[Carcinogenesis in the pancreas].

The pancreatic carcinogen DHPN (dihydroxypropylnitrosamin) was administered to Syrian golden hamsters. By intragastric administration more pancreatic carcinomas in the head of the gland were induced than by subcutaneous injections. After choledochojejunostomy the incidence of carcinomas was only 5--7% and the lesions were similar in multiplicity and distribution without relationship to the way of administration. The importance of biliary reflux in pancreatic tumor induction is discussed and the role of bile concerning the preferred localisation of the tumors in the head of the pancreas. After ligation of the main pancreatic duct in the splenic lobe, the incidence, location and type of proliferative lesions distal and proximal to the ligature were recorded and compared to those of DHPN-treated hamsters without duct ligation. Proliferative duct lesions, including carcinomas, developed on either side of the ligation. While after subcutaneous administration the incidence was similar to the in nonligated animals, a markedly decreased incidence was found in orally treated animals with duct ligation. The findings show that DHPN reaches the pancreatic duct cell via blood circulation. Furthermore, it is suggested that an unimpaired release of pancreatic juice in the duodenum is necessary for the enteral resorption of DHPN. Referring to clinical data and according to the results of these experiments the procedure of choice in pancreatic surgery is total pancreatectomy in case of the local operable malignant pancreatic tumor. Otherwise from the pancreatic remnant after Whipple's procedure pancreatic carcinoma may develop again from precancereous lesions.