Radical cystectomy for patients with pT4 urothelial carcinoma in a large population-based study

• To examine cancer-specific mortality (CSM) in patients with pT4N₀₋₃ M₀ urothelial carcinoma of the urinary bladder (UCUB) and to compare it to patients with pT3N₀₋₃ M₀, in a population-based cohort treated with radical cystectomy (RC).

• RCs were performed in 5625 pT3-T4b₀₋₃ M₀ patients with UCUB within 17 Surveillance, Epidemiology and End Results (SEER) registries between 1988 and 2006. • Univariable and multivariable models tested the effect of pT4a vs pT4b vs pT3 stages on CSM. • Covariates consisted of age, gender, race, lymph node status and SEER registries. • All analyses were repeated in 3635 pN(0) patients.

• Of 5625 patients, 2043 (36.3%) had pT4aN₀₋₃ , 248 (4.4%) had pT4bN₀₋₃ and 3334 had pT3N₀₋₃ (59.3%) UCUB. • The 5-year CSM was 57.6% vs 81.7% vs 53.9% for, respectively, pT4aN₀₋₃ vs pT4bN₀₋₃ vs pT3N₀₋₃ patients (all log-rank P= 0.008). • In multivariable analyses the rate of CSM was 2.3-fold higher in pT4b vs pT3 (P < 0.001), 1.1-fold higher in pT4a vs pT3 (P= 0.002) and 2.0-fold higher in pT4a vs pT4b patients. • After restriction to pN₀ stage, pT4b patients had a 2.3-fold higher rate of CSM than pT3 patients (P < 0.001) and pT4b patients had a 2.1-fold higher rate of CSM than pT4a patients (P < 0.001). • The CSM rate was the same for pT4a and pT3 patients (P= 0.1).

• Our findings indicate that patients with pT4a UCUB have similar CSM as those with pT3 UCUB. • Consequently, RC should be given equal consideration in patients with pT3 and pT4a UCUB.