Differences in overall survival of T2N0M0 bladder cancer patients vs. population-based controls according to treatment modalities

Abstract

Purpose: It is unknown to what extent overall survival (OS) of organ-confined (T2N0M0) urothelial carcinoma of the urinary bladder (UCUB) patients differs from age- and sex-matched population-based controls, especially when treatment modalities such as radical cystectomy (RC), trimodal therapy (TMT), or radiotherapy (RT) are considered. Methods: Relying on the Surveillance Epidemiology and End Results database (2004–2018), we identified newly diagnosed (2004–2013) T2N0M0 UCUB patients treated with either RC, TMT or RT. For each case, we simulated an age- and sex-matched control (Monte Carlo simulation), relying on Social Security Administration Life Tables with 5 years of follow-up, and compared OS with that of RC-, TMT-, and RT-treated cases. Additionally, we relied on smoothed cumulative incidence plots to display cancer-specific mortality (CSM) and other-cause mortality (OCM) rates for each treatment modality. Results: Of 7153 T2N0M0 UCUB patients, 4336 (61%) underwent RC, 1810 (25%) TMT, and 1007 (14%) RT. At 5 years, OS rate in RC cases was 65% vs. 86% in population-based controls (Δ = 21%); in TMT cases, 32% vs. 74% in population-based controls (Δ = 42%); and in RT, 13% vs. 60% in population-based control (Δ = 47%). Five-year CSM rates were highest in RT (57%), followed by TMT (46%) and RC (24%). Five-year OCM rates were the highest in RT (30%), followed by TMT (22%) and RC (12%). Conclusion: OS of T2N0M0 UCUB patients is substantially less than that of age- and sex-matched population-based controls. The biggest difference affects RT, followed by TMT. A modest difference was recorded in RC and population-based controls.