Objectives: To evaluate the effectiveness and side effects of prophylactic low-dose bacille Calmette-Guérin (BCG) Tokyo 172 strain.
Methods: We conducted a historical cohort study to compare the clinical usefulness of standard-dose versus low-dose BCG Tokyo 172 strain. A total of 156 patients with superficial bladder cancer (Stage Ta-T1) were historically allocated to either 40 or 80 mg of BCG after transurethral resection. Of the 156 patients, 89 had received standard-dose (80 mg) BCG from 1988 to 2000 and 67 had received low-dose (40 mg) BCG from 1996 to 2005. BCG was instilled into the bladder once a week for 6 consecutive weeks. We excluded 6 patients who did not complete the BCG treatment course. The median follow-up period was 66.9 months (range 2 to 176).
Results: Tumor recurrence developed in 21 (32.3%) of 65 patients in the 40-mg group and 29 (34.5%) of 85 patients in the 80-mg group. No significant difference was found in the incidence of tumor recurrence between the two groups (P = 0.6377). Tumor progression was found in 4 (6.2%) of 65 patients in 40-mg group and 9 (10.6%) of 85 patients in the 80-mg group. No significant difference was found in tumor progression between the two groups (P = 0.5010). The overall incidence of side effects and severity of pollakisuria were significantly lower in the 40-mg group than in the 80-mg group (P = 0.012 and P = 0.013, respectively).
Conclusions: The low-dose BCG Tokyo 172 strain achieved identical recurrence-free and progression-free survival as the standard dose with reduced toxicity.