The esophagus is a hollow muscular tube that connects the mouth to the stomach. Each time you swallow food or liquid, the esophagus transports it to the digestive system.
Esophageal cancer can develop when cells in the soft tissues lining this tube begin to grow and divide abnormally, forming a tumor. Tumors typically start in the innermost layer of the esophagus and then spread outward. The spread of cancer from the esophagus to the lymph nodes and other organs is called metastasis.
Esophageal cancer is considered rare compared with cancers of the breast, lung, or prostate. Nevertheless, the number of diagnoses for one of the two main types of esophageal cancer, adenocarcinoma, has risen dramatically in the past few decades.
Types of Esophageal Cancer
Most esophageal tumors can be classified as one of two types — adenocarcinoma or squamous cell carcinoma. A third type of esophageal cancer, called small cell carcinoma, is very rare. Because different types of cancer begin in different kinds of cells, they develop in different ways and call for different approaches to treatment.
Adenocarcinoma is the most common form of esophageal cancer in the United States, accounting for more than 50 percent of all new cases. It starts out in glandular cells, which are not normally present in the lining of the esophagus. These cells can grow there due to a condition called Barrett’s esophagus, which increases a person’s chance of developing esophageal cancer. Adenocarcinoma occurs mainly at the lower end of the esophagus and the upper part of the stomach, known as the gastroesophageal junction or the GE junction.
Adenocarcinoma of the esophagus occurs most often in middle-aged white men. Since the 1970s, the disease has become more common more rapidly than any other cancer in the United States. Doctors say the rise may be due to an increase in the number of people who develop gastroesophageal reflux disease (GERD), a condition in which contents from the stomach, such as acid, move up into the esophagus repeatedly, causing chronic inflammation. Researchers are trying to determine whether treating acid reflux may reduce the risk of esophageal cancer.
The second most common form of esophageal cancer is squamous cell carcinoma. This type of cancer begins when squamous cells, thin flat cells that line the inside of the esophagus, mutate and begin to grow uncontrollably. Squamous cell carcinoma of the esophagus is strongly linked with smoking and the consumption of excessive amounts of alcohol.
A third, rarer type of esophageal cancer is small cell carcinoma. Similar to small cell lung cancer, this type of esophageal cancer begins in neuroendocrine cells, a type of cell that releases hormones into the bloodstream in response to nerve signals.
Gastroesophageal Reflux Disease and Esophageal Cancer
Normally, a sphincter muscle at the end of the esophagus opens to allow food to enter the stomach and closes to prevent harmful digestive acids from bubbling back up into the esophagus. When this sphincter muscle does not function normally, however, it can lead to a condition known as GERD. Studies have shown that having severe GERD over the course of many years increases the chance of developing gastroesophageal adenocarcinoma.
Symptoms of Esophageal Cancer
In many cases, esophageal cancer is diagnosed after a person begins to experience symptoms. Some of the most common symptoms of esophageal cancer include:
- Difficulty swallowing. As the tumor grows, it can narrow the tube through which food and liquids move to the stomach.
- Pain or discomfort in the chest. Some people with esophageal cancer feel pressure or a burning sensation.
- Weight loss and lack of appetite. As swallowing becomes more difficult, many people begin to eat less, leading to involuntary weight loss.
- Other symptoms. Some patients with esophageal cancer experience other symptoms such as hoarseness, a persistent cough, hiccups, pneumonia, bone pain, and bleeding in the esophagus.
Because many of these symptoms are also associated with other medical conditions, having any of them does not necessarily mean that you have esophageal cancer. If you experience any of these symptoms, speak with your doctor. The earlier you are evaluated, the better the chance of detecting esophageal cancer at an earlier stage, when treatment can be more effective.