Preoperative prevalence of Barrett's esophagus in esophageal adenocarcinoma: a systematic review

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.

Methylation Biomarker Panel Performance in EsophaCap Cytology Samples for Diagnosing Barrett's Esophagus: A Prospective Validation Study

PURPOSE

Barrett's esophagus is the only known precursor of esophageal adenocarcinoma (EAC). Although endoscopy and biopsy are standard methods for Barrett's esophagus diagnosis, their high cost and risk limit their use as a screening modality. Here, we sought to develop a Barrett's esophagus detection method based on methylation status in cytology samples captured by EsophaCap using a streamlined sensitive technique, methylation on beads (MOB).

EXPERIMENTAL DESIGN

We conducted a prospective cohort study on 80 patients (52 in the training set; 28 in the test set). We used MOB to extract and bisulfite-convert DNA, followed by quantitative methylation-specific PCR to assess methylation levels of 8 previously selected candidate markers. Lasso regression was applied to establish a prediction model in the training set, which was then tested on the independent test set.

RESULTS

In the training set, five of eight candidate methylation biomarkers (p16, HPP1, NELL1, TAC1, and AKAP12) were significantly higher in Barrett's esophagus patients than in controls. We built a four-biomarker-plus-age lasso regression model for Barrett's esophagus diagnosis. The AUC was 0.894, with sensitivity 94.4% [95% confidence interval (CI), 71%-99%] and specificity 62.2% (95% CI, 44.6%-77.3%) in the training set. This model also performed with high accuracy for Barrett's esophagus diagnosis in an independent test set: AUC = 0.929 (P < 0.001; 95% CI, 0.810%-1%), with sensitivity=78.6% (95% CI, 48.8%-94.3%) and specificity = 92.8% (95% CI, 64.1%-99.6%).

CONCLUSIONS

EsophaCap, in combination with an epigenetic biomarker panel and the MOB method, is a promising, well-tolerated, low-cost esophageal sampling strategy for Barrett's esophagus diagnosis. This approach merits further prospective studies in larger populations.

Barrett's Esophagus and Esophageal Carcinoma: Can Biomarkers Guide Clinical Practice?

PURPOSE OF REVIEW

Despite gastrointestinal societal recommendations for endoscopic screening and surveillance of Barrett's esophagus, the rates of esophageal adenocarcinoma continue to rise. Furthermore, this current practice is costly to patients and the medical system without clear evidence of reduction in cancer mortality. The use of biomarkers to guide screening, surveillance, and treatment strategies might alleviate some of these issues.

RECENT FINDINGS

Incredible advances in biomarker identification, biomarker assays, and minimally-invasive modalities to acquire biomarkers have shown promising results. We will highlight recently published, key studies demonstrating where we are with using biomarkers for screening and surveillance in clinical practice, and what is on the horizon regarding novel non-invasive and minimally invasive methods to acquire biomarkers. Proof-of principle studies using in silico models demonstrate that biomarker-guided screening, surveillance, and therapeutic intervention strategies can be cost-effective and can reduce cancer deaths in patients with Barrett's esophagus.

Identification of Prognostic Phenotypes of Esophageal Adenocarcinoma in 2 Independent Cohorts

BACKGROUND & AIMS

Most patients with esophageal adenocarcinoma (EAC) present with de novo tumors. Although this could be due to inadequate screening strategies, the precise reason for this observation is not clear. We compared survival of patients with prevalent EAC with and without synchronous Barrett esophagus (BE) with intestinal metaplasia (IM) at the time of EAC diagnosis.

METHODS

Clinical data were studied using Cox proportional hazards regression to evaluate the effect of synchronous BE-IM on EAC survival independent of age, sex, TNM stage, and tumor location. We analyzed data from a cohort of patients with EAC from the Mayo Clinic (n=411; 203 with BE and IM) and a multicenter cohort from the United Kingdom (n=1417; 638 with BE and IM).

RESULTS

In the Mayo cohort, BE with IM had a reduced risk of death compared to patients without BE and IM (hazard ratio [HR] 0.44; 95% CI, 0.34-0.57; P<.001). In a multivariable analysis, BE with IM was associated with longer survival independent of patient age or sex, tumor stage or location, and BE length (adjusted HR, 0.66; 95% CI, 0.5-0.88; P=.005). In the United Kingdom cohort, patients BE and IM had a reduced risk of death compared with those without (HR, 0.59; 95% CI, 0.5-0.69; P<.001), with continued significance in multivariable analysis that included patient age and sex and tumor stage and tumor location (adjusted HR, 0.77; 95% CI, 0.64-0.93; P=.006).

CONCLUSION

Two types of EAC can be characterized based on the presence or absence of BE. These findings could increase our understanding the etiology of EAC, and be used in management and prognosis of patients.

Prior Diagnosis of Barrett's Esophagus Is Infrequent, but Associated with Improved Esophageal Adenocarcinoma Survival

BACKGROUND

Efforts to reduce mortality from esophageal adenocarcinoma (EA) have focused on screening and surveillance of Barrett's esophagus (BE).

AIMS

We sought to determine the frequency of prior diagnosis of BE in patients with EA and to evaluate the impact of a prior BE diagnosis on mortality in EA patients.

METHODS

This was a retrospective cohort study of patients diagnosed with EA in the VA during 2002-2016. We compared the distributions of EA stage and receipt of treatment between EA patients with and without a prior BE diagnosis and used Cox proportional hazards models to compare mortality risk (all-cause and cancer specific) unadjusted and adjusted for stage and treatment to assess their impact on any survival differences.

