The Efficacy of Multiparametric Magnetic Resonance Imaging and MRI-Targeted Biopsy in Risk Classification for Patients with Prostate Cancer on Active Surveillance.

PURPOSE - To determine if multiparametric-MRI (mpMRI)-targeted biopsies may replace systematic biopsies to detect higher grade prostate cancer (Gleason score ≥ 7), and whether biopsy may be avoided based on mpMRI among men with Gleason 3+3 prostate cancer on active surveillance (AS).

MATERIALS AND METHODS - We identified men with previously diagnosed Gleason score 3+3 prostate cancer on AS who underwent a mpMRI and a follow-up prostate biopsy. Suspicion for higher grade cancer was scored on a standardized 5-point scale. All patients received a systematic biopsy. Patients with mpMRI regions-of-interest also underwent an MRI-targeted biopsy. The detection rate of higher grade cancer was estimated for different mpMRI scores using 3 biopsy strategies: systematic, MRI-targeted, and combined.

RESULTS - Of 206 consecutive men on AS, 135 (66%) had a mpMRI region-of-interest. Overall, higher grade cancer was detected in 72 (35%) men. Higher mpMRI score was associated with an increased probability of detecting higher grade cancer (Wilcoxon-type trend test p < 0.0001). MRI-targeted biopsy detected higher grade cancer in 23% of men. MRI-targeted biopsy alone missed higher grade cancers in 17%, 12%, and 10% of patients with mpMRI scores of 3, 4, and 5, respectively.

CONCLUSIONS - MRI-targeted biopsies increased detection of higher grade cancer for men on AS compared to systematic biopsy alone; however a clinically relevant proportion of higher grade cancer was detected only using systematic biopsy. Despite the improved detection of disease progression using MRI-targeted biopsy, systematic biopsy cannot be excluded as part of surveillance for men with low risk prostate cancer.

The Journal of urology. 2016 Feb 23 [Epub ahead of print]

Pedro Recabal, Melissa Assel, Daniel D Sjoberg, Daniel Lee, Vincent P Laudone, Karim Touijer, James A Eastham, Hebert A Vargas, Jonathan Coleman, Behfar Ehdaie

Urology Service, Sidney Kimmel Center for Prostate and Urologic Cancers, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Urology Service, Fundacion Arturo Lopez Perez, Santiago, Chile., Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Urology, Weill-Cornell Medical College, New York Presbyterian Hospital, New York, NY, USA., Urology Service, Sidney Kimmel Center for Prostate and Urologic Cancers, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Urology Service, Sidney Kimmel Center for Prostate and Urologic Cancers, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Urology Service, Sidney Kimmel Center for Prostate and Urologic Cancers, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Urology Service, Sidney Kimmel Center for Prostate and Urologic Cancers, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Urology Service, Sidney Kimmel Center for Prostate and Urologic Cancers, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.