The esophagus is a muscular tube between the mouth and stomach. It's about 25 cm to 35 cm (10 to 14 inches) long in an average adult and about 2 cm (¾ inch) wide. The esophagus is made up of several layers. The cancer usually begins in the innermost layer and works its way outwards. Cancer can occur anywhere along the length of the esophagus. However, most esophageal cancers occur in the lower-third region of the esophagus.
Esophageal cancer is three times more common among men than women and is found more often in people of African descent than in Caucasians. Although it accounts for approximately 1% of all cancers in the North American population, esophageal cancer is the second most common cancer in parts of Asia.
As with most cancers, the actual causes of esophageal cancer are unknown. There are, however, some known risk factors in its development. Some of these include:
- age – this type of cancer is usually found in people over the age of 55
- alcohol abuse
- chewing tobacco
- poor nutritional status (i.e., not eating sufficient fruits and vegetables)
- consuming highly irritating foods or drinking very hot liquids – this likely causes injury to the mucosal tissue in the esophagus
- exposure to toxins such as solvents
- human papillomavirus (HPV) – this virus causes genital warts and has also been linked to esophageal cancer, although this link has not yet been proven
- ingestion of lye, which is a corrosive chemical substance (e.g., accidentally swallowing lye as a child)
Some cancerous tumours in the esophagus have spread there from elsewhere in the body. Cancers of the larynx, pharynx, tonsils, lungs, breast, liver, kidney, prostate, testicles, bone, and skin can all spread to the esophagus.
People with certain medical conditions can have an increased risk of developing esophageal cancer. These conditions include:
- achalasia: People with achalasia have difficulty emptying the esophagus because the muscles are unable to push the food effectively from the mouth to the stomach.
- gastroesophageal reflux disease (GERD): People who have had GERD (a condition where stomach acid splashes up into the esophagus) for a long time are at a higher risk of esophageal cancer.
- Plummer-Vinson syndrome and Barrett's esophagus: People with these disorders have abnormal cells in the esophagus that can become cancerous.
- tylosis: People with this skin disorder tend to have a higher incidence of esophageal cancer.
Symptoms and Complications
The symptoms of esophageal cancer generally don't begin to show until the tumour has progressed. They include:
- chest pain (radiating towards the back)
- hoarseness or coughing (when not explained by other causes such as a cold) – a rare initial symptom
- pain when swallowing
- persistent heartburn
- progressive difficulty in swallowing, starting with solids
- weight loss
While these symptoms can be signs of other difficulties, it's important to get them checked if they persist.
One of the most obvious problems associated with this type of cancer is difficulty swallowing. As the tumour gets larger, swallowing firm food becomes impossible and eventually only fluids can get by. After surgery where part of the esophagus is removed, swallowing may be hard for a time but should improve as healing progresses.
A second problem that arises is weight loss due to the problems associated with swallowing. Consulting a dietitian in order to maintain a good nutritional status is an important step in treating esophageal cancer. Poor nutrition can slow the healing process.
Finally, the cancer can spread to the rest of the body, most commonly the lungs and liver.
Complications can arise from the treatment as well as from the cancer, especially if the cancer has spread.
Making the Diagnosis
If other causes for the symptoms have been ruled out and esophageal cancer is suspected, your doctor may review your medical history, perform a physical exam, and do some of the following tests:
- barium swallow: This involves swallowing barium, which is then tracked by an X-ray. This test can show whether there are any structural changes or blockages in your esophagus, stomach, and small intestine.
- endoscopy: This involves inserting an endoscope (a tube with a light and camera) into the throat so that your doctor can see the lining of the esophagus. Your doctor will likely use some local freezing or give you some medication to make the procedure more comfortable. You may have a sore throat afterwards, but it will go away on its own in a couple of days. Endoscopy will help your doctor identify the type of tumour and where it is located in the esophagus.
- biopsy: While using the endoscope, your doctor may take some tissue from inside the esophagus to send it for microscopic evaluation.
