Prophylactic intravesical instillation of mitomycin C and cytosine arabinoside for prevention of recurrent bladder tumors following surgery for upper urinary tract tumors: A prospective randomized study

Background: A recurrence of bladder tumors following surgery for transitional cell carcinoma of the upper urinary tract is not rarely observed. A prospective randomized study was conducted to examine the significance of prophylactic intravesical instillation of mitomycin C (MMC) and cytosine arabinoside (Ara-C) to prevent recurrent bladder tumors after surgery for superficial transitional cell carcinoma of the upper urinary tract. Methods: The patients were randomized into an instillation group, who received postoperative intravesical instillation of MMC (20 mg) and Ara-C (200 mg) 28 times over a period of 2 years, and a non-instillation group. The non-recurrence rate was then compared between the groups. Results: Of the 27 patients registered, 25 patients (13 with instillation and 12 without instillation) were able to be evaluated with a median follow-up period of 45 months. The non-recurrence rate of bladder tumors in the instillation group was higher than that in the non-instillation group. Although the difference was not statistically significant, the P-value (P = 0.079) demonstrated a strong trend. When any possible bias was allowed for a multivariate analysis, the difference was almost significant (P = 0.0567). NO patients withdrew from this study due to any side-effects. Conclusion: The postoperative instillation of MMC and Ara-C may be a useful approach for reducing the recurrence of bladder tumors after surgery for upper urinary tract tumors.