The esophagus is the hollow, muscular tube that moves food and liquid from the throat to the stomach. The wall of the esophagus is made up of several layers of tissue, including mucous membrane, muscle, and connective tissue. Esophageal cancer starts at the inside lining of the esophagus and spreads outward through the other layers as it grows.
The wall of the esophagus has several layers:
- Mucosa - This is the layer that lines the inside of the esophagus and is comprised of three parts:
- The epithelium forms the innermost lining of the esophagus and is made up of flat, thin cells called squamous cells. This is where most cancers of the esophagus start.
- The lamina propria is a thin layer of connective tissue right under the epithelium.
- The muscularis mucosa is a very thin layer of muscle under the lamina propria.
- Submucosa: This is a layer of connective tissue just below the mucosa that contains blood vessels and nerves. In some parts of the esophagus, this layer also contains glands that secrete mucus.
- Muscularis Propria: This is a thick band of muscle under the submucosa. This layer of muscle contracts in a coordinated, rhythmic way to push food along the esophagus from the throat to the stomach.
- Adventitia: This is the outermost layer of the esophagus, which is formed by connective tissue.
Esophageal cancer starts in the inner layer (the mucosa) and grows outward (through the submucosa and the muscle layer). Since two types of cells can line the esophagus, there are two main types of esophageal cancer: squamous cell carcinoma and adenocarcinoma.
The esophagus is normally lined with squamous cells. The cancer starting in these cells is called squamous cell carcinoma. This type of cancer can occur anywhere along the esophagus. Cancers that start in gland cells are called adenocarcinomas. This type of cell is not normally part of the inner lining of the esophagus. Before an adenocarcinoma can develop, gland cells must replace an area of squamous cells, which is what happens in Barrett's esophagus. This occurs mainly in the lower esophagus, which is the site of most adenocarcinomas.
Cancers that start at the area where the esophagus joins and the first two inches of the stomach behave and are treated like esophagus cancers, so are grouped with esophageal cancers.
Risk Factors & Symptoms
Following are common risk factors for the disease:
- Tobacco and heavy alcohol use
- Barrett Esophagus (A condition in which the cells lining the lower part of the esophagus have changed or been replaced with abnormal cells that could lead to cancer of the esophagus. Gastric reflux may irritate the esophagus and cause Barrett esophagus.)
- Older Age
- Being Male
- Being African-American
Signs and Symptoms
The most common signs of esophageal cancer are painful or difficult swallowing and weight loss.
These and other symptoms may be caused by esophageal cancer or by other conditions. A doctor should be consulted if any of the following problems occur:
- Painful or difficult swallowing
- Weight loss
- Pain behind the breastbone
- Hoarseness and cough
- Indigestion and heartburn
Diagnosis and Staging
If a patient has symptoms that could be esophageal cancer, the doctor will test for fever and high blood pressure and check general signs of health. The patient will likely have one or more of the following tests:
An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
A series of x-rays of the esophagus and stomach. The patient drinks a liquid that contains barium (a silver-white metallic compound.) The liquid coats the esophagus and stomach and x-rays are taken. Also, called an Upper GI Series.
A procedure to look inside the esophagus to check for abnormal areas. An esophagoscope is inserted through the mouth or nose and down the throat into the esophagus. An esophagoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue samples, which are checked under a microscope for signs of cancer.
The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. The biopsy is usually done during an esophagoscopy. Sometimes a biopsy shows changes in the esophagus that are not cancer but may lead to cancer.
Stages of Esophageal Cancer
- Stage 0 (Carcinoma in Situ) - In stage 0, abnormal cells are found in the innermost layer of tissue lining the esophagus. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.
- Stage I - In stage I, cancer has formed and spread beyond the innermost layer of tissue to the next layer of tissue in the wall of the esophagus.
- Stage II - This stage is divided into stage IIA and stage IIB, depending on where the cancer has spread.
- Stage IIA: Cancer has spread to the layer of esophageal muscle or to the outer wall of the esophagus.
- Stage IIB: Cancer may have spread to any of the first three layers of the esophagus and to nearby lymph nodes.
- Stage III - In this stage, cancer has spread to the outer wall of the esophagus and may have spread to tissues or lymph nodes near the esophagus.
