The impact of neoadjuvant chemotherapy (NAC) on conditional survival (CS) among patients with muscle-invasive bladder cancer (MIBC).

Abstract

520 Background: Achieving a pathologic complete response (pCR) with NAC for MIBC is associated with a favorable prognosis. Patients with pathologic residual disease (pRD) generally have poor outcomes. However, prognosis after radical cystectomy (RC) improves with ongoing survivorship. Whether the difference in prognosis of patients with pCR and pRD is sustained over time has not been explored. Methods: We queried the National Cancer Database for patients who received NAC and RC for clinically localized MIBC (cT2-T4aN0M0) between 2002-2010. We identified patients with pCR (</= pTis) and pRD. Using Kaplan-Meier analysis, we assessed CS up to 5 years given survivorship of 0-4 years using log-rank test with multiple comparison adjustment. Results: The cohort comprised 1,554 patients (pCR: 314, pRD: 1,240). The median follow up was 2.38 (0.04-9.60) and 2.76 (0.01-9.97) years for pCR and pRD, respectively. Patients with pCR had lower stage (cT2= 79% vs. 72%; cT3= 14% vs. 18%; cT4= 7% vs. 10%), more recent diagnosis (2010: 31% vs. 19%), and were more often treated at a high-volume center (>15 RC/year: 61% vs. 49%). Patients with pCR had improved CS relative to those with pRD with survivorship up to 3 years, but the benefit associated with pCR becomes attenuated from 4 years post-RC (Table). Conclusions: MIBC patients with pRD after NAC have worse CS up to years 3 post-RC, but this difference diminishes after 4 years. These findings may inform patient counseling, surveillance intensity, and novel adjuvant approaches for patients with pRD, and are subject to confirmation with a forthcoming multivariable analysis. Probability of surviving to X years (95% CI). [Table: see text]