Esophageal Cancer Facts

Esophageal cancer begins when abnormal cells in the esophagus grow out of control. The esophagus is the muscular tube that carries food and liquids from your throat to your stomach.

The two main types of esophageal cancer are adenocarcinoma and squamous cell carcinoma. Although both begin in the esophagus, they tend to develop in different areas and have different risk factors. Adenocarcinoma is the most common type in the United States and usually develops in the lower esophagus. Squamous cell carcinoma can develop anywhere along the esophagus.

Esophageal cancer can be difficult to detect early because it may not cause noticeable symptoms until the tumor has grown. However, advances in endoscopy, surgery, radiation therapy, chemotherapy, immunotherapy, targeted therapy, and biomarker testing have expanded treatment options.

What are the main types of esophageal cancer?

• Adenocarcinoma: This cancer begins in glandular cells and usually develops in the lower part of the esophagus, close to the stomach. Chronic acid reflux, Barrett's esophagus, and excess body weight are important risk factors.

• Squamous cell carcinoma: This cancer begins in the thin, flat squamous cells that normally line the esophagus. It can occur anywhere in the esophagus, but it is more commonly found in the upper and middle portions. Tobacco and heavy alcohol use are important risk factors.

Rare cancers can also begin in the esophagus, including neuroendocrine tumors, lymphomas, melanomas, and sarcomas.

What is the esophagus?

The esophagus is a hollow, muscular tube that connects your throat to your stomach. It is part of the digestive system and is responsible for moving food and liquids into the stomach after you swallow. In adults, the esophagus is about 10 inches long. It begins behind the throat, travels through the chest, passes through an opening in the diaphragm, and connects with the upper part of the stomach.

What does the esophagus do?

When you swallow, muscles in the wall of the esophagus contract in coordinated waves. This movement is called peristalsis. It pushes food and liquid downward toward the stomach.

At the bottom of the esophagus is a ring of muscle called the lower esophageal sphincter. It opens to allow food into the stomach and then normally closes to help prevent stomach acid and other contents from flowing backward.

When stomach contents frequently flow back into the esophagus, it is called gastroesophageal reflux disease, or GERD. Long-term GERD can damage the lining of the esophagus and increase the risk of certain types of esophageal cancer.

What are the layers of the esophagus?

The wall of the esophagus contains several layers. These layers are important because doctors consider how deeply a tumor has grown through the esophageal wall when determining the stage of cancer.

From the inside outward, the main layers include:

• Mucosa: The innermost lining that comes into contact with food and liquids.

• Submucosa: Connective tissue containing blood vessels, nerves, and glands.

• Muscularis propria: Layers of muscle that contract to move food toward the stomach.

• Adventitia: The outer connective tissue surrounding the esophagus.

Unlike many organs in the digestive system, most of the esophagus does not have a protective outer layer called a serosa. This anatomy can affect how cancer spreads from the esophagus into nearby tissues.

How does esophageal cancer develop?

Cancer begins when cells develop abnormal changes that allow them to grow and divide when they normally would not. Most esophageal cancers begin in the innermost lining. As the tumor grows, it can extend deeper into the esophageal wall and eventually reach lymph nodes, nearby tissues, or distant organs.

Adenocarcinoma

Adenocarcinoma develops from glandular cells and usually occurs in the lower esophagus. It is strongly associated with Barrett's esophagus, a condition in which long-term acid reflux causes the cells lining the lower esophagus to change. Barrett's esophagus is not cancer. Most people with Barrett's esophagus never develop esophageal cancer. However, having Barrett's increases the risk of developing esophageal adenocarcinoma.

Squamous cell carcinoma

Squamous cell carcinoma develops from the flat squamous cells that normally line the esophagus. It can occur anywhere in the esophagus but is more commonly found in the upper and middle portions. Tobacco use and heavy alcohol consumption are major risk factors.