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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 two most common forms of esophageal cancer are named for the type of cells that become malignant:
- 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.
Estimated new cases and deaths from esophageal cancer in the
United States in 2007:
- New cases: 15,560
- Deaths: 13,940
Symptoms and Diagnosis
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.
To 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 x-rays
are taken. This procedure is also called an upper GI series.
- Esophagoscopy: A procedure to look inside the
esophagus to check for abnormal areas. An esophagoscope (a thin, lighted
tube) is inserted through the mouth or nose and down the throat into the
esophagus. Tissue samples may be taken for biopsy.
- Biopsy: The removal of cells or tissues so
they can be viewed under a microscope 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.
Causes
All cancers are caused by dysfunctions of proteins involved in cell division, apoptosis, or DNA repair (see general characteristics). Dysfunctional proteins may arise from gene mutations or protein interactions with environments. The following
factors may increase the risk of developing esophageal cancer:
- Tobacco use.
- Heavy alcohol use.
- Barrett´s 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´s esophagus.
- Older age.
- Being male.
- Being African-American.
Reference:
National Cancer Institute, USA.
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