Intravesical instillation of bacillus Calmette-Guérin (BCG) is most effective in the long term when selected as initial prophylactic treatment to prevent recurrence of superficial bladder cancer, according to a Japanese study.
The finding is based on a retrospective study of 213 patients with Ta-T1 transitional cell carcinoma of the bladder who received BCG instillations to prevent cancer recurrence following transurethral resection. The patients received six to eight weekly instillations of 40, 60, or 80 mg of Tokyo strain BCG. Another six to eight monthly instillations were given in some cases. Fourteen patients (6.6%) previously had received intravesical instillations of anti-cancer drugs.
Recurrence occurred in 68 patients (31.9%). Overall recurrence-free rates were 70.8%, 67.1%, and 57.6% at three, five, and 10 years, respectively, reported Takehiko Okamura, MD, of Aichi Anjo Kosei Hospital in Aichi, and colleagues. Progression occurred in 13 of the 68 patients. The mean interval to progression was 20 months. Progression-free survival rates at three, five, and 10 years were 94.5%, 93.6%, and 90.6%, respectively.
Recurrence-free rates were significantly higher among patients without previous intravesical treatment. The rates were 73.9%, 70.8%, and 60.7% at three, five, and 10 years in the no-previous-treatment group versus 26.8% and 17.9% at three and five years in the previous-treatment group. No patient in this group had 10 years of follow up.
Despite the retrospective design of the study and the existence of possible biases between the groups receiving BCG as first- and second-line treatment, the authors observed, study findings indicate that BCG should be used for first-line prophylaxis in this patient population.