplasms.