Purpose: The objective of this study was to evaluate the efficacy, defined by the 3-year tumor recurrence-free survival rate, of intravesical chemotherapy using pirarubicin (THP) in patients with low or intermediate-risk nonmuscle-invasive bladder cancer (NMIBC).
Patients and methods: Between October 2010 and January 2015, 206 patients were enrolled, and finally 113 were randomized to receive either a single immediate postoperative intravesical instillation of THP (30 mg) (Group A), or 8 additional weekly intravesical instillations of THP (30 mg) after a single postoperative instillation (Group B). The patients were examined by performing cystoscopy and urine cytology every 3 months after transurethral resection to determine bladder tumor recurrence. The primary endpoint was 3-year-recurrence-free survival rate.
Results: All 113 patients were bacillus Calmette-Guérin (BCG)-naïve. The 3-year recurrence free survival rate was 63.7% for Group A and 85.3% for Group B (log-rank test, P = .0070). In patients with intermediate recurrence risk, the 3-year recurrence-free survival rate was 63.4% in Group A and 86.1% in Group B (log-rank test, P = .0036). Cox regression analysis revealed that only additional instillation of THP was a significant independent factor for recurrence-free rate in patients with intermediate risk. No patient with progression was noted during this period. Frequent adverse effects (AEs) were frequent urination and micturition pain, and no severe AEs (Grade 3 or more) occurred.
Conclusion: Additional instillation of THP (30 mg) weekly for 8 weeks reduced the risk of tumor recurrence without severe AEs in BCG-naïve NMIBC patients with intermediate risk.