The esophagus is a muscular tube that connects the mouth to the stomach. It carries food and liquids to the stomach. It is about 10-13 inches long. At its smallest point, it is a little less than one inch wide.

The wall of the esophagus has several layers. Cancer of the esophagus starts from the inner layer and grows outward.

At the top of the esophagus is a special muscle that relaxes to let food or liquid enter. This muscle is called a sphincter. The lower part of the esophagus connects to the stomach. Another muscle here opens to allow food to enter the stomach. This muscle also keeps stomach acid and juices out of the esophagus. When stomach juices escape into the esophagus, we feel heartburn. The medical term for heartburn is reflux.

Long-term reflux of stomach acid into the esophagus sets up a special problem. It can change the cells in the lower end of the esophagus. They become more like the cells that line the stomach. These changed cells produce a condition called Barrett esophagus. The altered cells can change into cancer, so they should be closely watched by a doctor.

There are 2 main types of cancer of the esophagus. One type grows in the cells that form the top layer of the lining of the esophagus. These are called squamous cells, and cancer that starts there is known as squamous cell carcinoma. Squamous cell cancer can grow anywhere along the length of the esophagus. It accounts for about half of all cancers of the esophagus.

The other type usually starts near the opening to the stomach. It is called adenocarcinoma. This type of cancer cannot start unless squamous cells have been changed by acid reflux.

Revised: 11/17/2005