Reflux of Gastroduodenal Juice and Esophageal Carcinogenesis in Rats

Masataka Segawa

Second Department of Surgery, School of Medicine, Kanazawa University

This study was designed to investigate the role of reflux of gastroduodenal juice in the genesis of esophageal carcinoma. Male Wistar rats, weighing approximately 200 g, were subjected to one of the following three operative procedures: a reflux procedure through the stoma (Group 1, n=11) which allowed duodenal contents to flow into the forestomach and esophagus through the gastrojejunostoma, a reflux procedure through the glandular stomach (Group 2, n=18) which made duodenal contents flow backward into the forestomach and esophagus via the glandular stomach, and a sham operation (Group 3, n=22). The animals were given a standard maintenance diet and tap water without administration of a carcinogen, and were killed and examined 50 weeks after surgery. No pathological changes were detected in Group 3. On the other hand, squamous cell carcinoma was found in three animals (27%) in Group 1 and three animals (17%) in Group 2. The incidence in each group was significantly higher than that in Group 3 (p<0.025, p<0.05, respectively). Squamous cell carcinoma appeared in the esophagus in two rats and in the forestomach in one rat in Group 1, whereas it appeared in the forestomach in three rats in Group 2. Dysplasia, intramural cyst with hyperplasia, regenerative thickening and hyperplasia were also observed only in the two reflux groups. These lesions were regarded as paracancerous. In addition, columnar epithelial metaplasia (Barrett's esophagus) and mucinous adenocarcinoma were found in a rat in Group 1. These findings suggested that reflux esophagitis may be associated not only with the development of Barrett's esophagus and mucinous adenocarcinoma but also with the genesis of squamous cell carcinoma.

Key words
duodenal juice, gastric juice, reflux esophagitis, esophageal carcinogenesis, Barrett's esophagus

Reprint requests
Masataka Segawa Department of Surgery, Toyama City Hospital
292 Imaizumi, Toyama, 939 JAPAN

Accepted
November 11, 1992

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