Overview and Definition
As suggested by the term, esophageal cancer is cancer that affects the esophagus. The esophagus is the hollow, muscular tube that aids in moving the food from the mouth to the stomach. With esophageal cancer, malignant cells form tissue masses or tumours in the mucosal lining (inner layer) and grow outward through the submucosa and muscle layers of the esophagus.
There are two types of cells that form the esophageal lining; the type of cells affected by the malignancy dictates the type of esophageal cancer. Cancer of the esophagus may be one of the following types:
Squamous cell carcinoma - The type of cancer that develops from the squamous cells that line the entire esophagus.
Adenocarcinoma – The type of esophageal cancer that develops from gland cells, usually originating in the lower esophagus.
Other kinds of cancer may also start in the esophagus including melanomas, lymphomas, and sarcomas.
Causes and Risk Factors of Esophageal Cancer
Just like many types of cancer, the exact causes of esophageal cancer remain unknown. What is known, however, is that the condition develops due to genetic mutations that make cells grow and divide abnormally. When malignant cells grow, they can invade nearby organs and spread to other parts of the body. Various research and studies have established several risk factors that may increase one’s risk of developing the disease. Among them are:
Age - Most patients with osophageal cancer are aged 55 and above
Gender - Men have been found to be thrice more likely to develop this condition
Gastroesophageal reflux disease (GERD) - People with GERD who experience acid reflux from the stomach to the lower part of the esophagus are found to have a slightly higher risk of developing adenocarcinoma.
Barrett’s esophagus - If acid reflux remains untreated for a prolonged period, Barrett’s esophagus may develop. This could then result in esophageal carcinoma particularly in patients with chronic lymphocytic leukemia.
Achalasia - Achalasia is a condition where the lower end of the esophagus does not relax normally, such that the linings of the esophagus become regularly irritated. This is found to increase the risk of developing esophageal cancer.
Other conditions - Patients with tylosis (a genetic disorder characterised by the thickening of the soles and palms) and Plummer-Vinson syndrome (webs in the upper part of the esophagus) are more likely to suffer from squamous cell carcinoma.
Lifestyle factors - Cigarette smoking, alcohol abuse, obesity and unhealthy, low fibre diet can increase one’s risk of developing cancer.
Signs and Symptoms of Esophageal Cancer
Esophageal cancer symptoms, which usually do not appear until the cancer is already in its advanced stages, are the following:
Chest pain, epigastric pain or pain near the sternum
Dysphagia, a condition characterised by difficulty in swallowing
Frequent and worsening indigestion
Persistent coughing and/or hoarseness in the voice that doesn't go away
Unexplained weight loss
Diagnosis and Confirmatory Tests
There are several confirmatory tests that can be performed on patients showing signs of esophageal cancer. These include:
Barium swallow x-ray test – Also referred to as esophagram, this imaging test is performed to visualise and assess the structures of the esophagus. It is often recommended when a patient is having difficulty swallowing or suffering from abdominal pain and unexplained weight loss.
Endoscopy - This test involves the use of a thin, lighted tube with a video camera attached. The endoscope is passed down from the throat to the esophagus to physically examine and assess the organ. During the procedure, a sample tissue may be taken for biopsy.
Computed tomography (CT) scan of the abdomen or chest and other scans to assess possible spread of cancer cells.
Positron emission tomography (PET) to determine the stage of cancer if cancerous cells have been found.
Esophageal cancer is classified into five different stages:
Stage 0: Pre-cancerous condition
Stage 1: Non-aggressive, localised cancer
Stage 2: Cancer cells have reached the muscle layer and outer wall
Stage 3: Cancer may have spread beyond the esophagus affecting surrounding organs
Stage 4: Advanced stage wherein aggressive cancer cells have spread to other more distant organs
When to See a Doctor and Who to See
If you are experiencing any of the aforementioned symptoms, it is best to see a doctor immediately. If esophageal cancer is suspected, you will be referred to an oncologist for diagnosis and treatment. Cancer care typically involves a multidisciplinary team who will come up with a comprehensive treatment plan to improve prognosis. The team usually includes a medical oncologist (cancer specialist), a surgeon (surgical oncologist) for possible esophageal surgery, a radiologist/radiation oncologist (for radiotherapy), and a gastroenterologist for supportive and palliative care.
Treatment of Esophageal Cancer
Treatment of esophageal cancer depends on a variety of factors including the stage of cancer and the overall health and age of the patient. Treatment can be one or a combination of the following:
Surgery – A surgical procedure may be performed to remove a part or the entire esophagus along with localised cancer cells (usually for early stages).
Chemotherapy – This involves the use of powerful drugs that kill rapidly-multiplying cancer cells. This is usually used in combination with radiation therapy.
Radiation therapy – This uses strong beams to target, burn, and kill cancer cells.
Photodynamic therapy – This is used to kill early cancer cells using laser.
Electrocoagulation – This uses strong electric current to destroy non-aggressive cancer cells.
Treatment may also include palliative care aimed at relieving symptoms and allowing better quality of life, rather than killing cancer cells. Moreover, treatment must always include continuous follow-up appointments and regular tests to check for spread or recurrence of cancer, as well as to assess side effects of the treatment.
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National Cancer Institute: PDQ Esophageal cancer treatment. Bethesda, MD: National Cancer Institute. Date last modified 2/1/2013. Available at: http://www.cancer.gov/cancertopics/pdq/treatment/esophageal/HealthProfessional.
National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines): Esophageal and esophagogastric junction cancers. Version 2.2012. Available at http://www.nccn.org/professionals/physician_gls/pdf/esophageal.pdf.