If a diagnosis of cancer has been made, the next step is to discover the stage (i.e., how far the cancer has progressed). This will involve:
- blood tests
- chest X-ray
- computed tomography (CT) imaging scans of the chest and liver, which will show any tumours or other abnormalities
- endoscopic ultrasound to evaluate how deeply the cancer has penetrated the wall of the esophagus
- positron emission tomography (PET) scans can define the local extent of the cancer and evaluate whether it has spread or metastasized (spread from one part of the body to another)
The stages are:
- stage 0: very early cancer, found only in the first layer of the lining
- stage 1: cancer is still early in development, is in a small part of the esophagus but hasn't spread
- stage 2: cancer has spread deeper into the esophagus and may have invaded the lymph nodes near the esophagus
- stage 3: cancer has spread even deeper in the esophagus wall or has spread to nearby tissues and lymph nodes
- stage 4: cancer has spread to other parts of the body (usually the lungs or liver, although it may spread to other areas of the body as well)
- recurrent: cancer that has returned after treatment
Treatment and Prevention
The treatment of esophageal cancer depends on the stage of the illness or the progression of the disease. Like most cancers, the options for treatment are surgery, chemotherapy, radiation therapy, or a combination of the three.
Surgical treatment targets the cancer and aims at removing it. This is the most common treatment for esophageal cancer. Before recommending surgery, your doctor will consider your overall health as the operation can prove a long and demanding process.
If the entire esophagus is removed, the surgeon may create a new passage in the chest for food to pass through into the rest of the gastrointestinal tract using the bowel or stomach. Several different approaches can be used, with incisions required in the neck, chest, or abdomen.
Often the surgeon will begin with a "mini" operation on the abdomen to ensure no cancer has spread there. Occasionally, some parts of the procedure can be performed by inserting a thin tube with a light on the end into either the abdomen (laparoscopy) or chest area (thoracoscopy). The use of laparoscopy and thoracoscopy can help minimize the side effects after the operation.
In rare cases, for cancers very high in the esophagus (near the mouth or throat), surgery requires the removal of the structures in the neck, such as the voice box.
Swallowing might be difficult following the surgery, and reflux is often a problem. At first, the diet should be liquid, and then should progress to soft foods. A stent (a special type of tube) can also be left in place to widen the esophagus to make eating easier.
If surgery is not possible, a laser may be used to remove tumour cells and relieve blockages of the esophagus. To allow the esophagus to heal after surgery, stomach tubes passing directly through the skin into the stomach may allow feeding. These tubes are easily inserted at the time of surgery, or may even be inserted using a local anesthetic without involving a hospital stay.
Radiation therapy, also known as radiotherapy, can be either external or internal. External radiotherapy is aimed directly at the cancerous cells. Internal radiotherapy involves inserting a radioactive substance directly into the esophagus.
For people undergoing radiation therapy, there are several side effects to watch for. They include:
- loss of or change in your sense of taste or smell
- red, dry skin
- dry mouth
- sensitive mouth and gums
- sores in the mouth
- sore throat
- voice changes
These reactions are usually temporary but can cause great discomfort during treatment. Your health care team may be able to offer tips to help reduce the side effects.
Chemotherapy is treatment using medications that kill the cancer cells. Chemotherapy medications are usually injected directly into the veins. Because the medications then circulate throughout the body, the side effects, although temporary, are more generalized than those from radiotherapy. They include:
- hair loss
- increased risk of infection
- mouth sores
- nausea and vomiting
Chemotherapy is often given in conjunction with radiotherapy and in advanced stages of the disease, or where the person is too frail to tolerate surgery. This combination may offer similar chances for survival and cure as surgery.
Photodynamic therapy may be used to relieve the symptoms of esophageal cancer. This involves taking a medication to make the cancer cells more sensitive to light. Then, the affected area is exposed to a special light source, which kills the cancer cells.
After treatment for esophageal cancer, it's crucial to keep the esophagus open. To do so, esophageal dilation or bougienage might be performed. This procedure dilates (widens) the esophagus, making swallowing easier. This is not a permanent solution and might need to be repeated regularly.
As with many cancers, minimizing the risks could decrease the chances of developing esophageal cancer. This means stopping smoking, drinking in moderation, eating a healthy diet, and having any persistent throat problems checked by a doctor.
At this point, the best prevention is to be aware of the possible signs and symptoms and to act on them as soon as possible.
All material copyright MediResource Inc. 1996 – 2023. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/condition/getcondition/Cancer-of-the-Esophagus