EAU 2017: MRI as a follow up tool in active surveillance – results from an MRI-defined active surveillance cohort (387 men, median 5 year follow up)

London, England (UroToday.com) At this afternoon’s EAU 2017 Active Surveillance for Low-Risk Prostate Cancer poster session, Dr. Retter and colleagues from London, UK presented their research assessing the utilization of MRI in active surveillance (AS) algorithms. With improved MRI capabilities and a general increase in utilization of AS for low risk prostate cancer, studies evaluating when and how to use MRI in AS are very timely. The objective of this study was to report outcomes of a multiparametric MRI (mpMRI) based AS protocol at a single center of excellence.

The authors identified men with low- or intermediate-risk prostate cancer (n=387, 2004-2015) with inclusion criteria of Gleason score 3+3 or 3+4, PSA <20 ng/mL, and a baseline mpMRI. The biopsies were primarily performed via mpMRI-targeted or transperineal techniques when patients had any of the following: (i) MRI lesion discordant with original histology, (ii) progression on mpMRI, or (iii) change in clinical parameter(s). Among these men, 83% had Gleason 3+3 disease, while 17% had Gleason 3+4 disease. Importantly, 76% of men remained on AS at the time of analysis after a median follow-up time on AS of 5 years. Furthermore, 17% of men had active treatment and no prostate cancer-specific deaths were recorded. 5-year treatment free survival (TFS) was significantly better for men without baseline mpMRI lesions (85.1%) compared to men with visible lesions (78.3%; p=0.024), and TFS was 86.3% for men with Gleason 3+3 disease compared to 60.8% for Gleason 3+4 (p<0.001). A limitation of this study is that it is purely descriptive in nature without predictive models for risk of progression adjusted for relevant covariates.

At major AS centers for low risk prostate cancer, mpMRI is increasingly being utilized in surveillance algorithms. With the recent publication of the PROMIS trial data [1] highlighting diagnostic accuracy, mpMRI is going to be increasingly incorporated into AS algorithms. Our job is to cost-effectively delineate when (screening, follow-up, replace follow-up biopsies?) to use mpMRI for AS patients.

1. Ahmed HU, El-Shater Bosaily A, Brown LC, et al. Diagnostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study. Lancet 2017;389(10071):815-822.

Speaker(s): Adam Retter, Department of Radiology, University College London Hospital, London, United Kingdom

Co-Authors: F. Giganti, A. Kirkham, C. Allen, S. Punwani, M. Emberton, C. Moore

Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto
Twitter: @zklaassen_md

at the #EAU17 - March 24-28, 2017- London, England