Objective: To investigate the safety and efficacy of a maintenance regimen of bacillus Calmette-Guérin therapy including 6-week induction and 2-week maintenance instillation for patients with recurrent or multiple Ta, T1 tumors or carcinoma in situ of the urinary bladder.
Methods: This study was performed as single-arm multi-institutional study. The enrolled patients had been diagnosed with urothelial carcinoma of the bladder, including the presence of at least two bladder tumors, single tumors recurring within 12 months of follow-up, any Grade 3 Stage Ta or T1 tumor, and primary or recurrent biopsy proven carcinoma in situ. Patients received 81 mg intravesical bacillus Calmette-Guérin (Connaught strain). The instillation was repeated once a week for another 5 weeks, followed by once a week for 2 weeks at months 3, 6, 12, 18, 24, 30 and 36, for a total of 20 instillations in 3 years.
Results: From 28 hospitals, 202 patients were registered. A total of 186 patients matched the inclusion criteria: 139 patients in the Ta/T1group and 47 patients in the carcinoma in situ group. At the 4-year median point of follow-up, recurrence-free survival rates in the Ta/T1 group and the carcinoma in situ group were 76.7 and 77.7%, respectively. Completion rates for maintenance therapy in both groups at months 3, 6, 12, 24 and 36 were 81.7, 68.9, 58.1, 42.5 and 35.0%, respectively. Common toxicities were pain on urination, urinary frequency and gross hematuria. There was no treatment-related death.
Conclusions: This regimen may be feasible in patients with Ta/T1 tumor or carcinoma in situ; however, future Phase III randomized study is needed to determine whether this regimen would be truly safe and effective compared with 3-week maintenance regimen.