[Prophylactic intravesical instillation therapy in patients with superficial bladder cancer--results of a randomized prospective study].

A randomized prospective study was conducted for the purpose of investigating the efficacy of intravesical chemoprophylaxis of superficial bladder cancers. Eligible patients were randomized into three groups: 1) adriamycin (ADM) group; intravesical instillation with 50 mg of ADM dissolved in 100 ml physiological saline, 2) mitomycin C (MMC) group; intravesical instillation with 30 mg of MMC dissolved in 100 ml of physiological saline, 3) control group; transurethral resection or transurethral coagulation only. The characteristic features of our protocol consisted of frequent (six times) instillations of the drugs within two weeks after transurethral resection, followed by instillations on two consecutive days at four-week intervals for two years. Furthermore, large quantities (100 ml) of instillation fluid containing relatively low concentrations of the drugs (500 micrograms/ml for ADM or 300 micrograms/ml for MMC) were employed. One hundred and forty-four patients have been submitted to the study; 110 patients were fully evaluable for recurrence and 34 patients were eliminated as non-evaluable patients. The cumulative five-year non-recurrence rates of the patients with multiple tumors were 32% in the MMC group, 25% in the ADM group and 7% in the control group. The cumulative non-recurrence rates of the ADM and MMC groups were significantly higher than that of the control group. It is considered that this instillation therapy with ADM and MMC is useful for preventing the recurrence of superficial bladder cancers.