The prevalence of Barrett's oesophagus in a cohort of 1040 Canadian primary care patients with uninvestigated dyspepsia undergoing prompt endoscopy

Prevalence of Barrett's Esophagus and Esophageal Adenocarcinoma With and Without Gastroesophageal Reflux: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Although gastroesophageal reflux disease (GERD) symptoms are an essential criterion for Barrett's esophagus (BE) screening in most gastroenterology society guidelines, a significant proportion of BE and esophageal adenocarcinoma (EAC) cases do not endorse them. In a systematic review and meta-analysis, we aimed to study the prevalence of BE/EAC in those with and without GERD.

METHODS

A systematic search was conducted through 5 major databases for studies reporting prevalence of BE/EAC in patients with and without GERD. Pooled proportions and odds ratios (ORs) of BE, long-segment BE, short-segment BE, dysplasia, and EAC in patients with and without GERD were synthesized.

RESULTS

Forty-three articles (12,883 patients with GERD; 51,350 patients without GERD) were included in the final analysis. BE prevalence was 7% (95% confidence interval [CI], 5.8%-8.5%) and 2.2% (95% CI, 1.6%-3%) among individuals with and without GERD, respectively. EAC prevalence was 0.6% (95% CI, 0.4%-1%) and 0.1% (95% CI, 0%-0.2%) in those with and without GERD, respectively. The overall risks for BE (OR, 2.91; 95% CI, 2.06-4.11) and long-segment BE (OR,4.17; 95% CI, 1.78-9.77) were higher in patients with GERD, but the risk for short-segment BE (OR, 1.77; 95% CI, 0.89-3.52) did not differ between the two groups. In 9 population-based high-quality studies (2244 patients with GERD; 3724 patients without GERD), BE prevalence in patients without GERD was 4.9% (95% CI, 2.6%-9%). BE prevalence was highest in North American studies (10.6% [GERD] and 4.8% [non-GERD]).

CONCLUSIONS

BE prevalence in those without GERD is substantial, particularly in large high-quality population-based studies. These data are important to factor in future BE/EAC early detection guidelines.

Association between hiatal hernia and Barrett's esophagus: an updated meta-analysis with trial sequential analysis

Background

Barrett's esophagus (BE) is a precursor of esophageal adenocarcinoma. It is critical to recognize the risk factors associated with BE.

Objectives

The present meta-analysis aims to systematically estimate the association of hiatal hernia with the risk of BE.

Design

A meta-analysis with trial sequential analysis.

Data sources and methods

The PubMed, EMBASE, and Cochrane Library databases were searched. The pooled odds ratios (ORs) and adjusted ORs (aORs) with their 95% confidence intervals (CIs) were calculated for the combined estimation of unadjusted data and data adjusted for confounders, respectively. Heterogeneity was quantified using the Cochrane Q test and I² statistics. Subgroup, meta-regression, and leave-one-out sensitivity analyses were employed to explore the sources of heterogeneity.

Results

Forty-seven studies with 131,517 participants were included. Based on the unadjusted data from 47 studies, hiatal hernia was significantly associated with an increased risk of any length BE (OR = 3.91, 95% CI = 3.31-4.62, p < 0.001). The heterogeneity was significant (I² = 77%; p < 0.001) and the definition of controls (p = 0.014) might be a potential contributor to heterogeneity. Based on the adjusted data from 14 studies, this positive association remained (aOR = 3.26, 95% CI = 2.44-4.35, p < 0.001). The heterogeneity was also significant (I² = 65%; p < 0.001). Meta-analysis of seven studies demonstrated that hiatal hernia was significantly associated with an increased risk of long-segment BE (LSBE) (OR = 10.01, 95% CI = 4.16-24.06, p < 0.001). The heterogeneity was significant (I² = 78%; p < 0.001). Meta-analysis of seven studies also demonstrated that hiatal hernia was significantly associated with an increased risk of short-segment BE (OR = 2.76, 95% CI = 2.05-3.71, p < 0.001). The heterogeneity was not significant (I² = 30%; p = 0.201).

Conclusion

Hiatal hernia should be a significant risk factor for BE, especially LSBE.

Registration

PROSPERO registration number CRD42022367376.

Prescription ranitidine use and population exposure in 6 Canadian provinces, 1996 to 2019: a serial cross-sectional analysis

BACKGROUND

Ranitidine was the most prescribed histamine-2 receptor antagonist (H2RA) in Canada when recalled in 2019 because of potential carcinogenicity. We sought to compare geographic and temporal patterns in use of prescription ranitidine and 3 other HRAs and estimated population exposure to ranitidine in 6 provinces between 1996 and 2019.

METHODS

This population-based serial cross-sectional study used prescription claims for H2RAs dispensed from community pharmacies in Nova Scotia, Ontario, Manitoba, Saskatchewan, Alberta and British Columbia. We estimated the period prevalence of ranitidine use per 100 population by province, age category and sex. We estimated exposure to ranitidine between 2015 and 2019 using defined daily doses (DDDs).

RESULTS

Overall, 2.4 million ranitidine prescriptions were dispensed to patients aged 65 years and older, and 1.7 million were dispensed to younger adults. Among older adults, the median period prevalence of ranitidine use among females was 16% (interquartile range [IQR] 13%-27%) higher than among males. Among younger adults, the median prevalence was 50% (IQR 37%-70%) higher among females. Among older adults, between 1996 and 1999, use was highest in Nova Scotia (33%) and Ontario (30%), lower in the prairies (Manitoba [18%], Saskatchewan [26%], Alberta [17%]) and lowest in BC (11%). By 2015-2019, use of ranitidine among older adults dropped by at least 50% in all provinces except BC. We estimate that at least 142 million DDDs of prescribed ranitidine were consumed annually in 6 provinces (2015-2019).

INTERPRETATION

Over the 24-year period in 6 provinces, patients aged 65 years and older were dispensed 2.4 million prescriptions of ranitidine and younger adults were dispensed 1.7 million prescriptions of ranitidine. These estimates of ranitidine exposure can be used for planning studies of cancer risk and identifying target populations for cancer surveillance.

