Review article: prevalence of Barrett's oesophagus and metaplasia at the gastro-oesophageal junction

Endoscopic Surveillance of Intestinal Metaplasia of the Esophagogastric Junction: A Decision Modeling Analysis

INTRODUCTION

The incidence of esophagogastric junction adenocarcinoma (EGJAC) has been rising. Intestinal metaplasia of the esophagogastric junction (EGJIM) is a common finding in gastroesophageal reflux (irregular Z-line) and may represent an early step in the development of EGJAC in the West. Worldwide, EGJIM may represent progression along the Correa cascade triggered by Helicobacter pylori . We sought to evaluate the cost-effectiveness of endoscopic surveillance of EGJIM.

METHODS

We developed a decision analytic model to compare endoscopic surveillance strategies for 50-year-old patients after diagnosis of non-dysplastic EGJIM: (i) no surveillance (standard of care), (ii) endoscopy every 3 years, (iii) endoscopy every 5 years, or (iv) 1-time endoscopy at 3 years. We modeled 4 progression scenarios to reflect uncertainty: A (0.01% annual cancer incidence), B (0.05%), C (0.12%), and D (0.22%).

RESULTS

Cost-effectiveness of endoscopic surveillance depended on the progression rate of EGJIM to cancer. At the lowest progression rate (scenario A, 0.01%), no surveillance strategies were cost-effective. In moderate progression scenarios, 1-time surveillance at 3 years was cost-effective, at $30,989 and $16,526 per quality-adjusted life year for scenarios B (0.05%) and C (0.12%), respectively. For scenario D (0.22%), surveillance every 5 years was cost-effective at $77,695 per quality-adjusted life year.

DISCUSSION

Endoscopic surveillance is costly and can cause harm; however, low-intensity longitudinal surveillance (every 5 years) is cost-effective in populations with higher EGJAC incidence. No surveillance or 1-time endoscopic surveillance of patients with EGJIM was cost-effective in low-incidence populations. Future studies to better understand the natural history of EGJIM, identify risk factors of progression, and inform appropriate surveillance strategies are required.

Gastroesophageal reflux disease: risk factors, current possibilities of diagnosis and treatment optimisation

Gastroesophageal reflux disease (GERD) is one of the most common causes of health care seeking at the primary care level in many countries. At an epidemiological level, GERD has been shown to be associated with a number of risk factors: obesity, tobacco smoking, alcohol abuse, certain patterns of eating behaviour, and the use of several medications. GERD is now regarded as a heterogeneous disease and includes different phenotypes (erosive reflux disease, non-erosive reflux disease, hypersensitive oesophagus, functional heartburn), the proper diagnosis of which improves the effectiveness of therapy in patients with heartburn symptoms. Daily impedance–pH monitoring is known to be an integral part of the diagnostic algorithm for GERD and is a functional diagnostic method to record all types of refluxes entering the oesophagus regardless of pH, to assess their association with symptoms, and to determine whether patients with heartburn symptoms belong to a particular phenotype. Esophageal manometry plays a key role in the evaluation of patients with heartburn symptoms, as it helps to rule out other conditions that may mimic GERD: achalasia cardia and scleroderma esophagus. This technique is used to assess thoracic esophageal motility and sphincter function and in the assessment of patients prior to antireflux surgery or in the refractory course of GERD. The article describes in detail GERD risk factors (triggers of heartburn), as well as diagnostic aspects, taking into account a differentiated approach to patients with heartburn based on daily impedance–pH monitoring data in accordance with the current guidelines and recommendations.

Prevalence, clinical characteristics, and risk factors of Barrett esophagus in Vietnamese patients with upper gastrointestinal symptoms

