The impact of Helicobacter pylori on the presence of Barrett's esophagus in Azerbaijan, a high-prevalence area of infection.

There is a strong evidence that Helicobacter pylori infection is inversely associated with Barrett's esophagus. In a high-prevalence region of H. pylori, low rates of esophageal cancer and its precursor BE may indicate its preventive effect. The aim of this study is to determine the impact of H. pylori on characteristics of Barrett's esophagus. A total of 3317 outpatient upper endoscopy reports from 2013 to 2015 from an urban center in Azerbaijan from all patients with dyspepsia were retrospectively analyzed for patients with Barrett's esophagus. This was matched in a 1:2 ratio to age and gender matched control patients without Barrett's esophagus. The prevalence of H. pylori on Barrett's esophagus and the randomly selected control group were compared. There were 83 patients with BE and 167 control group cases. Biopsy-proven BE was diagnosed in 83 patients: 39 (47%) females, with mean age 43.1 ± 13.3 years. Of these, 13 (15.7%) had long segment and 70 (84.3%) had short segment Barrett's esophagus. A control group included 167 patients: 78 (46.7%) females, with mean age (45.8 ± 13.9). All patients were Caucasians. The rates of gastric inflammation, the presence of atrophy, and intestinal metaplasia in gastric specimens did not differ in patients versus controls. The prevalence of H. pylori was determined as 63.2% in male and 61.5 in female groups (odd ratio (OR) = 0.99 95%CI 0.97, 1.01; P = 0.22). Inflammation of gastric mucosa was strongly associated with the infection (67% vs. 33%; OR = 4.46 95% CI: 2.01, 9.92, P < 0.001). Atrophy was noted in majority of H. pylori-positive cases (OR = 1.43, 95% CI: 0.36, 5.65; P = 0.61). Gastric intestinal metaplasia was observed in 55.6% of H. pylori-positive patients and in 44.4% of negative individuals (OR = 0.74, 95% CI: 0.28, 1.94; P = 0.54). There was not a significant difference in the prevalence of HP in BE and control groups; 63.9% were positive for infection in BE cases and 61.7% of controls (OR = 1.10, 95% CI: 0.64, 1.90; P = 0.74). We found that neither presence of erosive esophagitis, length of BE nor dysplasia (45.5% of H. pylori-positive group, whereas 54.5%) was associated with the presence of the H. pylori infection (Table 1). In a predominantly Caucasian nation with a high prevalence of H. pylori gastritis, the presence of H. pylori was not inversely associated with the presence of Barrett's esophagus. These data challenge the mechanistic implications of this association.

Food impaction: etiology over 35 years and association with eosinophilic esophagitis.

With the emergence of eosinophilic esophagitis (EoE) as a common cause of food impaction (FI) and a presumed increase in incidence of EoE in the population, the effect on the incidence of FI has not been well described. The aim of this study is to describe the incidence of FI and endoscopic findings in these patients and the association with EoE. A population-based retrospective chart review of the Rochester Epidemiology Project database was performed to identify all patients within Olmsted County that presented with FI from 1976 to 2012. A review of all endoscopic findings, biopsy results, and demographic data was performed. 497 patients were identified with FI from 1976 to 2012. The overall incidence of FI has changed from 1976 to 2012 (Fig. 1) (P < 0.001). The peak incidence of 17.12 per 100,000 people occurred in the time period 1995 to 2000. Both the incidence of comorbid gastroesophageal reflux disease (GERD) and proton pump inhibitor (PPI) use increased over the time period of the study (P < 0.001 for both). Of these patients, 188 (46.7%) had no abnormalities on their endoscopy. The most common endoscopic finding was stricture in 71 (17.6%) patients followed closely by Schatzki's ring in 68 (16.9%) patients. 139 patients had biopsies performed within 2 years of FI and 50 (36.0%) of those were diagnosed with EoE. We present for the first time the changing incidence of FI over the last 35 years in a population-based setting. We also demonstrate the rise of EoE as an important clinical consideration in patients with FI.

Infections of the esophagus: an update on risk factors, diagnosis, and management.

