A population-based analysis of patterns of care in patients with high-risk non-muscle-invasive bladder cancer from Alberta, Canada.

Abstract

Introduction: Approximately three-quarters of patients newly diagnosed with bladder cancer have non-muscle-invasive disease (NMIBC). Among these patients, those with high-risk (HR) features should be managed more aggressively in an attempt to circumvent the elevated risk of recurrence/progression. Population-based data on the incidence of HR-NMIBC and receipt of guideline-recommended care are limited.

Methods: This retrospective, observational study gathered data from multiple linked provincial (Alberta) healthcare databases to describe baseline characteristics, treatment patterns, and survival outcomes in a population of individuals diagnosed with HR-NMIBC from 2010-2020. Data for all patients aged >18 years with T1, Tis, or high-grade Ta NMIBC ("high-risk") were analyzed using basic statistics, multivariate regression analyses and the Kaplan-Meier method.

Results: Of 6837 de novo NMIBC patients identified, 3874 (57%) were categorized as HR-NMIBC. The majority (82%) were male, with a median age of 72 years, and approximately half had a Charlson comorbidity index score ≥1. Following initial transurethral resection of bladder tumor (TURBT), 61% of the cohort received no adjuvant bacillus Calmette-Guérin (BCG) or chemotherapy, while 36% received BCG, 3% gemcitabine, and 1% mitomycin C. Patients underwent a median of four TURBT procedures. 'Adequate BCG' (≥5 induction doses + ≥2 maintenance doses) was received by 32% of BCG-treated and 12% of all HR-NMIBC patients. Survival was improved in patients receiving adequate BCG.

Conclusion: Data from this large, real-world population highlights poor use of induction/maintenance BCG therapy following TURBT among patients with HR-NMIBC.