The Preliminary Report of Rapid Production of Pancreas Cancer and Chelangiocarcinoma by Cyclic Injection of Carcinogens

Abstract

Background/Aims: It is well known thats N-nitrosobis (2-oxopropyl)amine (BOP)-induced pancreas cancer and cholangiocarcinoma in Syrian hamster is similar to that of humans in morphological, biological and immunological aspects. The cyclic administration of BOP and ethionine, cholinc-deficient diet and methionine is known to rapidly induce the ductal type of carcinoma in pancreas and bile duct. Authors studied whether the rapid production of this cancer can occur in Syrian hamster and what its features are.

Methods: Sixteen Syrian hamsters aged 6-7 weeks and weighing 100gm were used. All hamsters received 70 ㎎/㎏ body weight of BOP followed by three cycles of dl-ethionine, choline-deficient diet, 1-methionine and 20㎎/㎏ BOP. Hamsters were killed 9, 10 and 11 weeks after the beginning of the experiment and their gross and histologic features were observed.

Results: Nine cases, killed withan 10 weeks after the beginning of experiment, showed no development of cancer. Of seven Syrian hamsters, killed more than 10weeks after the beginning of experiment, the incidences of BOP-induced cancer included one case(14.3%) of pancreas cancer and five Cholangiocarcinomas(71.4%). The morphological change of pancreas carcinogenesis was shown at first in cell mitosis and atypia(6 weeks) and then in atypical ductal hyperplasia(9 weeks) and carcinoma in situ(10 weeks). The change in cholangiocarcinoma, first progressed with

ductular proliferation and surrounding fibrosis(6 weeks) followed by focal cholangiocarcinoina(10 weeks) and multiple invasive cholangiocarcinomas(11 weeks).

Conclusion: Pancreas cancer and intrahepatic cholangiocarcinomas can be induced rapidly within 10 weeks by cyclic injections of carcinogens in cyrian hamsters initiated with N-nitrosobis(2-oxopropyl)amine and the morphologic change, can be observed.