Magnetic Resonance Imaging as a Predictor of Early Discontinuation of Active Surveillance in Patients with Prostate...

Active surveillance (AS) is a well-established strategy for managing prostate cancer (PCa); however, available evidence indicates that approximately 28% of patients may experience progression within the first 5 years. Magnetic resonance imaging (MRI) may help optimize patient selection. This study assessed whether the presence of focal lesions (prostate imaging reporting and data system (PI-RADS) ≥ 3) on baseline MRI is associated with an increased risk of histological progression and AS discontinuation.

We conducted a retrospective study of consecutive patients enrolled in AS at a comprehensive cancer center since 2012, recorded in the Urodata platform, based on a prospectively maintained cohort and including patients meeting European Association of Urology (EAU) criteria for low- or favorable intermediate-risk PCa. Inclusion criteria were diagnostic and confirmatory transperineal biopsies performed with the institution's standard technique, available baseline MRI, and a minimum follow-up of one year. Patients with prior treatment were excluded. Histological progression was defined as an increase in Gleason grade group on follow-up biopsy compared with baseline. Progression at 5 years was evaluated using Kaplan-Meier curves and multivariable Cox proportional hazards models. Patients with PI-RADS ≥ 3 were classified as visible lesions on MRI (MRI+), and those with PI-RADS <3 as no visible lesions on MRI (MRI-).

A total of 105 patients were included, with a median age of 64 years (interquartile range (IQR) 59-70) and a median prostate-specific antigen (PSA) of 5.8 ng/mL (IQR 4.7-8.9). The median interval between initial and confirmatory biopsy was 24 months, and median follow-up was 6 years. Seventy-one patients were classified as MRI+. Baseline characteristics were similar between groups. Five-year progression-free survival was 41% in MRI+ versus 77% in MRI- groups (hazard ratios (HR) 5.5; 95% confidence interval (CI) 2.3-13). Only 28% of patients with PI-RADS 5 remained free of progression at 5 years. Baseline PSA >6 ng/mL and PSA density >0.2 were independently associated with histological progression.

The presence of PI-RADS ≥ 3 lesions on baseline MRI is significantly associated with an increased risk of histological progression and AS discontinuation. MRI may be a key tool for optimizing candidate selection for AS.