Intravesical thio-tepa: a study of 3H-thymidine uptake in normal urothelium and FANFT-induced tumors in rats.

Treatment of superficial low-grade bladder cancer often incorporates intravesical instillations of the alkylating agent thio-TEPA. Current dosages and administration schedules are empiric inasmuch as cytokinetic data are sparse. The FANFT-induced bladder rat tumor model closely approximates human bladder cancer. This study measuring 3H-thymidine uptake identified peaks of maximal synthetic activity at 3 and 9 days after thio-TEPA exposure in both normal and neoplastic urothelium. Thus, repeat instillation at these intervals may improve cytotoxicity and overall response rate.