RESULTS

Among 8564 EA patients, only 4.9% had a prior BE diagnosis. The proportion with prior BE diagnosis increased from 3.2% in EA patients diagnosed during 2005-2007 to 7.0% in those diagnosed during 2014-2016. EA patients with a prior BE diagnosis were more likely to have stage 1 disease and receive any treatment. A prior BE diagnosis was associated with lower all-cause mortality risk (hazard ratio [HR] unadjusted for stage, 0.69; 95% CI, 0.61-0.80), which was largely explained by the earlier stage of EA at the time of diagnosis (HR adjusted for stage, 0.87; 95% CI, 0.75-0.99). There was no evidence of lead time bias or length time bias.

CONCLUSIONS

Prior diagnosis of BE was associated with better survival, largely due to earlier EA stage at diagnosis.

Tethered capsule endomicroscopy for microscopic imaging of the esophagus, stomach, and duodenum without sedation in humans (with video)

BACKGROUND AND AIMS

Patients with many different digestive diseases undergo repeated EGDs throughout their lives. Tethered capsule endomicroscopy (TCE) is a less-invasive method for obtaining high-resolution images of the GI mucosa for diagnosis and treatment planning of GI tract diseases. In this article, we present our results from a single-center study aimed at testing the safety and feasibility of TCE for imaging the esophagus, stomach, and duodenum.

METHODS

After being swallowed by a participant without sedation, the tethered capsule obtains cross-sectional, 10 μm-resolution, optical coherence tomography images as the device traverses the alimentary tract. After imaging, the device is withdrawn through the mouth, disinfected, and reused. Safety and feasibility of TCE were tested, focusing on imaging the esophagus of healthy volunteers and patients with Barrett's esophagus (BE) and the duodenum of healthy volunteers. Images were compared with endoscopy and histopathology findings when available.

RESULTS

Thirty-eight patients were enrolled. No adverse effects were reported. The TCE device swallowing rate was 34 of 38 (89%). The appearance of a physiologic upper GI wall, including its microscopic pathology, was visualized with a tissue coverage of 85.4% ± 14.9% and 90.3% ± 6.8% in the esophagus of BE patients with and without endoscopic evidence of a hiatal hernia, respectively, as well as 84.8% ± 7.4% in the duodenum. A blinded comparison of TCE and endoscopic BE measurements showed a strong to very strong correlation (r = 0.7-0.83; P < .05) for circumferential extent and a strong correlation (r = 0.77-0.78; P < .01) for maximum extent (Prague classification). TCE interobserver correlation was very strong, at r = 0.92 and r = 0.84 (P < .01), for Prague classification circumferential (C) and maximal (M) length measurements, respectively.

CONCLUSIONS

TCE is a safe and feasible procedure for obtaining high-resolution microscopic images of the upper GI tract without endoscopic assistance or sedation.

Selection and Application of Tissue microRNAs for Nonendoscopic Diagnosis of Barrett's Esophagus

BACKGROUND & AIMS

MicroRNA (miRNA) is highly stable in biospecimens and provides tissue-specific profiles, making it a useful biomarker of carcinogenesis. We aimed to discover a set of miRNAs that could accurately discriminate Barrett's esophagus (BE) from normal esophageal tissue and to test its diagnostic accuracy when applied to samples collected by a noninvasive esophageal cell sampling device.

METHODS

We analyzed miRNA expression profiles of 2 independent sets of esophageal biopsy tissues collected during endoscopy from 38 patients with BE and 26 patients with normal esophagus (controls) using Agilent microarray and Nanostring nCounter assays. Consistently up-regulated miRNAs were quantified by real-time polymerase chain reaction in esophageal tissues collected by Cytosponge from patients with BE vs without BE. miRNAs were expressed from plasmids and antisense oligonucleotides were expressed in normal esophageal squamous cells; effects on proliferation and gene expression patterns were analyzed.

RESULTS

We identified 15 miRNAs that were significantly up-regulated in BE vs control tissues. Of these, 11 (MIR215, MIR194, MIR 192, MIR196a, MIR199b, MIR10a, MIR145, MIR181a, MIR30a, MIR7, and MIR199a) were validated in Cytosponge samples. The miRNAs with the greatest increases in BE tissues (7.9-fold increase in expression or more, P < .0001: MIR196a, MIR192, MIR194, and MIR215) each identified BE vs control tissues with area under the curve (AUC) values of 0.82 or more. We developed an optimized multivariable logistic regression model, based on expression levels of 6 miRNAs (MIR7, MIR30a, MIR181a, MIR192, MIR196a, and MIR199a), that identified patients with BE with an AUC value of 0.89, 86.2% sensitivity, and 91.6% specificity. Expression level of MIR192, MIR196a, MIR199a, combined that of trefoil factor 3, identified patients with BE with an AUC of 0.93, 93.1% sensitivity, and 93.7% specificity. Hypomethylation was observed in the promoter region of the highly up-regulated cluster MIR192-MIR194. Overexpression of these miRNAs in normal esophageal squamous cells increased their proliferation, via GRHL3 and PTEN signaling.

CONCLUSIONS

In analyses of miRNA expression patterns of BE vs non-BE tissues, we identified a profile that can identify Cytosponge samples from patients with BE with an AUC of 0.93. Expression of MIR194 is increased in BE samples via epigenetic mechanisms that might be involved in BE pathogenesis.

Screening for Barrett's Esophagus: Are New High-Volume Methods Feasible?

New improved methods are required for the early detection of esophageal adenocarcinoma in order to reduce mortality from this aggressive cancer. In this review we discuss different screening methods which are currently under evaluation ranging from image-based methods to cell collection devices coupled with biomarkers. As Barrett's esophagus is a low prevalence disease, potential screening tests must be applied to an enriched population to reduce the false-positive rate and improve the cost-effectiveness of the program.

Origins of Metaplasia in the Esophagus: Is This a GE Junction Stem Cell Disease?