The global prevalence of Barrett's esophagus: A systematic review of the published literature

BACKGROUND

Determining the prevalence of Barrett's esophagus is important for defining screening strategies. We aimed to synthesize the available data, determine Barrett's esophagus prevalence, and assess variability.

METHODS

Three databases were searched. Subgroup, sensitivity, and meta-regression analyses were conducted and pooled prevalence was computed.

RESULTS

Of 3510 studies, 103 were included. In the general population, we estimated a prevalence for endoscopic suspicion of Barrett's esophagus of (a) any length with histologic confirmation of intestinal metaplasia as 0.96% (95% confidence interval: 0.85-1.07), (b) ≥1 cm of length with histologic confirmation of intestinal metaplasia as 0.96% (95% confidence interval: 0.75-1.18) and (c) for any length with histologic confirmation of columnar metaplasia as 3.89% (95% confidence interval: 2.25-5.54) . By excluding studies with high-risk of bias, the prevalence decreased to: (a) 0.70% (95% confidence interval: 0.61-0.79) and (b) 0.82% (95% confidence interval: 0.63-1.01). In gastroesophageal reflux disease patients, we estimated the prevalence with afore-mentioned criteria to be: (a) 7.21% (95% confidence interval: 5.61-8.81) (b) 6.72% (95% confidence interval: 3.61-9.83) and (c) 7.80% (95% confidence interval: 4.26-11.34). The Barrett's esophagus prevalence was significantly influenced by time period, region, Barrett's esophagus definition, Seattle protocol, and study design. There was a significant gradient East-West and North-South. There were minimal to no data available for several countries. Moreover, there was significant heterogeneity between studies.

CONCLUSION

There is a need to reassess the true prevalence of Barrett's esophagus using the current guidelines in most regions. Having knowledge about the precise Barrett's esophagus prevalence, diverse attitudes from educational to screening programs could be taken.

Helicobacter pylori infection reduces the risk of Barrett's esophagus: A meta-analysis and systematic review

INTRODUCTION

The prevalence of Helicobacter pylori infection (HPI) has been decreasing in developed countries, with an increasing prevalence of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) at the same time. The aim of our meta-analysis was to quantify the risk of BE in the context of HPI.

METHODS

A systematic search was conducted in 3 databases for studies on BE with data on prevalence of HPI from inception until December 2016. Odds ratios for BE in HPI were calculated by the random effects model with subgroup analyses for geographical location, presence of dysplasia in BE, and length of the BE segment.

RESULTS

Seventy-two studies were included in the meta-analysis, including 84 717 BE cases and 390 749 controls. The overall analysis showed that HPI reduces the risk of BE; OR = 0.68 (95% CI: 0.58-0.79, P < .001). Subgroup analyses revealed risk reduction in Asia OR = 0.53 (95% CI: 0.33-0.84, P = .007), Australia OR = 0.56 (95% CI: 0.39-0.80, P = .002), Europe OR = 0.77 (95% CI: 0.60-0.98, P = .035), and North-America OR = 0.59 (95% CI: 0.47-0.74, P < .001). The risk was significantly reduced for dysplastic BE, OR = 0.37 (95% CI: 0.26-0.51, P < .001) for non-dysplastic BE, OR = 0.51 (95% CI: 0.35-0.75, P = .001), and for long segment BE, OR = 0.25 (95% CI: 0.11-0.59, P = .001) in case of HPI.

CONCLUSIONS

This extensive meta-analysis provides additional evidence that HPI is associated with reduced risk of BE. Subgroup analyses confirmed that this risk reduction is independent of geographical location. HPI is associated with significantly lower risk of dysplastic, non-dysplastic, and long segment BE.

Prevalence of Barrett's esophagus: An observational study from a gastroenterology clinic

INTRODUCTION AND AIMS

Barrett's esophagus is a condition that predisposes to esophageal adenocarcinoma. Our aim was to establish the prevalence of Barrett's esophagus at our center, as well as determine its associated factors.

MATERIALS AND METHODS

We retrospectively assessed the endoscopic reports of 500 outpatients seen at our Gastroenterology Service from November 2014 to April 2016. We determined the prevalence of Barrett's esophagus and analyzed the demographic, clinical, and endoscopic findings associated with that pathology.

RESULTS

The prevalence of Barrett's esophagus was 1.8%. The mean age of the patients with Barrett's esophagus was 58.7 years (range: 45-70) and there was a predominance of men (66%). In the subgroup of patients with symptoms of gastroesophageal reflux (n=125), Barrett's esophagus prevalence was 7.2%. In the multivariate analysis, the factors that were independently associated with Barrett's esophagus were gastroesophageal reflux (P=.005) and hiatal hernia (P=.006).

CONCLUSIONS

The overall prevalence of Barrett's esophagus was 1.8% in our population, with a prevalence of 7.2% in patients that had symptoms of gastroesophageal reflux.

Cost-effectiveness of chemoprevention with proton pump inhibitors in Barrett's esophagus

BACKGROUND

Proton pump inhibitors (PPIs) may reduce the risk of esophageal adenocarcinoma (EAC) in patients with Barrett's esophagus. PPIs are prescribed for virtually all patients with Barrett's esophagus, irrespective of the presence of reflux symptoms, and represent a de facto chemopreventive agent in this population. However, long-term PPI use has been associated with several adverse effects, and the cost-effectiveness of chemoprevention with PPIs has not been evaluated.

AIM

The purpose of this study was to assess the cost-effectiveness of PPIs for the prevention of EAC in Barrett's esophagus without reflux.

METHODS

We designed a state-transition Markov microsimulation model of a hypothetical cohort of 50-year-old white men with Barrett's esophagus. We modeled chemoprevention with PPIs or no chemoprevention, with endoscopic surveillance for all treatment arms. Outcome measures were life-years, quality-adjusted life years (QALYs), incident EAC cases and deaths, costs, and incremental cost-effectiveness ratios.

