Cancer is a disease in which cells grow in an abnormal way. Normally, the cells divide in a controlled manner. 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, spreading to other parts of the body. Esophageal cancer is the development of malignant cells in the esophagus.
Normal Anatomy and the Development of Esophageal Cancer
The esophagus is a muscular tube about 12 inches long that connects the throat to the stomach. It plays an important role in moving food down into the stomach. Chewed food is formed into a small group called a bolus. Once the bolus is swallowed, it is propelled down the esophagus, and into the stomach by a series of coordinated, rhythmic muscular contractions.
The esophagus has 2 muscular rings called the upper and lower sphincters. They open to allow food into the stomach and close to help keep food and stomach acids in the stomach during digestion.
Cell death and cell growth are a normal process in the body to replace old or damaged cells. The inside lining of the esophagus is an active area of the body that may have a high rate of cell turnover. Irritants introduced to the esophagus can increase inflammation and the rate of cell turnover, which increase the risk of a faulty growth-cancer. Irritants include stomach acid, alcohol, tobacco, and certain foods and chronic digestive conditions, such as gastroesophageal reflux disease (GERD).
Esophageal cancer tumors can cause blockages in the esophagus, which makes it difficult to swallow food. If the tumor grows beyond the esophageal layers, the cancer can penetrate nearby structures, such as the spine, the tube that carries air from the throat to the lungs (trachea), or the aorta (the body's largest artery). The cancer can cause damage to these structures and interfere with their function. It can also spread to lymph nodes or blood vessels, which can carry cancer cells to other areas of the body. The most common sites for metastatic esophageal cancer are the lungs, liver, kidney, and bones.
Types of Esophageal Cancer
There are 2 main types of esophageal cancer that are nearly all esophageal cancers found:
- Squamous cell carcinoma—Arise from the flat cells that make up the innermost lining of the esophagus.
- Adenocarcinoma—Arise from cells closest to the stomach. Associated with acid exposure in the esophagus from GERD. Barrett's esophagus is a change in esophageal cells which has a high risk of progressing into adenocarcinoma.
- Reviewer: Michael Woods, MD
- Review Date: 05/2015 -
- Update Date: 12/08/2015 -