(Cancer of the Esophagus)
Esophageal cancers develop in the cells that line the wall of the esophagus (the tube that connects the throat to the stomach).
Tobacco and alcohol use, human papillomavirus infections, and certain esophageal disorders are major risk factors for certain types of esophageal cancer.
Typical symptoms include difficulty swallowing, weight loss, and, later, pain.
The diagnosis is based on an endoscopy.
Unless discovered early, almost all cases of esophageal cancer are fatal.
Surgery, chemotherapy, and various other therapies can help relieve the symptoms.
The most common types of esophageal cancer are squamous cell carcinoma and adenocarcinoma, which develop in the cells that line the wall of the esophagus. Squamous cell carcinoma is more common in the upper part of the esophagus. Adenocarcinoma is more common in the lower part. These cancers may appear as a narrowing (stricture) of the esophagus, a lump, an abnormal flat area (plaque), or an abnormal connection (fistula) between the esophagus and the airways that supply the lungs. Less common types of esophageal cancer include leiomyosarcomas (cancers of the smooth muscle of the esophagus) and metastatic cancer (cancer that has spread from elsewhere in the body).
Each year in the United States, cancer of the esophagus accounts for an estimated 17,290 cases and 15,850 deaths. Both squamous cell carcinoma and adenocarcinoma are more common among men than women. Squamous cell carcinoma is more common among blacks, whereas adenocarcinoma is more common among whites. The frequency of adenocarcinoma has been increasing rapidly in the United States since the 1970s, especially among white men.
Tobacco use (any kind) and alcohol are the main risk factors for developing esophageal cancer, although more so for squamous cell carcinoma than for adenocarcinoma. People who have had certain human papillomavirus infections, who have had head and neck cancer, or who have undergone radiation therapy to the esophagus for treatment of other nearby cancers are at greater risk of developing esophageal cancer.
People with an existing disorder of the esophagus, such as achalasia, esophageal webs (Plummer-Vinson syndrome), or narrowing due to having once swallowed a corrosive substance (such as lye), are also at greater risk of developing squamous cell esophageal cancer. Most adenocarcinomas develop in people who have a precancerous condition called Barrett esophagus. Barrett esophagus develops from prolonged irritation of the esophagus caused by the repeated backflow of stomach acid (gastroesophageal reflux). Obese people have an increased risk of adenocarcinoma because of their higher risk of gastroesophageal reflux.
Early-stage esophageal cancer may go unnoticed. The first symptom of esophageal cancer is usually difficulty in swallowing solid foods, which develops as the growing cancer narrows the esophagus. Several weeks later, swallowing soft foods and then liquids and saliva becomes difficult. Weight loss is common, even when the person continues to eat well. People may have chest pain, which feels like it travels to the back.
As the cancer progresses, it commonly invades various nerves and other tissues and organs. The tumor may compress the nerve that controls the vocal cords, which can lead to hoarseness. Compression of surrounding nerves may cause spinal pain, paralysis of the diaphragm, and hiccups. The cancer usually spreads to the lungs, where it may cause shortness of breath, and to the liver, where it may cause fever and abdominal swelling. Spread to bones may cause pain. Spread to the brain may cause headache, confusion, and seizures. Spread to the intestines may cause vomiting, blood in the stool, and iron deficiency anemia. Spread to the kidneys often causes no symptoms.
In late stages, the cancer may completely block the esophagus. Swallowing becomes impossible, so secretions build up in the mouth, which can be very distressing.
Endoscopy, in which a flexible viewing tube (endoscope) is passed through the mouth to view the esophagus, is the best diagnostic procedure if esophageal cancer is suspected. Endoscopy also allows the doctor to remove a tissue sample (biopsy) and loose cells (brush cytology) for examination under a microscope.
An x-ray procedure called a barium swallow (in which the person swallows a solution of barium, which shows up on x-rays) can also show the obstruction. Computed tomography of the chest and abdomen and ultrasonography done through an endoscope (see ultrasound scanning) inserted in the esophagus may be used to further assess the extent of the cancer.
Because esophageal cancer usually is not diagnosed until the disease has spread, the death rate is high. Fewer than 5% of people survive more than 5 years. Many die within a year of noticing the first symptoms. Exceptions include adenocarcinomas that are diagnosed when they are still very shallow (superficial). These shallow cancers sometimes are cured by being burned away with radio waves (radiofrequency ablation) or cut away through an endoscope.
Surgery to remove a tumor offers the most prolonged relief but seldom cures, because the cancer usually has spread by the time of surgery. Chemotherapy combined with radiation therapy (see Combination Cancer Therapy) may relieve symptoms and lengthen survival time by a few months. Sometimes radiation therapy combined with chemotherapy is done before surgery and can increase survival.
Other measures are aimed at relieving symptoms, particularly difficulty swallowing. Such measures include stretching open the narrowed area of the esophagus and then inserting a flexible metal mesh tube (a stent) to keep the esophagus open, burning the cancer with a laser to widen the opening, and using radiation therapy to destroy the cancer tissue obstructing the esophagus.
Another technique for symptom relief is photodynamic therapy, in which a light-sensitive dye (contrast agent) is given by vein (intravenously) 48 hours before treatment. The dye is absorbed by cancer cells to a much greater degree than by the cells of normal surrounding esophageal tissue. When activated by light from a laser passed into the esophagus through an endoscope, the dye destroys cancer tissue, thus opening the esophagus. Photodynamic therapy destroys obstructing lesions more rapidly than radiation or chemotherapy in people who cannot tolerate surgery because of poor health.
Adequate nutrition makes any type of treatment more feasible and tolerable. People who can swallow may receive concentrated liquid nutritional supplements. People who cannot swallow may need to be fed through a tube placed through the wall of the abdomen into their stomach (gastrostomy tube).