RESULTS

Assuming 50% reduction in EAC, chemoprevention with PPIs was a cost-effective strategy compared to no chemoprevention. In our model, administration of PPIs cost $23,000 per patient and resulted in a gain of 0.32 QALYs for an incremental cost-effectiveness ratio of $12,000/QALY. In sensitivity analyses, PPIs would be cost-effective at $50,000/QALY if they reduce EAC risk by at least 19%.

CONCLUSIONS

Chemoprevention with PPIs in patients with Barrett's esophagus without reflux is cost-effective if PPIs reduce EAC by a minimum of 19%. The identification of subgroups of Barrett's esophagus patients at increased risk for progression would lead to more cost-effective strategies for the prevention of esophageal adenocarcinoma.

Embryological signaling pathways in Barrett's metaplasia development and malignant transformation; mechanisms and therapeutic opportunities

Barrett's metaplasia of the esophagus (BE) is the precursor lesion of esophageal adenocarcinoma (EAC), a deadly disease with a 5-year overall survival of less than 20%. The molecular mechanisms of BE development and its transformation to EAC are poorly understood and current surveillance and treatment strategies are of limited efficacy. Increasing evidence suggests that aberrant signaling through pathways active in the embryological development of the esophagus contributes to BE development and progression to EAC. We discuss the role that the Bone morphogenetic protein, Hedgehog, Wingless-Type MMTV Integration Site Family (WNT) and Retinoic acid signaling pathways play during embryological development of the esophagus and their contribution to BE development and malignant transformation. Modulation of these pathways provides new therapeutic opportunities. By integrating findings in developmental biology with those from translational research and clinical trials, this review provides a platform for future studies aimed at improving current management of BE and EAC.

Barrett esophagus: diagnostic challenges

The incidence of esophageal adenocarcinoma and associated mortality has risen dramatically over the past several decades, and, thus, it is increasingly important to understand its pathogenesis and risk factors. Barrett esophagus is the established precursor to esophageal adenocarcinoma that progresses through a metaplasia-dysplasia-carcinoma sequence. Its risk of transforming to carcinoma is not as high as previously reported and there appears to be a biological heterogeneity among patients with this disease. The overall prevalence of Barrett esophagus in the United States ranges from 1% to 25% and is closer to 5% in patients with gastroesophageal reflux disease. Because of the frequency of Barrett esophagus and associated implications, it is important for the practicing pathologist to have a thorough understanding of this disease and its diagnostic pitfalls. In this review, we will discuss issues associated with the diagnosis of Barrett esophagus, including the definition of Barrett esophagus and its distinction from carditis with intestinal metaplasia. We will also discuss challenges in the grading of dysplasia and new variants of dysplasia, including crypt dysplasia and foveolar-type dysplasia. Finally, we will touch upon the evaluation of dysplasia in endoscopic mucosal resection specimens.

Hiatal hernia and the risk of Barrett's esophagus

BACKGROUND AND AIM

Barrett's esophagus has been associated with the presence of hiatal hernia; however, to date no meta-analysis of the relationship has been performed. We aimed to conduct a systematic review and meta-analysis, providing a quantitative estimate of the increased risk of Barrett's esophagus associated with hiatal hernia.

METHODS

A search was conducted through four electronic databases (Medline, PubMed, Embase, and Current Contents Connect) to 4 April 2012, for observational studies of Barrett's esophagus patients. We calculated pooled odds ratios and 95% confidence intervals using a random effects model for the association of hiatal hernia with any length Barrett's esophagus, as well as with short segment Barrett's esophagus and long segment Barrett's esophagus. 33 studies comprising 4390 Barrett's esophagus patients were eligible for the meta-analysis.

RESULTS

Hiatal hernia was associated with an increased risk of Barrett's esophagus of any length (odds ratio 3.94; 95% confidence interval 3.02-5.13). Heterogeneity was present (I2 = 82.03%, P < 0.001), and the Egger test for publication bias was significant (P = 0.0005). The short segment Barrett's esophagus subgroup analysis likewise showed an increased risk (odds ratio 2.87; 95% confidence interval 1.75-4.70). The strongest association was between hiatal hernia and long segment Barrett's esophagus (odds ratio 12.67; 95% confidence interval 8.33-19.25). The increased risk was present even after adjusting for reflux and body mass index.

CONCLUSIONS

 The presence of hiatal hernia was associated with an increased risk of Barrett's esophagus, even after adjusting for clinically significant confounders. The strongest association was found between hiatal hernia and long segment Barrett's esophagus.

Prevalence and predictors of columnar lined esophagus in gastroesophageal reflux disease (GERD) patients undergoing upper endoscopy

OBJECTIVES

Chronic gastroesophageal reflux disease (GERD) is a risk factor for Barrett's esophagus (BE), the most important surrogate marker for the development of esophageal adenocarcinoma (EAC). The need to document the presence of intestinal metaplasia in esophageal biopsies from a columnar lined esophagus (CLE) to diagnose BE is debated. The objective of this study was to prospectively evaluate the prevalence and risk factors of CLE in a large cohort of GERD patients undergoing upper endoscopy.

METHODS

Consecutive patients presenting to the endoscopy unit at a tertiary referral center for their index upper endoscopy for evaluation of GERD symptoms were enrolled in this prospective cohort study. Patients were asked to complete a validated GERD questionnaire that documents the onset of GERD symptoms (heartburn and acid regurgitation) and grades the frequency and severity of symptoms experienced over the past year. Demographic information, body mass index, and use of aspirin/nonsteroidal antiinflammatory drugs were recorded. Endoscopic details including length of CLE, presence and size of hiatal hernia were noted. Patients with CLE (cases) were compared with those without CLE (controls) using Fischer's exact test and t-test. All factors that were statistically significant (P<0.05) were then entered into stepwise logistic regression to evaluate for independent predictors of CLE.

