Basic characteristics of esophageal cancer

Esophageal cancer is a disease that results from cancerous changes in normal esophageal cells.

The esophagus is a hollow, muscular tube that carries food from the pharynx to the stomach. The esophageal wall consists of a mucosal layer (lining), a muscular layer, and connective tissue. Most esophageal cancers occur in the lining of the esophagus and gradually expand to the outer layer as they grow.

Gastrointestinal (digestive) system anatomy; drawing shows the esophagus, liver, stomach, small intestine, and large intestine.

The esophagus and stomach are part of the upper gastrointestinal tract.

The two most common types of esophageal cancer, based on the type of cancerous cells, include:

Squamous cell carcinoma: a malignant tumor that occurs in the squamous epithelium of the esophagus, also called epidermoid carcinoma. It is commonly found in the upper and middle segments of the esophagus, but may occur anywhere in the esophagus.

Adenocarcinoma: Cancer that begins in glandular cells. Glandular cells in the esophageal wall produce and release fluid such as mucus. Most adenocarcinomas occur in the lower part of the esophagus, near the stomach.

Esophageal cancer is more common in men.

Men have three times the risk of developing esophageal cancer than women. The risk of esophageal cancer increases with age. Black people are more likely to develop esophageal squamous cell carcinoma than Caucasians.

In the United States, the incidence of esophageal adenocarcinoma has gradually increased over the past 20 years, and today esophageal adenocarcinoma is more common than esophageal squamous cell carcinoma. In contrast, the incidence of esophageal squamous cell carcinoma is gradually decreasing.