The majority of esophageal cancers are squamous cell or adenocarcinoma. Although the incidence of squamous cell carcinoma (SCC) is decreasing in the United States, the incidence of adenocarcinoma arising out of Barrett’s esophagus is rising dramatically .
The epidemiology, etiologic factors, and clinical manifestations of adenocarcinoma and SCC of the esophagus will be reviewed here. Small cell carcinoma and sarcomas arising in the esophagus as well as the diagnosis, staging, and treatment of esophageal cancer are discussed separately. (See "Extrapulmonary small cell cancer" and "Diagnosis and staging of esophageal cancer" and "Local treatment for gastrointestinal stromal tumors, leiomyomas, and leiomyosarcomas of the gastrointestinal tract", section on 'Esophagus'.)
In the United States, an estimated 18,170 cases of esophageal cancer will be diagnosed in 2013, and 15,450 deaths are expected from the disease . Worldwide, an estimated 482,300 new esophageal cancer cases and 406,800 deaths occurred in 2008 .
Incidence rates vary internationally by nearly 16-fold, with the highest rates found in Southern and Eastern Africa and Eastern Asia, and the lowest rates in Western and Middle Africa and Central America in both males and females . In the highest-risk area, stretching from Northern Iran through the central Asian republics to North-Central China (often referred to as the “esophageal cancer belt”), 90 percent of cases are squamous cell carcinomas (SCC) [4,5]. Major risk factors in these areas are not well understood, but are thought to include poor nutritional status, low intake of fruits and vegetables, and drinking beverages at high temperatures. In contrast, in low-risk areas such as the United States and several Western countries, smoking and excessive alcohol consumption account for about 90 percent of the total cases of esophageal SCC . Country-specific rates of incidence and mortality are available in the World Health Organization GLOBOCAN database. (See 'Smoking and alcohol' below.)
Temporal trends in incidence vary for the two major histologic types of esophageal cancer. Incidence rates for adenocarcinoma of the esophagus have been increasing in several Western countries, in part due to increases in known risk factors such as overweight and obesity. In contrast, rates for SCC have been steadily decreasing in these same countries because of long-term reductions in tobacco use and alcohol consumption. However, SCC of the esophagus has been increasing in certain Asian countries such as Taiwan, probably as a result of increases in tobacco and alcohol consumption .