Barrett's esophagus

Barrett's oesophagus is a premalignant metaplastic change of the oesophageal mucosa. Due to its relationship with oesophageal reflux disease and the development of adenoma-carcinoma of the oesophagus the problem arouses increasing interest. In the wide pathogenesis of the disease most probably the composite effect of the refluxed HCl content and duodenal juices play a part. In the diagnosis in addition to fundamental methods--endoscopy and histology--increasingly chromoendoscopy and fluorescent endoscopy are involved. Dispensarization of patients is essential and depends on the degree of pathohistological epithelial changes. Treatment of Barrett's oesophagus can be divided into conservative, where the drug of choice are proton pump inhibitors, and surgical treatment. Promising is endoscopic ablation of the epithelium in combination with subsequent antisecretory therapy.     

Barrett's esophagus

Barrett's esophagus is an acquired condition resulting from severe esophageal mucosal injury. It still remains unclear why some patients with gastroesophageal reflux disease develop Barrett's esophagus whereas others do not. The diagnosis of Barrett's esophagus is established if the squamocolumnar junction is displaced proximal to the gastroesophageal junction and if intestinal metaplasia is detected by biopsy. Despite this seemingly simple definition, diagnostic inconsistencies remain a problem, especially in distinguishing short segment Barrett's esophagus from intestinal metaplasia of the gastric cardia. Barrett's esophagus would be of little importance were it not for its well-recognized association with adenocarcinoma of the esophagus. The incidence of esophageal adenocarcinoma continues to increase and the 5-year survival rate for this cancer remains dismal. However, cancer risk for a given patient with Barrett's esophagus is lower than previously estimated. Current strategies for improved survival in patients with esophageal adenocarcinoma focus on cancer detection at an early and potentially curable stage. This can be accomplished either by screening more patients for Barrett's esophagus or with endoscopic surveillance of patients with known Barrett's esophagus. Current screening and surveillance strategies are inherently expensive and inefficient. New techniques to improve the efficiency of cancer surveillance are evolving rapidly and hold the promise to change clinical practice in the future. Treatment options include aggressive acid suppression, antireflux surgery, chemoprevention, and ablation therapy, but there is still no clear consensus on the optimal treatment for these patients.     

Barrett's esophagus

Barrett's esophagus is an acquired metaplastic abnormality in which the normal stratified squamous epithelium lining of the esophagus is replaced by an intestinal-like columnar epithelium. While in itself a benign and asymptomatic disorder, the clinical importance of this relatively common condition relates to its role as a precursor lesion to esophageal adenocarcinoma, the incidence of which has dramatically increased in Western populations in recent years. Although known to arise as a consequence of chronic gastroesophageal reflux, the cellular and molecular mechanisms underlying development Barrett's esophagus and its progression to cancer remain unclear.     

Is chemotherapy associated with development of Barrett's esophagus?

Columnar-lined or Barrett's esophagus is a premalignant condition. It is almost unvariably due to chronic gastroesophageal reflux. Since there are some reports that Barrett's esophagus can be induced by chemotherapy, we investigated 20 male patients, treated with chemotherapy for testicular cancer, and 18 female patients, treated with high-dose chemotherapy for breast cancer. Only one patient in the testicular cancer group had Barrett's esophagus of the circumferential type, in addition to typical reflux esophagitis and a hiatal hernia four years after chemotherapy. In the breast cancer group one patient had an indeterminate junction. Our results do not support the hypothesis that chemotherapy poses a substantially increased risk for the development of Barrett's esophagus.     