RESULTS

A total of 1058 patients with GERD symptoms were prospectively enrolled. On index endoscopy, the prevalence of CLE was 23.3%, whereas of CLE with documented intestinal metaplasia was 14.1%. On univariate analysis, male gender, Caucasian race, heartburn duration of >5 years, presence and size of hiatal hernia were significantly associated with the presence of CLE compared with controls (P<0.05). On multivariate analysis, heartburn duration >5 years (odds ratio (OR): 1.50, 95% confidence interval (CI): 1.07-2.09, P=0.01), Caucasian race (OR: 2.40, 95% CI: 1.42-4.03, P=0.001), and hiatal hernia (OR: 2.07, 95% CI: 1.50-2.87, P<0.01) were found to be independent predictors for CLE. CLE length was significantly associated with the presence of intestinal metaplasia (P<0.001).

CONCLUSIONS

If BE is defined by the presence of CLE alone on upper endoscopy, up to 25% of GERD patients are diagnosed with this lesion. Enrolling all these patients in surveillance programs would have significant ramifications on health-care resources.

Systematic review: patterns of reflux-induced symptoms and esophageal endoscopic findings in large-scale surveys

BACKGROUND & AIMS

This systematic review assesses findings of endoscopic surveys in the general population with regard to gastroesophageal reflux disease (GERD).

METHODS

Systematic searches were conducted in PubMed and EMBASE. Authors were contacted for additional, unpublished data.

RESULTS

Data on 61,281 individuals were included from 3 general population studies (Kalixanda study [Sweden], Loiano-Monghidoro study [Italy], SILC study [China]) and 8 health-check studies (Japan, n = 1; China, n = 1; Taiwan, n = 4; Korea, n = 2). The prevalence of reflux esophagitis was 15.5% (Kalixanda), 11.8% (Loiano-Monghidoro), and 6.4% (SILC); it ranged from 3.4% to 8.5% in health-check studies in Japan, China, and Korea (n = 4), but was higher (mean, 15.6%; range, 9.0%-24.6%; n = 4) in Taiwan. Hiatus hernia prevalence was 23.9% (Kalixanda), 43.0% (Loiano-Monghidoro), and 0.7% (SILC), and 0.8%-19.5% in health-check studies (n = 7). For endoscopically suspected esophageal metaplasia (ESEM), the prevalence was 10.3% (Kalixanda), 3.6% (Loiano-Monghidoro), and 1.8% (SILC), and 0.0%-3.4% in health-check studies (n = 4). The prevalence of reflux esophagitis among individuals without symptom-defined GERD was 12.1% (Kalixanda), 8.6% (Loiano-Monghidoro), 6.1% (SILC), and 1.6%-22.8% (health-check studies; n = 6). For individuals without symptom-defined GERD, the prevalence of ESEM was 9.4% (Kalixanda), 2.8% (Loiano-Monghidoro), and 1.8% (SILC).

CONCLUSIONS

The prevalence of reflux esophagitis is higher in Sweden and Italy than in China, Korea, and Japan, but is within the range reported in Taiwan. Hiatus hernia and ESEM are generally more prevalent in Europe than in Asia. A considerable proportion of individuals without symptom-defined GERD has reflux esophagitis or ESEM.

Reflux and sex: what drives testing, what drives treatment?

Gastroesophageal reflux (GER) affects ∼10-20% of American adults. Although symptoms are equally common in men and women, we hypothesized that sex influences diagnostic and therapeutic approaches in patients with GER. PubMed database between 1997 and October 2011 was searched for English language studies describing symptoms, consultative visits, endoscopic findings, use and results of ambulatory pH study, and surgical therapy for GER. Using data from Nationwide Inpatient Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality, we determined the sex distribution for admissions and reflux surgery between 1997 and 2008. Studies on symptoms or consultative visits did not show sex-specific differences. Even though women are less likely to have esophagitis or Barrett's esophagus, endoscopic studies enrolled as many women as men, and women were more likely to undergo ambulatory pH studies with a female predominance in studies from the US. Surgical GER treatment is more commonly performed in men. However, studies from the US showed an equal sex distribution, with Nationwide Inpatient Sample data demonstrating an increase in women who accounted for 63% of the annual fundoplications in 2008. Despite less common or severe mucosal disease, women are more likely to undergo invasive diagnostic testing. In the US, women are also more likely to undergo antireflux surgery. These results suggest that healthcare-seeking behavior and socioeconomic factors rather than the biology of disease influence the clinical approaches to reflux disease.

Developing a nonendoscopic screening test for Barrett's esophagus

Barrett's esophagus (BE) arises as a complication of chronic gastro-esophageal reflux disease and is the precursor lesion for esophageal adenocarcinoma. The prevalence of esophageal adenocarcinoma has been increasing in Western countries and the overall prognosis from this cancer remains dismal. Surveillance for BE is highly controversial since although early cancer detection through surveillance programs benefits individuals, surveillance has not been proven to reduce population mortality from the disease. One factor contributing to this apparent paradox is that an estimated >80% cases of BE are undiagnosed and, therefore, do not have the benefit of surveillance. Some form of screening modality is required to achieve more comprehensive detection of BE, which in turn, may lead to early detection of cancerous lesions and early intervention in order to reduce progression to invasive and symptomatic cancer. The advent of endoscopic therapy makes this paradigm attractive. A number of methods could be considered for screening. These include a nonendoscopic sampling method using a Cytosponge that needs to be coupled with a biomarker to obtain required levels of sensitivity and specificity. For screening to be recommended consideration needs to be given to the point of delivery, cost and acceptability to patients.

