What are the causes or risk factors for esophageal cancer?
Esophageal cancer occurs because changes occur in the DNA of cells that line the esophagus. The exact reason for these changes or mutations is uncertain, but there are known risk factors for developing these cancers.
- Squamous cell cancer of the esophagus is related to the use of alcohol and tobacco products, both smoke and smokeless. When the two are used together, the risk of this type of cancer increases.
- Adenocarcinoma involves the lower third of the esophagus and is thought to be related to gastro-esophageal reflux disease (GERD). When acid backwashes from the stomach into the lower esophagus, inflammation and cell damage may occur. Over a period of time, abnormal cells begin to form (metaplasia) and if the GERD is not treated and inflammation continues, the lining of the esophagus begins to change the way it looks and functions (dysplasia).
- Barrett's esophagus describes abnormal dysplasia and is thought to perhaps be a precursor to the development of further cell mutations and adenocarcinoma.
- Smoking increases the risk of adenocarcinoma.
- Other potential risk factors for esophageal cancer include esophageal burns due to accidental or intentional swallowing of caustic materials such as bleach; unusual infections with yeast, fungi, or human papillomavirus (HPV); and certain unusual foods (for example betel nuts that are prominent in some Asian diets).
- Esophageal cancer tends to be a disease of older people, usually occurring after the age of 65, and tends to affect males much more frequently than females.
- Achalasia, a motility disease of the esophagus where it does not contract appropriately, increases the risk of esophageal cancer.
- There are some chromosome and gene abnormalities that are associated with an increased risk of esophageal cancer.
- There has been a shift in the type of esophageal cancer that is now prevalent in the United States and Western Europe. In the past, squamous cell cancer was the most common worldwide, but that has changed. Adenocarcinoma is more common than squamous cell cancer in western countries, including the U.S. The reason for this change has yet to be determined.