Dr. Emberton then highlighted the recently published MAPPED study  – the first randomized trial using change in MRI prostate cancer tumor volume as a primary endpoint. This study was a randomized, double-blind, placebo controlled trial of men (n=42) with biopsy proven low-intermediate risk prostate cancer who had a lesion of 0.2 ml or greater on T2-weighted MRI. Patients were randomized to daily Dutasteride 0.5 mg or placebo for 6 months; lesion volume was assessed at baseline, 3 and 6 months with an exit biopsy after 6 months. Men in the Dutasteride arm had a 36% reduction in prostate tumor volume from baseline to 6 months, compared to a 12% increase in tumor volume in the placebo arm (difference in reduction: 48%, 95%CI 27.4-68.3, p<0.0001).
Dr. Emberton then shifted gears and demonstrated some of the latest MRI technology, namely the 13C hyper-polarized MRI. He subsequently showed images of 13C lactate hyperpolarizing MRI images localizing to a Gleason 3+4 tumor and essentially providing a “heat map” of prostate cancer corresponding to prostate biopsy. This has the technology to further improve accuracy of detection using targeted biopsy platforms. Furthermore, he feels this will start a gradual transition from an anatomically defined treatment to MRI-lesion based therapy.
In Dr. Emberton’s opinion, who may be a candidate for focal therapy? Men with a discrete lesion on MRI, clinically significant prostate cancer, and the opportunity to apply a margin around the tumor (~5mm). Furthermore, he feels that a man may be a candidate for focal therapy if they are highly motivated to preserve genitourinary function, and are aware and willing to accept treatment uncertainties and salvage treatment strategies. Dr. Emberton concluded with a slide remarking that our therapies for prostate cancer should be complimentary and not mutually exclusive: as disease severity increases, the spectrum of treatment should move from active surveillance focal therapy whole gland treatment.
Speaker: Mark Emberton, University College London, London, UK
Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre
Twitter: @zklaassen_md at the EAU - Update on Prostate Cancer – September 15-16, 2017, Vienna, Austria
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.
2. Moore CM, Robertson NL, Jichi F, et al. The effect of dutasteride on magnetic resonance imaging defined prostate cancer: MAPPED—A randomized, placebo controlled, double-blind clinical trial. J Urol 2017;197(4):1006-1013.