Positive association between dietary fat intake and risk of gastric stump carcinoma in rats

Effect of high- and low-fat diets on gastric stump carcino-genesiswas experimentally investigated. A total of 130 Wistar malerats weighing 250–300 g received either sham operationor Billroth II partial gastrectomy, the resection of the distaltwo-thirds glandular stomach and reconstruction of gastro-jejunostomy.After surgery, each group of rats was switched from a standarddiet (CRF-1) to a special diet containing either 15% soybeanoil (high-fat) or 0.5% soybean (low-fat), fed ad libitum andtap water, and were killed 50 weeks after surgery. Gastric tumourswere observed only in the animals that underwent gastrectomy,while no tumours were detected in the animals following thesham operation. Tumours located invariably at the gastrojejunostoma,were carcinomas or adenomas in histology. Carcinomas developedin 12 of 29 gastrectomy animals (41%) fed the high-fat dietand 4 of 27 gastrectomy animals (15%) fed the low-fat diet.The difference was significant (P < 0.05). The incidenceof adenoma was also significantly higher in the gastrectomyanimals fed the high-fat diet (38%) than that in those fed thelow-fat diet (15%) (P < 0.05). A daily faecal output of bileacids was significantly greater in the gastrectomy animals fedthe high-fat diet (19.0 ± 16.4 µmol/day) than thatin those fed the low-fat diet (11.2 ± 6.2 µmol/day;P < 0.05). This study suggests that increased fat intakeis associated with a high risk of gastric stump carcinoma.