Comparison of sterile water irrigation versus intravesical mitomycin C in preventing recurrence of nonmuscle invasive bladder cancer after transurethral resection

INTRODUCTION: Early recurrence of nonmuscle invasive bladder cancer (NMIBC) following transurethral resection (TUR) remains relatively high. An immediate single instillation of mitomycin C (MMC) reduces the recurrence rates in the first 2 years but has not shown benefits in tumor progression or overall survival. Distilled water irrigation has shown to delay tumor recurrence by osmolysis of tumor cells. There are only limited clinical studies comparing the efficacy of MMC with continuous sterile water irrigation (CSWI) in preventing the recurrence of NMIBC after TUR in clinical setting. MATERIALS AND METHODS: A prospective, randomized, open-label, two-arm, single-center, pilot study was conducted between December 2013 and September 2015 at a tertiary-care center in South India. Patients were randomized into CSWI group (n = 19) or single dose intravesical MMC group (n = 17) following TUR for NMIBC and analyzed. All patients were followed up with flexible cystoscopy and urine cytology at 3 months interval for 1 year. Recurrence-free rate was estimated as the primary criterion for outcome analysis. RESULTS: At the end of 12 months, recurrence-free rates for MMC and CSWI groups were 47.1% and 52.6%, respectively. The mean recurrence-free interval for MMC and CSWI groups were 10.9 months and 9.8 months, respectively. The difference in recurrence-free rate or recurrence-free interval between two groups was statistically nonsignificant. Further, the complications in MMC group were significantly higher than that in CSWI group (P = 0.047). CONCLUSIONS: Continuous bladder irrigation with sterile water after TUR may be comparable to immediate single dose intravesical MMC in preventing tumor recurrence in NMIBC.