Esophageal cancer occurs when cancer cells develop in the esophagus, a tube-like structure that runs from your throat to your stomach. Food goes from the mouth to the stomach through the esophagus. The cancer starts at the inner layer of the esophagus and can spread throughout the other layers of the esophagus and to other parts of the body (metastasis).
There are two main types of esophageal cancer. One type is squamous cell carcinoma. Squamous cells line the inner esophagus, and cancer developing from squamous cells can occur along the entire esophagus. The other type is called adenocarcinoma. This is cancer that develops from gland cells. To develop adenocarcinoma of the esophagus, squamous cells that normally line the esophagus are replaced by gland cells. This typically occurs in the lower esophagus near the stomach and is believed to be largely related to acid exposure to the lower esophagus.
What Are the Symptoms of Esophageal Cancer?
Early on there may be no symptoms. In more advanced cancers, symptoms of esophageal cancer include:
What Are Risk Factors for Esophageal Cancer?
There are a number of factors which increase a person's risk of developing esophageal cancer. They include:
- Smoking or other use of tobacco
- Heavy alcohol use
- Gastroesophageal reflux disease (GERD), in which contents and acid from the stomach back up into the esophagus
- Barrett's esophagus, a condition that affects the lower part of the esophagus and can lead to esophageal cancer; Barrett's esophagus may be caused by GERD. Over time, stomach acid in the esophagus can cause changes in the cells that increase risk for adenocarcinoma.
In addition, certain groups -- men, the elderly, and people who are obese -- are at greater risk for esophageal cancer. Risk of adenocarcinoma of the esophagus is higher in white men, but squamous cell carcinoma of the esophagus is more common in Asian men and men of color.
How Is Esophageal Cancer Diagnosed?
To diagnose esophageal cancer, your doctor will review your symptoms, medical history, and examine you. In addition, he or she may order certain blood tests and X-rays.
Tests for esophageal cancer may include:
- Barium swallow X-ray, in which you drink a liquid that coats your esophagus. This makes the esophagus stand out on the X-ray so that your doctor can identify certain problems.
- Endoscopy: the doctor passes an endoscope, a thin, lighted tube, down your throat into your esophagus to examine it. Endoscopic ultrasound uses sound waves to provide more information about the extent of tumor involvement in nearby tissues.
- Biopsy: during an endoscopy, the doctor can take cells or tissue from your esophagus. The cells are examined under a microscope for the presence of cancer.
Other tests, including computed tomography (CT) scans, positron emission tomography (PET) scan, thoracoscopy, and laparoscopy, may be performed to determine if the cancer has spread, or metastasized, outside of the esophagus. This process is called "staging." The doctor needs this information in order to plan your treatment.
What Are the Stages of Esophageal Cancer?
The stages of esophageal cancer are given a number (I through IV); the higher the number, the more advanced the cancer. The stages are:
- Stage 0 . Abnormal cells (not yet cancer) are found only in the layer of cells that line the esophagus.
- Stage I . Cancer cells are found only in the layer of cells that line the esophagus.
- Stage II . The cancer has reached the muscle layer or the outer wall of the esophagus. In addition, the cancer may have spread to 1 to 2 nearby lymph nodes (small glands that are part of the immune system).
- Stage III . The cancer has reached deeper into the inner muscle layer or the connective tissue wall. It may have spread beyond the esophagus into surrounding organ and/or has spread to more lymph nodes near the esophagus.
- Stage IV . This is the most advanced stage. The cancer has spread to other organs in the body and/or to lymph nodes far from the esophagus.
There are several tests to determine the stage of esophageal cancer, including:
- Chest X-ray .
- Bronchoscopy. Thetrachea(windpipe) and airways are examined with a bronchoscope, a thin, lighted tube that is inserted through the nose or mouth. This test is used to check for cancer involvement in the trachea or branching airways.
- CT scan. A procedure that creates sharp pictures of the inside of the body.
- Endoscopicultrasound, or endosonography . Used during endoscopy, sound waves bounce off organs in the body to create pictures called sonograms. This test can provide more information on the size and extent of the tumor.
- Thoracoscopy . An endoscope is placed into the chest through an incision to examine the inside of the chest to look for lymph nodes and other chest organs that may have cancer spread. Biopsies can be done during this procedure.
- Laparoscopy . The lighted tube is inserted through an incision in the abdomen to examine the abdominal organs and take tissue samples to check for cancer spread.
How Is Esophageal Cancer Treated?
As with many cancers, esophageal cancer treatment has a greater chance of success if the cancer is caught early. Unfortunately, by the time esophageal cancer is diagnosed for many people, it is often already in an advanced stage (has spread throughout the esophagus and beyond).
Treatment of esophageal cancer depends on many factors, including the stage of the cancer and the overall health of the patient.
- Surgery . Part or all of the esophagus may be removed.
- Radiation therapy. Kills cancer cells with radiation.
- Chemotherapy. Powerfuldrugs that attack cancer cells throughout the body; typically used in combination with radiation therapy and/or surgery.
- Targeted therapy. Newer treatments that target specific aspects of a cancer to curb cancer growth and spread.
- Immunotherapy. Helps the immune system to attack cancer cells.
- Photodynamic therapy. Targets cancer cells with a special laser light.
- Electrocoagulation. Uses electric current to destroy cancer cells.
- Cryotherapy. Freezes cancer cells to help shrink a tumor.
Endoscopic mucosal resection may be done to treat precancers or very small early cancers by removing the inner lining of the esophagus. Radiofrequency ablation treatment using a device that targets cancer cells with radiofrequency energy is sometimes used for early cancers.
In addition, your doctor may recommend that you take part in a clinical trial, in which new drugs or treatments are tested in patients. The success of these tests helps determine if the drugs or treatments will be approved by the Food and Drug Administration.
How Are the Stages of Esophageal Cancer Treated?
Treatment options for esophageal cancer by stage may involve the following:
- Stage 0 . Options include surgery, photodynamic therapy, radiofrequency ablation, or endoscopic muscosal resection.
- Stage I, II, and III . Surgery, chemotherapy, radiation
- Stage IV . Chemotherapy, radiation, targeted therapy, immunotherapy; treatment for this stage focuses on "palliative" therapy. Palliative therapy is meant to relieve the pain and difficulty swallowing caused by cancer.
According to the American Cancer Society, the percentages of people who live for at least five years after being diagnosed with esophageal cancer (taking into account that some people with esophageal cancer will have other causes of death) is 43% for localized cancer to the esophagus, 23% for cancer that has spread regionally, and 5% with distant cancer spread.