Effectiveness of an Immediate Mitomycin C Instillation in Patients with Superficial Bladder Cancer Receiving Periodic Mitomycin C Instillation

PURPOSE: We analyzed the impact of immediate intravesical mitomycin C instillation after transurethral resection of the bladder (TURB) on tumor recurrence and progression in patients with periodic mitomycin C instillation. MATERIALS AND METHODS: Between June 2000 and June 2006, a retrospective study was performed in a total of 115 patients with primary bladder tumors receiving a 6-week course of mitomycin C instillation after TURB. The patients were assigned to two groups: 53 patients in the immediate mitomycin C (I-MMC) group were treated by immediate instillation of mitomycin C after TURB and periodic instillation (6 times, 1 time per week), and 62 patients in the MMC group received only periodic instillation. Tumor recurrence and progression were compared in the two groups. RESULTS: During the mean follow-up period of 46.5 months in the I-MMC group and 47.2 months in the MMC group, early recurrence (within 1 year) occurred in 6 of 53 patients (11.3%) in the I-MMC group and in 18 of 62 patients (29.0%) in the MMC group (p<0.02). Although a significantly lower early recurrence rate was observed in the I-MMC group, this difference was not significant for recurrence within 2 or 3 years or for total recurrence. Progression was not significantly different between the two groups regarding the early and total period. CONCLUSIONS: Our study confirmed the positive effect of a single, immediate mitomycin C instillation in patients with non-muscle-invasive bladder tumors who received periodic mitomycin C instillation. This benefit was limited to early recurrence and was not maintained with long-term follow-up. This approach can be an alternative to periodic mitomycin C instillation without immediate instillation.