- Stage IV - This stage is divided into stage IVA and stage IVB, depending on where the cancer has spread
- Stage IVA: Cancer has spread to nearby or distant lymph nodes
- Stage IVB: Cancer has spread to distant lymph nodes and/or organs in other parts of the body.
Knowing the stage assists the doctor in determining a prognosis. It also better helps you understand the care and treatment that will be required.
Different types of treatment are available for patients with esophageal cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. (A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer)
Your treatment options depend on the stage of cancer, your overall health and your preferences about treatment. In metastatic disease, the location and extent of the esophageal cancer is also an important consideration.
In all cases, treatment should be individualized for you. Although cancers are classified into particular stages, each person is unique. You do not have to rush to make a decision, so consider the options carefully. Research shows that cancer survivors of all educational levels and backgrounds can have a hard time communicating with their health care team. One of the best ways to improve communication with your health care team is to prepare your visits so that you can best make use of the time.
A treatment plan is a way to deal with both the short and long term goals of managing your esophageal cancer. There are several treatment options for esophageal cancer, depending on the cancer stage and the patient’s age and general health. Patients have time for second opinions and to talk through all of their options with their doctors and develop a treatment plan that best fits their needs.
It helps to learn more about the side effects from your treatment(s) before you begin, so you will know what to expect. When you know more, you can work with your health care team to manage your quality of life during and after treatment.
Many people with esophageal cancer find it hard to eat because they have trouble swallowing. The esophagus may be narrowed by the tumor or as a side effect of treatment. Some patients may receive nutrients directly into a vein. Others may need a feeding tube (a flexible plastic tube that is passed through the nose or mouth into the stomach) until they are able to eat on their own.
There are effective and readily available medications to address traditional side effects from cancer treatment (such as nausea, diarrhea, constipation and mouth sores.) Also, as newer 'targeted therapies' become available, they tend to leave people with fewer traditional side effects.
Keep in mind that everyone reacts differently to treatment and experiences side effects differently. There are coping mechanisms and strategies that can help.
Surgery is the most common treatment for cancer of the esophagus. Part of the esophagus may be removed in an operation called an esophagectomy. A portion of the esophagus is removed. The doctor will connect the remaining healthy part of the esophagus to the stomach so the patient can still swallow. A plastic tube or part of the intestine may be used to make the connection. If the esophagus is partly blocked by the tumor, an expandable metal stent (tube) may be placed inside the esophagus to help keep it open.
Surgery of the esophagus has some risks. A heart attack or a blood clot in the lungs or the brain can occur during or after the operation. Infection is a risk with any surgery and lung complications, such as pneumonia are common.
Although no longer common, a leak at the place where the stomach is connected to the esophagus may develop and require another operation. After the operation, the stomach may empty too slowly because the nerves that control its contractions can be affected by surgery, which can lead to frequent nausea and vomiting. Strictures (narrowing) can form where the esophagus is surgically connected to the stomach, which may cause problems swallowing for some patients.
After surgery, bile and stomach contents can enter the esophagus because the lower esophageal sphincter is often removed or changed by the surgery. This can cause symptoms such as heartburn. Sometimes antacids or motility drugs can help relieve these symptoms.
Radiation Therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Side effects of external radiation therapy may include skin changes, nausea and vomiting, diarrhea, fatigue, painful sores in the mouth and throat and dry mouth or thick saliva. During treatment by external radiation, the radiation kills the normal cells in the lining, which can lead to painful swallowing. This starts shortly after beginning treatment but typically improves within a few weeks of finishing.
Most side effects of radiation are temporary, but some rare serious side effects can be permanent. In some cases, radiation to the chest can also cause lung damage, which may lead to problems breathing and shortness of breath.
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.
Side effects depend on the specific drugs and the dose and include hair loss, loss of appetite, nausea and vomiting, diarrhea, fatigue, and mouth sores. In addition, certain chemotherapy drugs can cause numbness and tingling of the hands and feet.
Immunotherapy helps your body’s immune system to identify, attack, and kill cancer cells.
Side effects may include fatigue, diarrhea, skin rash, itching, cough, joint pain, fever, or nausea.
Laser therapy is a cancer treatment that uses a laser beam(a narrow beam of intense light) to kill cancer cells.
Electrocoagulation is the use of an electric current to kill cancer cells.