Efficacy of Bladder Instillations with Mitomycin or Bacillus Calmette–Guérin in Patients with T1 High-Grade Bladder Cancer

Abstract

Objectives: To evaluate the efficacy of instillations with mitomycin C (MMC) or bacillus Calmette–Guérin (BCG) in patients with T1 high-grade bladder cancer (BC). Patients and Methods: From 2007 to 2015, 186 patients admitted to Taichung Veteran General Hospital with new diagnosis of T1 high-grade BC receive transurethral resection of the bladder tumor (TURBT) and 6 weekly adjuvant instillation following. Histological stage followed the WHO grading system. End point evaluation was recurrence and progression to muscle invasive BC. Results: A total of 118 patients received 6 weekly intravesical instillation chemotherapy with MMC and 68 with BCG. Above all, 93 patients received immediate intravesical MMC after TURBT. The mean follow-up period was 46.78 ± 19.05 months in the MMC group versus 50.13 ± 24.18 months in the BCG group (P = 0.512). The BCG group showed better outcomes with longer 5-year recurrence-free survivals (64.6% vs. 50.0%, P of log rank = 0.008*) and progression-free survivals (94.1% vs. 87.3%, P of log rank = 0.023*). The treatment efficacy of BCG in comparison to MMC was further adjusted in uni-multivariate analysis model (recurrence: Hazard ratio [HR] =0.511, 95% confidence interval [CI] = 0.304–0.858, P= 0.011*; progression: HR = 0.216, 95% CI = 0.068–0.683, P= 0.009*). We also explore smoker, multiple lesions, and tumor diameter >3 cm to be risk factors for recurrence. Conclusions: For patients with T1 high-grade nonmuscle invasive BC, the adjuvant therapy with BCG, as opposed to MMC, resulted in better outcomes based on recurrence and progression with tolerable complications. For immediate single instillations, in comparison, the efficacy was lower in preventing tumor recurrence and progression in the current stage.