Tongue-like Barrett＇s esophagus is associated with gastroesophageal reflux disease

AIM： To test this hypothesis of barrett esophagus （BE） classified into two types and to further determine if there was any correlation between the shape of endoscopically suspected esophageal metaplasia （ESEM）, prevalence of reflux esophagitis （RE） and heartburn. METHODS： A total of 6504 Japanese who underwent endoscopy for their annual stomach check-up were enrolled in this study. BE was detected without histological confirmation that is ESEM. We originally classified cases of ESEM into 3 types based on its shape： Tongue-like （T type）, Dome-like （D type） and Wave-like （W type） ESEM. The respective subjects were prospectively asked to complete questionnaires concerning the symptoms of heartburn, dysphagia, and abdominal pain for a one-month period. RESULTS： ESEM was observed in 10.3% of 6504 subjects （ESEM 〈 1 cm, 9.4%; 1cm≤ESEM 〈 3 cm, 1.7%; ESEM≥3 cm, 0.5%）. The frequency of ESEM was significantly higher in males compared with female subjects. Statistical analysis showed that the prevalence of heartburn and RE were significantly higher in the T type ESEM than in the W type ESEM （P 〈 0.05）. CONCLUSION： The T type ESEM was strongly associated with reflux symptoms and RE whereas the W type ESEM was not associated with GERD.     

Biomarkers of Barrett's esophagus

Barrett's esophagus is the strongest risk for esophageal adenocarcinoma(EAC). Metaplasia in patients with BE may progress to dysplasia and then invasive carcinoma. Well-defined diagnostic, progressive, predictive, and prognostic biomarkers are needed to identify the presence of the disease, estimate the risk of malignant transformation, and predict the therapeutic outcome and survival of EAC patients. There are many predictive and prognostic markers that lack substantial validation, and do not allow stratification of patients with gastroesophageal reflux disease in clinical practice for outcome and effectiveness of therapy. In this short review we summarize the current knowledge regarding possible biomarkers, focusing on the pathophysiologic mechanisms to improve prognostic and therapeutic approaches.     

Epidemiologic risk factors for Barrett's esophagus and associated adenocarcinoma.

The incidence of esophageal adenocarcinoma (AC) has increased dramatically in the Western world over the past 20 years and the majority of these cancers arise on the background of the preinvasive lesion Barrett's esophagus. The epidemiologic factors that contribute to an individual's susceptibility for Barrett's esophagus and associated cancer are likely to be multifactorial. However, the short time frame over which the incidence of adenocarcinoma has increased, and the increase across populations, provides a strong argument for environmental factors as etiologic agents, perhaps interacting with genetically determined characteristics that define personal susceptibility. In this review we discuss the epidemiologic evidence for the proposed demographic and environmental risk factors for the development of both Barrett's esophagus and AC. The current evidence suggests that significant risk factors include male sex, Caucasian race, and the presence of duodenogastroesophageal reflux disease. The susceptibility for reflux disease may in turn be influenced by factors such as obesity, the use of drugs that lower the lower-esophageal sphincter tone, and a protective effect of Helicobacter pylori colonization. There appears to be a weak association between smoking and AC. The role of dietary factors has not been studied adequately and deserves further attention. An understanding of the factors that predispose to the development and progression of Barrett's esophagus is crucial to the implementation of effective screening and prevention programs.     

Barrett's esophagus in childhood

This study describes the clinical, radiologic, esophageal function test, endoscopic, and histologic findings of Barrett's esophagus in 11 children aged 6-14 yr. All had long-standing symptoms of gastroesophageal reflux, which had begun in the first year of life in 10 of the 11. Eight of the 11 patients had mid or upper esophageal strictures and 10 of the 11 required fundoplication. Most patients had low lower esophageal sphincter pressures and abnormal pH probe studies. Only 6 of the 11 children had the characteristic pink-red appearance of the mucosa at endoscopy. Fifty endoscopic biopsy specimens taken at multiple levels in the esophagus contained columnar-lined epithelium above the gastroesophageal junction. Five of the patients had specialized (intestinal-type) epithelium as part of the histologic spectrum. The clinical expression of Barrett's esophagus in children is similar to that in adults except that strictures appear to be more common in children, and the endoscopic appearance of the mucosa is not always typical in color. As in adults, gastroesophageal reflux appears to be the etiology. In children beyond infancy, Barrett's esophagus is the most common indication for antireflux surgery at our institution. Biopsy specimens should be taken from multiple levels in the esophagus to avoid overdiagnosis and to establish the diagnosis with certainty.