The incidence of esophageal adenocarcinoma (EAC) and its precursor lesion Barrett's esophagus (BE) has been increasing steadily in the western world in recent decades. Understanding the cellular origins of BE and the conditions responsible for their malignant transformation would greatly facilitate risk assessment and identification of patients at risk of progression, but this topic remains a source of debate. Here, we review recent findings that have provided support for the gastroesophageal junction (GEJ) as the main source of stem cells that give rise to BE and EAC. These include both gastric cardia cells and transitional basal cells. Furthermore, we discuss the role of chronic injury and inflammation in a tumor microenvironment as a major factor in promoting stem cell expansion and proliferation as well as transformation of the GEJ-derived stem cells and progression to EAC. We conclude that there exists a large amount of empirical support for the GEJ as the likely source of BE stem cells. While BE seems to resemble a successful adaptation to esophageal damage, carcinogenesis appears as a consequence of natural selection at the level of GEJ stem cells, and later glands, that expand into the esophagus wherein the local ecology creates the selective landscape for cancer progression.

Hyperinsulinemia Promotes Esophageal Cancer Development in a Surgically-Induced Duodeno-Esophageal Reflux Murine Model

Hyperinsulinemia could have a role in the growing incidence of esophageal adenocarcinoma (EAC) and its pre-cancerous lesion, Barrett's Esophagus, a possible consequence of Gastro-Esophageal Reflux Disease. Obesity is known to mediate esophageal carcinogenesis through different mechanisms including insulin-resistance leading to hyperinsulinemia, which may mediate cancer progression via the insulin/insulin-like growth factor axis. We used the hyperinsulinemic non-obese FVB/N (Friend leukemia virus B strain) MKR (muscle (M)-IGF1R-lysine (K)-arginine (R) mouse model to evaluate the exclusive role of hyperinsulinemia in the pathogenesis of EAC related to duodeno-esophageal reflux. FVB/N wild-type (WT) and MKR mice underwent jejunum-esophageal anastomosis side-to end with the exclusion of the stomach. Thirty weeks after surgery, the esophagus was processed for histological, immunological and insulin/Insulin-like growth factor 1 (IGF1) signal transduction analyses. Most of the WT mice (63.1%) developed dysplasia, whereas most of the MKR mice (74.3%) developed squamous cell and adenosquamous carcinomas, both expressing Human Epidermal growth factor receptor 2 (HER2). Hyperinsulinemia significantly increased esophageal cancer incidence in the presence of duodenal-reflux. Insulin receptor (IR) and IGF1 receptor (IGF1R) were overexpressed in the hyperinsulinemic condition. IGF1R, through ERK1/2 mitogenic pattern activation, seems to be involved in cancer onset. Hyperinsulinemia-induced IGF1R and HER2 up-regulation could also increase the possibility of forming of IGF1R/HER2 heterodimers to support cell growth/proliferation/progression in esophageal carcinogenesis.

Determining Risk of Barrett's Esophagus and Esophageal Adenocarcinoma Based on Epidemiologic Factors and Genetic Variants

BACKGROUND & AIMS

We developed comprehensive models to determine risk of Barrett's esophagus (BE) or esophageal adenocarcinoma (EAC) based on genetic and non-genetic factors.

METHODS

We used pooled data from 3288 patients with BE, 2511 patients with EAC, and 2177 individuals without either (controls) from participants in the international Barrett's and EAC consortium as well as the United Kingdom's BE gene study and stomach and esophageal cancer study. We collected data on 23 genetic variants associated with risk for BE or EAC, and constructed a polygenic risk score (PRS) for cases and controls by summing the risk allele counts for the variants weighted by their natural log-transformed effect estimates (odds ratios) extracted from genome-wide association studies. We also collected data on demographic and lifestyle factors (age, sex, smoking, body mass index, use of nonsteroidal anti-inflammatory drugs) and symptoms of gastroesophageal reflux disease (GERD). Risk models with various combinations of non-genetic factors and the PRS were compared for their accuracy in identifying patients with BE or EAC using the area under the receiver operating characteristic curve (AUC) analysis.

RESULTS

Individuals in the highest quartile of risk, based on genetic factors (PRS), had a 2-fold higher risk of BE (odds ratio, 2.22; 95% confidence interval, 1.89-2.60) or EAC (odds ratio, 2.46; 95% confidence interval, 2.07-2.92) than individual in the lowest quartile of risk based on PRS. Risk models developed based on only demographic or lifestyle factors or GERD symptoms identified patients with BE or EAC with AUC values ranging from 0.637 to 0.667. Combining data on demographic or lifestyle factors with data on GERD symptoms identified patients with BE with an AUC of 0.793 and patients with EAC with an AUC of 0.745. Including PRSs with these data only minimally increased the AUC values for BE (to 0.799) and EAC (to 0.754). Including the PRSs in the model developed based on non-genetic factors resulted in a net reclassification improvement for BE of 3.0% and for EAC of 5.6%.

CONCLUSIONS

We used data from 3 large databases of patients from studies of BE or EAC to develop a risk prediction model based on genetic, clinical, and demographic/lifestyle factors. We identified a PRS that increases discrimination and net reclassification of individuals with vs without BE and EAC. However, the absolute magnitude of improvement is not sufficient to justify its clinical use.

Development and Validation of a Model to Determine Risk of Progression of Barrett's Esophagus to Neoplasia

BACKGROUND & AIMS

A system is needed to determine the risk of patients with Barrett's esophagus for progression to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC). We developed and validated a model to determine of progression to HGD or EAC in patients with BE, based on demographic data and endoscopic and histologic findings at the time of index endoscopy.

METHODS

We performed a longitudinal study of patients with BE at 5 centers in United States and 1 center in Netherlands enrolled in the Barrett's Esophagus Study database from 1985 through 2014. Patients were excluded from the analysis if they had less than 1 year of follow-up, were diagnosed with HGD or EAC within the past year, were missing baseline histologic data, or had no intestinal metaplasia. Seventy percent of the patients were used to derive the model and 30% were used for the validation study. The primary outcome was development of HGD or EAC during the follow-up period (median, 5.9 years). Survival analysis was performed using the Kaplan-Meier method. We assigned a specific number of points to each BE risk factor, and point totals (scores) were used to create categories of low, intermediate, and high risk. We used Cox regression to compute hazard ratios and 95% confidence intervals to determine associations between risk of progression and scores.