The dichotomy in carcinogenesis of the distal esophagus and esophagogastric junction: intestinal-type vs cardiac-type mucosa-associated adenocarcinoma

Adenocarcinoma of the distal esophagus and esophagogastric junction continues to rise in incidence. An intestinal metaplasia (Barrett esophagus)-dysplasia-carcinoma sequence induced by gastroesophageal reflux disease is well established. However, a significant number of adenocarcinomas in the vicinity of the esophagogastric junction are seen in the background of gastric/cardiac-type mucosa without intestinal metaplasia. Thus, the aim of this study was to investigate the role of Barrett esophagus (intestinal-type mucosa) in the classification and prognosis of tumors of the distal esophagus and esophagogastric junction. Clinicopathological and molecular characteristics were examined in 157 consecutively resected adenocarcinomas of the distal esophagus and esophagogastric junction and were compared between tumors arising in association with intestinal-type and cardiac-type mucosa. Intestinal-type mucosa-associated adenocarcinomas were more likely to be associated with younger age (P=0.0057), reflux symptoms (P<0.0001), proximal location (P=0.0009), lower T stage (P<0.0001), fewer nodal metastases (P=0.0001), absence of lymphatic (P<0.0001), venous (P=0.0060) or perineural (P<0.0001) invasion. Histologically, intestinal-type mucosa-associated tumors were more likely to be low-grade glandular tumors (P=0.0095) of intestinal or mixed immunophenotype (P=0.015) and express nuclear β-catenin (P=0.0080), whereas tumors arising in a background of cardiac-type mucosa were more frequently associated with EGFR amplification (P=0.0051). Five-year overall survival rate was significantly higher in patients with intestinal-type mucosa-associated tumors (28 vs 9%, P=0.0015), although no survival benefit was seen after adjusting for potential confounders. Our findings support the theory that multiple distinct pathways of tumorigenesis exist in the vicinity of the esophagogastric junction, including one in which tumors arise from dysplastic intestinal metaplasia (intestinal pathway), and one potentially involving dysplasia of the cardiac-type mucosa (non-intestinal pathway). Additional studies are warranted to further clarify their pathogenesis and the molecular mechanisms involved.

Barrett's esophagus: a review of the literature

Barrett's esophagus (BE) is the premalignant lesion of esophageal adenocarcinoma (EAC) defined as specialized intestinal metaplasia of the tubular esophagus that results from chronic gastroesophageal reflux. Which patients are at risk of having BE and which are at further risk of developing EAC has yet to be fully established. Many aspects of the management of BE have changed considerably in the past 5 years alone. The aim of this review is to define the critical elements necessary to effectively manage individuals with BE. The general prevalence of BE is estimated at 1.6-3% and follows a demographic distribution similar to EAC. Both short-segment (<3 cm) and long-segment (≥3 cm) BE confer a significant risk for EAC that is increased by the development of dysplasia. The treatment for flat high-grade dysplasia is endoscopic radiofrequency ablation therapy. The benefits of ablation for non-dysplastic BE and BE with low-grade dysplasia have yet to be validated. By understanding the intricacies of the development, screening, surveillance, and treatment of BE, new insights will be gained into the prevention and early detection of EAC that may ultimately lead to a reduction in morbidity and mortality in this patient population.

Global epidemiology of Barrett's esophagus

Barrett's esophagus (BE) is defined as a metaplastic change of the distal esophageal epithelium from squamous to columnar type epithelium with the presence of intestinal metaplasia. There is a striking geographic variation in the prevalence rates of BE. Most epidemiological data on BE are derived from patients undergoing endoscopy and do not reflect prevalence rates in the general population. BE is much more common in the West when compared with Asia and Africa. Although BE is less common in Asia, the demographics are similar to the West, being predominantly found in older men with longer duration of reflux symptoms. Some studies from the West have suggested an increase in prevalence rates of BE. An increase in prevalence rates will have significant implications for health resource utilization and costs, due to the small but significant risk of developing esophageal adenocarcinoma. Endoscopic surveillance with the aim of detecting early lesions has been advocated. Compared with conventional white-light endoscopy with blind four-quadrant biopsies, the use of image-enhanced endoscopy, including chromoendoscopy, may improve detection of subtle mucosal irregularities and facilitate targeted biopsies. However, a truly cost-effective surveillance strategy remains to be determined.

Meta-analyses of the effect of symptoms of gastroesophageal reflux on the risk of Barrett's esophagus

OBJECTIVES

Esophageal adenocarcinoma (EAC) is a devastating disease that has risen in incidence over the past several decades. Barrett's esophagus (BE) is an associated premalignant lesion. Current preventative efforts rely on endoscopic screening of individuals with gastroesophageal reflux disease (GERD) symptoms and surveillance endoscopy for those with BE. However, some recent studies have found a high prevalence of BE in patients without GERD, and others have found little or no association with GERD. We hypothesized that studies of higher-quality design show weaker associations of GERD with BE, and that GERD is only weakly associated with short-segment Barrett's esophagus (SSBE).

METHODS

We performed a systematic literature search in multiple online electronic databases regardless of language. Eligible studies required visualization of columnar mucosa and histological confirmation of intestinal metaplasia, and GERD symptoms ascertained by questionnaire or interview. The highest-quality sampling design was defined a priori by both cases and controls identified among unselected research volunteers ("research design") rather than by patients selected for endoscopy for clinical indications ("clinical design"), which introduces selection and ascertainment bias. A priori, heterogeneity was defined by Cochrane's Q P<0.20 and the inconsistency index (I(2); 25% low, 50% moderate, and 75% high). Heterogeneity of results can reflect significant differences in study design or effect modification by strata of outcomes.

RESULTS

Systematic review identified 13,392 citations. Evaluation identified 108 potentially relevant journal articles, of which 26 met eligibility. Of these, 14 studies identified cases of BE and controls based on clinical indication ("clinical design"), and 6 used the "research design." The remaining six studies identified cases of BE from patients undergoing endoscopy for clinical indication and controls among patients without known BE ("cases clinical/controls research"). The summary odds ratio (OR) for the association of GERD with BE from all studies was 2.90 (95% confidence interval (CI), 1.86-4.54), but the results were very heterogeneous (P=0.0001; I(2)=89%). When stratified by BE length and sampling design, the studies with clinical design showed substantial, but heterogeneous, associations with SSBE (OR, 2.38; 95% CI, 1.21-4.70; P=0.02; I(2)=62%), and stronger and homogeneous association with long-segment BE (LSBE; fixed effects OR, 2.96; 95% CI, 1.69-5.19; P=0.25; I(2)=25%). In the research study design, stratifying by length of BE resolved the heterogeneity and showed a strong association between GERD and LSBE (fixed effects OR, 4.92; 95% CI, 2.01-12.0; P=0.30; I(2)=19%) and no association with SSBE (fixed effects OR, 1.15; 95% CI, 0.763-1.73; P=0.84; I(2)=0%). Funnel plots showed potential evidence for bias against dissemination of small negative studies.

