According to the American Cancer Society, more than 16,000 Americans are diagnosed with esophageal cancer each year. It affects men much more often than women. Middle-aged men who are overweight with a history of acid reflux (heartburn) seem to be at the highest risk. Because the disease often has no symptoms in the early stages, it is usually detected at a more advanced stage that is more challenging to treat.
The esophagus is a foot-long tube that carries food and liquids from the mouth to the stomach. Its lining has several layers. Esophageal cancer begins in the cells of the inside lining. It then grows into the channel of the esophagus and the esophageal wall.
A sphincter, a special muscle that relaxes to let food in or out, is on each end of the esophagus. The one at the top lets food or liquid into the esophagus. The one on the bottom lets food enter the stomach.
This sphincter also prevents stomach contents from going back into the esophagus. If stomach juices with acid and bile come into the esophagus, it causes indigestion or heartburn. Reflux and gastroesophageal reflux disease (GERD) are the medical names for heartburn.
If you have reflux for a long time, the cells at the end of the esophagus change to become more like the cells in the intestinal lining. This is called Barrett’s esophagus, and it is a pre-malignant condition which can become esophageal cancer, and needs to be watched closely.
Esophageal Cancer Types
The types of esophageal cancer are named after the cells where they begin.
Adenocarcinoma is the most common type of esophageal cancer in western societies, especially in white males. It starts in gland cells in the tissue, most often in the lower part of the esophagus near the stomach. The major risk factors include reflux and Barrett’s esophagus.
Squamous cell carcinoma or cancer, also called epidermoid carcinoma, begins in the tissue that lines the esophagus, particularly in the middle and upper parts. In the United States, this type of esophageal cancer is on the decline. Risk factors include smoking and drinking alcohol.
This is the most common type of esophageal cancer worldwide. In other countries, including Iran, northern China, India and southern Africa, this type of esophageal cancer is much more common than in the United States.
The best thing you can do to prevent esophageal cancer is to not smoke or drink too much alcohol. Visit our prevention and screening section to learn how to manage your risk.
Esophageal Cancer Risk Factors
Anything that increases your chance of getting esophageal cancer is a risk factor. Long-term heartburn or reflux is a factor in half of esophageal cancers. Other esophageal cancer causes and risks include:
- Long-term history of smoking: Half of squamous cell esophageal cancers involve smoking. Smoking also increases the risk of adenocarcinoma.
- Drinking too much alcohol, especially if you smoke
- Barrett's esophagus, a condition in which chronic acid reflux causes changes in the cells lining the lower esophagus
- Age: Most cases of esophageal cancer are in people over 55.
- Gender: Men are three times more likely than women to develop esophageal cancer.
- Achalasia, a disease in which the sphincter, or muscle, at the bottom of the esophagus fails to open and move food into the stomach
- Tylosis, a rare, inherited disorder that causes excess skin to grow on the soles of the feet and palms. It has a near 100% chance of developing into esophageal cancer.
- Esophageal webs: These flaps of tissue protrude into the esophagus, making swallowing difficult
- Lye ingestion or being around dry-cleaning chemicals
- Diet and weight: Risk is higher if you are overweight, tend to overeat or do not eat a healthy diet
- History of other squamous cell cancers related to tobacco use
Not everyone with risk factors gets esophageal cancer. However, if you have risk factors, you should discuss them with your doctor.