Most esophageal cancers can be classified as one of two types: adenocarcinoma or squamous cell carcinoma. A third type of esophageal cancer, called small cell carcinoma, is very rare. These different types of cancer begin in different kinds of cells in the esophagus. They develop in unique ways and call for approaches to treatment that are unique to each person.
Adenocarcinoma is the most common form of esophageal cancer in the United States, making up more than half of all new cases. It starts out in glandular cells, which are not normally present in the lining of the esophagus. These cells can grow there due to a condition called Barrett’s esophagus, which increases a person’s chance of developing esophageal cancer. Adenocarcinoma occurs mainly at the lower end of the esophagus and the upper part of the stomach.
Adenocarcinoma of the esophagus occurs most often in middle-aged, overweight, white men. Since the 1970s, the incidence of this disease has grown faster than almost any other cancer in the United States. Doctors say the rise may be due to an increase in the number of people with gastroesophageal reflux disease (GERD), a condition in which contents from the stomach, such as acid and bile, move up into the esophagus repeatedly, causing chronic inflammation.
Recent studies have shown that treating acid reflux reduces the risk of esophageal cancer.
Squamous Cell Carcinoma
The second most common form of esophageal cancer is squamous cell carcinoma. It begins when squamous cells (thin, flat cells lining the inside of the esophagus) begin to grow uncontrollably. Squamous cell carcinoma of the esophagus is strongly linked with smoking and drinking too much alcohol.
Small Cell Carcinoma
A third, rarer type of esophageal cancer is small cell carcinoma. It begins in neuroendocrine cells, a type of cell that releases hormones into the bloodstream in response to signals from nerves.