Esophageal cancer is one of those diseases that sneaks up on people. The symptoms in many cases may not show up until the advanced stages of the illness. Dr. Bruce D. Greenwald, a professor of medicine in the division of gastroenterology and hepatology at the University of Maryland School of Medicine, said that the cancer has probably grown enough to block the esophagus by the time symptoms appear.It is estimated that about 17,000 people were diagnosed with esophageal cancer — about three times as many men as women. Greenwald, also chairman of the Esophageal Cancer Action Network, said those at greatest risk can get screened.
What is esophageal cancer, and who is likely to get it?
The esophagus is a muscular tube that connects the mouth to the stomach. With esophageal cancer, the cells lining the inside of the tube become cancerous.
Esophageal cancer is more common in those over 50 years old and about three times as likely in men compared to women.
There are two main types of esophageal cancer — squamous cell cancer, which occurs most often in the middle of the esophagus, and adenocarcinoma, which occurs most often in the lower part. Adenocarcinoma is the most common in the U.S.
Heavy alcohol and tobacco use are major risk factors for esophageal cancer, especially squamous cell cancer. Risk factors for adenocarcinoma include gastroesophageal reflux disease (GERD), Barrett's esophagus and obesity. In GERD [also called acid reflux], acid from the stomach escapes into the esophagus. The most common symptom of GERD is heartburn, a burning sensation in the chest. GERD may present in more unusual ways, such as chronic cough, hoarse voice, sore throat or even loss of dental enamel.
In Barrett's esophagus, the normal cells lining the lower esophagus are replaced by a different cell type due to chronic acid reflux, which damages the normal lining. Over time, these Barrett's cells can undergo a precancerous change called dysplasia. Dysplasia may progress to adenocarcinoma. Severe heartburn that goes away may be a sign that Barrett's esophagus has formed.
Obesity is another risk factor, probably due mostly to increased acid reflux in those who are overweight.
What are the symptoms?
Esophageal cancer may have no symptoms until it is in late stages. At that time, the most common symptom is difficulty swallowing or the sensation of food getting stuck before it reaches the stomach. This happens when the cancer has grown large enough to block the opening of the esophagus. Other symptoms may include chest pain and weight loss.
Early stage esophageal cancer often has no symptoms. It may be detected as part of a screening program. Screening those with chronic GERD [a major risk factor] may make sense. This is especially true in men, those who have severe GERD (especially nighttime heartburn or regurgitation) and other risk factors like being overweight. Those with Barrett's esophagus are checked regularly to detect any precancerous changes.
What screening or tests can diagnose esophageal cancer?
Screening for esophageal cancer is usually done by upper endoscopy [which is the most effective test for diagnosis]. In this outpatient procedure, a small flexible tube with a video camera and light at the tip is passed into the esophagus. This is usually done when a person is given medicine to make them sleepy. During endoscopy, a small sample of the cancer can be removed and examined under a microscope to make a diagnosis.
Other tests may be done to diagnose esophageal cancer. The most common are imaging tests and include barium swallow, computed tomography (CT) scan, magnetic resonance imaging (MRI) and positron emission tomography (PET) scan.
Newer techniques for screening for esophageal cancer are being studied. One of these uses an ultrathin endoscope passed into the esophagus while [the patient is] awake. The other uses a tiny sponge tied to a string and wrapped in a capsule. This sponge is swallowed, then removed by the string after the capsule dissolves. The sponge captures cells lining the esophagus, which can be studied to look for cancer.
Can it be confused with other diseases?
Other conditions can cause difficulty with swallowing. Chronic acid reflux may produce scarring in the esophagus, which narrows the esophageal opening and can block food and liquid. Eosinophilic esophagitis causes inflammation in the esophagus that stiffens the wall. This results in difficulty swallowing as well. These conditions can be detected through upper endoscopy and imaging studies.
How do you treat it, and how likely are patients to survive?
Treatment of esophageal cancer depends on the stage. Most cancers are diagnosed after they have spread through the wall of the esophagus and into adjacent tissues or lymph nodes. This stage of cancer is typically treated with chemotherapy, radiation therapy or both. Surgery may also be used to remove the diseased part of the esophagus. Very early cancers — those limited to the innermost lining of the esophagus — can be treated through upper endoscopy. These treatments can include removal or destruction of the cancerous cells.
Stage is one of the best predictors of survival. Data from the 2000s shows five-year survival [after diagnosis] when the cancer has spread to adjacent lymph nodes or other tissues is 21 percent. For those with cancer spread to other parts of the body, five-year survival is 4 percent. Early stage cancer, confined to the esophagus, has a 40 percent five-year survival [rate]. However, for very early cancers — usually those detected by screening — endoscopic treatment or surgery can produce five-year survival rates greater than 80 percent.
Where can I find more information?
More information about esophageal cancer can be found at websites for the National Cancer Institute (cancer.gov/types/esophageal), American Cancer Society (cancer.org), the National Comprehensive Cancer Network (.nccn.org/patients/guidelines/esophageal/) and the Esophageal Cancer Action Network (ecan.org).