Maintenance Therapy with 3-monthly Bacillus Calmette-Guérin for 3 Years is Not Superior to Standard Induction Therapy in High-risk Non-muscle-invasive Urothelial Bladder Carcinoma: Final Results of Randomised CUETO Study 98013

Abstract

Background: Bacillus Calmette-Guérin (BCG) maintenance therapy for 3 yr following BCG induction can reduce the progression of urothelial bladder carcinoma versus BCG induction alone, but is associated with high toxicity.

Objective: To investigate whether a modified 3-yr BCG maintenance regimen following induction therapy is more effective than standard BCG induction therapy alone and exhibits a low toxicity profile.

Design, setting, and participants: Patients from the outpatient clinics of the participating centres with high-risk non-muscle-invasive bladder carcinoma (NMIBC) were randomised between October 1999 and April 2007.

Intervention: Participants received BCG induction once-weekly for 6 wk (no maintenance arm) or BCG induction followed by one BCG instillation every 3 mo for 3 yr (maintenance arm).

Outcome measurements and statistical analysis: Primary endpoints were disease-free interval (DFI) and time to progression (TTP). Secondary endpoints included survival duration and toxicity. Differences between treatment arms were tested using Student's t test and χ(2) and log-rank tests.

Results and limitations: A total of 397 patients were randomised, 195 to the no-maintenance and 202 to the maintenance arm. A median time to recurrence was not reached in either treatment arm. DFI was similar between the arms (hazard ration [HR] 0.83; 95% CI 0.61-1.13; p=0.2) with disease relapse at 5 yr of 33.5% and 38.5%, respectively. TTP was also similar between the treatment arms (HR 0.79; 95% CI 0.50-1.26; p=0.3), with a progression rate at 5 yr of 16% and 19.5%, respectively. There were no significant differences between the treatment groups for overall survival and cancer-specific survival at 5 yr. Twenty and five patients in the maintenance and no-maintenance arms, respectively, stopped treatment because of toxicity. The most common local side effects were frequency (65% of patients), dysuria (63%), and haematuria (43%); the most frequent systemic side effects were general malaise (7.2%) and fever (34%).

Conclusions: In NMIBC patients treated with maintenance therapy comprising a single BCG instillation every 3 mo for 3 yr following standard induction BCG, we did not observe a decrease in recurrence and progression rates versus induction therapy alone.

Patient summary: Patients who undergo surgery to remove bladder cancer are usually treated with bacillus Calmette-Guérin (BCG) for 6 wk if there is a high risk of disease recurrence. Extending BCG therapy by 3 yr can further minimise disease recurrence and progression, but is associated with more side effects. We report that a modified 3-yr BCG treatment regimen showed low toxicity, but seemed to be no more effective than 6-wk treatment.

Trial registration: CUETO 98013.

Keywords: Bacillus Calmette-Guérin; Bladder cancer; Maintenance therapy.