Infectious esophagitis is a leading cause of esophagitis worldwide. While esophageal infections have traditionally been associated with immunocompromised patients, these disorders are becoming increasingly recognized in immunocompetent individuals. The three most common etiologies of infectious esophagitis are Candida, herpes simplex virus, and cytomegalovirus. Human papilloma virus infection can also involve the esophagus in the form of ulcerative lesions and papillomas. Less common etiologies include various other fungal, bacterial, and viral organisms. This review provides a comprehensive update on risk factors, diagnosis, and management of both common and less common infections of the esophagus.

The 2018 ISDE achalasia guidelines.

Achalasia is a relatively rare primary motor esophageal disorder, characterized by absence of relaxations of the lower esophageal sphincter and of peristalsis along the esophageal body. As a result, patients typically present with dysphagia, regurgitation and occasionally chest pain, pulmonary complication and malnutrition. New diagnostic methodologies and therapeutic techniques have been recently added to the armamentarium for treating achalasia. With the aim to offer clinicians and patients an up-to-date framework for making informed decisions on the management of this disease, the International Society for Diseases of the Esophagus Guidelines proposed and endorsed the Esophageal Achalasia Guidelines (I-GOAL). The guidelines were prepared according the Appraisal of Guidelines for Research and Evaluation (AGREE-REX) tool, accredited for guideline production by NICE UK. A systematic literature search was performed and the quality of evidence and the strength of recommendations were graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Given the relative rarity of this disease and the paucity of high-level evidence in the literature, this process was integrated with a three-step process of anonymous voting on each statement (DELPHI). Only statements with an approval rate >80% were accepted in the guidelines. Fifty-one experts from 11 countries and 3 representatives from patient support associations participated to the preparations of the guidelines. These guidelines deal specifically with the following achalasia issues: Diagnostic workup, Definition of the disease, Severity of presentation, Medical treatment, Botulinum Toxin injection, Pneumatic dilatation, POEM, Other endoscopic treatments, Laparoscopic myotomy, Definition of recurrence, Follow up and risk of cancer, Management of end stage achalasia, Treatment options for failure, Achalasia in children, Achalasia secondary to Chagas' disease.

Obesity and GERD impair esophageal epithelial permeability through 2 distinct mechanisms.

BACKGROUND: The mechanism by which obesity leads to damage independent of reflux is unclear. We aimed to determine the influence of obesity on mean nocturnal baseline impedance (MNBI), a functional measure of the epithelial barrier, in the presence and absence of acid reflux, using ambulatory pH impedance measurements. METHODS: Twenty-four-hour pH impedance studies performed off medications in Caucasian men with a normal endoscopic examination were assessed for level of acid exposure and MNBI. Four patient groups were studied: Group 1, Not obese and normal acid exposure; Group 2, Obese and normal acid exposure; Group 3, Not obese and increased acid exposure; and Group 4, Obese with increased acid exposure. RESULTS: One hundred patients were studied (25 in each group). Mean esophageal mucosal impedance (MI) was substantially lower in obese patients without reflux (Group 2) and non-obese patients with reflux (Group 3) compared to normal controls (non-obese, no reflux, Group 1). MI was progressively lower in the distal (vs the proximal) esophagus in GER patients, compared to those without GER. This difference persisted in the presence or absence of obesity. In contrast, in obese patients, the mean MI was significantly lower throughout the esophagus when compared to the non-obese patients and also persisted in the presence and absence of accompanying reflux. Obesity and reflux were both independently negatively correlated with MI. CONCLUSION: Obesity is associated with abnormal esophageal MNBI. In contrast to gastro-esophageal reflux, this decrease is pan-esophageal. These data may support a systemic mechanism by which obesity alters the esophageal barrier function.

Assessing the incidence trend and characteristics of eosinophilic esophagitis in children in Olmsted County, Minnesota.

