Abstract
Histologic observations were performed on the pancreatoduodenal region of a female Syrian golden hamster treated with 10mg /kg body weight N-nitrosobis (2-oxopropyl) amine (BOP) once a week for 6 weeks with and without cholecystectomy. Cholecystectomy was perfomed 5 weeks before the first BOP initiation.
Pancreatoduodenal cancer occurred in 10 of the 13 (77%) hamsters receiving cholecystectomy plus BOP injection (group 1), and in 11 of the 14 (79%) hamsters injected with the BOP alone (group 2).
Macroscopically, common bile duct dilatation occurred in 7 out of 10 (70%) hamsters in group 1 and 8 out of 11 (73%) hamsters in group 2. Histologically, common bile duct obstruction was induced by common duct cell carcinoma in 5 out of 7 (71%) hamsters in group 1 and by pancreatic duct cell carcinoma in 7 out of 8 (88%) hamsters in group 2 with a significant difference between the groups.
In a clinical study, 10 patients who had had bile duct dilatation associated with gallstones or cholecystectomy were found among 50 patients with pancreato-duodenal cancer. Three of them had cholecystectomy, and 2 had a gallbladder out of function. Carcinoma was in the region of the lower bile duct or the ampulla of Vater in all 5 patients. This finding, combined with the observation of the incidence of carcinoma in the common bile duct in hamsters with cholecystectomy in the experimental study, suggests the involvement of the condition of the gallbladder excised or out of function in the incidence of cancer in the lower biliary tract.
