Long-term outcome of a low-dose intravesical bacillus Calmette-Guerin therapy for carcinoma in situ of the bladder: results after six successive instillations of 40 mg BCG.

Background: In Japan, bacillus Calmette-Guerin (BCG: Tokyo 172 strain) instillation is generally performed at a dose of 80 mg once weekly for eight consecutive weeks; however, many adverse effects including severe ones have been reported. We employed a dose of 40 mg once a week for six consecutive weeks in principle for carcinoma in situ (CIS) of the bladder, and retrospectively evaluated its effectiveness and safety.

Methods: A total of 43 patients with CIS of the bladder were treated by this method and followed-up for a subsequent 12-79 months (median, 54 months). The patients consisted of 35 males and eight females aged 45-87 years (mean, 67.5 years). Intravesical BCG instillation at a dose of 40 mg was conducted once a week for six consecutive weeks.

Results: A complete response (CR) was achieved in 84% of the patients, in whom the recurrence-free rate was 72.4% after 3 years and 61.9% after 5 years. The median CR duration was 37.5 months. Two patients underwent total cystectomy, but none died of bladder cancer. As adverse effects, bladder irritation symptoms were observed in 48.8%, pyuria in 46.5%, macroscopic hematuria in 18.6% and fever (>37.5 degrees C) in 9.3%. There were no severe adverse effects requiring discontinuation of drug administration.

Conclusions: Our present study corroborated both the effectiveness and safety of low-dose BCG therapy for CIS of the bladder. This therapy warrants further study by prospective randomized trials in the future.