Every area in the human body is lined or surfaced with a specialised type of cells that suits its function in that area. For example, the lining (skin) on our body is different compared to the lining (mucosa) inside our mouth. This is due to different functions of both the linings. Similarly, the lining of the oesophagus whose primary function is to move ingested food to the stomach is different from the lining inside the stomach where it faces an extremely harsh acidic environment to digest the food ingested.
In Barrett’s oesophagus, there is a change in the lining of the oesophagus. Some of its lining is replaced by a type of tissue similar to that normally found in the intestine. This is called intestinal metaplasia.
Barrett’s oesophagus is closely associated with gastro-oesophageal reflux disease (GORD), in which food and gastric liquids can enter the oesophagus from the stomach. It is presumed that the frequent entry of these liquids into the oesophagus lead to the change of the oesophageal lining.
Barrett’s oesophagus causes no symptoms in itself. However, a small number of people with this condition develop a relatively rare but often deadly type of cancer of the oesophagus called oesophageal adenocarcinoma. This condition was described in the early 1950’s by an Australian surgeon Dr. Norman Rupert Barrett, who noticed that cells lining and extending from the lower oesophagus were secreting red mucus without causing inflammation. He believed these cells made up a tubular stomach in patients who had a short oesophagus, however, ten years later he discovered that the mucus-secreting cells were an abnormality of normal cells, which now is known to lead to oesophageal cancer. Hence this condition is named in honour of Dr. Barrett.
Causes and Symptoms
The exact causes of Barrett’s oesophagus are unknown, but it is thought to be caused in part by the same factors that cause GORD. Although people who do not have heartburn can have Barrett’s oesophagus, it is found about three to five times more often in people with this condition. About 10-20% of people with chronic GORD will develop Barrett’s oesophagus.
The oesophagus is a muscular tube that transports food from the mouth to the stomach. When a person swallows, the muscles of the oesophagus relax where the food is and contract above and below the food. Through a sequential and well synchronised way of the same process in subsequent segments food is slowly pushed towards the stomach. This is known as peristalsis. This is the reason food never comes out after we swallow, even if we were in a position of upside down or lying down. Going further at the entrance to the stomach there are strong muscles surrounding the oesophageal tube called sphincters that remain contracted all the time to prevent acids from the stomach from entering the oesophagus. These open only when there is food in the area above to let the food inside the stomach. When people belch to release swallowed air or gas from carbonated beverages, the sphincters relax and small amounts of food or drink may come back up briefly. This condition is called reflux.
When a person experiences this regularly, especially when not trying to belch, then it is considered a medical problem or disease. The stomach produces acid and enzymes and when this mixture refluxes into the oesophagus frequently, it may produce symptoms. These symptoms, often called acid reflux, are usually described by people as heartburn, indigestion or gas. The symptoms usually consist of a burning sensation below and behind the lower part of the breastbone or sternum. Most people have experienced these symptoms at least once, typically as a result of overeating. Other situations that provoke GORD symptoms include obesity, eating certain types of food, and pregnancy. In most people, GORD symptoms may last for only a short time and require no treatment. However, if the symptoms persist and occur regularly then a doctor should be consulted to investigate further. These symptoms, if continuing for some time without relief from ‘over-the-counter’ antacid agents, can contribute to the development of GORD and eventually Barrett’s Oesophagus.
The average age of patients diagnosed with Barrett’s oesophagus is 60. In younger ages GORD is common rather than Barett’s oesophagus. It is about twice as common in men as in women, and much more common in caucasians than in people of other ethnicities.
Barrett’s oesophagus has no simple cure, besides surgical removal, which is only performed if the patient has a very high risk of developing oesophageal cancer. Treating the associated acid reflux is important. Most physicians recommend treating GORD with acid-blocking drugs, since this is sometimes associated with an improvement in the extent of the Barrett’s tissue. While this is also practiced at the Centre for Digestive Diseases, patients who present with Barrett’s oesophagus may at times undergo treatment with argon plasma coagulation which “burns away” the Barrett’s tissue. This procedure allows the gastroenterologist to remove tissue while performing a panendoscopy. It involves using argon gas and electrical current to result in the very shallow burn of the abnormal tissue without any direct contact. As a result Barrett’s oesophagus can be successfully treated if it covers only a short area. An upcoming effective method to remove Barrett’s tissue and, therefore, reduce the chance of getting oesophageal cancer, is to freeze off the Barrett’s tissue and it becomes replaced with normal oesophageal lining provided the patient remains on acid suppressing medications.