Esophageal cancer is highly aggressive and is a common cancer both worldwide and in the US. In the past two decades, the incidence and mortality of esophageal cancer in the US have both increased, where as the incidence and mortality of other cancers have decreased. Although esophageal squamous cell carcinoma and esophageal adenocarcinoma differ in their histology and epidemiologic distribution, some of their risk factors (e.g. dietary deficiencies and tobacco) and underlying mechanisms of carcinogenesis are the same. Intensive research into risk factors combined with the ability to identify precursor lesions (e.g.squamous dysplasia in esophageal squamous cell carcinoma and Barrett's esophagus in esophageal adenocarcinoma) has paved the way for studies of chemoprevention for esophageal cancer, some of which have shown promising results.