This study compares the outcomes of 151 patients with micropapillary urothelial carcinoma with 1,346 pure urothelial carcinoma patients treated at five academic centers of excellence in North America and Europe.
This is the first study to present a comprehensive comparison of these two patient subgroups with long-term follow-up by interrogating granular institutional-curated metrics rather than relying on population-based databases. Strict inclusion and exclusion criteria ensured that only those patients who were treated according to internationally accepted best practice standards were part of the study. The data suggest that the presence of micropapillary variant is associated with more aggressive disease at presentation, and these features portend poor prognosis compared with patients with pure urothelial carcinoma by unadjusted survival analysis. However, after accounting for disease stage and lymphovascular invasion by multivariable models, the presence of micropapillary urothelial carcinoma was not independently associated with clinical outcomes.
These findings highlight the importance of identifying the presence of micropapillary variant in primary bladder tumors, as this may flag patients who may benefit from more aggressive management at the outset.
Written by: Anirban P. Mitra, MD, Ph.D., Resident, Institute of Urology, University of Southern California, Los Angeles, CA, USA and Sia Daneshmand, MD., Associate Professor of Urology (Clinical Scholar), Director of Urologic Oncology, Director of Clinical Research, Urologic Oncology Fellowship Director, USC/Norris Comprehensive Cancer Center, Institute of Urology
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