Esophageal cancer develops in the inner lining of the esophagus. Because the esophagus may be lined by one of two types of cells—gland cells or squamous cells—doctors use the cell type to diagnose the disease, either as an adenocarcinoma or as a squamous cell carcinoma:
Adenocarcinomas of the esophagus are the most common type of esophageal cancer in the United States. Esophageal adenocarcinomas form in the mucus-forming gland cells of the esophageal lining, often in the lower part of the esophagus. Obesity and persistent acid reflux, which may or may not develop into Barrett"s esophagus, are associated with a higher risk for adenocarcinomas of the esophagus.
Squamous cell carcinomas develop in the thin, flat cells that make up the outermost layer of skin, most commonly in the upper and middle areas of the esophagus. Heavy alcohol and tobacco use are linked to an increased risk for squamous cell carcinoma of the esophagus.
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