Epidemiology of esophageal cancer, especially adenocarcinoma of the esophagus and esophagogastric junction.

The incidence of adenocarcinoma of the esophagus and esophagogastric junction (EGJ) has been increasing over the past 15 years in western countries. Surgical series and population-based studies show that, by 1994, adenocarcinomas of the esophagus accounted for half of all esophageal cancer among white men. The causes of this increase in incidence remain to be elucidated. Esophageal adenocarcinomas and a portion of EGJ adenocarcinomas arise from long and short segments of specialized intestinal metaplasia (Barrett's esophagus). The prevalence of long segments of Barrett's esophagus (> 3 cm) in patients having endoscopy for reflux symptoms is 3%, and 1% in those undergoing endoscopy for any clinical indication. However, a silent majority of patients with Barrett's esophagus remain unrecognized in the general population and may not be diagnosed unless adenocarcinoma develops. Recent studies document a rise in the diagnosis of specialized intestinal metaplasia of the cardia. Nearly all these patients have associated carditis, and Helicobacter pylori infection has been linked to this condition. The possible origin of EGJ adenocarcinomas in the sequence carditis--specialized intestinal metaplasia needs to be clarified. Smoking and obesity are additional risk factors for adenocarcinoma of the esophagus and EGJ. Current data does not confirm H. pylori as a risk factor for cancer of the EGJ.