First, addressing improved diagnostic methods to reduce prostate cancer over-diagnosis, Taneja highlighted the PRECISION trial recently published in the New England Journal of Medicine. This is a randomized comparison of TRUS biopsy and pre-biopsy MRI followed by MRI-targeted biopsy in men with suspicion of prostate cancer. He highlighted notable features of this trial including the lack of systematic biopsy in the MRI arm and the omission of biopsy in patients with Pi-RADS2 1-2 lesions. While this study was initially designed to demonstrate the non-inferiority of the MRI-based approach with respect to clinically significant cancer (GS>=3+4) and clinically insignificant cancer (GS3+3), the final manuscript presented a superiority analysis as well. While patients in the MRI-arm were significantly less likely to be diagnosed with clinically insignificant disease, diagnosis of clinically significant cancer was higher. Despite these promising outcomes, Dr. Taneja raised key issues with the adoption of this approach, namely: 1) can the quality of MRI interpretation be reproduced widely; 2) what are the cost implications of such wide use of MRI; 3) what about missed cancer, both in the omission of systematic biopsy in patients with abnormal MRI and the omission of biopsy entirely in patients with PiRADs v2 1-2.
Second, he moved on to data assessing the utilization and intensity of active surveillance. He highlighted the work of Inoue et al. recently published in Annals of Internal Medicine based on the NIH R01 grant of Prostate Modeling to Identify Surveillance Strategies. Utilizing a cohort of 2500 patients from well annotated active surveillance cohorts, the authors considered the effect of varying surveillance intensity of the delay to diagnosis of disease progression. Each of included cohorts had vastly differing inclusion and exclusion criteria. Thus, as may be expected, progression to treatment rates varied substantially between studies. However, spacing biopsies every two years instead of annually was expected to reduce the total number of biopsies by 32-38% while only incurring a delay in the detection of upgrading by 3-5 months. Dr. Taneja raised a few issues regarding the application of these data: 1) the selection of patients for active surveillance, including the evolving role of MRI, MRI-targeted biopsy, and biomarkers; 2) the definition of disease progression, and 3) the generalizability of findings given differences between AS populations.
Finally, he highlighted the evolving role of androgen receptor targeting earlier in advanced prostate cancer. While both LATITUDE and STAMPEDE demonstrated an overall survival benefit of adding abiraterone to ADT in patients with csPCa. He chose to focus on STAMPEDE as these data are more generalizable on the basis of the inclusion of patients with metastatic disease, node positive disease, and high-risk non-metastatic disease. They found a statistically significant benefit in terms of both overall survival and failure-free survival. Dr. Taneja highlighted that this benefit appeared to be restricted to younger patients (<70 years of age). Before widespread adoption of these data, Dr. Taneja highlighted the following considerations: 1) the cost of widespread adoption of androgen axis blockade earlier in prostate cancer and 2) the effect on quality of life in terms of Grade 3-4 adverse events and cardiovascular events.
Presented by: Samir Taneja, MD, NYU Langone Medical Center
Written by: Christopher J.D. Wallis, Urology Resident, University of Toronto @WallisCJD at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA