What is esophagus cancer?
Esophagus cancer (esophageal carcinoma) is a malignant tumor that arises from cells of the esophagus (food pipe). It is the sixth most common cause of cancer around the world and over 15,000 new esophageal cancer cases occur in the United States every year. Esophageal adenocarcinoma has become the more common type of esophagus cancer in recent decades and is closely associated with chronic gastroesophageal reflux disease (GERD).
Overall esophageal cancer is more 3 to 4 times more common in men than women. Alcohol and tobacco consumption which are known risk factors for squamous cell carcinoma (SCC) are more common practices among men. Similarly GERD, a major risk factor for adenocarcinoma, is more common among men. HPV infection, certain foods, dietary habits and nutritional deficiences may also be associated with esophagus cancer.
Types of Esophagus Cancer
There are two types of esophagus cancer – adenocarcinoma and squamous cell carcinoma (SCC). In the past squamous cell carcinoma (SCC) was the most common type of esophageal cancer in the United States. It still is the most common type in developing nations.
However, in recent decades adenocarcinoma has now become the more common type among Americans. Adenocarcinoma arises from the small mucus-producing cells of the esophagus. It is usually preceded by changes in these esophageal cells that Squamous cell carcinoma (SCC) arises from the cells lining the esophagus.
Read more on esophagus problems.
Causes of Esophageal Cancer
As with other types of cancer, there is genetic damage to these cells which causes the cells to become abnormal and multiply rapidly while invading healthy tissue. This genetic damage may be caused by a host of different mechanical and chemical injuries leading to esophagitis, infections particularly with the human papilloma virus (HPV) and may also be related to genetic defects that are inherited.
Alcohol, Smoking and Acid Reflux
The majority of esophageal cancer cases appear to be due to toxic substances that can cause genetic damage of the esophagus cells. Alcohol use and tobacco consumption appear to be the main toxins implicated in squamous cell carcinoma (SCC). Chronic GERD where the stomach acid and enzymes enter the esophagus and damages the tissue appears to be one of the main risk factors for adenocarcinoma.
Foods and Dietary Habits
Esophageal cancer has also been associated with a number of different foods, food toxins, dietary habits and nutritional deficiencies. This includes:
- Areca nuts and/or betel leaves
- Beverages that are scalding-hot consumed on a regular basis
- Folate deficiency
- Fungi that produce toxins (like aflatoxin) which may taint foods such as corn and nuts
- Red meat
- Selenium deficiency
- Zinc deficiency
Other Causes and Risk Factors
- Bisphosphanates (oral)
- Caustic substances that are consumed intentionally or accidentally.
- Plummer-Vinson syndrome
- Poor orodental hygiene.
Signs and Symptoms
The most common symptoms esophageal cancer is difficulty swallowing (dysphagia). Initially there is difficulty swallowing solids. As the cancer progresses and the esophagus becomes narrower, then even liquids are difficult to swallow. This can lead to recurrent aspiration pneumonia when food cannot be swallowed and enters the respiratory tract.
Read more on esophageal dysphagia.
Over time pain arises which is typically felt behind the breastone (restrosternal pain) and/or the upper middle abdomen (epigastric pan). Sometimes it may be a pressure or burning sensation and can be mistaken for indigestion. There may also be bleeding from the tumor which may not always be grossly evident. Instead complications of a persistent bleed, such as iron deficieny anemia, may be detected.
A hoarse voice and persistent cough may also arise. Often this is not associated with esophageal cancer and may be mistaken for other conditions. Weight loss is common in most cancers particularly in the advanced stages. However, it is likely to arise earlier in esophageal cancer due to a loss of appetite as a result of the difficult swallowing.
Diagnosis (Tests and Scans)
A biopsy (small tissue sample) may be necessary. The sample is sent to a laboratory for microscopic examination that confirms the presence of malignant (cancerous cells). Imaging studies are necessary to identify the presence of the cancer. This may include:
- Positron emission tomography (PET scan) and computed tomography (CT scan) for staging
Early diagnosis of esophageal cancer greatly improves the outcome if the appropriate treatment is commenced as soon as possible. A barium swallow and/or endoscopy should be performed on adults experiencing difficulty swallowing (dysphagia) even if there are no other symptoms of esophageal cancer present.
Staging of Esophageal Cancer
Positron emission tomography (PET) and computed tomography (CT) scans are used for staging.
- Stage 0: Carcinoma in situ where the cancer cells are on the lining of the esophagus and not invaded deeper tissue.
- Stage I: The cancer has invaded beneath the outermost (superficial) layers of the esophagus lining.
- Stage II: The cancer has invaded deeper to the muscular layer of the esophagus wall.
- Stage III: The cancer has invaded the deepest layers of the esopohagus wall and spread to neighboring tissue.
- Stage IV: The cancer has spread beyond the esophagus to other parts of the body.
Treatment of Esophagus Cancer
The treatment of esophageal cancer depends on several factors like the type of cancerous tumor and stage of the cancer. Treatment options typically include surgery, chemotherapy and/or radiation therapy to remove the tumor or kill the cancer cells. Sometimes treatment may be conducted in advanced stages of esophageal cancer where a cure is not possible but the treatment helps with easing symptoms (palliative) and improving the person’s quality of life.
A part of the esophagus where the cancer occurs may be removed (esophagectomy) and sometimes a portion of the stomach may also be removed (esophagogastrectomy). In the case of very small tumors, surgery may focus on removing these tumors without removing a portion of the esophagus.
Chemotherapy involves the use of drugs that can target and destroy the cancer cells. It is often used in conjunction with radiation therapy. Chemotherapy may be done before or after cancer surgery.
Radiation therapy involves the use of beams of radiation to destroy the cancer cells. Similar to chemotherapy it may be done before or after surgery. The radiation may be delivered externally over the area where the cancer is located or it can be delivery internallly.