Current knowledge of pancreatic carcinogenesis in the hamster and its relevance to the human disease.

Syrian hamsters present a unique species for induction of pancreatic tumors that in many aspects resemble human pancreatic cancer. The specific response of Syrian hamsters, in contrast to may other rodents, for development of pancreatic ductal (ductular) tumors is not yet known. All pancreatic carcinogens thus far tested show certain common features. They are all nitrosamines that possess or can be metabolized to compounds with 2-oxopropyl- or 2-hydroxypropyl substituents. All but one, N-nitroso-methyl(2-oxopropyl)amine, occur or metabolize to nitrosamines with the ability to cyclize and form structures resembling glucose. Hence it is suggested that this cyclic structure may be responsible for the pancreatic carcinogenicity of these nitrosamines, as has been proposed for the pancreatotropic effect of streptozotocin. It is also of further interest that one pancreatic ductal (ductular) carcinogen, N-nitroso-2-methoxy-2,6-dimethylmorpholine, which possesses a totally cyclic structure, acts, like streptozotocin, as beta-cell cytotoxic and diabetogenic when given in a high single dose. Modification of pancreatic tumor induction has been demonstrated by specific procedures. A high fat diet significantly increases both the incidence and number of induced cancers. Methods for early diagnosis and therapy are being developed and their significance and applicabilities for clinical use will be of major importance. Compared with the other most common types of human cancer, pancreatic cancer has extraordinary characteristics, which make the disease one of the most mysterious of maladies. Consequently, pancreatic cancer represents a serious international problem and requires urgent resolution, especially with regard to its etiology, early diagnosis, prevention, and therapy.