Clinical models of chemoprevention for the esophagus

The two principal types of esophageal cancer are (1) adenocarcinoma, derived from Barrett's metaplasia, and (2) squamous cell carcinoma, which arises from epithelial dysplasia. Adenocarcinoma occurs frequently in the United States and rarely in the Middle East and Far East, whereas the opposite is true for esophageal squamous cell carcinoma. Both cancers have a poor prognosis. Chemoprevention is likely to be a viable approach to reduce the incidence of and mortality from these diseases. Approaches for the chemoprevention of esophageal adenocarcinoma and squamous cell carcinoma are presented in this article, and events associated with both the initiation and promotion/progression stages of these diseases are addressed. The results of completed trials for the chemoprevention of these cancers are summarized, and suggestions are made for future trials involving additional strategies and endpoints.