The current barrier for investigation of Barrett esophagus (BE) in Asia is diagnostic standardization, which is a challenge to identify its true risk factors. This study aimed to investigate the prevalence, clinical characteristics and risk factors of BE in Vietnamese patients with upper gastrointestinal symptoms.A cross-sectional study was conducted on consecutive outpatients who underwent upper gastrointestinal endoscopy. Endoscopically suspected esophageal metaplasia (ESEM) which was clearly visible at least 1 cm above the gastroesophageal junction at endoscopy was taken biopsy. At least 1 biopsy per 2 cm in tongues of ESEM and 4 biopsies per 2 cm of circumferential ESEM were taken. The diagnostic criterion for BE was replacement of the normal squamous epithelial lining by columnar epithelium confirmed by histology.A total of 1947 patients were recruited. Forty-seven out of 58 patients with ESEM were histologically confirmed BE. The prevalences of BE and hiatal hernia (HH) were 2.4% (95% confidence interval [CI], 1.7-3.1%) and 2.3% (95% CI, 1.6-2.9%), respectively. Heartburn and/or regurgitation presented in only 61.7% (95% CI, 46.4-75.5%) of patients with BE. In multivariate analysis, the only 2 factors significantly associated with BE were HH (OR 7.53; 95% CI, 3.13-18.11; P < .001) and typical reflux symptom (OR 2.07; 95% CI, 1.12-3.83; P = .020).BE is not uncommon in Vietnamese patients with upper gastrointestinal symptoms. In addition, typical reflux symptoms and HH are the risk factors for BE in Vietnamese.

Screening for Barrett's Esophagus: Balancing Clinical Value and Cost-effectiveness

In predisposed individuals with long standing gastroesophageal reflux disease (GERD), esophageal squamous mucosa can transform into columnar mucosa with intestinal metaplasia, commonly called Barrett’s esophagus (BE). Barrett’s mucosa can develop dysplasia, which can be a precursor for esophageal adenocarcinoma (EAC). However, most EAC cases are identified when esophageal symptoms develop, without prior BE or GERD diagnoses. While several gastrointestinal societies have published BE screening guidelines, these vary, and many recommendations are not based on high quality evidence. These guidelines are concordant in recommending targeted screening of predisposed individuals (eg, long standing GERD symptoms with age > 50 years, male sex, Caucasian race, obesity, and family history of BE or EAC), and against population based screening, or screening of GERD patients without risk factors. Targeted endoscopic screening programs provide earlier diagnosis of high grade dysplasia and EAC, and offer potential for endoscopic therapy, which can improve prognosis and outcome. On the other hand, endoscopic screening of the general population, unselected GERD patients, patients with significant comorbidities or patients with limited life expectancy is not cost-effective. New screening modalities, some of which do not require endoscopy, have the potential to reduce costs and expand access to screening for BE.

Natural history, pathophysiology and evaluation of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is one of the most common diseases encountered by both internists and gastroenterologists. GERD can cause a wide variety of symptoms ranging from heartburn and regurgitation to more atypical symptoms such as cough, chest pain, and hoarseness. The diagnosis is often times made on the basis of history and clinical symptomatology. The prevalence of GERD is currently estimated to be 8-33% with the incidence of disease only expected to increase over time. Although most cases of GERD can be diagnosed based on symptoms and clinical presentation, the diagnosis of GERD can be challenging when symptoms are atypical. In this review, we provide a comprehensive summary of the epidemiology, pathophysiology, evaluation and diagnosis of gastroesophageal reflux disease.

Modern diagnosis of GERD: the Lyon Consensus

Clinical history, questionnaire data and response to antisecretory therapy are insufficient to make a conclusive diagnosis of GERD in isolation, but are of value in determining need for further investigation. Conclusive evidence for reflux on oesophageal testing include advanced grade erosive oesophagitis (LA grades C and D), long-segment Barrett's mucosa or peptic strictures on endoscopy or distal oesophageal acid exposure time (AET) >6% on ambulatory pH or pH-impedance monitoring. A normal endoscopy does not exclude GERD, but provides supportive evidence refuting GERD in conjunction with distal AET <4% and <40 reflux episodes on pH-impedance monitoring off proton pump inhibitors. Reflux-symptom association on ambulatory reflux monitoring provides supportive evidence for reflux triggered symptoms, and may predict a better treatment outcome when present. When endoscopy and pH or pH-impedance monitoring are inconclusive, adjunctive evidence from biopsy findings (histopathology scores, dilated intercellular spaces), motor evaluation (hypotensive lower oesophageal sphincter, hiatus hernia and oesophageal body hypomotility on high-resolution manometry) and novel impedance metrics (baseline impedance, postreflux swallow-induced peristaltic wave index) can add confidence for a GERD diagnosis; however, diagnosis cannot be based on these findings alone. An assessment of anatomy, motor function, reflux burden and symptomatic phenotype will therefore help direct management. Future GERD management strategies should focus on defining individual patient phenotypes based on the level of refluxate exposure, mechanism of reflux, efficacy of clearance, underlying anatomy of the oesophagogastric junction and psychometrics defining symptomatic presentations.

