Esophageal Carcinoma

 

Esophageal Carcinoma

 

The esophagus is a hollow tube like structure that connects the pharynx with the stomach. It is a part of the digestive system, which simply helps in the movement of food from the mouth to the stomach. The esophagus is made up of layers: mucosa, submucosa, muscularis externa and tunica externa (innermost layer to outermost layer). There are squamous cells as well as glandular cells in the esophagus.

 

The predominant forms of esophageal cancer are adenomacarcinoma and squamous cell cancer. Lymphoma, melanoma, sarcoma and small cell cancer are the other rare forms of esophageal cancer.

 

Types of esophageal carcinoma

Esophageal squamous cell carcinoma: It is the most prevalent type and mainly occurs in the middle of the esophagus

Esophageal adenocarcinoma: It mostly occurs in the lower part of the esophagus.

Epidemiology

Esophageal cancer is one of the most frequently occurring cancers in the world. The disease is more common in males than in females. The geographical distribution of this form of cancer is very unequal. Although the incidence of this disease is much less in United States and Britain, the frequency is dramatically high in some Asian countries like China, Turkmenistan, Iran, and Uzbekistan. All these countries form the “Esophageal Cancer Belt”, where almost 60 % of esophageal cancer cases are detected.

Esophageal squamous cell carcinoma is the common form of esophageal cancer in China while esophageal adenocarcinoma is more frequent in Western countries.

Risk factors include the following:

  • Smoking: Smoking is highly associated with esophageal cancer. It increases the risk of esophageal cancer significantly.
  • Alcohol consumption: Heavy drinkers are more prone to development of esophageal cancer. Alcohol and smoking together may be responsible for as many as 90% of esophageal cancer worldwide, especially squamous cell.
  • Diet: A diet with vegetables and fruits may reduce the risk of esophageal cancer.
  • Obesity: The incidence of adenocarcinoma of the esophagus is relatively more in overweight people.
  • Barrett’s esophagus: This refers to a condition in which there is an abnormal growth of intestinal type of cells in the lower part of the esophagus. Although this is a protective mechanism of the body against Gastroesophageal Reflux Disease (GERD), the changes in the esophagus may lead to cancer in this region.
  • Age: The risk of esophageal cancer increases with age.
  • Sex: Males are more prone to this disease than females.
  • Gastroesophageal reflux disease (GERD): The contents of stomach sometimes flow back in the esophagus. This condition is called GERD or simply reflux. Gastric acid can severely damage the esophagus, which may lead to adenocarcinoma of the esophagus.

Symptoms

  • Pain and difficulties with swallowing food, especially solid food
  • Heartburn
  • Hoarseness in voice
  • Pain behind the breastbone
  • Weight loss
  • Indigestion and regurgitation of undigested food
  • Vomiting blood or passing old blood with bowel movements

Diagnosis

Chest x-ray: The chest x-ray is an important tool in diagnosing esophageal cancer. The images of the organs inside the body are obtained with the help of x-rays.

Barium swallow: This is an imaging technique, which is based on the use of x-rays to obtain a series of images of the esophagus. The contrasting material used in this procedure is a metallic compound, barium sulphate. The patient drinks a solution of the compound, which coats the surface of the whole digestive tract. The images can be studied to detect any abnormal growth in the esophagus.

Esophagoscopy: This is a procedure to look inside the esophagus to check for abnormal areas with the help of an instrument called esophagoscope (tube with light and lens). It is inserted through the mouth or nose and down the throat into the esophagus. It can also help in removal of tissue samples for biopsy.

Ultrasonography of the neck: Neck ultrasonography has been shown to be superior to clinical examination in detecting metastatic lymph nodes in the neck. It is a low-cost investigation and with an adequately trained operator, has the potential to change treatment decisions. It should be available as a minimum investigation in centers treating esophageal cancer.

Biopsy: It refers to the removal of tissues or cells for examination in a laboratory. The cells are viewed under microscope to detect signs of cancer.

Scans: Many types of scans may be used to stage esophageal cancer as well as give information about preferred treatment including PET-CT scanning.

Treatment

Surgery

Surgery is the mainstay treatment for esophageal cancer. Surgery can be performed in a number of ways. It can be done as an open procedure or as laparoscopy. These are the following:

Surgical excision of small tumors: Small tumors at an early stage of the disease can be removed by surgery. An endoscope may be used for these surgeries.

Esophagectomy: Esophagectomy is the surgical resection of a part of esophagus which has the tumor. The stomach is then lifted up and connected to the esophagus again. Sometimes doctors use a part of the colon or a plastic tube to compensate for the resection. Nearby lymph nodes are removed and studied in the laboratory under a microscope.

Esophageal stent: Sometimes the esophagus is blocked by the tumor. In such cases, a stent is placed in the esophagus to keep it open to allow the movement of food and liquids into the stomach.

Esophagogastrectomy: This is a surgery in which a part of the esophagus and a part of the upper stomach are removed. The remaining esophagus is then connected to the stomach.

Providing nutrition during treatment: Nutrition is temporarily provided to patients during treatment either through the vein or by inserting a feeding tube through the mouth or nose into the stomach so that nutrition reaches the stomach directly.

Radiation therapy

Radiation therapy is used along with chemotherapy in people with esophageal cancer for better effects. It can be used as adjuvant or neo-adjuvant therapy. It can also be used to reduce the size of large tumors at advanced stage so that it does not obstruct the flow of food through it. High energy x-rays are used to kill the cancer cells in the esophagus. This can be done in two ways:

External radiation therapy: Radiation is given by a machine from outside the body at the affected region.

Internal radiation therapy: Radioactive substance sealed in a needle or wire is placed near the affected region. Radiation emitted from this radioactive substance kills the cancer cells. The esophagus is kept open during radiation therapy with the help of a plastic tube.

Chemotherapy

Chemotherapy is the use of drugs to treat cancer. It can be swallowed or administered through veins. It can also be specifically directed at the cancer-affected region. For stage I and II, chemotherapy can be given to patients as neo-adjuvant therapy (before the surgery) or as adjuvant therapy (after the surgery). Chemotherapy can be used in combination with radiation therapy. For advanced stages, especially when cancer has spread extensively throughout the body to slow down the progression of the disease.

For esophageal cancer, radiochemotherapy is increasingly being used.

Laser therapy, radiofrequency ablation, and electrocoagulation: These more limited procedures may be used for pre-cancerous or very early cancer treatment. They may also be used to help shrink tumors when surgery is not possible.

Prognosis

Prognosis of an esophageal cancer patient is dependent on a number of factors. The most important among them is the stage of the tumor at the time of detection. The five year survival rate for patients detected early (stage I) with esophageal cancer is high. If detected at a stage when the cancer has spread in the tissue then the survival rate comes down. Prognosis of patients diagnosed with advanced stage of the disease is very poor. At this stage, the disease can only be treated but cannot be cured.

References

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  9. This article was originally published on September 3, 2012 and last revision and update was 9/4/2015.