Esophageal carcinogenesis in the rat: a model for aerodigestive tract cancer.

A number of chemical carcinogens have been used to study the process of esophageal carcinogenesis. Among the most prominent of these models is the induction of cancer of the esophagus in the rat by the nitrosamine N-nitrosomethylbenzylamine (NMBA). In the rat, tumors can occur within 15 weeks of carcinogen administration. The rat model has been used to investigate the mechanism of action of several chemopreventive agents. Among these, the garlic-derived agent diallyl sulfide has been shown to be a specific inhibitor of NMBA metabolism. Other investigators have used the model to seek out the relationship of dietary factors and alcohol in esophageal tumorigenesis. With striking histologic parallels to human esophageal carcinoma, the NMBA model provides useful information to study this cancer.