Intravesical instillation of mitomycin C in the prophylactic treatment of recurring superficial transitional cell carcinoma of the bladder.

Twenty-six patients with an elevated recurrence rate of stage O or A bladder tumours were treated prophylactically after transurethral resection (TUR) with short-term intravesical instillations of mitomycin C in a non-randomised study. The data before intravesical chemotherapy (IVC) were taken as the internal control for each patient. Mitomycin C was administered in one course of 10 daily doses of 40 mg, starting 24 to 48 hours after TUR. The average follow-up was 13.9 months before and 28.5 months after IVC. Before IVC, the average number of recurrences was 2.6, with an average recurrence rate of 1 every 5.3 months. After IVC there was no tumour recurrence in 4 patients, with a mean of 12.2 months' follow-up, but there was tumour recurrence in 22 patients. For 17 patients (77%) the free interval averaged 2.3 times longer than the mean interval of recurrence before IVC and for 18 patients (82%) the recurrence rate averaged 3.3 times less than the recurrence rate before IVC.