Previous studies reported increased eosinophilic esophagitis (EoE) incidence in children. It is unclear whether this reported increased EoE incidence is true or due to increased recognition and diagnostic endoscopy among children. A population-based study that evaluated EoE incidence in OC, Minnesota, from 1976 to 2005 concluded that EoE incidence increased significantly over the past three 5-year intervals (from 0.35 [range: 0-0.87] per 100,000 person-years for 1991-1995 to 9.45 [range: 7.13-11.77] per 100,000 person-years for 2001-2005). The aim of this study is to assess the change of incidence and characteristics of EoE in children in the same population between 2005 and 2015 and compare the findings to those reported in the previous study. We retrospectively reviewed the electronic medical records from Olmsted Medical Center and Mayo Clinic between 2005 and 2015, using Rochester Epidemiology Project (REP) resources. All children with EoE diagnosis based on the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) guidelines were included. The incidence and characteristics of children with EoE during the study period were compared to those diagnosed between 1995 and 2005. The incidence of EoE in children adjusted for age and sex was 5.31 per 100,000 population person-years in 1995, 15.2 in 2005, and 19.2 in 2015. Change in annual incidence and seasonal variation were not significant, (P = .48) and (P = .32), respectively. Between 2005 and 2015, 73 children received an EoE diagnosis (boys 49; 67%) compared to 16 children (boys 10; 62.5) between 1995 and 2005. Mean (SD) age at diagnosis was 7.5 (5.2) and 12.8 (4.3) years, respectively. Symptoms differed by age of presentation, with vomiting the most common in children younger than 5 years (41.1% and 43.5%) and dysphagia in those older than 5 years (35.6% and 60.9%). The incidence of EoE was not increased for any specific age-group during the study period (P = .49). This study showed increased incidence of EoE in children in Olmsted County between 2005 and 2015 compared to the incidence between 1995 and 2005 (5.31 per 100,000 population person-years in 1995, 15.2 in 2005, and 19.2 in 2015). However, between 2005 and 2015, the change of incidence was not statically significant, (P = .48) despite the steady increase of EGD performed during the same time frame (64 in 2005 to 144 in 2015). By comparing children diagnosed between 2005 and 2015 to those diagnosed between 1995 and 2005, the mean age at diagnosis was younger in the former group, 7.5 versus 12.8 years. Vomiting replaced dysphagia as the most common clinical presentation. Otherwise, the presenting symptom of EoE in children remained consistent across specific age groups.

Outcomes of oesophageal self-dilation for patients with refractory benign oesophageal strictures.

BACKGROUND: Current management of refractory benign oesophageal strictures with endoscopic dilations and stenting leads to resolution of dysphagia in only 30% of patients. Oesophageal self-dilation may be an alternative. AIM: To evaluate the efficacy and safety of oesophageal self-dilation at a tertiary referral centre. METHODS: We conducted a retrospective review of patients with refractory benign oesophageal strictures who participated in oesophageal self-dilation at Mayo Clinic (Rochester, MN, USA) between 2003 and 2017. Clinical data including stricture characteristics, Dakkak and Bennett Dysphagia Score, number and dates of endoscopies, and complications were collected. A two-tailed paired Student's t test was used to compare the measures of efficacy, with differences considered significant at a 5% probability level. RESULTS: We identified 52 patients with refractory strictures treated with self-dilation. The median number of endoscopic interventions was reduced from 9.5 (range 5-30) to 0 (range 0-3) within 12 months before and after self-dilation, respectively (P < 0.0001). A median intervention-free interval of 417 days (IQR 256-756 days) was observed. The mean dysphagia score at baseline was 2.5 (95% CI 2.2-2.8) and 0.33 (95% CI 0.11-0.53) after self-dilation. 23 of 27 (85%) patients who received enteral nutrition prior to self-dilation had their feeding tubes removed. CONCLUSIONS: Oesophageal self-dilation is an effective way of maintaining oesophageal patency in refractory benign oesophageal strictures, with safety comparable to current standard of care. Prospective studies are needed to further validate the role of self-dilation in treatment of refractory benign oesophageal strictures.

Reliability of histologic assessment in patients with eosinophilic oesophagitis.

BACKGROUND: The validity of the eosinophilic oesophagitis (EoE) histologic scoring system (EoEHSS) has been demonstrated, but only preliminary reliability data exist. AIM: Formally assess the reliability of the EoEHSS and additional histologic features. METHODS: Four expert gastrointestinal pathologists independently reviewed slides from adult patients with EoE (N = 45) twice, in random order, using standardised training materials and scoring conventions for the EoEHSS and additional histologic features agreed upon during a modified Delphi process. Intra- and inter-rater reliability for scoring the EoEHSS, a visual analogue scale (VAS) of overall histopathologic disease severity, and additional histologic features were assessed using intra-class correlation coefficients (ICCs). RESULTS: Almost perfect intra-rater reliability was observed for the composite EoEHSS scores and the VAS. Inter-rater reliability was also almost perfect for the composite EoEHSS scores and substantial for the VAS. Of the EoEHSS items, eosinophilic inflammation was associated with the highest ICC estimates and consistent with almost perfect intra- and inter-rater reliability. With the exception of dyskeratotic epithelial cells and surface epithelial alteration, ICC estimates for the remaining EoEHSS items were above the benchmarks for substantial intra-rater, and moderate inter-rater reliability. Estimation of peak eosinophil count and number of lamina propria eosinophils were associated with the highest ICC estimates among the exploratory items. CONCLUSION: The composite EoEHSS and most component items are associated with substantial reliability when assessed by central pathologists. Future studies should assess responsiveness of the score to change after a therapeutic intervention to facilitate its use in clinical trials.

