The esophagus is the hollow muscular tube that carries solid food and liquids from the throat to the stomach during digestion. Cancer of the esophagus begins in the innermost layer of esophageal tissue and grows outward.
According to the American Cancer Society, about 16,470 people in the United States will be diagnosed with esophageal cancer in 2008.
Types of Esophageal Cancer
The two main types of esophageal cancer are squamous cell carcinoma, which usually arises from the cells of the upper or middle of the esophagus, and adenocarcinoma. A third, rarer type of esophageal cancer is small cell carcinoma, which is a kind of neuroendocrine tumor.
While adenocarcinoma is a rare type of cancer in this country, the incidence of adenocarcinoma of the lower end of the esophagus and upper part of the stomach (known as the gastroesophageal, or GE, juncture) has increased more rapidly since the 1970s than any other cancer in the US, especially in young and middle-aged white men. Doctors suspect that this may be due in part to an increasing incidence of gastroesophageal reflux disease, or GERD. Researchers are seeking to determine if treating acid reflux may reduce the risk of esophageal cancer.
GERD develops as a result of chronic backward flow of stomach acid contents into the esophagus. Normally, a muscle at the end of the esophagus, called a sphincter, opens to allow food to enter the stomach and closes to prevent harmful digestive acids from the stomach from bubbling up into the esophagus. When stomach juices gurgle into the esophagus -- a condition called "reflux" -- the result is heartburn. GERD is also called long-term acid reflux.
Long-term irritation of the esophagus due to exposure to stomach acid (GERD) may lead over time to a condition known as Barrett's esophagus. This is a condition in which squamous cell tissue lining the lower part of the esophagus near the opening of the stomach is replaced by glandular tissue similar to that in the stomach lining in response to constant exposure to stomach acids. In a small percentage of patients, these cells can become cancerous and lead to cancer (adenocarcinoma) of the esophagus.
For more information about GERD and Barrett's esophagus, visit that section of this cancer information overview.
