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Overview

The esophagus is a long flexible tube that connects the stomach to the throat. After food is swallowed, the esophagus carries it to the stomach for digestion. The inside of the esophagus is lined with epithelium, a type of cell that secretes fluid and protects the inner muscular layers of the organ. Deeper layers of the esophagus are muscular. As the muscles contract and relax, food is moved down the esophagus into the stomach. There are approximately 12,000 new cases of esophageal cancer yearly in the United States. In approximately 90% of people with esophageal cancer, dysphagia (difficulty swallowing) is the first symptom.

Further information about cancer is available from sources such as The National Cancer Institute's Cancernet and The American Cancer Society's Cancer Resource Center.

Risk Factors

Many factors cause or contribute to esophageal cancer. The most prominent risk factors are cigarette smoking and excessive alcohol intake. These two factors are believed to contribute to 80% of the cases of esophageal cancer in the United States. Family history may play a role as well. Gastro-esophageal reflux disease (GERD) is linked to cancers occurring in the lower third of the esophagus - close to where the esophagus connects to the stomach. GERD occurs when acidic stomach contents flow back into the esophagus. GERD can cause dysplasia (abnormal cell growth), a condition that may lead to cancer.

Staging of Esophageal Cancer

The severity of cancer is described in terms of its stage. Stage 1 is least severe; stage 4 is most severe. These stages correlate with prognosis. In other words, a person with stage 1 cancer can be expected to live longer and is more likely to recover fully than a person with stage 4 cancer.

Cancer is staged on the basis of three criteria: tumor depth, lymph node involvement, and metastasis (spread). These criteria are abbreviated T (tumor depth), N (lymph node involvement) and M (metastasis).

Tumor depth

In the diagram below, tumor depths of d (dysplasia) through T2 are illustrated. Tis refers to carcinoma in situ, meaning cancer that is confined to a localized area. T1 tumors extend into the lamina propria or submucosa , the tissue layers on the inside of the esophagus. T2 tumors invade the inner muscular layer, known as the muscularis propria. T3 tumors extend into the outer layer of the esophagus (the adventitia). T4 tumors extend outside the esophagus. T3 and T4 tumors are more often associated with lymph node involvement and metastasis.

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Lymph node involvement

Lymph nodes are small bean-shaped organs that filter the blood and fight infections and other diseases. They are connected to each other by a network of vessels that forms the lymphatic system, one of the body's main defenses against disease.

Cancer spreads from the site where it started (the primary site) to other parts of the body through the blood vessels and the lymphatic system. Lymph node spread is diagnosed with a lymph node biopsy. In this procedure,a a physician takes a sample of the patient's lymph nodes and has them analyzed for evidence of cancer. The less lymph node involvement, the better.

Metastasis

Metastasis means spreading from the original or primary tumor site to other parts of the body. In general, the further away from the primary site that metastasis is found, the worse the likelihood of curing the cancer. Metastasis is diagnosed with bone scans, PET scans, CAT scans, and other procedures.