Incidence and predictors of osteoporotic fractures in patients with Barrett's oesophagus: a population-based nested case-control study.

BACKGROUND: Proton pump inhibitors (PPI) are inconsistently associated with osteoporotic fractures. Barrett's oesophagus (BO) patients are treated with high PPI doses for prolonged periods, but there are limited data on the incidence of osteoporosis and fractures in this group pf patients. AIM: To estimate the incidence of (and risk factors for) low bone mass (osteoporosis and/or osteopenia) related fractures in a population-based BO cohort. METHODS: All subjects with BO and a diagnosis of osteoporosis and fractures were identified using Rochester Epidemiology Project resources. The incidence rates of all and osteoporotic fractures in these subjects were compared to an age- and gender similar population in Olmsted County to determine standardised incidence ratios (SIR). Predictors were assessed using Cox proportional hazards models. RESULTS: Five hundred and twenty-one patients were included (median [IQR] age 61 [52, 72] years; 398 [76%] men) of whom 113 (21.7%) had fractures, and 46 (8.8%) had osteoporotic fractures. The incidence of all fractures and osteoporotic fractures was comparable to that of an age- and gender-matched population (SIR 1.09; 95% CI 0.92-1.29: SIR 1.05; 95% CI 0.85-1.29). PPI use, dose or duration of use was not associated with osteoporotic fracture risk (HR 0.87; 95% CI 0.12-6.39). Independent risk factors for osteoporotic fractures included older age, female gender and higher co-morbidity index. CONCLUSIONS: The incidence of osteoporotic fractures was not increased in BO patients compared to the general population. In addition, PPI use was not associated with increased fracture risk regardless of the duration of therapy or dose.

The clinical significance of esophagogastric junction outflow obstruction and hypercontractile esophagus in high resolution esophageal manometry.

BACKGROUND: Although major manometric abnormalities, the significance of esophagogastric junction outflow obstruction (EGJOO) and hypercontractile esophagus (HE) is poorly understood. We sought to determine long term outcomes for EGJOO and HE. METHODS: High-resolution impedance manometry (HRIM) studies conducted from 5/30/2012 to 8/1/2014 consistent with EGJOO and HE and normal studies from 5/30/12 to 11/1/12 were identified. Standardized follow up was conducted with a phone survey utilizing the impact dysphagia questionnaire (IDQ-10). KEY RESULTS: 56 EGJOO, 40 HE patients and 33 controls were identified. Structural evaluation with EGD and esophagram did not differ among groups. Use of opiates in EGJOO (P<.05) and of anticholinergics in EGJOO and HE patients was more prevalent than in controls (P<.005). Dysphagia was more common in EGJOO (P<.05) and chest pain more common in HE (P<.005) at presentation. While HE patients were more likely to be symptomatic (P<.05), the majority of EGJOO and HE patients overall were asymptomatic at a mean 2.8 years follow up without medical or procedural intervention in the majority (72.5%). Symptom persistence at follow up was predicted by maximum distal contractile integral (DCI) and IRP in both EGJOO and HE (P<.05). CONCLUSIONS & INFERENCES: The majority of patients with EGJOO and HE appear to have a benign clinical course similar to controls in the absence of specific treatment. However, the combination of abnormal IRP and DCI in both HE and EGJOO appears to discriminate an important subset of patients who may benefit from treatment. Further refinement of manometric criteria may therefore provide more useful clinical definitions of EGJOO and HE.

The course of achalasia one to four decades after initial treatment.

