PI-RADS v2 and Adverse Prostate Cancer Outcomes: A Cross-cohort Replication Study Across Three Centers

Magnetic resonance imaging (MRI) coupled with Prostate Imaging-Reporting and Data System (PI-RADS) provides standardization for assessing the clinical significance of prostate cancer (PCa). The association between PI-RADS and clinical endpoints has remained underexplored due to limited follow-up data.

Association of PI-RADS with prostate cancer-specific mortality (PCSM), overall survival (OS), metastasis-free survival (MFS), and biochemical recurrence (BCR) was investigated across three retrospective cohorts focusing on the PI-RADS v2 era. The Helsinki University Hospital included 4674 men with clinical suspicion of PCa (MRI during 2015-2019, median follow-up [mFU] 5.0 yr), Tampere University Hospital (N = 1159; 2016-2021, mFU 2.3 yr) with men diagnosed with PCa, and Lille University Hospital (N = 301; 2016-2024, mFU 6.2 yr) with radical prostatectomy-treated men with PCa.

In Helsinki cohort, multivariable Cox regression found PI-RADS score 5 to be significantly associated with PCSM (hazard ratio 18.4, 95% confidence interval [6.62-51.1]), along with biopsy GG 5 (5.45 [1.82-16.3]), Charlson's Comorbidity Index (1.53 [1.42-1.7]), and prostate-specific antigen (1.28 [1.11-1.5]). PI-RADS score 5 associated with OS in the Helsinki and Tampere cohorts, and MFS and BCR in the Lille cohort. Main limitation of the work is that all data is retrospective.

PI-RADS score 5 is associated with elevated risk of adverse outcomes. The presented clinically strong endpoints have potential to affect decision-making in MRI-based PCa diagnosis and prognosis.