EFFECT OF STREPTOZOTOCIN DIABETES ON DEVELOPMENT OF NITROSAMINE-INDUCED PANCREATIC-CARCINOMA WHEN DIABETES INDUCTION OCCURS AFTER NITROSAMINE EXPOSURE

Diabetes mellitus has been suggested as a possible risk factor for the development of pancreatic cancer in humans. Previous studies in our l aboratory have shown, however, that streptozotocin (STZ) diabetes inhi bits the development of cancer of the exocrine pancreas in hamsters wh en STZ is administered prior to treatment with the pancreatic carcinog en N-nitrosobis(2-oxopropyl)amine (BOP). It has been reported by other s that the concurrent administration of BOP and STZ enhances pancreati c carcinogenesis in hamsters. The purpose of the present study was to determine the effect of STZ diabetes on the development of BOP-induced pancreatic carcinoma when STZ is given following exposure to BOP. Gro ups of Syrian golden hamsters were treated with either BOP only (singl e s.c. injection, 40 mg/kg body wt at week 0), BOP (single s.c. inject ion, 40 mg/kg body wt at week 0) plus STZ (50 mg/kg body wt x 3 daily i. p. doses at weeks 10, 20 or 30), STZ only (50 mg/kg body wt x 3 dai ly i.p. doses at weeks 10, 20 or 30), or neither BOP nor STZ. The expe riment was terminated at 40 weeks after BOP treatment. No significant difference was seen in the incidence of pancreatic cancer between thos e animals receiving BOP only at week 0 and those receiving BOP at week 0 plus STZ at weeks 10, 20 or 30 of the study. The results would appe ar to indicate that STZ diabetes, established after BOP tumor initiati on, plays no apparent role in the modulation of pancreatic carcinogene sis.