.

Barrett’s esophagus is a condition in which there is an abnormal (metaplastic) change in the mucosal cells lining the lower portion of the esophagus, from normal stratified squamous epithelium to simple columnar epithelium with interspersed goblet cells that are normally present only in the small intestine, and large intestine. This change is considered to be a premalignant condition because it is associated with a high incidence of further transition to esophageal adenocarcinoma, an often-deadly cancer.[1][2] The main cause of Barrett’s esophagus is thought to be an adaptation to chronic acid exposure from reflux esophagitis.[3] Barrett’s esophagus is diagnosed by endoscopy: observing the characteristic appearance of this condition by direct inspection of the lower esophagus; followed by microscopic examination of tissue from the affected area obtained from biopsy. The cells of Barrett’s esophagus are classified into four categories: nondysplastic, low-grade dysplasia, high-grade dysplasia, and frank carcinoma. High-grade dysplasia and early stages of adenocarcinoma may be treated by endoscopic resection or radiofrequency ablation.[4] Later stages of adenocarcinoma may be treated with surgical resection or palliation. Those with nondysplastic or low-grade dysplasia are managed by annual observation with endoscopy, or treatment with radiofrequency ablation. In high-grade dysplasia, the risk of developing cancer might be at 10% per patient-year or greater.[1] The incidence of esophageal adenocarcinoma has increased substantially in the Western world in recent years.[1] The condition is found in 5–15% of patients who seek medical care for heartburn (gastroesophageal reflux disease, or GERD), although a large subgroup of patients with Barrett’s esophagus are asymptomatic. The condition is named after surgeon Norman Barrett (1903–1979) even though the condition was originally described by Philip Rowland Allison in 1946.[5][6][7]

Management of Barrett’s Oesophagus
Many people with Barrett’s esophagus do not have dysplasia. Medical societies recommend that if a patient has Barrett’s esophagus, and if the past two endoscopy and biopsy examinations have confirmed the absence of dysplasia, then the patient should not have another endoscopy within three years.[23][24][25] Endoscopic surveillance of people with Barrett’s esophagus is often recommended, although little direct evidence supports this practice.[1] Treatment options for high-grade dysplasia include surgical removal of the esophaguses (esophagectomy) or endoscopic treatments such as endoscopic mucosal resection or ablation (destruction).[1] The risk of malignancy is highest in the United States in Caucasian men over fifty years of age with more than five years of symptoms. Current recommendations include routine endoscopy and biopsy (looking for dysplastic changes). Although in the past physicians have taken a watchful waiting approach, newly published research supports consideration of intervention for Barrett’s esophagus. Balloon-based radiofrequency ablation, invented by Ganz, Stern, and Zelickson in 1999, is a new treatment modality for the treatment of Barrett’s esophagus and dysplasia, and has been the subject of numerous published clinical trials.[26][27][28][29] The findings demonstrate radiofrequency ablation has an efficacy of 90% or greater with respect to complete clearance of Barrett’s esophagus and dysplasia with durability up to five years and a favorable safety profile.[26][27][28][29] Anti-reflux surgery has not been proven to prevent esophageal cancer. However, the indication is that proton pump inhibitors are effective in limiting the progression of esophageal cancer. Laser treatment is used in severe dysplasia, while overt malignancy may require surgery, radiation therapy, or systemic chemotherapy. A recent five-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.[30] 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 the detection of three different genetic abnormalities was associated with as much as a 79% chance of developing cancer in six years.[31] Endoscopic mucosal resection has also been evaluated as a management technique.[32] Additionally an operation known as a Nissen fundoplication can reduce the reflux of acid from the stomach into the esophagus.[33] In a variety of studies, nonsteroidal anti-inflammatory drugs (NSAIDS), like aspirin, have shown evidence of preventing esophageal cancer in people with Barrett’s esophagus.[34][35] 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.

References
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