BACKGROUND: Most follow-up studies of achalasia are limited to <5 years. AIM: To study the long-term efficacy of pneumatic dilation (PD) and myotomy in achalasia at least 10 years after treatment. METHODS: We performed a retrospective cohort study of achalasia patients with >10 years follow-up after initial myotomy or pneumatic dilation. Symptom recurrence which required repeat dilation or surgery was compared between pneumatic dilation and myotomy. RESULTS: One hundred and fifty patients (112 myotomy, 38 pneumatic dilation) of similar characteristics were studied. The mean duration of follow-up after initial treatment was 17.5 ± 7.2 years (10-40 years). Symptoms recurrence rate was 60.7% (100% pneumatic dilation patients vs. 47.3% myotomy), hazard ratio 0.24 demonstrating a lower need for repeat dilation or surgery with myotomy than pneumatic dilation (P = 0.008). All pneumatic dilation patients underwent myotomy in 4 ± 4 (0-16 years). Forty of 53 myotomy patients had symptom recurrence prompting further treatment: 16 pneumatic dilation, 11 myotomy and 13 both. The mean time to repeat procedure was 6.9 years (0-40). The myotomy group required fewer dilations and/or surgeries than the pneumatic dilation group (1.6 vs. 3.6, P < 0.001). 13 patients (10.1%) progressed to end-stage achalasia (five myotomy, eight pneumatic dilation) over 40 years. At last follow-up, 57/62 (92%) patients had absent or mild dysphagia, 53/62 (85%) patients had regurgitation less than once per week and 37 (60.7%) had heartburn episodes <1/week similar for pneumatic dilation and myotomy (P = 0.27). CONCLUSION: Although the majority of patients treated for achalasia do well after decades of treatment, most patients may need a series of endoscopic and/or surgical procedures to maintain effective symptom control.

Baseline impedance measured during high-resolution esophageal impedance manometry reliably discriminates GERD patients.

BACKGROUND: Baseline impedance measured with ambulatory impedance pH monitoring (MII-pH) and a mucosal impedance catheter detects gastroesophageal reflux disease (GERD). However, these tools are limited by cost or patient tolerance. We investigated whether baseline impedance measured during high-resolution impedance manometry (HRIM) distinguishes GERD patients from controls. METHODS: Consecutive patients with clinical HRIM and MII-pH testing were identified. Gastroesophageal reflux disease was defined by esophageal pH <4 for ≥5% of both the supine and total study time, whereas controls had an esophageal pH <4 for ≤3% of the study performed off PPI. Baseline impedance was measured over 15 seconds during the landmark period of HRIM and over three 10 minute intervals during the overnight period of MII-pH. KEY RESULTS: Among 29 GERD patients and 26 controls, GERD patients had a mean esophageal acid exposure time of 22.7% compared to 1.2% in controls (P<.0001). Mean baseline impedance during HRIM was lower in GERD (1061 Ω) than controls (2814 Ω) (P<.0001). Baseline mucosal impedance measured during HRIM and MII-pH correlated (r=0.59, P<.0001). High-resolution esophageal manometry baseline impedance had high diagnostic accuracy for GERD, with an area under the curve (AUC) of 0.931 on receiver operating characteristics (ROC) analysis. A HRIM baseline impedance threshold of 1582 Ω had a sensitivity of 86.2% and specificity of 88.5% for GERD, with a positive predictive value of 89.3% and negative predictive value of 85.2%. CONCLUSIONS & INFERENCES: Baseline impedance measured during HRIM can reliably discriminate GERD patients with at least moderate esophageal acid exposure from controls. This diagnostic tool may represent an accurate, cost-effective, and less invasive test for GERD.

Presence of intraepithelial food antigen in patients with active eosinophilic oesophagitis.

BACKGROUND: Although eosinophilic oesophagitis (EoE) is putatively mediated by an abnormal response to food antigen, the oesophagus is considered relatively impermeable to large molecules. AIM: To assess whether food antigens penetrate the oesophageal mucosa in patients with EoE. METHODS: Anti-gliadin staining was performed in three groups: active EoE, inactive EoE and EoE patients on a low or gluten free diet. To appraise the specificity of our results, we also performed gliadin staining on six patients without oesophageal disease who were consuming gluten. The groups with EoE on gluten also underwent endoscopic infusion with gluten containing soy sauce and repeat biopsies during the endoscopy. We measured eosinophil density, dilated intercellular spaces (on a 0-4+ scale) and gliadin in oesophageal mucosa by immunofluorescence. RESULTS: Patients with active EoE had significantly greater epithelial density of anti-gliadin staining when compared to inactive EoE (P < 0.0065) and gluten-free patients (P < 0.0008) at baseline and after soy infusion. Gliadin was not detected in non-EoE control patients. The distribution of gliadin was both cytoplasmic and nuclear. There was good correlation of dilated intercellular spaces grade and total gliadin staining intensity (r = 0.577, P = 0.0077). Acute oesophageal perfusion of a commercial gliadin-rich soy sauce did not lead to an increase in gliadin staining in active or inactive EoE. CONCLUSION: These findings suggest, although do not prove, that antigen penetration in active eosinophilic oesophagitis might be facilitated by impairment of epithelial integrity.

