Esophageal cancer is a relatively uncommon type of cancer in the United States. It is more prevalent in southern Africa, Iran, India and northern China where the incidence of the disease may be up to 100 times more than that in the United States. It was, in fact, in China that the first recorded case of esophageal cancer was found, some 2,000 years ago.
Esophageal cancer develops in the esophagus, which is a muscular tube that connects the oropharynx to the stomach. The lenth of esophagus is appromiately 25 cm. For a normal adult, the diameter of the esophagus at its smallest point is three quarters of an inch.
While relatively uncommon in the United States, esophageal cancer still affects thousands of individuals each year. The American Cancer Society projects more than 14,000 new cases of the disease in 2004; an estimated 13,300 deaths, on the other hand, will occur because of the disease in the same period.
Esophageal cancer is a treatable and curable disease. The problem often lies in how to detect the disease while it is still at an early stage. Most cases are diagnosed at an advanced stage, since it is usually at this juncture that the symptoms of esophageal cancer manifest themselves.
The two main types of esophageal cancer are squamous cell carcinoma and adenocarcinoma. The former used to account for most cases of esophageal cancer. Recent research has found, however, that squamous cell carcinomas now account for less than 50% of esophageal cancers.
Squamous cell carcinoma can start just about anywhere along the esophagus, since squamous cells line the entire esophagus.
On the other hand, adenocarcinoma develops in grandular tissue. It often occurs near the stomach, in the lower esophagus. It develops only when grandular cells replace an area of squamous cells.
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