[Prophylactic effect of pirarubicin (THP) on postoperative recurrence of superficial bladder cancer in terms of intravesical retention time].

In order to determine the modality of prophylactic intravesical instillation of pirarubicin (THP = tetrahydropyranyladriamycin) following transurethral resection (TUR) of superficial bladder cancer, a prospective randomized study was performed. A total of 79 patients were randomized into "2-hour instillation" (A), "5-min instillation" (B) and "control" (C) groups. Prophylactic efficacy and side effects were analyzed in each group. In groups A and B, 20 mg of THP was first dissolved in 10 ml of distilled water, adjusted to 40 ml with saline and was administered intravesically once a week for 10 weeks, starting from 1 week after TUR. The recurrence-free rate was calculated in 65 evaluable patients. The one-year recurrence-free rate was 70.2% in group A, 62.8% in group B and 52.1% in group C. The one-year recurrence-free rate was significantly higher in group A than in group C. Adverse effects were observed in 21.4% of the patients in group A and 40.7% in group B. There was no significant difference in the occurrence rate of side effects between these two groups. Taking the prophylactic efficacy and side effects into consideration, "2-hour instillation" seemed to be better than "5-min instillation".