Esophageal cancer occurs when cancer cells develop in the esophagus, a tube-like structure that runs from your throat to your stomach. Food goes from the mouth to the stomach through the esophagus. The cancer starts at the inner layer of the esophagus and can spread throughout the other layers of the esophagus and to other parts of the body (metastasis).
There are two main types of esophageal cancer. One type is squamous cell carcinoma. Squamous cells line the inner esophagus, and cancer developing from squamous cells can occur along the entire esophagus. The other type is called adenocarcinoma. This is cancer that develops from gland cells. To develop adenocarcinoma of the esophagus, squamous cells that normally line the esophagus are replaced by gland cells. This typically occurs in the lower esophagus near the stomach and is believed to be largely related to acid exposure to the lower esophagus.
What Are the Symptoms of Esophageal Cancer?
Early on there may be no symptoms. In more advanced cancers, symptoms of esophageal cancer include:
- Difficulty or pain when swallowing
- Weight loss
- Pain in the chest, behind the breastbone
- Indigestion and heartburn
What Are Risk Factors for Esophageal Cancer?
There are a number of factors which increase a person's risk of developing esophageal cancer. They include:
- Gastroesophageal reflux disease (GERD), in which contents and acid from the stomach back up into the esophagus, significantly increase the risk of adenocarcinoma of the esophagus. It is estimated that about 30% of esophageal cancers are related to GERD.
- Smoking or other use of tobacco.
- Heavy alcohol use.
- Barrett's esophagus, a condition that affects the lower part of the esophagus and can lead to esophageal cancer. Barrett's esophagus may be caused by GERD. Over time, stomach acid in the esophagus can cause changes in the cells that increase risk for adenocarcinoma.
In addition, certain groups -- men, the elderly, and African-Americans -- are at greater risk for esophageal cancer.
How Is Esophageal Cancer Diagnosed?
To diagnose esophageal cancer, your doctor will review your symptoms, medical history, and examine you. In addition, he or she may order certain blood tests and X-rays.
Tests for esophageal cancer may include:
- Barium swallow X-ray, in which you drink a liquid that coats your esophagus. This makes the esophagus stand out on the X-ray so that your doctor can identify certain problems.
- Endoscopy: the doctor passes an endoscope, a thin, lighted tube, down your throat into your esophagus to examine it. Endoscopic ultrasound uses sound waves to provide more information about the extent of tumor involvement in nearby tissues.
- Biopsy: during an endoscopy, the doctor can take cells or tissue from your esophagus. The cells are examined under a microscope for the presence of cancer.
Other tests, including computed tomography (CT) scans, positron emission tomography (PET) scan, thoracoscopy, and laparaoscopy, may be performed to determine if the cancer has spread, or metastasized, outside of the esophagus. This process is called "staging." The doctor needs this information in order to plan your treatment.