Esophageal cancer is a disease in which malignant (cancer) cells form in the tissues of the esophagus.

The esophagus is the hollow, muscular tube that moves food and liquid from the throat to the stomach. The wall of the esophagus is made up of several layers of tissue, including mucous membrane, muscle, and connective tissue. Esophageal cancer starts at the inside lining of the esophagus and spreads outward through the other layers as it grows.

The stomach and esophagus are part of the upper digestive system.

The two most common forms of esophageal cancer are named for the type of cells that become malignant (cancerous):

• Squamous cell carcinoma: Cancer that forms in squamous cells, the thin, flat cells lining the esophagus. This cancer is most often found in the upper and middle part of the esophagus, but can occur anywhere along the esophagus. This is also called epidermoid carcinoma.
• Adenocarcinoma: Cancer that begins in glandular (secretory) cells. Glandular cells in the lining of the esophagus produce and release fluids such as mucus. Adenocarcinomas usually form in the lower part of the esophagus, near the stomach.

Smoking, heavy alcohol use, and Barrett esophagus can increase the risk of developing esophageal cancer.

Risk factors include the following:

• Tobacco use.
• Heavy alcohol use.
• Barrett esophagus: A condition in which the cells lining the lower part of the esophagus have changed or been replaced with abnormal cells that could lead to cancer of the esophagus. Gastric reflux (the backing up of stomach contents into the lower section of the esophagus) may irritate the esophagus and, over time, cause Barrett esophagus.
• Older age.
• Being male.
• Being African-American.

The most common signs of esophageal cancer are painful or difficult swallowing and weight loss.

These and other symptoms may be caused by esophageal cancer or by other conditions. A doctor should be consulted if any of the following problems occur:

• Painful or difficult swallowing.
• Weight loss.
• Pain behind the breastbone.
• Hoarseness and cough.
• Indigestion and heartburn.

Tests that examine the esophagus are used to detect (find) and diagnose esophageal cancer.

The following tests and procedures may be used:

• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• Barium swallow: A series of x-rays of the esophagus and stomach. The patient drinks a liquid that contains barium (a silver-white metallic compound). The liquid coats the esophagus and stomach, and x-rays are taken. This procedure is also called an upper GI series.
  
  Barium swallow. The patient swallows barium liquid and it flows through the esophagus and into the stomach. X-rays are taken to look for abnormal areas.
• Esophagoscopy: A procedure to look inside the esophagus to check for abnormal areas. An esophagoscope is inserted through the mouth or nose and down the throat into the esophagus. An esophagoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue samples, which are checked under a microscope for signs of cancer.
  
  Esophagoscopy. A thin, lighted tube is inserted through the mouth and into the esophagus to look for abnormal areas.
• Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. The biopsy is usually done during an esophagoscopy. Sometimes a biopsy shows changes in the esophagus that are not cancer but may lead to cancer.