OBJECTIVES: A high percentage of MIUC patients experience DR after undergoing RC despite its curative intent. This study aimed to address the lack of data on the survival of patients after DR, using data from a US-based real-world cohort and CheckMate-274 study.

METHODS: De-identified patient-level data from the US Flatiron Health database for patients with history of RC prior to diagnosis of advanced urothelial carcinoma (aUC) were matched to the CheckMate-274 study population experiencing DR via propensity scores. The list of variables used to match the two cohorts was determined based on their clinical influence on survival outcomes and availability in the database. Sex, age at aUC diagnosis, and ECOG performance score were selected for propensity score calculations, and to create matched pairs between the cohorts from the database and the trial. The matched database cohort was described relative to cisplatin eligibility status and first-line (1L) systemic treatment. Post-DR survival was evaluated using standard Kaplan-Meier analysis for the overall matched cohort.

RESULTS: Prior to matching, 461 patients from the database met the inclusion criteria. During match-adjustments, 184 matched pairs of patients from the trial and the database created a balanced cohort of patients. In the matched cohort from the database, mean age was 68 years, 63% of patients were male, 24% were cisplatin-eligible, 18% were cisplatin-ineligible, and 58% had unknown cisplatin eligibility status due to missing values in the database. Landmark survival estimates with 95% confidence intervals for the overall matched cohort for the years 1, 2, and 5 were 50% (43-59%), 29% (23-37%), and 15% (10-23%), respectively. Small sample sizes and missing data limited meaningful and robust survival analyses stratified by cisplatin eligibility status.

CONCLUSIONS: The study provided real-world survival estimates for aUC patients that underwent RC prior to DR, while indirectly filling an existing gap of data for the adjuvant treatment setting.