Prostate zonal impact of 5α-reductase inhibitors on multiparametric MRI characteristics and detection of prostate cancer.

Abstract

To assess the impact of 5α-reductase inhibitors (5-ARIs) on multiparametric magnetic resonance imaging (mpMRI) features of Prostate Imaging-Reporting and Data System (PI-RADS) lesions and their influence on the detection of clinically significant prostate cancer (csPCa), with a focus on differences between prostate zones. We retrospectively reviewed data from 1108 PI-RADS version 2 score 3-5 lesions in 718 patients across a multi-institutional cohort, all of whom underwent magnetic resonance imaging (MRI)-targeted biopsy. A subset of 66 lesions from patients receiving 5-ARI therapy was matched to lesions from untreated patients and independently reviewed by an experienced radiologist in a blinded fashion. Apparent diffusion coefficient (ADC) values were quantified for each lesion and for peripheral and transition zones. Among the 1108 lesions, 90 (8%) were in patients on 5-ARI therapy for ≥3 months prior to mpMRI. Multivariable analysis demonstrated that 5-ARI use was associated with significantly reduced odds of detecting csPCa on targeted biopsy (odds ratio [OR] 0.32, 95% confidence interval [CI] 0.18-0.57). Stratified analysis revealed a pronounced reduction in csPCa detection in peripheral zone lesions (OR 0.20, 95% CI 0.05-0.68), but not in transition zone lesions (OR 0.38, 95% CI 0.11-1.18). Blinded radiological review showed higher mean ADC values in peripheral zone lesions among 5-ARI users (869 vs 765 mm²/s; P = 0.04) and lower lesion conspicuity (P = 0.027). There were no significant imaging differences in the transition zone. Treatment with 5-ARIs is associated with decreased detection of csPCa on MRI-targeted biopsy, especially for peripheral zone lesions. These effects may be attributable to increased ADC values and reduced lesion conspicuity, suggesting a potential increase in false-positive mpMRI findings in patients receiving 5-ARIs.