Cancer of the esophagus (also referred to as esophageal cancer) starts in the inner layer (the mucosa) and grows outward (through the submucosa and the muscle layer). Since 2 types of cells can line the esophagus, there are 2 main types of esophageal cancer:
Squamous cell carcinoma:The esophagus is normally lined with squamous cells. Cancer starting in these cells is called squamous cell carcinoma. This type of cancer can occur anywhere along the oesophagus. Once, squamous cell carcinoma was by far the more common type of oesophageal cancer in the United States. This has changed over time, and now it makes up less than half of esophageal cancers in this country.
Adenocarcinoma:Cancers that start in gland cells are called adenocarcinomas. This type of cell is not normally part of the inner lining of the esophagus. Before an adenocarcinoma can develop, gland cells must replace an area of squamous cells, which is what happens in Barrett’s esophagus. This occurs mainly in the lower esophagus, which is where most adenocarcinomas start. Adenocarcinomas that start at the area where the esophagus joins the stomach (the GE junction, which includes about the first 2 inches of the stomach called the cardia), tend to behave like cancers in the esophagus (and are treated like them, as well), so they are grouped with esophagus cancers.