Cancer-Specific Survival of Trimodal Therapy Versus Radical Cystectomy in T2N0M0 Non-Urothelial Bladder Cancer

We hypothesized that, within organ-confined (OC, T2N0M0) non-urothelial carcinoma of urinary bladder (non-UCUB) patients, trimodal therapy (TMT) use does not differ from radical cystectomy (RC) regarding cancer control outcomes.

Within the SEER database (2004-2021), rates of TMT versus RC use in OC non-UCUB patients were calculated. Nearest-neighbor 1:1 propensity score matching (PSM) for age, sex, race/ethnicity, and histological subtype was applied. Cumulative incidence plots depicted 5-year cancer-specific (CSM) and other-cause mortality (OCM) rates. Multivariable competing risks regression (CRR) models were fitted. Sensitivity analyses were performed within squamous cell (SCC), neuroendocrine (NEC), and adenocarcinoma (ADK) and other histological subtypes.

Of 814 OC non-UCUB patients, 310 (38%) received TMT versus 504 (62%) RC. After PSM, 5-year CSM rate was 50% after TMT versus 29% after RC and TMT was associated with 2.1-fold higher CSM relative to RC (multivariable HR [mHR]: 2.1, p < 0.001). In sensitivity analyses within 229 (28%) SCC, TMT patients had higher 5-year CSM rates relative to their RC-counterparts (67% vs. 22%, mHR: 4.3, p < 0.001). Similarly, within 314 (39%) NEC, TMT patients had higher 5-year CSM rates relative to their RC-counterparts (mHR: 1.8, p < 0.001). Conversely, within 118 (28%) ADK and 153 (19%) other subtypes, CSM after TMT did not differ from CSM after RC (33% vs. 15%, mHR: 1.4 and 43% vs. 33%, mHR: 1.4; p = 0.4).

In OC non-UCUB patients TMT is associated with significantly higher CSM than RC. Most pronounced survival disadvantage was recorded within SCC and NEC patients.