RESULTS

Of 4584 patients in the database, 2697 were included in our analysis (84.1% men; 87.6% Caucasian; mean age, 55.4 ± 20.1 years; mean body mass index, 27.9 ± 5.5 kg/m²; mean length of BE, 3.7 ± 3.2 cm). During the follow-up period, 154 patients (5.7%) developed HGD or EAC, with an annual rate of progression of 0.95%. Male sex, smoking, length of BE, and baseline-confirmed low-grade dysplasia were significantly associated with progression. Scores assigned identified patients with BE that progressed to HGD or EAC with a c-statistic of 0.76 (95% confidence interval, 0.72-0.80; P < .001). The calibration slope was 0.9966 (P = .99), determined from the validation cohort.

CONCLUSIONS

We developed a scoring system (Progression in Barrett's Esophagus score) based on male sex, smoking, length of BE, and baseline low-grade dysplasia that identified patients with BE at low, intermediate, and high risk for HGD or EAC. This scoring system might be used in management of patients.

From Heartburn to Barrett's Esophagus, and Beyond

BACKGROUND

Gastroesophageal reflux disease (GERD) affects an estimated 20% of the population in the USA, and its prevalence is increasing worldwide. About 10-15% of patients with GERD will develop Barrett's esophagus (BE).

AIMS

The aims of this study were to review the available evidence of the pathophysiology of BE and the role of anti-reflux surgery in the treatment of this disease.

RESULTS

The transformation of the squamous epithelium into columnar epithelium with goblet cells is due to the chronic injury produced by repeated reflux episodes. It involves genetic mutations that in some patients may lead to high-grade dysplasia and cancer. There is no strong evidence that anti-reflux surgery is associated with resolution or improvement in BE, and its indications should be the same as for other GERD patients without BE.

CONCLUSIONS

Patients with BE without dysplasia require endoscopic surveillance, while those with low- or high-grade dysplasia should have consideration of endoscopic eradication therapy followed by surveillance. New endoscopic treatment modalities are being developed, which hold the promise to improve the management of patients with BE.

Recent Advances in Screening for Barrett's Esophagus

OPINION STATEMENT

PURPOSE OF REVIEW: There is a pressing need for effective strategies to halt the increase in both the incidence and mortality of esophageal adenocarcinoma (EAC). Screening for Barrett's esophagus, which is the only known precursor of EAC, remains a ripe area for research, particularly with regard to identifying the target population, screening tools, and management of screen-detected populations. This review aims to explore in depth the rationale for screening for Barrett's esophagus, recent biotechnological advances which may have the potential of making screening feasible, and also highlight the challenges which will have to be overcome in order make screening for BE a realistic prospect.

RECENT FINDINGS

Imaging techniques such as portable transnasal endoscopy have the advantage of providing an immediate diagnosis of Barrett's esophagus as well as other significant pathologies such as reflux esophagitis and cancer; however, larger studies in non-enriched community screening populations are required to evaluate their feasibility. The capsule sponge is a cell-sampling device coupled with a biomarker, which has been most extensively evaluated with very promising results as regards feasibility, acceptability, accuracy, and cost-effectiveness. Its effectiveness in increasing the detection of Barrett's esophagus in primary care is currently being evaluated. Several Barrett's esophagus risk prediction scores have been developed with variable degrees of accuracy. Several minimally and non-invasive screening techniques have been studied including imaging and cell-sampling devices. Barrett's risk assessment models need to be further validated in independent, relevant screening populations with clear cut-offs for recommending screening to be defined.

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.

Inhibition of pRB Pathway Differentially Modulates Apoptosis in Esophageal Cancer Cells

Esophageal cancer is the sixth most common cause of cancer-related death worldwide. Current chemotherapy regimens include a combination of 5-fluorouracil (5-FU) and cisplatin, but more efficient therapy strategies are needed to increase 5-year survival. Alterations in the signaling pathway of the tumor suppressor gene Rb-1, which encodes a phosphoprotein (pRB) that negatively regulates the G1/S transition of the cell cycle, are present in 70% of all tumors, but its role in esophageal cancer is still unclear. Most of these are alterations leading to up-regulation of the activity of cyclin-dependent kinases (CDKs) to phosphorylate pRB, which suggests that keeping the wild type pRB phosphorylated might be advantageous. Besides proliferation, pRB also regulates apoptosis induced by tumor necrosis factor-alpha (TNF-α) and DNA-damage. We investigated the status of phosphorylation of pRB along esophageal tumorigenesis stages, as well as whether hyperphosphorylation of pRB could suppress apoptosis induced by cisplatin, 5-FU, or TNF-α in esophageal cancer cells. pRB phosphorylation increased progressively from normal esophageal tissue to metaplasia and adenocarcinoma, suggesting that pRB phosphorylation increases along esophageal tumor stages. When RB-1 was knocked down or CDK inhibitors reduced the levels of phosphorylated pRB, opposite apoptotic effects were observed, depending on the combination of drugs tested: whereas TNF-α- and cisplatin-induced apoptosis increased, 5-FU-induced apoptosis decreased. Taken together, these data suggest that pRB plays a role in esophageal adenocarcinoma and that, depending on the type of anti-cancer treatment, combining CDK inhibitors and chemotherapy has the potential to increase the sensitivity of esophageal cancer cells to cell death.

Who Deserves Endoscopic Screening for Esophageal Neoplasia?

Despite the availability of safe and effective endoscopic treatment of Barrett's esophagus (BE)-related dysplasia and neoplasia, the incidence and mortality from esophageal adenocarcinoma (EAC) have continued to increase. This likely stems from the large population of patients that develop EAC outside of a BE screening and surveillance program. Identification of BE with screening followed by enrollment in an appropriate surveillance/risk stratification program could be a strategy to address both the incidence of and mortality from EAC. This article summarizes the rationale and challenges for BE screening, the risk factors for BE, and the currently described BE risk assessment tools.

