BOP (N-nitroso-bis-2-oxyropyl-amine)-induced tumor spectrum in the European hamster: a further model of colon carcinogenesis?

In the European hamster (EH) weekly subcutaneous (s.c.) injections of BOP (N-nitroso-bis-2-oxypropyl-amine) (LD50, males: 174 mg/ kg boy-weight (b.w.) , females: 118 mg/kg b.w. induced adenocarcinomas of the colon in 77% (1/10 LD50), 70 % (1/20 LD50) and 87 % (1/40 LD50) of the treated animals combined incidence for both sexes (c.i.). Cholangiocellular carcinomas were produced in a dose-dependent manner with an incidence of 97 % (1/10 LD50), 43 % (1/20LD50) and 27 % (1/40 LD50). The incidence of tumors in the respiratory tractwas 43 % (1/10 LD50), 10 % (1/20 LD50) and 3 % (1/40 LD50) in the treated EH's. Transitional cell papillomas and carcinomas of the urinary tract were found in 30 % (1/10 LD50), 17 % (1/20 LD50) and 20 % (1/40 LD50) of the animals. Neoplasms of the exocrine pancreas occured in 6 % (overall incidence) of the BOP-treated EH's. The data presented in this paper show a difference between the BOP-induced tumor spectrum in European hamsters and that of Syrian hamsters. Th e high incidence of colon adenocarcinomas which developed dose-dependently may provide a further model of colon carcinogenesis.