The esophagus is a muscular tube that carries food and liquid from the mouth to the stomach. The esophagus is usually between 10 and 13 inches long. The normal adult esophagus is roughly three fourths of an inch across at its smallest point.
The wall of the esophagus has several layers. Cancer of the esophagus -- also referred to as esophageal cancer -- starts from its inner layer and grows outward. The layer that lines the inside of the esophagus is called the mucosa. The mucosa has 2 parts: the epithelium and the lamina propria. The epithelium forms the lining of the esophagus and is made up of flat, thin cells called squamous cells. The lamina propria is a thin layer of connective tissue right under the epithelium.
The next layer is the sub mucosa. Some parts of the esophagus have mucus-secreting glands in this layer. The layer under the sub mucosa is a thick band of muscle called the muscular is propria. This layer of muscle contracts in a coordinated, rhythmic way to force food along the esophagus from the throat to the stomach. The outermost layer of the esophagus is formed by connective tissue. It is called the adventitia
Below the detail about esophageal cancer:
TypesThe main forms of esophageal cancer are:
- Squamous cell carcinoma -- occurs in the squamous cells lining the esophagus
- Adenocarcinoma -- occurs in glandular tissue, most often in the lower part of the esophagus near the stomach. An estimated nine out of 10 malignant stomach tumors are adenocarcinomas.
Although once responsible for the large majority of esophageal cancer cases, squamous cell carcinoma now ranks second to adenocarcinoma, which studies have confirmed is now the predominant type of esophageal tumor in the western hemisphere. The two types of cancer affect various populations differently. Squamous cell carcinoma is more likely among African Americans, while adenocarcinoma is more likely among Caucasians, according to the American Cancer Society
Risk FactorsPerhaps the greatest risk factor for esophageal cancer is long-term smoking and alcohol use, especially when the two habits are combined.
Other risk factors include:
- Barrett's Esophagus -- a condition in which chronic acid reflux causes changes in the cells lining the lower esophagus, increasing the risk of adenocarcinoma
- Achalasia -- a disease in which the esophagus fails to move food into the stomach properly
- Tylosis -- a rare, inherited disorder that causes excess skin to grow on the soles of the feet and palms and has a near 100% chance of developing into esophageal cancer
- Esophageal webs -- flaps of tissue that protrude into the esophagus, making swallowing difficult
- Lye or other caustic substances -- when ingested, such substances can cause scarring that may progress to cancer years later
SymptomsSymptoms of esophageal cancer may not be evident during its early stages of development, making early diagnosis less likely. Although a cancer diagnosis may be unlikely for individuals suffering the following symptoms, people should consider contacting a doctor when experiencing:
- Difficulty swallowing (dysphagia)
- Pain, pressure or burning in the throat or chest
- Weight loss
- Vomiting
- Hoarseness
- Hiccups
- Chronic cough
DiagnosisPatients who experience symptoms of esophageal cancer should contact a doctor, who will likely take several steps to determine the cause of the symptoms. These steps may include:
- Consulting with the patient to determine the individual’s medical history
- Taking X-rays of the gastrointestinal tract
- Performing various tests, including endoscopic examination, or esophagoscopy
Esophagoscopy is performed using a thin tube inserted via the mouth to examine the inside of one’s esophagus. The instrument can illuminate the interior of the esophagus and provide images that can be analyzed by doctors. It can also collect cell samples from the stomach for lab analysis.
If a patient is diagnosed with esophageal cancer, doctors next will work to determine whether the cancer has spread using additional methods such as CT scans. Treatment will be largely dependent on the cancer’s stage, or level of involvement.
TreatmentAs with any cancer diagnosis, a treatment plan will depend on a variety of factors and will be specific to the individual patient. Doctors rely on medical tests to determine the extent of the cancer and whether it has spread beyond the stomach, a process called staging. By ascertaining the cancer’s current state and considering the myriad factors relating to an individual patient, appropriate treatment can be planned by the doctor and discussed with the patient.
Common treatment options include:
- Surgery
- Chemotherapy
- Radiation therapy
- Photodynamic therapy
The most common treatment method, surgery, may involve removal of the cancerous portions of the esophagus and neighboring lymph nodes (esophagectomy) or complete removal of the esophagus and the top portion of the stomach (radical esophagectomy). The second most common treatment is the combination of chemotherapy, which aims to shrink tumors and eliminate cancer cells, and radiation therapy, which targets cancer cells with radiation. Photodynamic therapy, which involves use of laser-activated chemicals to destroy tumors, is also implemented.