Epidemiology, treatment patterns and effectiveness of adherence to Bacillus Calmette-Guérin therapy in intermediate and high-risk non-muscle-invasive bladder cancer patients: a retrospective cohort analysis using German health claims data.

PURPOSE: To assess the epidemiology, treatment patterns, and Bacillus Calmette-Guérin (BCG) instillations in Non-Muscle-Invasive Bladder Cancer (NMIBC) patients to evaluate guidelines compliance and effectiveness of adherence on real-world outcomes.

METHODS

NMIBC patients with BCG-treatment were identified in a retrospective cohort study using German health claims data. The first BCG prescription was defined as index date. Crude and standardized annual incidence were calculated. Subsequent treatment regimens were described based on prescriptions to assess adherence. BCG-maintenance adherents were compared with non-adherents using a landmark time approach and Cox proportional hazard model.

RESULTS

The annual standardized incidence per 100,000 for intermediate- and high-risk NMIBC patients ranged from 7.6 to 10.4 in males and 1.2 to 1.9 in females from 2017 to 2021. The main cohort consisted of 817 patients (mean age: 72.5; male: 78%). Most patients (98%) received transurethral resection of bladder tumor (TURBT) as initial treatment followed by BCG, with a median number of 13 BCG instillations per patient (IQR: 8-21). 28% continued BCG in the maintenance phase at 24 months post-induction and 62% received at least one Re-TURBT post-index. BCG maintenance-adherent patients showed lower risk compared with non-adherent patients: adjusted hazard ratio (aHR): 0.92 [0.73-1.18] for all-cause death; aHR: 0.49 [0.36-0.67] for advanced treatment; aHR: 0.65 [0.53-0.80] for disease progression.

CONCLUSION

Real-world compliance with clinical guidelines may require improvement based on BCG maintenance duration and adherence to treatment schedules. The benefits of BCG adherence in improving oncology-relevant outcomes support guidelines recommendations for sufficient BCG maintenance.