Barrett's Esophagus

Barrett's esophagus (sometimes called Barrett's syndrome, CELLO, columnar epithelium lined lower oesophagus or colloquially as Barrett's) refers to an abnormal change (metaplasia) in the cells of the lower end of the esophagus thought to be caused by damage from chronic acid exposure, or reflux esophagitis. Barrett's esophagus is found in about 10% of patients who seek medical care for heartburn (gastroesophageal reflux). It is considered to be a premalignant condition and is associated with an increased risk of esophageal cancer.

The condition is named after Dr. Norman Barrett (1903–1979), Australian-born British surgeon at St Thomas' Hospital, who described the condition in 1957.

Causes and Symptoms

Barrett's esophagus is caused by gastroesophageal reflux disease, GERD (UK: GORD), which allows the stomach's contents to damage the cells lining the lower esophagus. However, not every person who has GERD will develop Barrett's esophagus. Researchers are unable to predict which heartburn sufferers will develop Barrett's esophagus. While there is no relationship between the severity of heartburn and the development of Barrett's esophagus, there is a relationship between chronic heartburn and the development of Barrett's esophagus. Sometimes people with Barrett's esophagus will have no heartburn symptoms at all. In rare cases, damage to the esophagus may be caused by swallowing a corrosive substance such as lye.

The change from normal to premalignant cells that indicates Barrett's esophagus does not cause any particular symptoms. However, warning signs that should not be ignored include:

• frequent and longstanding heartburn
• trouble swallowing (dysphagia)
• vomiting blood
• pain under the breastbone where the esophagus meets the stomach
• unintentional weight loss because eating is painful

Pathology

Barrett's esophagus is marked by the presence of columnar epithelia in the lower esophagus, replacing the normal squamous cell epithelium—an example of metaplasia. The secretory columnar epithelium may be more able to withstand the erosive action of the gastric secretions; however, this metaplasia confers an increased risk of adenocarcinoma.

The metaplastic columnar cells may be of two types: gastric (similar to those in the stomach, which is NOT technically Barrett's esophagus) or colonic (similar to cells in the intestines). A biopsy of the affected area will often contain a mixture of the two. Colonic-type metaplasia is the type of metaplasia associated with risk of malignancy in genetically susceptible people.

The metaplasia of Barrett's esophagus is grossly visible through a gastroscope, but biopsy specimens must be examined under a microscope to determine whether cells are gastric or colonic in nature. Colonic metaplasia is usually identified by finding goblet cells in the epithelium and is necessary for the true diagnosis of Barrett's.

There are many histologic mimics of Barrett's esophagus (i.e. goblet cells occurring in the transitional epithelium of normal esophageal submucosal gland ducts, "pseudogoblet cells" in which abundant foveolar (gastric) type mucin simulates the acid mucin true goblet cells). Assessment of relationship to submucosal glands and transitional-type epithelium with examination of multiple levels through the tissue may allow the pathologist to reliably distinguish between goblet cells of submucosal gland ducts and true Barrett's esophagus (specialized columnar metaplasia). Use of the histochemical stain Alcian blue pH 2.5 is also frequently used to distinguish true intestinal-type mucins from their histologic mimics. Recently, immunohistochemical analysis with antibodies to CDX-2 (specific for mid and hindgut intestinal derivation) has also been utilized to identify true intestinal-type metaplastic cells.

After the initial diagnosis of Barrett's esophagus is rendered, affected persons undergo annual surveillance to detect changes that indicate higher risk to progression to cancer: development of dysplasia. There is considerable variability in assessment for dysplasia among pathologists. Recently, gastroenterology and GI pathology societies have recommended that any diagnosis of high grade dysplasia in Barrett's be confirmed by at least two fellowship trained GI pathologists prior to definitive treatment for patients.

Treatment

Current recommendations include routine endoscopy and biopsy (looking for dysplastic changes) every 12 months or so while the underlying reflux is controlled with proton pump inhibitor drugs in combination with measures to prevent reflux. Proton pump inhibitor drugs have not yet been proven to prevent esophageal cancer. Laser treatment is used in severe dysplasia, while overt malignancy may require surgery, radiation therapy, or systemic chemotherapy. Additionally, a recent 5-year random-controlled trial has shown that photodynamic therapy using photofrin is statistically more effective in eliminating dysplastic growth areas than sole use of a proton pump inhibitor. There is presently no reliable way to determine which patients with Barrett's esophagus will go on to develop esophageal cancer, although a recent study found that the detection of three different genetic abnormalities were associated with as much as a 79% chance of developing cancer in 6 years. Endoscopic mucosal resection (EMR) has also been evaluated as a management technique.

Barrx Radiofrequency Ablation

The HALO Radiofrequency Ablation Technology System has been studied in clinical studies conducted since 2003. Complete eradication of non-dysplastic and dysplastic disease at rates exceeding 90% has been shown in numerous studies.

The HALO ablation technology is designed to remove the Barrett's epithelium in a short, well-tolerated endoscopic procedure and offers an alternative to "watchful waiting" for patients with intestinal metaplasia, low-grade dysplasia, and high-grade dysplasia.

This procedure is now commonly performed as an Outpatient procedure in many hospitals throughout the United states.

Additionally an operation known as a Nissen fundoplication can reduce the reflux of acid from the stomach into the esophagus.

In a variety of studies, non-steroidal anti-inflammatory drugs (NSAIDS), like aspirin, have shown evidence of preventing esophageal cancer in Barrett's esophagus patients. However, none of these studies have been randomized, placebo controlled trials, which are considered the gold standard for evaluating a medical intervention. In addition, the best dose of NSAIDs for cancer prevention is not yet known.