Bladder Cancer: A Comparison Between Non-urothelial Variant Histology and Urothelial Carcinoma Across All Stages and Treatment Modalities.

The purpose of this study was to evaluate stage at presentation, treatment rates, and cancer-specific mortality (CSM) of non-urothelial variant histology (VH) bladder cancer (BCa) relative to urothelial carcinoma of the urinary bladder (UCUB).

Within the Surveillance, Epidemiology, and End Results registry (SEER, 2004-2016), patients with VH BCa and UCUB were identified. Stage at presentation and treatment rates, as well as multivariably adjusted and matched CSM rates according to TNM stage within each histologic subtype, were reported.

Of all 222,435 eligible patients with BCa, 11,147 (5.0%) harbored VH. Among those, squamous cell carcinoma accounted for 3666 (1.6%) patients, adenocarcinoma for 1862 (0.8%), neuroendocrine carcinoma for 1857 (0.8%), and other VH BCa for 3762 (1.7%) of the study cohort. Patients with VH BCa showed invariably more advanced TNM stage at presentation compared with patients with UCUB. Treatment rates according to TNM stages showed similar distribution of cystectomy rates in VH BCa and UCUB. However, important differences in the distribution of radiotherapy and chemotherapy rates existed within VH BCa and in comparison with UCUB. Furthermore, even after multivariable adjustment and matching with UCUB, squamous cell carcinoma exhibited higher CSM (hazard ratios, 1.43-1.95; all P < .01) across all stages. All other VH predominantly exhibited higher CSM than UCUB in either non-muscle-invasive or muscle-invasive nonmetastatic stages.

TNM stage at diagnosis is invariably more advanced in all patients with VH BCa versus patients with UCUB. Of all VH BCa, in multivariably adjusted stage for stage analyses, squamous cell carcinoma appears to have the worst natural history. All other VH subgroups exhibited more aggressive natural history than UCUB in nonmetastatic stages only.

Clinical genitourinary cancer. 2020 Jul 18 [Epub ahead of print]

Marina Deuker, Thomas Martin, Franziska Stolzenbach, Giuseppe Rosiello, Claudia Collà Ruvolo, Luigi Nocera, Zhe Tian, Andreas Becker, Luis Kluth, Frederik C Roos, Derya Tilki, Shahrokh F Shariat, Peter C Black, Wassim Kassouf, Fred Saad, Felix Chun, Pierre I Karakiewicz

Department of Urology, University Hospital Frankfurt, Frankfurt am Main, Germany; Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montréal Health Center, Montréal, Québec, Canada. Electronic address: ., Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montréal Health Center, Montréal, Québec, Canada., Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montréal Health Center, Montréal, Québec, Canada; Martini-Klinik Prostate Cancer Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany., Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montréal Health Center, Montréal, Québec, Canada; Department of Urology and Division of Experimental Oncology, URI, Urological Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy., Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montréal Health Center, Montréal, Québec, Canada; Department of Urology, University of Naples Federico II, Naples, Italy., Department of Urology, University Hospital Frankfurt, Frankfurt am Main, Germany., Martini-Klinik Prostate Cancer Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany., Department of Urology, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria; Institute for Urology and Reproductive Health, I.M. Sechenov First Moscow State Medical University, Moscow, Russia; Department of Urology, University of Jordan, Amman, Jordan., Department of Urologic Sciences, Vancouver Prostate Centre, University of British Columbia, Vancouver, British Colombia, Canada., Department of Urology, McGill University Health Centre, Montréal, Québec, Canada.