Adherence to guideline recommendations for multimodality treatment of patients with pT2–3 M0 non-urothelial carcinoma of the urinary bladder: Temporal trends and survival outcomes

Objectives: To analyze contemporary multimodality treatment rates, defined as radical cystectomy plus chemotherapy and/or radiotherapy, for pT2–3 any N-stage M0 non-urothelial carcinoma of urinary bladder patients. Additionally, we tested for the effect of multimodality treatment versus radical cystectomy alone on cancer-specific mortality. Methods: Within the Surveillance, Epidemiology and End Results database (2004–2015), 887 pT2–3 any N-stage M0 non-urothelial carcinoma of urinary bladder patients treated with radical cystectomy were identified. Kaplan–Meier plots, and univariable and multivariable Cox regression analyses focused on cancer-specific mortality rates. Results: Squamous cell carcinoma was recorded in 499 (56.3%) patients, neuroendocrine carcinoma in 246 (27.7%) and adenocarcinoma in 142 (16.0%). The highest proportion of multimodality treatment patients was recorded in neuroendocrine carcinoma (69.1%), relative to adenocarcinoma (34.5%) and squamous cell carcinoma (26.4%). A statistically significant annual increase was recorded in multimodality treatment rates in neuroendocrine carcinoma patients (46.7–74.2%, P < 0.01), but not in adenocarcinoma or squamous cell carcinoma patients. The 5-year cancer-specific mortality rate in neuroendocrine carcinoma patients was significantly lower after multimodality treatment versus radical cystectomy alone (37.0% vs 51.5%; P < 0.01), but no statistically significant differences were recorded in both adenocarcinoma (46.1% vs 35.5%; P = 0.8) and squamous cell carcinoma (41.4% vs 31.1%; P = 0.8) patients. In multivariable analyses, for neuroendocrine carcinoma patients, multimodality treatment was an independent predictor of a lower cancer-specific mortality rate (hazard ratio 0.58, P = 0.03). Conclusions: Multimodality treatment has been increasingly used during the study period in neuroendocrine carcinoma patients, and it has translated into a cancer-specific mortality benefit. This is not the case for other non-urothelial carcinoma of urinary bladder patients, such as adenocarcinoma or squamous cell carcinoma.