Oesophageal cancer is the name for cancers that arise in the tissues of the oesophagus, the tube that connects the throat to the stomach. Abnormal cells can form a tumour, leading to problems with swallowing food, and can spread through the body.…
What is Barrett's esophagus?
Barrett's esophagus is when the cells lining the esophagus - the tube that connects the mouth and the stomach - change to resemble the lining of the stomach, due to damage from acid reflux. This condition can potentially increase the risk of developing esophageal cancer in the future.
Barrett's esophagus occurs when the lining of the esophagus, which is sensitive to stomach acid, becomes chronically irritated due to repeated exposure to this harsh acid. Stomach acids travel into the esophagus if there is heartburn, otherwise known as gastro-esophageal reflux disease (GORD). The lining of the esophagus, which normally has pinkish, flat cells (squamous cells) to allow the easy passage of food, change with chronic exposure to stomach acids, into red, tall cells (columnar cells, also known as columnar epithelium) that secrete acid-repellent mucus, much like the lining of the stomach. This change in cell structure is known as metaplasia, and this defines Barrett's esophagus. It commonly occurs at the lower portion of the esophagus, where exposure to stomach acid is greatest; however, occasionally it can occur higher up.
In certain cases, with ongoing exposure to stomach acids, the cells continue to change to become cancerous, i.e. esophageal cancers. While the majority of people with Barrett's esophagus will not develop esophageal cancer, the potential is always there and the number of cases is increasing.
Risk factors for Barrett's esophagus include:
- Heartburn - this predisposes chronic stomach acid travelling into the esophagus. Heartburn can be exacerbated by alcohol, spicy foods, peppermint, caffeine, lying flat, obesity and smoking;
- Age - the average age of diagnosis with Barrett's esophagus is 55 years;
- Gender and ethnicity - Barrett's esophagus is more common in white (Caucasian) men;
- Smoking, and;
- Metabolic syndrome - studies have found that Barrett's esophagus is associated with metabolic syndrome, regardless of the presence of reflux symptoms. Metabolic syndrome is not a disease, but a collection of risk factors that occur at the same time. These are abdominal obesity, high blood pressure, high level of triglycerides, low level of good cholesterol (high density lipoprotein) and impaired fasting glucose.
Cellular changes of Barrett's esophagus
The hallmark of Barrett's esophagus is metaplasia, where squamous cells of the esophagus change into columnar cells. The columnar cells resemble stomach or intestinal lining cells, which may offer some protection from acid reflux. However, with ongoing exposure to stomach acids, these cells can become abnormal, known as dysplasia. Dysplasia is a precancerous stage, which can progress to cancer or alternatively recover if risk factors are removed.
In low-grade dysplasia, the architecture of the Barrett's cells become more distorted. The cells appear larger and their pattern abnormal and irregular.
In high-grade dysplasia, the cellular disorganization is even greater. The cells appear large and multi-layered. The risk of developing esophageal cancer from this grade is quite high.
Signs and symptoms
- Difficulty or pain swallowing;
- Recurring discomfort or burning in the chest, often following food or drinks;
- Regurgitation of excessive saliva and/or food into the mouth, and;
- Vomiting, weight loss and feeling full when eating.
Sometimes acid reflux has no symptoms, so metaplasia can be occurring silently. This can make Barrett's esophagus difficult to diagnose.
Methods for diagnosis
Gastroscopy (upper endoscopy)
During a gastroscopy procedure, you'll be sedated and a long, thin and flexible tube (endoscope) will be carefully fed down to the esophagus. Imaging of the area will be carried out via a light and a small camera attached to the tube. Barrett's esophagus tissue can appear pink or red compared to the usual pale-colored esophageal lining. Gastroscopy can be used to take a biopsy of any suspicious-looking areas for further diagnosis.
A biopsy is a tissue sample taken for microscopic examination by a pathologist in the laboratory to check for cancer and other diseases. For Barrett's esophagus, the biopsy is taken during a gastroscopy and the pathologist will then determine if any cellular changes are present and check to make sure any of the abnormalities are not cancerous.
Twenty-four hour ambulatory pH monitoring
Ambulatory pH monitoring involves a very thin wire being threaded through your nose and into your esophagus. It is attached to a small recording device that determines the acid levels in the lower esophagus. Because symptoms can be minimal or non-existent in Barrett's esophagus, the pH monitoring can help with diagnosing silent acid reflux and the effects of medications on reducing acid levels in the esophagus.
Types of treatment
Barrett's metaplasia and low-grade dysplasia is often treated with lifestyle changes, antireflux medications and follow-up gastroscopy. High-grade dysplasia can be treated with a number of gastroscopic or surgical options.
Reducing acid reflux into the esophagus can help prevent or reduce the progression of Barrett's esophagus. Acid reflux can be less severe if you avoid caffeine, alcohol, peppermint and spicy foods. Stopping smoking and reducing your weight if overweight or obese can also reduce acid reflux. Elevating the head of your bed with bricks can help to reduce acid reflux when lying down.
Acid reflux medication
Medications, such as proton pump inhibitors and/or histamine-2 blockers, which can decrease the amount of stomach acid produced, can be used to control symptoms, promote healing and reduce the risk of progression to dysplasia and esophageal cancer.
Endoscopic therapy with endoscopic mucosal resection or radiofrequency ablation can be used in some cases of high-grade dysplasia. This is usually reserved for cases where the dysplasia has not spread into deeper layers of the esophagus and there has been no spread to lymph nodes.
Endoscopic mucosal resection
Endoscopic mucosal resection is performed during an endoscopy. An instrument called a snare is used to remove the affected esophageal tissue.
Radiofrequency ablation and cryotherapy can be used in conjunction with endoscopic mucosal resection to destroy the remaining abnormal cells.
Cryotherapy uses liquid nitrogen or carbon dioxide to destroy cells.
Photodynamic therapy uses chemical agents called photosensitizers and a laser light to destroy abnormal cells.
This is surgery to remove all or part of the esophagus. It is generally reserved for extensive high-grade dysplasia or a confirmed cancer. If a cancer extends into the stomach, part of the stomach is removed, along with part of the esophagus (oesophago-gastrectomy). The whole esophagus might need to be removed (total esophagectomy), in which case it may be replaced with part of the bowel.
Treatment side effects
One of the most common complications from treatment is stricture formation, which is the narrowing (stenosis) and tightening of the esophagus due to scarring. The more of the esophagus that has been subjected to treatment, the greater the risk of stenosis. Bleeding can occur from esophageal endoscopic procedures and also from surgery. In some cases, bleeding can be severe due to the high density of blood vessels in the esophagus. Nausea and mild discomfort can result from radiofrequency ablation. Pain-relief medication is usually required.
Barrett's esophagus can progress to esophageal cancer. The type of cancer it causes is known as an adenocarcinoma.
If caught before it progresses to cancer, treatment for Barrett's esophagus has a very good prognosis. However, esophageal cancer has a poor prognosis.
The progress of Barrett's esophagus can be reduced by limiting acid reflux into the esophagus. Unfortunately, in some cases the acid reflux may not produce symptoms, so prevention may not be possible if the condition goes undiagnosed. You can reduce your risk by maintaining a healthy body weight, not smoking, avoiding foods and substances that worsen acid reflux and by taking medication if recommended by your doctor to lessen the damage caused by stomach acid.