Barrett's esophagus: best practices for treatment and post-treatment surveillance

Barrett's esophagus (BE) is a premalignant condition that increases the risk of esophageal adenocarcinoma (EAC). Significantly more common in the Western world, risk factors include increased age, male sex, white race, gastro-esophageal reflux disease (GERD), central obesity, and cigarette smoking. The rates of progression to cancer depend on the grade of Barrett's dysplasia. Screening for BE is recommended in patients with GERD and additional risk factors. Endoscopic surveillance of patients with BE likely improves overall outcomes. Advanced endoscopic imaging can help increase the efficiency of current endoscopic surveillance. Endoscopic therapy is safe and effective for the treatment of dysplastic BE and intramucosal EAC, but ongoing surveillance following treatment is necessary. This review will cover screening, surveillance, advanced imaging, chemoprevention, endoscopic treatment, and post-treatment surveillance of BE.

Review: Surveillance of patients with Barrett oesophagus

There has been a rapid increase in the incidence of oesophageal adenocarcinoma in most Western countries over the past thirty years. Barrett's oesophagus (BE) is a common premalignant lesion of oesophageal adenocarcinoma, although the risk of developing cancer in BE remains low. Therefore, screening is not recommended in the general population. Surveillance of BE is recommended to detect high grade dysplasia or carcinoma in an early stage, although there is no clear evidence that surveillance leads to a reduced mortality. This review discusses the several screening and surveillance techniques, including chromoendoscopy, narrow band imaging, autofluorescence imaging and confocal laser endomicroscopy, pointing out the areas that are well established as well as the new techniques that require more research.

Pathogenesis and progression of oesophageal adenocarcinoma varies by prior diagnosis of Barrett's oesophagus

Background:

The absolute risk of oesophageal adenocarcinoma (EA) among individuals with Barrett's oesophagus (BE) is low and a majority of EA cases are diagnosed among individuals with no prior BE diagnosis. To ensure that insights from EA case–control studies are transferable to clinical management of BE populations, we conducted a case–case study to compare the clinical presentation, medical history and survival of EA cases with and without a prior BE diagnosis in the Surveillance, Epidemiology and End Results Medicare database.

Methods:

Eligible EA cases were diagnosed at age ⩾68 years during 1994–2009. There were 5271 EA cases in this study, 87% of which did not have a prior diagnosis of BE (EA-no prior BE).

Results:

Multivariable case–case comparisons evidenced adverse associations of GERD, ever cigarette smoking, hypertension, dyslipidemia, weight loss, peptic ulcer and irritable bowel disease each in EA-prior BE compared with EA-no prior BE. Obesity, metabolic syndrome, impaired fasting glucose and diabetes did not differ between groups. EA-prior BE cases were diagnosed with less advanced disease, were more likely to undergo surgery and less likely to receive chemotherapy and radiotherapy, and had better overall mean survival (2.5 vs 1.4 years). This survival advantage persisted in the multivariable Cox model (HR=0.69, 95%CI: 0.60, 0.78), despite adjustment for many factors including stage, grade and clinical interventions.

Conclusions:

This study provides evidence that EA cases occurring among individuals previously diagnosed with BE are different from the large majority of EA cases that occur without a prior BE diagnosis. Regardless of whether these differences emanate from aetiology, biology and/or selection biases, they underscore the importance of a prudent approach in using knowledge from EAC case–control studies in the management of BE populations.

Tethered capsule endomicroscopy: from bench to bedside at a primary care practice

Due to the relatively high cost and inconvenience of upper endoscopic biopsy and the rising incidence of esophageal adenocarcinoma, there is currently a need for an improved method for screening for Barrett’s esophagus. Ideally, such a test would be applied in the primary care setting and patients referred to endoscopy if the result is suspicious for Barrett’s. Tethered capsule endomicroscopy (TCE) is a recently developed technology that rapidly acquires microscopic images of the entire esophagus in unsedated subjects. Here, we present our first experience with clinical translation and feasibility of TCE in a primary care practice. The acceptance of the TCE device by the primary care clinical staff and patients shows the potential of this device to be useful as a screening tool for a broader population.

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.

Volatile organic compounds in plasma for the diagnosis of esophageal adenocarcinoma: a pilot study

BACKGROUND AND AIMS

A noninvasive screening test that can detect esophageal adenocarcinoma (EAC) at an earlier stage could improve the prognosis associated with EAC. The role of plasma volatile organic compounds (VOCs) for the diagnosis of EAC has not been previously studied.

METHODS

Plasma samples were collected from subjects with EAC and GERD before endoscopy. Twenty-two preselected VOCs were analyzed with selected ion flow tube mass spectrometry.

RESULTS

The headspaces from 39 plasma samples (20 EAC, 19 GERD) were analyzed. The levels of 9 VOCs (acetonitrile, acrylonitrile, carbon disulfide, isoprene, 1-heptene, 3-methylhexane, [E]-2-nonene, hydrogen sulfide, and triethylamine) were significantly altered in EAC patients compared with GERD patients. A multivariable logistic regression analysis was performed to build a model for the prediction of EAC. The model identified patients with EAC with an area under the curve of 0.83 (95% confidence interval, 0.67-0.98).

CONCLUSIONS

Plasma VOCs may be useful in diagnosing EAC. Larger studies are needed to confirm our pilot study observations.

Enhancing High Value Care in Gastroenterology Practice

BACKGROUNG & AIMS

The objective of this review is to identify common areas in gastroenterology practice where studies performed provide an opportunity for enhancing value or lowering costs.

METHODS

We provide examples of topics in gastroenterology where clinicians could enhance value by either using less invasive testing, choosing a single best test, or by using patient symptoms to guide additional testing.

