Background: A series of bacillus Calmette-Guérin (BCG) bladder instillations is the gold standard therapy to prevent recurrence after transurethral resection of bladder tumor (TUR-Bt) of non-muscle-invasive bladder cancer (NMIBC). However, in some cases the outcome is not optimal with the standard 6- to 8-week protocol and therefore interest has focused on additional maintenance therapy. The present study was conducted to assess the utility of single monthly intravesical instillation treatments for up to 1 year in Japanese patients.
Methods: A total of 75 stage Ta and T1 patients who had undergone TUR-Bt were retrospectively evaluated, all first receiving 80 mg BCG (Tokyo 172 strain) given once a week, 6-8 times, for primary prophylaxis. Comparison was then made of groups with (group A, 48 patients) and without (group B, 27 patients) additional maintenance BCG therapy given once a month 6-8 times.
Results: Recurrence-free survival rates at 5 years in groups A and B were 83.0 and 51.9% (P = 0.006), despite the greater proportion of T1 patients and the longer follow-up period in the group A patients. Significant protection against recurrence persisted on multivariate analysis with adjustment for age, stage, grade, and tumor number.
Conclusions: These findings indicate maintenance BCG therapy of single intravesical instillations given once a month with our protocol to be definitely effective for prophylactic use, especially in stage Ta patients. Further evaluation of parameters such as the continuance period and dose protocol is warranted.