Sebaceous gland metaplasia in the oesophagus of a cynomolgus monkey (Macaca fascicularis)

Microscopical evaluation of tissues from a mature female cynomolgus monkey assigned to a 13-week oral toxicity study revealed nests of sebaceous cells within the mucosa of the distal oesophagus. The sebaceous cell nests showed normal differentiation from basally-oriented seboblasts to centrally-orientated mature sebocytes. No excretory ducts were found, but solitary or small groups of vacuolated sebocytes were present in the overlying normal, non-keratinized squamous epithelium. The finding of sebaceous cells, of presumed ectodermal origin, in the oesophageal mucosa, which is of endodermal origin, is of scientific interest. Different theories may explain the existence of this peculiarity, but sebaceous gland metaplasia is the most plausible. The mucosal change was thought to be unrelated to treatment and is the first case of sebaceous gland metaplasia reported in the oesophagus of a non-human primate.

Comparative Multi-Epitope-Ligand-Cartography reveals essential immunological alterations in Barrett's metaplasia and esophageal adenocarcinoma

Background

Barrett's esophagus (BE) is caused by gastroesophageal reflux with consecutive mucosal inflammation, predisposing patients to the development of esophageal adenocarcinoma (EAC). We investigated changes in T cell-related mucosal combinatorial molecular protein patterns in both diseases using the novel Multi-Epitope-Ligand-Cartography, a unique robotic whole-cell imaging technology that simultaneously visualizes dozens of proteins in structurally intact tissues and correlates cellular localization of proteins with function.

Results

Biopsies were taken during endoscopy from BE, EAC, and normal control tissue, and proteomic microscopy was performed on 32 different epitopes. When the significance level was set to p < 0.0005 and the search depth to five antibody combinations, controls and BE can be differentiated by 63, controls and EAC by 3222, and BE from EAC by 1521 distinct protein combinations.

For example, the number of activated apoptotic naïve and memory T cells was significantly increased only in BE, whereas the number of activated apoptotic helper and regulatory T cells was significantly elevated in BE and EAC. In contrast, the number of activated apoptotic cytotoxic T cells was significantly elevated only in EAC. Confirming different pathways in BE and EAC, the number of T lymphocytes with p53 expression and downregulation of bcl2 expression (CD3⁺p53⁺Bcl2^-NfkB^-) was significantly increased in EAC compared to BE and controls. Interestingly, the number of precursor T cells (CD7⁺) was significantly elevated only in EAC. These cells lack Bax and caspase-8, suggesting impaired apoptosis in the early stages of T cell differentiation.

Conclusion

Proteomic analysis showed for the first time that proteins, which are critically involved in the mucosal immune system of the esophagus, are distinctly expressed in BE and EAC, whereas others are comparably altered in both diseases, suggesting that many pathogenic events might be shared by both diseases. Topological proteomic analysis, therefore, helps us to understand the different pathogenic events in the underlying disease pathways.

Current and past smoking significantly increase risk for Barrett's esophagus

BACKGROUND & AIMS

Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma; the incidence of this cancer is rapidly increasing in Western populations. However, few population-based studies of BE have been conducted, so little is known about potentially modifiable causes of this disease.

METHODS

The study included patients with newly diagnosed BE, confirmed by histology and categorized as simple BE (without dysplasia, n = 285) or dysplastic BE (with dysplasia, n = 108). We recruited 2 separate control groups: endoscopy patients with acute inflammatory changes (inflammation controls, n = 313) and population controls sampled from a population register (n = 644). Data were collected through standardized questionnaires and telephone interviews. We fit logistic regression models to calculate odds ratios (ORs) for BE associated with salient exposures by using each set of controls.