CONCLUSIONS

In the highest-quality studies, GERD symptoms are not associated with SSBE, but increased the odds of LSBE by fivefold. GERD symptoms can serve as a reliable predictor of LSBE, but not SSBE. If SSBE is considered worthy of identification, then current screening practices do not select patients at risk for endoscopy, and alternative methods of selection for screening need to be developed.

The prevalence of and risk factors for Barrett's esophagus in a Korean population: A nationwide multicenter prospective study

OBJECTIVE

The aim of this study was to evaluate the prevalence of Barrett's esophagus (BE) in the general Korean population by evaluating screening esophagogastroduodenoscopy. In addition, the risk factors for BE were identified.

METHOD

An esophagogastroduodenoscopy examination was performed in 25,536 subjects who had upper endoscopy screening from January 2006 to July 2006.

RESULTS

Two hundred and fifteen subjects were confirmed to have BE by pathology, thus the prevalence of BE was calculated to be 0.84%. The endoscopic findings were subdivided into 2 groups: BE without reflux esophagitis (RE), which included 167 (77.7%), and BE with RE, which included 48 (22.3%). The analysis of symptoms showed that only 60.1% of the subjects with BE had reflux symptoms. Chest pain [odds ratio (OR): 1.48, 95% confidence interval (CI): 1.04-2.11] and epigastric soreness (OR: 1.42, 95% CI: 1.05-1.93) were found more frequently in the subjects with BE compared with the normal subjects. The multivariate analysis showed that the risk factors for all subjects with BE were a male sex (OR: 1.82, 95% CI: 1.32-2.50), nonsteroidal anti-inflammatory drug use (OR: 2.02, 95% CI: 1.28-3.20), hiatal hernia (OR: 5.66, 95% CI: 3.70-8.66), and an age > or = 60 compared with an age < 40 (OR: 1.81, 95% CI: 1.07-3.09). There was no significant difference associated with RE.

CONCLUSIONS

The prevalence of BE in Korean patients presenting for a routine health check-up was 0.84%, lower than reported in Western countries. Among the subjects with BE 77.7% did not have endoscopic erosions and there were no reflux symptoms in 39.9%. These results suggest that regular endoscopic screening with a high index of suspicion is necessary for the diagnosis of BE.

Screening and surveillance of Barrett's esophagus

Esophageal adenocarcinoma (EAC) is the most rapidly increasing cancer in the Western world and Barrett's esophagus (BE) is the only known precursor lesion for this lethal cancer. Long-term survival may be improved if EAC is diagnosed early, providing an opportunity for early intervention. Screening for BE in patients with gastroesophageal reflux disease is not routinely recommended; however, if diagnosed, enrollment into a surveillance program may be beneficial. Surveillance of all patients with known BE is probably not cost-effective and factors predictive of BE progression to dysplasia/EAC are poorly understood. Screening and surveillance examinations are also faced with challenges in the endoscopic detection of intestinal metaplasia and dysplasia. Future application of molecular biomarkers may help identify the patients with BE most likely to progress, and the use of novel imaging methods may improve outcomes of BE screening and surveillance.

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.

The application of Prague C and M criteria in the diagnosis of Barrett's esophagus in an ethnic Chinese population

OBJECTIVES

To investigate the prevalence of endoscopically suspected esophageal metaplasia (ESEM) in an ethnic Chinese population by endoscopic and pathologic evaluation and to assess the utility of Prague C and M criteria.

METHODS

Consecutive patients who received esophagogastroduodenoscopy either as a part of therapy for various upper abdominal symptoms or as an annual health check-up were evaluated for the existence of ESEM and Barrett's esophagus (BE). Biopsy with standardized random four pieces every 2 cm from the four quarters of esophagus with ESEM lesion was performed. BE was defined by histological verification of specialized intestinal metaplasia and gastric metaplasia and was categorized according to the Prague C and M criteria.

RESULTS

A total of 5,179 subjects were screened from Jan. 2007 to Dec. 2007. This study enrolled 4,797, including 3,386 for referral endoscopy and 1,411 for screening endoscopy. Prevalence of BE among the referral endoscopy, screening endoscopy, and overall was 1.06%, 0.35%, and 0.85%, respectively. A total of 41 subjects with BE were detected among 93 ESEM subjects. Short segment BE (75.6%, n=31) was more prevalent than long segment BE (24.4%, n=10). The proportions of BE from subjects with ESEM by Prague C and M criteria were C< or =1M1 38.9% (19/50), C< or =1M2 40% (12/30), and CxM> or =3 76.9% (10/13).

CONCLUSIONS

On the basis of the standardized protocol with random four-quadrate endoscopic biopsy, we have demonstrated the utility of Prague C and M criteria to characterize the BE in an ethnic Chinese population.

Prevalence and clinical characteristics of Barrett's esophagus in a Chinese general population

BACKGROUND

The prevalence of Barrett esophagus (BE) remains elusive in the general populations.

GOALS

The purpose of this study was to identify the prevalence and clinical characteristics of BE in a Chinese general population.

STUDY

Between June 2003 and December 2006, consecutive subjects were evaluated via upper gastrointestinal endoscopy during a routine health examination. Patients were evaluated for any abnormalities, including endoscopically suspected esophageal metaplasia (ESEM) and erosive esophagitis (EE). Biopsies were attained from patients with ESEM to confirm a diagnosis of BE. The demographic data and endoscopic findings were retrospectively analyzed.

