What Is Esophageal Cancer

  • 4 years ago
What Is Cancer of the Esophagus?
Cancer of the esophagus (also called esophageal cancer) starts when cells in the lining of the esophagus begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer?

To understand esophagus cancer, it helps to know about the normal structure and function of the esophagus.

The esophagus
The esophagus is a hollow, muscular tube that connects the throat to the stomach. It lies behind the trachea (windpipe) and in front of the spine. In adults, the esophagus is usually between 10 and 13 inches (25 to 33 centimeters [cm]) long and is about ¾ of an inch (2cm) across at its smallest point.


color illustration of the digestive system which shows the location of the esophagus, stomach, pancreas, transverse colon, descending colon, sigmoid colon, anus, rectum, appendix, cecum, ascending colon, small intestine, gallbladder and liver
At the opening of the upper esophagus there is a special ring of muscle (called the upper esophageal sphincter) that relaxes to open the esophagus when it senses food or liquid coming toward it.

When you swallow, food and liquids travel through the inside of the esophagus (called the lumen) to reach the stomach.

The lower part of the esophagus that connects to the stomach is called the gastroesophageal (GE) junction. A special ring of muscle near the GE junction, called the lower esophageal sphincter, controls the movement of food from the esophagus into the stomach. Between meals, it closes to keep the stomach’s acid and digestive juices out of the esophagus.

Where esophageal cancer starts
Esophageal cancer can start anywhere along the esophagus. It starts in the inner layer of the esophagus wall (see below), and grows outward through the other layers.


illustration showing the location of the esophagus in the body as well as a detailed cross section showing the layers of the esophagus including the mucosa (epithelium, lamina propria, muscularis mucosa), submucosa, muscularis propria and adventitia
The esophagus wall
The wall of the esophagus has several layers:

Mucosa: This layer lines the inside of the esophagus. It has 3 parts:

The epithelium is the innermost lining of the esophagus and is normally made up of flat, thin cells called squamous cells. This is where most cancers of the esophagus start.
The lamina propria is a thin layer of connective tissue right under the epithelium.
The muscularis mucosa is a very thin layer of muscle under the lamina propria.
Submucosa: This is a layer of connective tissue just below the mucosa that contains blood vessels and nerves. In some parts of the esophagus, this layer also includes glands that secrete mucus.

Muscularis propria: This is a thick layer of muscle under the submucosa. It contracts in a coordinated way to push food down the esophagus from the throat to the stomach.