[Prophylactic effect of etretinate on the recurrence of superficial bladder tumors--results of a randomized control study].

The recurrence preventing effect of Etretinate on 174 superficial bladder tumors was examined by a randomized study using the envelope method. After transurethral resection of the bladder tumor, the tumor-free patients were divided into two groups, one administered one 10 mg capsule of Etretinate once a day, and the other group untreated (control group). As a rule, the patients were examined for recurrence every 3 months. There were 9 drop outs (9.6%) in the Etretinate group, and 8 (10%) in the control group. Therefore, 85 subjects in the Etretinate group and 72 patients in the control group were analyzed for statistics. The recurrence rate during the observation period of over 2 years was 38% in the control group and 18% in the Etretinate group, the number of relapsing cases in the latter group tending to be decreased (P less than 0.1). The cumulative recurrence inhibition rate for cases observed over one year tested by the Kaplan Meier method tended to be higher in the Etretinate group compared to the control group (P less than 0.1). Etretinate administration had a high recurrence inhibitory effect (P less than 0.05) in the cases of relapse, multiple tumors, and tumors less than 1 cm. Side effects of Etretinate administration were seen in 21 cases (22.3%). The major symptoms were dry lips, cheilitis, stomatitis, dermal desquamation, etc., and drug use was discontinued in 7 cases (7.4%). The symptoms all disappeared after drug administration was discontinued.