RESULTS

Relative to never smokers, risks of simple BE were significantly higher among former smokers (OR, 2.39; 95% confidence interval, 1.59-3.60) and current smokers (OR, 2.41; 95% confidence interval, 1.39-4.17), compared with population controls. Smoking conferred more than a 4-fold increase in risk for dysplastic BE; this increase in risk remained long after individuals quit smoking. We found no conclusive association between BE and passive smoking and no evidence of independent associations between body mass index (BMI) and simple BE or dysplastic BE, after adjusting for reflux and other factors. Analyses with inflammation controls produced qualitatively similar risk estimates for smoking and BMI to those obtained for population controls, but they were markedly attenuated for reflux, as expected.

CONCLUSIONS

Current and past smoking significantly increases risk for BE, but BMI does not, after adjustment for the effect of reflux.

Barrett's esophagus and endoscopically assessed esophagogastric junction integrity in 1000 consecutive Turkish patients undergoing endoscopy: a prospective study

Barrett's esophagus (BE) appears to be more common in Western than in Asian countries. BE is a complication of gastroesophageal reflux disease (GERD). Anatomical abnormalities of the esophagogastric junction (EGJ) are an important factor in the pathogenesis of GERD. We aimed to determine the prevalence of BE in Turkey, which is geographically located between Europe and Asia, and to investigate the frequency of BE according to the degree of anatomical disruption in the EGJ. This prospective study was performed on 1000 consecutive patients referred for endoscopy for any clinical indication. All patients underwent a structured interview that assessed major symptoms of GERD (regurgitation and heartburn). BE was diagnosed when specialized intestinal metaplasia was detected histologically in the esophageal biopsy specimens. Endoscopically assessed integrity of the EGJ was classified as one of three types, as follows: 1 Normal EGJ. The endoscope shaft was gripped tightly by the cardia in retroflexed endoscopy, or it was gripped less tightly but the cardia was seen to open and close with respiration. 2 Widened EGJ. The cardia was open during all phases of respiration in retroflexed endoscopy, but there was no endoscopic evidence of hiatal hernia (HH) on the antegrade view. 3 HH. The axial length from the EGJ to the diaphragmatic hiatus was at least 2 cm. BE was found in 12 patients (1.2%). Normal EGJ was seen in 90.7% of patients, widened EGJ in 4.3%, and HH in 5%. Patients with widened EGJ had a significantly higher incidence of major reflux symptoms and erosive esophagitis compared with those with normal EGJ (P= 0.001). BE was found in 14% of patients with HH and in 0.5% of patients with a normal EGJ (P= 0.001). None of the patients with widened EGJ had BE. In terms of BE frequency, these patients did not differ significantly from those with normal EGJ (P= 0.793) but did differ significantly from those with HH (P= 0.014). The prevalence of BE was 1.2% in a Turkish population undergoing endoscopy for any reason. In terms of EGJ integrity, comparison of the groups showed that even in the absence of HH, patients with widening of the EGJ had an increased prevalence of major reflux symptoms and erosive esophagitis. However, histologically confirmed BE was not seen among patients with widened EGJ.

Neoplastic precursor lesions in Barrett's esophagus

Barrett's esophagus, currently defined as endoscopically apparent columnar metaplasia of the esophagus with histologic documentation of goblet cells, is the precursor to esophageal adenocarcinoma. However, not all patients with this disorder require intensive surveillance. Pathologic diagnosis and grading of dysplasia in mucosal biopsies remains the best and most widely used method of determining which patients are at highest risk for neoplastic progression. The task of diagnosing dysplasia suffers from considerable interobserver variability. Therefore, consultation with expert gastrointestinal pathologists to confirm the diagnosis of dysplasia before definitive management is highly advisable. Adjunctive methods to improve reproducibility, such as immunostaining for alpha-methylacyl-CoA racemase, show promise but require confirmation in larger studies. This article focuses on dysplasia in Barrett's esophagus in terms of its classification, pathologic diagnostic criteria, limitations, natural history, and treatment.

