Presentation Authors: John Pfail*, François Audenet, Alberto Martini, Kyrollis Attalla, Nikhil Waingankar, Matthew Galsky, John Sfakianos, New York, NY
Introduction: Approximately, 30-40% of bladder cancer patients treated with neoadjuvant chemotherapy (NAC) will have a pathologic complete response. Delayed radical cystectomy (RC) may compromise the outcome of patients not sensitive to NAC. The aim of our study was to compare overall survival (OS) between patients responsive and nonresponsive to NAC at time of RC to those who underwent RC alone.
Methods: The National Cancer Data Base was queried for patients who underwent RC with or without NAC for MIBC from 2004-2015. Covariates including age, sex, race, insurance, income, education, county, facility type, Charlson-Deyo comorbidity index, and clinical size (cT) were balanced using inverse probability of treatment weighting (IPTW). 6-month conditional landmark analyses, from the time of surgery, along with Cox proportional hazards models were conducted to analyze differences in OS. All models were stratified by pathological stage.
Results: 11,287 were included in our analysis (Table 1). The 5-year IPTW-adjusted rates of OS were 44.7% (95% CI: 43.5 - 45.9, p < 0.001) for NAC+RC vs 38.4% (95% CI: 37.4 - 49.4, p < 0.001) for RC alone (HR: 0.864, 95% CI: 0.832 - 0.896, p < 0.001). The 6-month conditional landmark analysis revealed an increased risk of death (HR: 1.31 95% CI 1.23 - 1.39 and HR: 1.22 95% CI 1.11 - 1.35; both p < 0.001) and decreased median OS (23.5 vs. 32.2 mos.; p < 0.001 and 19.3 vs. 22.3 mos.; p=0.218) in patients treated with NAC+RC compared to RC alone, for pT3 and pT4 disease, respectively (Figure 1).
Conclusions: Patients with pT3 or pT4 disease after NAC experienced a significant increased risk of death and decrease in median OS when compared to pathological stage-matched patients who underwent RC alone. Given the possible delay to definitive treatment by RC, for patients nonresponsive to NAC, further research is warranted to accurately determine patient selection for NAC.