The esophagus begins at the level of the cricopharyngeus and traverses the length of the neck to pass through the mediastinum. It then pierces the right crus of the diaphragm and after a short abdominal component joins the stomach at the cardia. For descriptive purposes the esophagus is referred to as cervical (∼6 cm), thoracic (∼25 cm), and abdominal (∼4 cm). Surgeons often refer to the esophagus in divisions of one-third, upper, middle, and distal, as this better relates to the operative options in esophagectomy.
Although not as common as cancer of other sites such as prostate, breast, and colorectum, esophageal cancer has a high lethality rate, the incidence being close to the cancer-specific mortality. Thus, in the USA in 2006, esophageal carcinoma was the 15th commonest cancer, with an estimated 14,550 cases, but it had the 8th highest mortality rate, with an estimated 13,770 deaths.
Esophageal cancer is remarkable for its marked variation by geographical region, ethnicity, and gender. There is a greater than tenfold difference in incidence rates between countries with a low incidence, for example, the United States, and those with a high incidence such as high-risk areas in Iran and China. More than 90% of esophageal cancers are either squamous cell carcinomas (SCCs) or adenocarcinomas, with other tumor types such as melanomas, stromal tumors, lymphomas, or neuroendocrine cancers occurring only rarely in the esophagus.