[Effect of intrabladder instillation of various anticancer agents on carcinogenesis in rat bladder]

After administration of N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) to 6-week-old, female F344 rats, various anticancer agents and immunotherapeutic agents were injected into the bladder and their effects were investigated. Injection of adriamycin and mitomycin C (MMC) into the bladder a total of 12 times, 4 weeks after administration of BBN markedly promoted carcinogenesis of the bladder. Injection of bleomycin, cis-dichlorodiamine platinum (CDDP) and picibanil into the bladder a total of 12 times, 4 weeks after administration of BBN did not promote carcinogenesis and CDDP exhibited a tendency to inhibit carcinogenesis. Injection of MMC, CA (cytarabine) and MMC + CA into the bladder a total of 12 times, 4 weeks after administration of BBN indicated that CA has the potential to inhibit the bladder carcinogenesis-promoting effect of MMC. Injection of CDDP and MMC into the bladder a total of 12 times, 20 weeks after administration of BBN inhibited proliferation of bladder carcinoma. Additionally, administration each of CDDP and MMC alone exhibited a carcinogenic effect on the bladder. The above-described results show that considerable care should be taken and that long-term observation of course is required with the use of anticancer agents such as ADM and MMC.