He highlighted the PROMIS trial (Diagnostic Accuracy of Multi-Parametric MRI and TRUS biopsy in Prostate Cancer), in which 576 biopsy-naive men with suspicion of prostate cancer underwent 1.5T mpMRI and transrectal ultrasound-guided (TRUS) biopsy, as well as template prostate mapping biopsy as a gold standard for cancer detection. The aim of this study was to evaluate the sensitivity and specificity of mpMRI in detecting clinically significant prostate cancer. The authors of the study found mpMRI to have a 93% sensitivity for detection of Gleason >4+3=7 disease, as well as 88% sensitivity for any Gleason 7 disease. Based on these data, the authors concluded that 27% of men with a negative MRI could potentially be spared undergoing a biopsy. Furthermore, there is 18% increased detection of clinically significant disease when mpMRI is employed.
He then discussed additional research focusing on the diagnostic utility of mpMRI in prostate cancer screening, including one study in which 100 patients underwent 3T mpMRI and subsequently underwent radical prostatectomy. The prostatectomy specimen was then mapped by a dedicated GU pathologist and these findings were compared with the patients imaging. 99 of 100 patients included in the study had at least one clinically significant cancer lesion detected on imaging, indicating a 99% negative predictive value. This suggests that many men who undergo mpMRI and do not have lesions concerning for clinically significant disease may be able to avoid a prostate biopsy.
Data from the NIH was also presented that addition of mpMRI to PSA screening alone significantly increases the sensitivity of clinically significant prostate cancer detection from 71% to 89%. Additionally, incorporating mpMRI-targeted biopsy demonstrates a 30% increase in the diagnosis of clinically significant lesions over standard TRUS-biopsy.
Cost-effectiveness of mpMRI for prostate cancer screening was discussed. There was cost analysis using data from the PROMIS trial which determined that mpMRI prior to up to two target fusion biopsies was the most cost-effective strategy. A second cost-effectiveness study estimating the expense of up front mpMRI versus the standard of care showed (TRUS biopsy) for a hypothetical patient with a PSA >4ng/dL suggested that cost was nearly identical between the two strategies. Quality-adjusted life years were higher with up-front mpMRI.
He concluded that we can improve prostate cancer screening with the use of mpMRI, because it improves our detection sensitivity for clinically significant disease, and that it is a cost-effective strategy.
Presented by: Jonathan Bloom, MD, Society of Urologic Oncology clinical fellow at the National Institutes of Health
Moderators: Marc A. Dall'Era, MD and Edward M. Schaeffer, MD, PhD
Session Chair: Martin E. Gleave, MD, FRCSC, FACS
Written by: Brian Kadow, MD, Fox Chase Cancer Center, Philadelphia, PA at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC