Real-world Patterns and Trends of Intravesical Chemotherapy for Non-muscle Invasive Bladder Cancer: Insights from a Large Prospective German Cohort

BACKGROUND/AIM: Intravesical instillation therapy is the standard of care for patients with non-muscle-invasive bladder cancer (NMIBC) following transurethral resection (TURBT). Adherence to early and adjuvant instillation guidelines in real-world settings remain largely unknown. This was a large, prospective, non-interventional study aimed to evaluate practice patterns, temporal trends, adverse events, and guideline adherence in Germany. PATIENTS AND METHODS: Between 2011 and 2019, 960 patients with NMIBC were enrolled across 102 urology practices. Data were collected using standardised case report forms. Early instillation was defined as administration within 24 hours after TURBT. Descriptive statistics, logistic regression and joinpoint regression were conducted. RESULTS: Of the 960 patients (median age 72 years; 77% male), 49.1% received an early postoperative instillation. After an initial decline [annual percentage change (APC) -5.2%], the use of early instillation increased after 2017 [APC 34.9%, average annual percentage change (AAPC) 3.5%]. The preferred agent shifted from mitomycin to doxorubicin, which accounted for over 70% of early instillations by 2019. Only a small proportion of patients received guideline-based risk-stratified recommendations for adjuvant instillations. During the adjuvant treatment phase, 64.7% of patients continued to maintenance. Adverse events were reported in 23.9% and were mostly mild; 3.5% discontinued treatment due to toxicity. The 1-year recurrence rate was 4.6%. There were no changes in demographics and pathology over time. CONCLUSION: This study highlights persistent gaps in the real-world implementation of guideline-recommended intravesical therapy in Germany. Despite long-standing high-level evidence, early instillations remain underutilised. The increasing use of doxorubicin for early instillation may reflect changes in drug availability, cost, or tolerability. Recommendations for adjuvant instillations appear to be suboptimal. Structured pathways and improved care coordination are needed to enhance adherence to evidence-based NMIBC management.