Overview: the changing nature of esophageal cancer.

Squamous cell carcinomas of the esophagus, while still frequent in many locations throughout the world, now comprise a smaller percentage of esophageal cancers in the United States than was previously believed. Such tumors occur most often in black men and in association with tobacco and alcohol abuse. Adenocarcinomas of the distal esophagus represent an increasing proportion of esophageal tumors. These neoplasms arise in columnar epithelium (ie, Barrett's esophagus) or extend into the esophagus from their site of origin in the proximal stomach. Esophageal adenocarcinomas appear more often in white than black subjects and in men more than women. The clinical features and diagnostic approaches to squamous cell tumors and adenocarcinomas of the esophagus are similar.