Objectives: We carried out a prospective, randomized, controlled trial to investigate the efficacy and safety of both induction and maintenance therapy with intravesical instillation of bacillus Calmette-Guérin (BCG) for high-risk non-muscle invasive bladder cancer (NMIBC).
Methods: Intravesical instillation of 80 mg Tokyo strain was given to patients with high-risk NMIBC, including carcinoma in situ (CIS), once weekly for eight consecutive weeks as induction therapy. Patients who achieved complete response (CR) were randomly assigned to either the maintenance group or the observation group.
Results: A total of 90 patients were enrolled. After induction therapy, 75% of the patients achieved CR and 53 of them were enrolled in the randomized comparative phase. A total of four maintenance instillations were given. Median follow-up was 26.5 and 28.7 months after randomization in the maintenance and the observation group, respectively. Although it was not statistically significant, the 2-year recurrence-free survival rate in the maintenance group (95.8%) was higher than that in the observation group (74.1%, P = 0.078). Univariate analysis identified maintenance therapy as a significant factor influencing recurrence. During induction therapy, 82.2% of patients experienced urination-related adverse drug reactions, but most events were not serious. There were fewer adverse drug reactions with maintenance therapy than with induction therapy. Neither induction therapy nor maintenance therapy reduced patients' quality of life (QOL).
Conclusions: These findings show high levels of efficacy and safety of BCG induction treatment for high-risk NMIBC, and suggest that the number of maintenance instillations could probably be reduced without reducing treatment efficacy or influencing QOL.