Pancreatic carcinogenicity of N-nitrosobis(2-oxopropyl)-amine in diabetic and non-diabetic Chinese hamsters.

To examine the role of diabetes in pancreatic cancer, 4 groups of Chinese hamsters--2 from genetically diabetic and 2 from non-diabetic lines--were treated with N-nitrosobis(2-oxo-propyl)amine (BOP) at different dose levels and intervals. In one group (referred to as the VA group), BOP was given weekly at a 5 mg/kg body wt. level for 18 or 23 weeks, whereas the other group (the EP group) received a weekly dose of 2.5 mg/kg body wt. for life. Except for diet and experimental design, all other laboratory conditions were similar in the two institutions. No VA hamster developed tumors. Three of 22 non-diabetic EP hamsters (but none of the diabetic hamsters) developed pancreatic hyperplastic and neoplastic lesions, comprising ductular cell adenomas (3 hamsters), carcinoma in situ (1 hamster), a well-differentiated adenocarcinoma (1 hamster), and a poorly differentiated adenocarcinoma (1 hamster) with regional lymph node metastases. In addition, over 50% of the EP hamsters had neoplasms for which the incidences and morphology did not vary between diabetic and non-diabetic groups or between the sexes. These were primarily of the liver (cholangiomas), lungs (adenomas) and skin (trichoepitheliomas, squamous cell carcinomas). The differing carcinogenic response of the two hamster groups to BOP apparently is not related to the total BOP dose, but rather to other factors, including the length of observation time.