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Definition

Esophageal cancer is a malignancy that develops in tissues lining the hollow, muscular canal (esophagus) along which food and liquid travel from the throat to the stomach.

Description

Esophageal cancers originate in the inner layers of the lining of the esophagus and grow outward. In time, they can obstruct the passage of food and liquid, making swallowing painful and difficult.

Types of esophageal cancer

Squamous cell carcinoma is the most common type of esophageal cancer. It can develop at any point along the esophagus, whose entire length is normally lined with thin, flat squamous cells that resemble tiny roof shingles. Although squamous cell carcinoma once accounted for nearly 90% of all esophageal cancers, it now represents 50-60%.

Adenocarcinoma originates in glandular tissue not normally present in the lining of the esophagus. Before adenocarcinoma can develop, glandular cells must replace a section of squamous cells. Known as Barrett's esophagus, this precancerous condition is characterized by chronic acid reflux, in which acids and other digestive juices escape from the stomach, flow backward into the esophagus, and may cause heartburn.

Esophageal cancer statistics

About 12,300 new cases of esophageal cancer will be diagnosed in the United States during 1998. During the same 12-month period, about 9,100 men and 2,800 women will die of this disease.

Esophageal cancer is three times more common in men than in women, and three times more common among Blacks than among whites. Men and women between the ages of 45 and 70 have the greatest risk of developing esophageal cancer, but the disease can occur at any age.

Squamous cell carcinoma is the most common form of esophageal cancer in Blacks. Adenocarcinoma is the most common form in whites.

Causes & symptoms

The cause of esophageal cancer is unknown, but a number of risk factors have been identified. Drinking about 13 ounces of alcohol every day for an extended period of time raises the risk of developing esophageal cancer by 18%. That likelihood increases to 44% in individuals who also smoke one or two packs of cigarettes a day.

Risk factors

Other risk factors associated with esophageal cancer include:

• Nutritional deficiencies. A diet low in fruits, vegetables, zinc, riboflavin, and vitamins A and can increase an individual's vulnerability to esophageal cancer.
• Lye ingestion. Children (and others) who swallow household cleansers containing chemicals that can burn and destroy cells may develop squamous cell esophageal cancer in later life.
• Achalasia. Squamous cell esophageal cancer develops in about 6% of patients with this condition, which prevents the lower esophageal sphincter (muscle) from relaxing enough to let food pass into the stomach.
• Tylosis. People who have this rare inherited disease have excess skin on the palms of their hands and the soles of their feet. They are almost certain to develop esophageal cancer, and should have regular screenings to detect the disease in its early, most curable stages.
• Esophageal webs. This condition, in which tissue protrudes into the esophagus, can make swallowing difficult. People who have anemia or abnormalities of the fingernails, tongue, spleen, or other organs may develop esophageal webs. About 10% of those who do will develop squamous cell esophageal cancer.

Symptoms

Patients with early esophageal cancer may be hoarse and have hiccups or elevated calcium levels, but symptoms characteristic of the disease generally don't appear until the tumor has grown so large that the patient cannot be cured.

Dysphagia (trouble swallowing or a sensation of having food stuck in the throat or chest) is the most common symptom. Swallowing problems may occur occasionally at first, and patients often react by eating more slowly and chewing their food more carefully and, as the tumor grows, switching to soft foods or a liquid diet. Without treatment, the tumor will eventually prevent even liquid from passing into the stomach.

A sensation of burning or slight mid-chest pressure is a rare, often-disregarded symptom of esophageal cancer. Painful swallowing is usually a symptom of a large tumor obstructing the opening of the esophagus. It can lead to weight loss, physical wasting, and malnutrition.

Anyone who:

• Has trouble swallowing
• Loses a significant amount of weight without dieting
• Can not eat solid food because it is too painful to swallow should see a doctor.

Diagnosis

A barium swallow is usually the first test performed on a patient whose symptoms suggest esophageal cancer. This special x-ray can highlight any bumps or flat raised areas on the normally smooth surface of the esophageal wall. It can also detect large, irregular areas that narrow the esophagus in patients with advanced cancer, but it cannot provide information about disease that has spread beyond the esophagus. A double contrast study is a barium swallow with air blown into the esophagus to improve the way the barium coats the esophageal lining.

Esophagoscopy is a diagnostic procedure in which a thin lighted tube (esophagoscope) is passed through the mouth, down the throat, and into the esophagus. Cells that appear abnormal are removed for biopsy.

Once a diagnosis of esophageal cancer has been confirmed through biopsy, additional tests are performed to determine whether the disease has spread (metastasized) to tissues or organs near the original tumor or in other parts of the body. This is called staging.

Stages of esophageal cancer

Stage 0 is the earliest stage of the disease. Cancer cells are confined to the inner lining of the esophagus.

Stage I esophageal cancer involves only a small part of the esophagus. The disease has not spread to nearby tissues, lymph nodes, or other organs.

In Stage IIA, cancer has invaded the thick, muscular layer of the esophagus that propels food into the stomach and may involve connective tissue covering the outside of the esophagus. In Stage IIB, cancer has spread to lymph nodes near the esophagus and may have invaded deeper layers of esophageal tissue.

Stage III esophageal cancer has spread to tissues or lymph nodes near the esophagus or to the trachea (windpipe) or other organs near the esophagus.