Recurrence of superficial bladder carcinoma after intravesical instillation of mitomycin-C. Comparison of exposure times.

A total of 70 patients were treated with intravesical instillations of Mitomycin-C (MMC) following transurethral resection for superficial bladder carcinoma. In this randomised prospective study the influence of 2 exposure times (0.5 and 1 h) was studied in relation to tumour recurrence, recurrence interval, tumour progression and toxicity. The number of patients with recurrent tumours was significantly lower in the 1-h group. Tumour progression was seen in only 2 patients in each group and all had primary or secondary carcinoma in situ of the bladder or prostatic urethra. Fourteen patients were excluded from further evaluation because of side effects. A longer instillation time over a longer period and a lower dose of MMC are recommended.