RESULTS

The topics selected for review are selected in esophageal, pancreatic, and colorectal cancer; functional gastrointestinal diseases (irritable bowel syndrome, bacterial overgrowth, constipation); immune-mediated gastrointestinal diseases; and pancreaticobiliary pathology. We propose guidance to alter practice based on current evidence.

CONCLUSIONS

These studies support the need to review current practice and to continue performing research to further validate the proposed guidance to enhance value of care in gastroenterology and hepatology.

Progression of Barrett's esophagus toward esophageal adenocarcinoma: an overview

In Barrett's esophagus, normal squamous epithelium is replaced by a metaplastic columnar epithelium as a consequence of chronic gastroesophageal reflux disease. There is a strong association with esophageal adenocarcinoma. In view of the increasing incidence of esophageal adenocarcinoma in the western world, it is important that more attention be paid to the progression of Barrett's esophagus toward esophageal adenocarcinoma. Recently, several molecular factors have been identified that contribute to the sequence towards adenocarcinoma. This might help identify patients at risk and detect new targets for the prevention and treatment of esophageal adenocarcinoma in the future.

Epidemiology of Barrett's esophagus and esophageal adenocarcinoma in Spain. A unicentric study

INTRODUCTION

Barrett's esophagus (BE) is an acquired disease defined by the presence of intestinal metaplasia with goblet cells in the distal esophagus. The prevalence of BE has increased dramatically over the last years.

AIMS

The primary aims of the study were to analyze the characteristics of BE and esophageal adenocarcinoma (EAC) in a Spanish health district during a follow-up period.

METHODOLOGY

Sociodemographic factors, alcohol consumption and cigarette smoking were analyzed. We also studied the histological behavior and cause of death in each group.

RESULTS

In the present study 430 patients were included, 338 with BE and 92 with EAC. Incidence rates have risen from 2.25 and 1.25 per 100,000 inhabitants in 1996 to 6.5 and 4.75 per 100,000 in 2011, respectively. In the EAC group, male gender, age and alcohol consumption were higher in comparison to the BE group, and the overall survival was 23 months. In the BE group, the main causes of death were non-esophageal cancer and cardiovascular disease.

CONCLUSIONS

The incidence and prevalence rates of AEC and BE have risen over the past years. Risk factors for these conditions were male gender, age and alcohol consumption. Long BE (> 3 cm) is involved in dysplasia progression. AEC diagnosis mainly occurs after neoplasia is detected and, in a few cases, due to a previous BE. Cardiovascular diseases and non-esophageal cancers have been found to be the main cause of death in BE patients.

Diagnosis and Surveillance of Barrett's Esophagus: Addressing the Transatlantic Divide

BACKGROUND

Barrett's esophagus is a premalignant condition of the esophagus leading to esophageal adenocarcinoma. No consensus exists between the UK and USA concerning the diagnosis of Barrett's esophagus. Although the diagnostic procedure is common, the required findings and diagnostic criteria vary. Both guidelines require endoscopy showing columnar epithelia lining the esophagus, but the US guidelines require the additional finding of intestinal metaplasia on biopsy to confirm diagnosis. Achievement of a consensus is of particular importance due to the established progression from Barrett's esophagus to esophageal adenocarcinoma. Of further importance is the increasing incidence of esophageal adenocarcinoma, a condition with poor overall survival, leading to various opinions on the utility of surveillance in patients.

DISCUSSION

A review of the vast array of literature revealed that substantial evidence exists in favor of both diagnostic criteria; hence, there is no easy way to identify the "correct" method of diagnosing Barrett's esophagus. USA recommends surveillance of Barrett's esophagus, whereas UK does not advocate it unless dysplasia is present. Surveillance was found to be effective, but this varied as did cost-effectiveness. Further research into diagnostic methods for Barrett's esophagus is needed to address areas of limited understanding, such that agreement can be reached and practice standardized. Surveillance was generally advocated, but with different criteria and time intervals, and new methods are being evaluated.

Management of Barrett's esophagus: From screening to newer treatments

Barrett's esophagus is a premalignant condition of the esophagus in which the squamous epithelium of the lower end of the esophagus is replaced with columnar epithelium. Since the incidence of esophageal adenocarcinoma is on the rise, the major gastroenterology societies have come up with their recommendations for screening and surveillance. Specific factors like obesity, white race, age over 50 years, early age of onset of GERD, smoking and hiatal hernia have been identified as increasing the risk of Barrett's esophagus and adenocarcinoma. The diagnosis requires both endoscopic identification of columnar-lined mucosa and histological confirmation with biopsy. Most medical societies recommend screening people with GERD and other risk factors with endoscopy, but other alternatives employing less invasive methods are currently being studied. Surveillance strategies vary depending on the endoscopic findings and the Seattle biopsy protocol with random 4-quadrant sampling is recommended. Biomarkers have shown promising results, but more studies are needed in the future. White light endoscopy is the standard practice, but other advanced imaging modalities have shown variable results and hence more studies are awaited for further validation. Endoscopic eradication techniques, including both resection and ablation, have shown good but variable results for treating dysplastic lesions confined to the mucosa. Resection procedures to remove visible lesions followed by ablation of the dysplastic mucosa have shown the best results with higher eradication rates and lower recurrence rates. Surgical management is reserved for lesions with sub-mucosal invasion and lymph node spread with increased risk of metastasis.

Magnitude of Missed Esophageal Adenocarcinoma After Barrett's Esophagus Diagnosis: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

A proportion of patients with Barrett's esophagus (BE) are diagnosed with esophageal adenocarcinoma (EAC) within 1 year of an endoscopic examination that produced negative findings. These cases of missed cancers have not been well studied, despite current surveillance strategies for BE. We performed a systematic review and meta-analysis to determine the magnitude of missed EAC in cohorts of patients with BE.

