Cancer is a disease in which cells grow in an uncontrolled way. If cells keep dividing when new cells are not needed, a mass of tissue called a tumor forms.
A tumor can be benign or malignant. A benign tumor is not cancer and will not spread to other parts of the body. A malignant tumor is cancer. Cancer cells invade and damage tissue around them. They can also enter the lymph and blood streams. From there, they spread to other parts of the body. Esophageal cancer is when cancer cells develop in the esophagus.
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Normal Anatomy and the Development of Esophageal Cancer
The esophagus is a muscular tube. It is about 12 inches long and connects the throat to the stomach. Chewed food is formed into a small mass in the mouth. Once the food is swallowed, the esophagus moves it down into the stomach. It uses rhythmic squeezing of the muscles.
The esophagus has 2 muscular rings called the upper and lower sphincters. The upper sphincter is controlled by swallowing. It allows food to move into the esophagus. The lower sphincter (LES) allow food to pass into the stomach. Once food passes through, the LES closes to help keep food and stomach acids in during digestion.
The inside lining of the esophagus is an active area. There can be a lot of cell damage which increases the need for new cell growth. The damage can be from stomach acid, alcohol, tobacco, and certain foods. Long term problems, such as gastroesophageal reflux disease (GERD), also cause damage and cell turnover. Higher rates of cell turnover raise the risk of cancer.
Tumors can cause blockages in the esophagus. This can make it hard to swallow food. The tumor can also grow beyond the esophagus. It can spread to the spine, airway, or a major artery. The cancer can cause damage to these structures as well. It can also spread to lymph nodes or blood vessels. There, the cancer can spread to other areas of the body, such as the lungs, liver, kidney, and bones.
Types of Esophageal Cancer
There are 2 main types of esophageal cancer:
- Squamous cell carcinoma—start from the innermost lining of the esophagus.
- Adenocarcinoma—start from cells closest to the stomach. This is linked to acid exposure in the esophagus from GERD. Barrett's esophagus is a change in esophageal cells which can lead to adenocarcinoma.
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References
Esophageal and esophagogastric junction cancer. EBSCO DynaMed Plus website. Available at: https://www.dynamed.com/condition/esophageal-and-esophagogastric-junction-cancer. Accessed April 22, 2022.
Esophagus cancer. American Cancer Society website. Available at http://www.cancer.org/acs/groups/cid/documents/webcontent/003098-pdf.pdf. Accessed April 22, 2022.
Esophageal cancer. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/gastrointestinal-disorders/tumors-of-the-gi-tract/esophageal-cancer. Accessed April 22, 2022.
General information about esophageal cancer. National Cancer Institute website. Available at: https://www.cancer.gov/types/esophageal/patient/esophageal-treatment-pdq#section/all. Accessed April 22, 2022.