Impact of magnetic resonance imaging-based diagnostic pathway on oncologic outcomes of localised prostate cancer between primary treatment modalities: a Will-Rogers phenomenon?

Background The MRI pathway (pre-biopsy MRI-targeted plus saturation biopsies, MRI-Bx) outperforms transrectal ultrasound systematic prostate biopsy (TRUS-Bx) in diagnosing clinically significant prostate cancer (csPCa). However, there is a dearth of data on how this paradigm shift influences biochemical recurrence (BCR)-free survival in patients after radical prostatectomy (RP) or radiotherapy (RT). We aim to evaluate BCR-free survival in the MRI-Bx era stratified by primary treatment modalities in a large contemporary cohort.Methods We retrospectively reviewed localised prostate cancer patients diagnosed by MRI-Bx or TRUS-Bx and treated with RP or RT between 2010 and 2021. Patients diagnosed and staged by PSMA-PET were excluded. BCR was defined as two successive prostatic specific antigen (PSA) > 0.2 ng/mL after RP or a rise of 2 ng/mL from PSA nadir after RT within 3 years. Kaplan-Meier (KM) analyses and multivariable Cox proportional hazards regression were performed for BCR-free survival.Results A total of 1674 men included (1061 RP, 613 RT; 1075 TRUS-Bx, 599 MRI-Bx; median follow-up 38 months). Across all risk group, MRI-Bx yielded higher BCR-free survival at all timepoints in RP patients, especially in high-risk disease (3-year: 85% vs. 71%). In RT patients, MRI-Bx yielded no significant difference across all timepoints. On multivariable regression, MRI-Bx approach independently predicted BCR in RP patients (hazard ratio (HR) 0.60, 95% CI 0.40-0.90, p = 0.013) but not in RT patients (HR 0.94, 95% CI 0.31-3.85, p = 0.945) after adjusting for age, PSA, clinical T stage, Gleason grade group, adjuvant ADT and EAU risk groups. In terms of GG concordance after RP, MRI-Bx demonstrated decreased GG upgrading than TRUS-Bx group (23.1% vs. 27.4%) but increased GG downgrading (20.6% vs. 14.4%), which was statistically significant (p = 0.025).Conclusions Patients managed via the MRI pathway exhibited improved BCR-free survival following RP, reflecting a risk migration consistent with the Will-Rogers phenomenon. This survival advantage was attenuated in the RT cohort, potentially due to difference in BCR definition and adjuvant ADT use. The risk reclassification in the RP cohort after MRI pathway adoption underscores the necessity of new risk models integrating quantitative MRI parameters to better select patients for surgery. Longer follow-up is required to determine the impact on overall and cancer-specific survival.