Role of oral pentosan polysulfate in Bacillus Calmette–Guérin therapy in patients with non-muscle-invasive bladder cancer

Purpose: Intravesical Bacillus Calmette–Guérin (BCG) instillation, although an important treatment for non-muscle-invasive bladder cancer, exerts local and systemic adverse effects. Pentosan polysulfate (PPS) is a bladder mucosal protective drug that acts by replacing mucus in the glycosaminoglycan layer of the damaged urothelium. We hypothesized that co-administration of oral PPS with BCG instillation would relieve BCG-related adverse effects without affecting its efficacy. Materials and Methods: A total of 217 patients receiving BCG instillation were enrolled. They were placed in two groups and analyzed retrospectively: group A (n=122) received BCG instillation only and group B (n=95) received 100 mg of PPS thrice daily during the BCG treatment. Results: After BCG instillation, the rate of BCG-treatment discontinuation owing to adverse effects was 15.6% in group A and 6.3% in group B (p=0.034). The proportion of patients with bacteriuria after BCG was higher in group B; however, no statistical difference was observed (28.7% vs. 41.1%; p=0.057). The proportion of patients with pyuria was significantly higher in group B (81.1% vs. 91.6%; p=0.029). The proportion of patients using antibiotics was significantly higher in group A (73.8% vs. 43.2%; p=0.001). The recurrence rate within 1 year was 29 (23.8%) in group A vs. 19 (20.0%) in group B (p=0.507). Univariate and multivariate analyses showed that antibiotic use had a statistically significant effect on BCG discontinuation. Conclusions: Oral PPS effectively decreased the discontinuation rate and antibiotic use without affecting the BCG efficacy.