METHODS

We searched MEDLINE, EMBASE, and Web of Science from their inception to May 31, 2015 to identify cohort studies of adults with BE (baseline nondysplastic BE ± BE with low-grade dysplasia) and at least a 3-year follow-up period, providing data on missed and incident EACs (diagnosed within 1 year and diagnosed more than 1 year after the initial endoscopy in which BE was diagnosed, respectively). The main outcome measure was pooled proportion of missed and incident EACs (of all EACs detected after initial endoscopy) among BE cohorts, using a random effects model.

RESULTS

In a meta-analysis of 24 studies reporting on 820 missed and incident EACs, 25.3% were classified as missed (95% confidence interval: 16.4%-36.8%) and 74.7% as incident EACs (95% CI: 63.2%-83.6%), although there was substantial heterogeneity among studies (I2 = 74%). When the analysis was restricted to nondysplastic BE cohorts (15 studies), 23.9% of EACs were classified as missed (95% confidence interval: 15.3%-35.4%; I2 = 0%). In a meta-analysis of 10 studies with follow-up periods of ≥5 years (a total of 239 EACs), 22.0% were classified as missed (95% confidence interval: 8.7%-45.5%), with substantial heterogeneity (I2 = 68%).

CONCLUSIONS

Among adults with nondysplastic BE (or BE with low-grade dysplasia) at their index endoscopy and at least a 3-year follow-up period, 25% of EACs are diagnosed within 1 year after the index endoscopy. Additional resources should be allocated to detect missed EAC.

Advances in the endoscopic diagnosis and treatment of Barrett's neoplasia

Barrett's oesophagus is a well-recognised precursor of oesophageal adenocarcinoma. The incidence of oesophageal adenocarcinoma is continuing to rise in the Western world with dismal survival rates. In recent years, efforts have been made to diagnose Barrett's earlier and improve surveillance techniques in order to pick up cancerous changes earlier. Recent advances in endoscopic therapy for early Barrett's cancers have shifted the paradigm away from oesophagectomy and have yielded excellent results.

ACG Clinical Guideline: Diagnosis and Management of Barrett's Esophagus

Barrett's esophagus (BE) is among the most common conditions encountered by the gastroenterologist. In this document, the American College of Gastroenterology updates its guidance for the best practices in caring for these patients. These guidelines continue to endorse screening of high-risk patients for BE; however, routine screening is limited to men with reflux symptoms and multiple other risk factors. Acknowledging recent data on the low risk of malignant progression in patients with nondysplastic BE, endoscopic surveillance intervals are attenuated in this population; patients with nondysplastic BE should undergo endoscopic surveillance no more frequently than every 3-5 years. Neither routine use of biomarker panels nor advanced endoscopic imaging techniques (beyond high-definition endoscopy) is recommended at this time. Endoscopic ablative therapy is recommended for patients with BE and high-grade dysplasia, as well as T1a esophageal adenocarcinoma. Based on recent level 1 evidence, endoscopic ablative therapy is also recommended for patients with BE and low-grade dysplasia, although endoscopic surveillance continues to be an acceptable alternative. Given the relatively common recurrence of BE after ablation, we suggest postablation endoscopic surveillance intervals. Although many of the recommendations provided are based on weak evidence or expert opinion, this document provides a pragmatic framework for the care of the patient with BE.

Mechanisms of esophageal adenocarcinoma formation and approaches to chemopreventive intervention

The incidence of esophageal adenocarcinoma (EAC), a debilitating and highly lethal malignancy, has risen dramatically over the past 40 years in the United States and other Western countries. To reverse this trend, EAC prevention and early detection efforts by clinicians, academic researchers and endoscope manufacturers have targeted Barrett's esophagus (BE), the widely accepted EAC precursor lesion. Data from surgical, endoscopic and pre-clinical investigations strongly support the malignant potential of BE. For patients with BE, the risk of developing EAC has been estimated at 11- to 125-fold greater than that of the individual at average risk. Nevertheless, screening for BE in symptomatic patients (ie, with symptoms of reflux) and surveillance in patients diagnosed with BE have not had a substantial impact on the incidence, morbidity or mortality of EAC; the overwhelming majority of EAC patients are diagnosed without a pre-operative diagnosis of BE. This article will discuss the current state of the science of esophageal adenocarcinoma prevention, including ideas about carcinogenesis and its underlying genomic and molecular level mechanisms, and suggest strategies for a systems approach to targeted preventive management.

Esophageal Adenocarcinoma: The Influence of Medications Used to Treat Comorbidities on Cancer Prognosis

Esophageal adenocarcinoma has undergone a continuous rise in incidence since the early 1970s and is the fastest rising cancer among white men in the United States. Epidemiologic studies have demonstrated that medications commonly used to treat multiple chronic conditions (for example, aspirin, non-aspirin nonsteroidal anti-inflammatory drugs, and statins) as well as powerful acid suppressants such as proton pump inhibitors are associated with a reduced risk of esophageal adenocarcinoma. The chemopreventive potential of these classes of medications appears to be especially applicable to persons with Barrett's esophagus, the only known premalignant condition for esophageal adenocarcinoma. However, it is not known whether these medications also influence cancer recurrence and cancer-specific mortality in persons diagnosed with esophageal adenocarcinoma. This is an important question because most patients with esophageal adenocarcinoma have 1 or more comorbid conditions at the time of their cancer diagnosis and are receiving medication to treat these conditions. This article summarizes the evidence on the associations between 4 commonly used classes of medications and (1) risk of developing esophageal adenocarcinoma and Barrett's esophagus and (2) risk of cancer recurrence and cancer-specific mortality in patients with esophageal adenocarcinoma.

