PI-RADS v2 is a Strong Prognostic Marker for Adverse Outcomes in Prostate Cancer

ImportanceMagnetic Resonance Imaging (MRI) coupled with Prostate Imaging-Reporting and Data System (PI-RADS) provides a standardized scoring system for assessing the clinical significance of prostate cancer (PCa). The association between PI-RADS scores and key clinical end-points remains underexplored due to limited follow-up data. ObjectiveTo evaluate the association of PI-RADS with prostate cancer-specific mortality (PCSM), overall survival (OS), metastasis-free survival (MFS), and biochemical recurrence (BCR) across three cohorts. Design, Setting, ParticipantsA retrospective registry cohort, Helsinki University Hospital (HUS) for men with clinical suspicion of PCa, included 4,674 men who underwent diagnostic MRI during the PI-RADS version-2 era (2015-2019, median follow-up [mFU] 5.0 years). Validation cohorts were: Tampere University Hospital (n=1,474, 2016-2021, mFU 2.2 years) and Lille University Hospital (N=301, 2016-2024, mFU 6.2 years). ExposuresDiagnostic MRI imaging was scored using PI-RADS v2. Main outcomes and measuresPrimary outcomes were PCSM, OS, MFS, and BCR. Secondary measures included clinical confounders, such as age, Grade Group (GG), and Charlsons Comorbidity Index (CCI). Results84 of 4,674 HUS-cohort patients (1.7%) died of PCa, with 79 patients (94%) presenting with PI-RADS score 5. Multivariable Cox regression adjusted for clinical confounders found PI-RADS score 5 was significantly associated with PCSM (Hazard Ratio (HR) 18.4, 95% CI [6.62-51.1], p<0.001), along with biopsy GG 5 (HR 5.45 [1.82-16.3], p=0.002), CCI (HR 1.53 [1.42-1.7], p<0.001), and log2-PSA (HR 1.28 [1.11-1.5], p<0.001). Kaplan-Meier curves demonstrated negligible PCSM after negative MRI (nMRI; PI-RADS score 0-2) (log-rank p<0.001). PI-RADS score 5 was associated with OS in the Helsinki and Tampere cohorts (p<0.001) and MFS and BCR in the Lille cohort (p<0.001). Conclusion and relevancePI-RADS score 5 is strongly associated with an increased risk of PCSM and other clinically relevant outcomes. A non-suspicious MRI associates with a negligible risk of adverse outcomes. These findings support the use of MRI for risk stratification in PCa.