RESULTS

Of the 19,812 endoscopies performed, 56 patients (0.28%) were diagnosed with ESEM and 3129 patients (15.7%) with EE. Twelve of the 56 patients diagnosed with ESEM (0.06% of the total number of patients who underwent endoscopy) were confirmed to have BE after histologic analysis of the biopsies. Patients with BE were older than patients without BE (61.6 vs. 51.7 y), and only one of the 12 patients diagnosed with BE (8.3%) reported typical gastroesophageal reflux symptoms. A majority of the BE patients were categorized as short-segment BE (91.7%) and concomitant EE was found in 4 (33.3%). Smoking, alcohol, and metabolic disorders seemed to be associated with the presence of BE and EE.

CONCLUSIONS

The prevalence of BE in a Chinese general population was lower than that in other reported studies, particularly in comparison with the studies originating from Western countries. Patients with advanced age and metabolic disorders are risk factors for developing BE.

Should patients with Barrett's oesophagus be kept under surveillance? The case for

Oesophageal adenocarcinoma is associated with high mortality rates and its incidence is increasing more rapidly than any other gastrointestinal cancer in the Western world. Several factors, including gastro-oesophageal reflux disease, smoking, alcohol and male gender, are associated with oesophageal adenocarcinoma but none can be used to identify accurately those individuals who will develop adenocarcinoma. It is generally accepted that oesophageal adenocarcinoma arises predominantly in Barrett's oesophagus and it is arguable that Barrett's oesophagus is currently the only clinically useful predictor of oesophageal adenocarcinoma. Surveillance - periodic testing to detect adenocarcinoma or its precursor, high grade dysplasia - is widely recommended for patients with Barrett's oesophagus with the aim of reducing mortality from oesophageal adenocarcinoma. The annual incidence of oesophageal adenocarcinoma in patients with Barrett's oesophagus is 0.5%-1.0% although there is marked variation between studies, attributable variously to publication bias, concurrent acid suppression therapy and differences in patient characteristics. There is limited evidence that surveillance reduces the incidence of oesophageal adenocarcinoma or consequent mortality and the cause of death for patients undergoing surveillance is often unrelated to oesophageal disease. There are, nonetheless, observational studies which suggest that surveillance is associated with earlier detection of malignancy and a reduction in mortality; in addition, data from modelling studies suggest that surveillance can be cost-effective. Furthermore, the advent of new, non-surgical treatments (endoscopic mucosal resection, photodynamic therapy, argon plasma coagulation) for high grade dysplasia and early cancer has reduced the risks associated with therapy for disease detected during surveillance. Surveillance programs have high drop out rates and, for patients who continue surveillance, adherence to standard, published protocols is highly variable. The establishment of specialist Barrett's oesophagus surveillance programs, with coordinator support, has considerable potential to improve adherence to current guidelines, pending the acquisition and publication of data from ongoing studies of chemoprophylaxis and surveillance in the management of Barrett's oesophagus. In consequence, although there is a paucity of data providing unequivocal demonstration of benefit, there is no proof that surveillance is ineffective. It is, therefore, appropriate to offer surveillance for Barrett's oesophagus in accordance with locally-applicable published guidelines after a full informed discussion of the risks and benefits of surveillance and therapy; continued participation should be reviewed regularly to accommodate changes in the patient's health and expectations.

Expression of alpha-methylacyl coenzyme A racemase in the dysplasia carcinoma sequence associated with Barrett's esophagus

Two different studies demonstrated alpha-methylacyl coenzyme A racemase (AMACR) to be a highly specific marker in Barrett's neoplastic lesions. Reactive atypia was positive in 3/30 cases in these studies. We present a retrospective study of early Barrett's adenocarcinoma treated with surgery (2000-2005, n=29; M:F=5:1, median age 67 years). We analyzed the role of AMACR expression in reactive and neoplastic lesions associated with the disease of 77 different specimens (60 biopsy and 17 surgical specimens) of these patients. In our cohort, 70% of cases demonstrated infiltration of the submucosa, 38% were poorly differentiated, and/or 31% demonstrated lymph vessel infiltration. We used a multi-tissue array, with reactive and neoplastic samples for each patient to analyze the immunoreactivity of AMACR. Barrett's epithelium that was negative for dysplasia and columnar epithelial cell changes indefinite for dysplasia (n=30) did not demonstrate AMACR immunoreactivity. AMACR immunoreactivity was demonstrated in 27% (8/30) of cases of Barrett's epithelium with columnar epithelial cell changes indefinite for dysplasia. Altogether 91% of cases with low-grade dysplasia were AMACR-positive and 96% of cases with high-grade dysplasia and early Barrett's adenocarcinoma were positive for AMACR. In summary, the sensitivity of AMACR expression in low-grade dysplasia and subsequent early Barrett's adenocarcinoma was significantly higher in our study compared with previous data. This might be a new diagnostic marker for dysplasia carcinoma sequence in Barrett's low-grade neoplastic lesions. Further studies are required to investigate this point with well-defined controls having at least 5-years follow-up.

Prevalence of Barrett’s esophagus in patients with moderate to severe erosive esophagitis

AIM: To investigate the proportion of patients with moderate-severe erosive esophagitis (EE) who will have Barrett’s esophagus (BE) after healing of inflammation.

METHODS: Patients with EE of Los Angeles (LA) class B, C and D who underwent follow-up endoscopy documenting complete mucosal healing.

RESULTS: A total of 86/169 patients were suspected of having BE (38 before healing and 48 after healing of EE) and, 46/86 eventually had the histological confirmation. At index esophago-gastro-duodenoscopy (EGD), BE was suspected in 38/169 (22%), and ultimately, histologically confirmed in 20 of these. In 11 patients where biopsies were performed in the presence of inflammation, BE was detected in 2 and missed in 5 (including 2 dysplasias). In 131/169 patients (77.5%), BE was not suspected at index EGD. After healing of EE though, 48 patients had suspicion of BE who underwent biopsies, and in 26 of these histology was positive for BE. The length of inflammation had a linear correlation with the length of BE (P = 0.01). Out of multiple variables to predict BE, only the suspicion at index endoscopy was statistically significant (P = 0.01).