Methylated B3GAT2 and ZNF793 Are Potential Detection Biomarkers for Barrett's Esophagus

BACKGROUND

Barrett's esophagus (BE) is a preneoplastic condition in which normal esophageal squamous epithelium (SQ) is replaced by specialized intestinal metaplasia. It is the presumed precursor for esophageal adenocarcinoma (EAC) as well as the strongest risk factor for this cancer. Unfortunately, many patients with BE go undiagnosed under the current BE screening guidelines. The development of noninvasive and accurate BE detection assays could potentially identify many of these undiagnosed BE patients.

METHODS

DNA methylation is a common epigenetic alteration in BE. Therefore, we conducted a genome-wide methylation screen to identify potential BE biomarkers. Samples from SQ (N = 12), stomach (N = 28), and BE (N = 29) were analyzed and methylation levels at over 485,000 CpG sites were compared. Pyrosequencing assays were used to validate the results and MethyLight assays were developed to detect the methylated alleles in endoscopic brushings.

RESULTS

We discovered two genes, B3GAT2 and ZNF793, that are aberrantly methylated in BE. Clinical validation studies confirmed B3GAT2 and ZNF793 methylation levels were significantly higher in BE samples (median = 32.5% and 33.1%, respectively) than in control tissues (median = 2.29% and 2.52%, respectively; P < 0.0001 for both genes). Furthermore, gene-specific MethyLight assays could accurately detect BE (P < 0.0001 for both) in endoscopic brushing samples.

CONCLUSION

B3GAT2 and ZNF793 are hypermethylated in BE, and the methylation status of these genes can be used to detect BE in tissue samples.

IMPACT

These findings support the development of methylated B3GAT2 and ZNF793 as biomarkers for noninvasive assays for the detection of BE.

Detection of fluorescent organic nanoparticles by confocal laser endomicroscopy in a rat model of Barrett's esophageal adenocarcinoma

For many years, novel strategies for cancer detection and treatment using nanoparticles (NPs) have been developed. Esophageal adenocarcinoma is the sixth leading cause of cancer-related deaths in Western countries, and despite recent advances in early detection and treatment, its prognosis is still very poor. This study investigated the use of fluorescent organic NPs as potential diagnostic tool in an experimental in vivo model of Barrett’s esophageal adenocarcinoma. NPs were made of modified polysaccharides loaded with [4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran] (DCM), a well-known fluorescent dye. The NP periphery might or might not be decorated with ASYNYDA peptide that has an affinity for esophageal cancer cells. Non-operated and operated rats in which gastroesophageal reflux was surgically induced received both types of NPs (NP-DCM and NP-DCM-ASYNYDA) by intravenous route. Localization of mucosal NPs was assessed in vivo by confocal laser endomicroscopy, a technique which enables a “real time” and in situ visualization of the tissue at a cellular level. After injection of NP-DCM and NP-DCM-ASYNYDA, fluorescence was observed in rats affected by esophageal cancer, whereas no signal was observed in control non-operated rats, or in rats with simple esophagitis or Barrett’s esophagus mucosa. Fluorescence was observable in vivo 30 minutes after the administration of NPs. Interestingly, NP-DCM-ASYNYDA induced strong fluorescence intensity 24 hours after administration. These observations suggested that NPs could reach the tumor cells, likely by enhanced permeability and retention effect, and the peptide ASYNYDA gave them high specificity for esophageal cancer cells. Thus, the combination of NP platform and confocal laser endomicroscopy could play an important role for highlighting esophageal cancer conditions. This result supports the potential of this strategy as a targeted carrier for photoactive and bioactive molecules in esophageal cancer diagnosis and treatment.

Epidemiology, Diagnosis, and Management of Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) is rapidly increasing in incidence in Western cultures. Barrett's esophagus is the presumed precursor lesion for this cancer. Several other risk factors for this cancer have been described, including chronic heartburn, tobacco use, white race, and obesity. Despite these known associations, most patients with EAC present with symptoms of dysphagia from late-stage tumors; only a small number of patients are identified by screening and surveillance programs. Diagnostic analysis of EAC usually commences with upper endoscopy followed by cross-sectional imaging. Endoscopic ultrasonography is useful to assess the local extent of disease as well as the involvement of regional lymph nodes. T1a EAC may be treated endoscopically, and some patients with T1b disease may also benefit from endoscopic therapy. Locally advanced disease is generally managed with esophagectomy, often accompanied by neoadjuvant chemoradiotherapy or chemotherapy. The prognosis is based on tumor stage; patients with T1a tumors have an excellent prognosis, whereas few patients with advanced disease have long-term survival.

Local Synthesis of Pepsin in Barrett's Esophagus and the Role of Pepsin in Esophageal Adenocarcinoma

OBJECTIVE

Despite widespread use of proton pump inhibitors (PPIs), the incidence of esophageal adenocarcinoma (EAC) continues to rise. PPIs reduce reflux acidity, but only transiently inactivate gastric enzymes. Nonacid reflux, specifically nonacid pepsin, contributes to carcinogenesis in the larynx. Given the carcinogenic potential of pepsin and inefficacy of PPIs to prevent EAC, the presence and effect of pepsin in the esophagus should be investigated.

METHODS

Normal and Barrett's biopsies from 8 Barrett's esophagus patients were collected for pepsin analysis via Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR). Human esophageal cells cultured from healthy patients were treated with pepsin (0.01-1 mg/mL; 1-20 hours), acid (pH 4)±pepsin (5 minutes); real-time RT-PCR, ELISA, and cell migration were assayed.

RESULTS

Pepsin was detected in all 8 Barrett's and 4 of 8 adjacent normal specimens. Pepsinogen mRNA was observed in 22 Barrett's, but not in normal adjacent samples. Pepsin induced PTSG2 (COX-2) and IL-1β expression and cell migration in vitro.

CONCLUSIONS

Pepsin is synthesized by metaplastic, Barrett's esophageal mucosa. Nonacid pepsin increases metrics of tumorigenicity in esophageal epithelial cells in vitro. These findings implicate refluxed and locally synthesized pepsin in development and progression of EAC and, in part, explain the inefficacy of PPIs in the prevention of EAC.