Instillation Strategies for Non-Muscle-Invasive Bladder Cancer in the Bacillus Calmette-Guerin Shortage Era: A Simple Solution for BCG Discontinuation

Objective: Among intravesical instillation protocol in patients with non-muscle-invasive bladder cancer (NMIBC), chemotherapy agents have been widely used during the bacillus Calmette-Guérin (BCG) shortage era since the patient might under the risk of BCG discontinuation. This study evaluates the efficacy of incomplete BCG instillation compared with pure chemotherapy instillation protocol. Materials and Methods: Patients newly diagnosed with intermediate- and high-risk NMIBC who received incomplete BCG intravesical instillation or chemotherapy instillation were retrospectively included. Patients were divided into three groups according to different intravesical instillation schedules: [BCG only], [BCG + Chemo], and [Chemo only]. Comparisons between these three groups were performed. Bladder recurrence-free survival (RFS) was analyzed as the primary endpoint. Results: A total of 475 patients who received intravesical instillations were enrolled. Compared to the [Chemo only] group, the [BCG + Chemo] group had significantly better bladder RFS (p = 0.027). Multivariate analysis of recurrence revealed the [BCG + Chemo] regimen has a hazard ratio 0.381 (95% CI 0.154– 0.941, p = 0.037). The total instillation number > 12 was associated with better RFS (p = 0.001) compared with other instillation numbers. Conclusion: For NMIBC patients facing the risk of unexpected BCG instillation interruption, instead of starting instillation with chemotherapy agents, receiving BCG first till stoppage then shifting to chemotherapy agents is recommended.