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.

Keywords: Bladder cancer; Life expectancy; Life tables; SEER.