CONCLUSION: BE was seen in 46/169 (27%) patients with EE of LA class B, C and D. The length of EE can predict the length of underlying BE segment. Even when suspected, BE and associated dysplasia can be missed in the presence of inflammation; therefore, repeat evaluation should be considered after complete healing of esophagitis.

Barrett's esophagus: incidence and prevalence estimates in a rural Mid-Western population

BACKGROUND AND AIMS

Barrett's esophagus (BE) predisposes to adenocarcinoma of the esophagus and survival in esophageal adenocarcinoma is low. We studied patients diagnosed with BE in the Marshfield Epidemiologic Study Area (MESA). Our objectives were to estimate the prevalence of diagnosed BE, estimate the annual incidence of initial diagnosis of BE, and characterize the demographics of patients diagnosed with BE.

METHODS

We retrospectively reviewed medical records of patients diagnosed with BE until December 31, 2002. The esophagogastroduodenoscopy (EGD) reports were reviewed to establish the presence of columnar epithelium. All slides were retrieved and reviewed by a gastrointestinal pathologist to establish the presence of intestinal metaplasia and dysplasia. Chart abstraction was conducted using a standardized form.

RESULTS

BE was histologically confirmed in 216 patients. All were white, 165 (76%) were male, and 81% had a hiatal hernia. Median age at diagnosis was 65.5 yr (range 17-94). Long-segment BE (LSBE) was present in 112 (51.9%) patients. The prevalence of histologically confirmed BE in MESA was 261.8 (95% CI 222.5-301.1) per 100,000 people. The incidence of an initial diagnosis of BE between 1996 and 2002 was 32.7 per 100,000 person-years (95% CI 27.1-38.2) and did not change significantly over the study period despite an increase in EGD rates. At the initial diagnosis, 41.7% of the patients were on proton pump inhibitors. Dysplasia was present in 24.5% of patients.

CONCLUSION

The incidence of initial diagnosis of BE in a stable white population did not change significantly over a 7-yr period, despite an increase in EGD rates.

Identification of Fn14/TWEAK receptor as a potential therapeutic target in esophageal adenocarcinoma

Given the poor survival rate and efficacy of current therapy for esophageal adenocarcinoma (EAC), there is a need to identify and develop new therapeutic targets for treatment. Microarray analysis (Affymetrix U133A GeneChips, Robust Multi-Chip Analysis) was used to expression profile 11 normal squamous and 18 Barrett's esophagus biopsies, 7 surgically resected EACs and 3 EAC cell lines. Two hundred transcripts representing potential therapeutic targets were identified using the following criteria: significant overexpression in EAC by analysis of variance (p = 0.05, Benjamini Hochberg false discovery rate); 3-fold increase in EAC relative to normal and Barrett's esophagus and expression in at least 2 of the 3 EAC cell lines. From the list of potential targets we selected TNFRSF12A/Fn14/TWEAK receptor, a tumor necrosis factor super-family receptor, for further validation based on its reported role in tumor cell survival and potential as a target for therapy. Fn14 protein expression was confirmed in SEG-1 and BIC-1 cell lines, but Fn14 was not found to affect tumor cell survival after exposure to chemotherapeutics as expected. Instead, a novel role in EAC was discovered in transwell assays, in which modulating Fn14 expression affected tumor cell invasion. Fn14's potential as a therapeutic target was further supported by immunohistochemistry on a tissue microarray of patient samples that showed that Fn14 protein expression increased with disease progression in EAC.

High prevalence of reflux oesophagitis among upper endoscopies of Iranian patients

BACKGROUND AND AIM

To reinvestigate the prevalence of reflux esophagitis among upper endoscopies in a series of Iranian patients, considering the high prevalence of reflux esophagitis (76%) reported by an earlier Iranian study and the scanty data regarding prevalence of gastroesophageal reflux disease from Iran and the Middle East.

METHODS

Patients referred for upper endoscopy to an outpatient gastroenterology clinic in Tehran (May 2005-January 2006) were interviewed using a questionnaire before endoscopy. Gastroesophageal reflux disease was defined as having any degree of reflux esophagitis on endoscopy, or having heartburn or regurgitation on a weekly basis during the preceding 3 months. Reflux esophagitis was diagnosed and graded using Los Angeles classification. Check-up patients were excluded. Gastroesophageal reflux disease, nonerosive reflux disease, and reflux esophagitis groups were compared with non-gastroesophageal reflux disease patients with regard to the following factors: sex, age, body mass index (BMI), hiatus hernia, smoking, alcohol use, and level of education.

RESULTS

Out of 501 consecutive patients undergoing upper endoscopy (195 men, 306 women; mean+/-SD of age, 44.7+/-15 years; mean+/-SD of BMI, 24.9+/-4.4), 50 and 48% had reflux esophagitis with and without exclusion of the patients on acid-suppressing drugs in the past 2 weeks, respectively. Most had grade A (90%) or B (9%) reflux esophagitis. Only one patient (0.2%) had Barrett's esophagus. By Rome-II criteria, 116 had dyspepsia symptoms (predominant), of whom 41% had reflux esophagitis. High BMI (>25) and hiatus hernia both showed statistically significant associations with gastroesophageal reflux disease, whereas nonerosive reflux disease and reflux esophagitis were associated only with high BMI and hiatus hernia, respectively. Although the nonerosive reflux disease patients were of a lower education level than non-gastroesophageal reflux disease patients, no significant association of education level with gastroesophageal reflux disease and reflux esophagitis was found.

CONCLUSION

This study showed a significantly higher prevalence of reflux esophagitis among Iranian upper-endoscopy outpatients compared with the findings of non-Iranian studies.