Videoendoscopy and histopathology of the esophagogastric junction in patients with gastroesophageal reflux disease

BACKGROUND AND AIMS

During endoscopy the stomach is considered to rise at the level of the 'gastric' folds; however, anatomical studies have demonstrated that the proximal gastric folds may in fact be esophageal. This prospective study was designed to assess the histopathology of endoscopically visible proximal gastric folds in patients with gastroesophageal reflux disease.

METHODS

35 consecutive patients (20 males) with gastroesophageal reflux disease underwent video endoscopy, including biopsy sampling from the endoscopically visible esophagogastric junction (0 cm, 0.5 cm and 1.0 cm distal to the rise of gastric folds and 0.5 cm and 1.0 cm proximal to it). Endoscopy was digitally recorded and reviewed for assignment of biopsy level. Columnar-lined esophagus and esophagitis were cataloged according to the Paull-Chandrasoma histopathologic classification and the Los Angeles endoscopic classification.

RESULTS

Endoscopy: Normal endoscopic esophagogastric junction was seen in 11 (31%) patients and visible columnar-lined esophagus < or = 0.5 cm in 24 (69%).

HISTOLOGY

Columnar-lined esophagus extended 1.0 cm in 22.8% of patients and 0.5 cm in 51.4%, distal to the rise of the gastric folds. In all patients columnar-lined esophagus was interposed between squamous epithelium and gastric oxyntic mucosa. Thus, so-called gastric folds contained mucosa of esophageal origin in all patients. Intestinal metaplasia (Barrett esophagus) was detected in eight (22.9%) patients.

CONCLUSIONS

Endoscopy cannot exclude histopathologic columnar-lined esophagus within gastric rugae. Thus, visible 'gastric' folds should not be used for definition of the esophagogastric junction but as a reference landmark for biopsy sampling during endoscopy.

Temporal changes in the endoscopic frequency of new cases of Barrett's esophagus in an Australian health region

OBJECTIVES

The number of patients diagnosed with Barrett's esophagus (BE) has increased in recent decades, although data from populations outside Europe and North America are scarce. This increase has significant implications for health resource utilization and costs. We sought to determine changes in the endoscopic frequency of new cases of BE in an Australian population during the period 1990-2002.

METHODS

We identified all persons newly diagnosed with BE in an Australian health region in 1990, 1998, and 2002. BE cases were categorized as short segment (SSBE) (<3 cm), long segment (>or=3 cm), or undefined length. We compared the total number of esophagogastroduodenoscopies (EGD) and the number of new cases of BE for the three time periods.

RESULTS

Between 1990 and 2002, the endoscopic frequency of new cases of BE increased from 2.9 to 18.9 per 1,000 endoscopies (p<0.001). The greatest increase was for SSBE, increasing from no new cases in 1990 to 6.2 new cases per 1,000 EGD in 2002. In contrast there was a 17% decrease (2.3-1.9 new cases per 1,000 EGD) for long segment BE during the same period. There were 3,090 EGDs undertaken in 1990, 3,518 in 1998, and 2,593 in 2002, an increase of 14% over the first 8-yr interval (p<0.001), and a decline of 26% over the subsequent 4 yr (p<0.001).

CONCLUSIONS

In an Australian population undergoing EGD, the endoscopic frequency and absolute number of new cases of BE, particularly SSBE disease, has increased significantly between 1990 and 2002. This increased frequency of patients diagnosed with BE has broad future economic and clinical implications.

Does screening for Barrett's esophagus and adenocarcinoma of the esophagus prolong survival?

Despite the paucity of data supporting its use, screening upper endoscopy for patients with chronic gastroesophageal reflux disease symptoms to assess for Barrett's esophagus and esophageal adenocarcinoma has become a widely accepted practice. We apply the principles of screening to Barrett's esophagus and esophageal adenocarcinoma. Critical application of the key criteria of screening to this situation demonstrates that several criteria are unfulfilled. Key data are not available with which to judge other criteria. The major fault with screening for Barrett's esophagus is that the at-risk population is too broadly characterized and that too many cancers occur outside of this risk pool. Thus, recommendations for screening cannot be endorsed. Efforts may be better directed at further research identifying groups at risk for esophageal adenocarcinoma, developing more accurate and less-invasive methods of diagnosis, and discovering the underlying factors which continue to drive the increased incidence of this disease.