Oesophageal lichen planus: the efficacy of topical steroid-based therapies.

BACKGROUND: Oesophageal lichen planus is an idiopathic inflammatory disorder characterized by significant oesophageal stricturing. Oesophageal lichen planus is a rare, difficult to diagnose, and likely an under recognized disease. As a result, there is no standardized approach to therapy and treatment strategies vary. AIM: To examine the utility of topical steroid therapy (fluticasone or budesonide) in the management of oesophageal lichen planus. METHODS: A retrospective chart review was conducted of patients diagnosed with oesophageal lichen planus who underwent baseline and follow up endoscopy pre and post topical steroid therapy between 1995 and 2016 at Mayo Clinic, Rochester MN. Average time between upper GI endoscopy was 3.2 months (0.7-11.7). Swallowed steroid preparations included fluticasone 880 µg twice daily or budesonide 3 mg twice daily. Patients were reviewed for symptomatic response to therapy using the Dakkak-Bennett dysphagia score (0-4, no dysphagia to total aphagia). Pre- and post-endoscopic findings were assessed. Additional baseline demographic, endoscopic, and histologic data were also obtained. RESULTS: We identified 40 patients who met the inclusion criteria. A significant reduction in median dysphagia score from 1 (0-4) to 0 (0-3) after steroid therapy (P < 0.001) was noted. 62% of patients reported resolution of their dysphagia after receiving topical corticosteroids. 72.5% had an endoscopic response to steroid therapy. CONCLUSION: Topical swallowed budesonide or fluticasone appear to effective treatment for oesophageal lichen planus.

Systematic review with meta-analysis: prevalent vs. incident oesophageal adenocarcinoma and high-grade dysplasia in Barrett's oesophagus.

BACKGROUND: The proportion of oesophageal adenocarcinoma that is detected concurrently with initial Barrett's oesophagus diagnosis is not well studied. AIM: To compare the proportion of prevalent adenocarcinoma vs. incident adenocarcinoma found during surveillance of Barrett's. METHODS: We performed a systematic search of MEDLINE, EMBASE and Web of Science (from their inception to 31 May 2015) for cohort studies in adults with Barrett's (nondysplastic Barrett's ± Barrett's with low-grade dysplasia) with minimum average follow-up of 3 years, and providing numbers of prevalent adenocarcinoma detected (concurrently with Barrett's diagnosis and up to 1 year afterwards) vs. incident adenocarcinoma detected (greater than 1 year after Barrett's diagnosis). Pooled weighted proportions of prevalent and incident adenocarcinoma were calculated, using a random effects model. RESULTS: On meta-analysis of 13 studies reporting on 603 adenocarcinomas in 9657 Barrett's patients, 85.1% of adenocarcinomas were classified as prevalent [95% confidence interval (CI), 78.1-90.2%) and 14.9% as incident (95% CI, 9.8-21.9%), with substantial heterogeneity (I(2) = 66%). Among nine studies reporting on 787 high-grade dysplasia and oesophageal adenocarcinomas in 8098 Barrett's patients, the proportion of prevalent high-grade dysplasia-oesophageal adenocarcinoma was similar at 80.5% (95% CI, 68.1-88.8%, I(2) = 87%). These results remained stable across multiple subgroup analyses including study quality, setting, duration of follow-up and presence of baseline dysplasia. CONCLUSIONS: In our meta-analysis, four of five patients diagnosed with adenocarcinoma or high-grade dysplasia at index endoscopy or within 1 year of Barrett's follow-up were considered to be prevalent cases. Continued efforts are needed to identify patients with Barrett's before the development of adenocarcinoma.