Prebiopsy Biparametric Magnetic Resonance Imaging Combined with Prostate-specific Antigen Density in Detecting and Ruling out Gleason 7-10 Prostate Cancer in Biopsy-naive Men

Background: Multiparametric magnetic resonance imaging (MRI) combined with prostate-specific-antigen density (PSAd) enhances the detection of significant prostate cancer (sPCa). However, it is unclear whether simple biparametric (bp) MRI, which reduces scan sequences, time, and cost, may be an equally effective noninvasive tool for detecting and ruling out sPCa and avoiding biopsies in biopsy-naive men. Objective: To assess the diagnostic accuracy, predictive values, and best biopsy strategy combining bpMRI and PSAd in detecting and ruling out sPCa (Gleason score >= 7). Design, setting, and participants: Assessment of 808 biopsy-naive men with clinical suspicion of localised PCa (prostate-specific antigen <20 ng/ml, rectal examination = 4) or PSAd >= 0.15 ng/ml/cc. This reduced the number of men requiring biopsies by 41% (329/808) and overdiagnosis of insignificant cancers by 45% (79/177), while missing only 5% (17/329) of men with sPCa. Study limitations included single-centre analysis and combined biopsies as the reference standard. Conclusions: Combination of bpMRI with PSAd improves diagnostic accuracy and predictive values for sPCa detection in biopsy-naive men. Restricting biopsies to men with highly suspicious bpMRI findings (score >= 4) or PSAd >= 0.15 ng/ml/cc was the best biopsy strategy in our patient cohort, effectively balancing risks and benefits. Studies are needed to validate our findings in other patient populations. Patient summary: This report shows that biopsy-naive men with clinical suspicion of prostate cancer who have low- or equivocal-suspicion biparametric magnetic resonance imaging results and a low prostate-specific antigen density may not require immediate prostate biopsies. (C) 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved.