Predictors of progression in Barrett's esophagus: current knowledge and future directions

Classification and prediction of chemoradiotherapy response and survival from esophageal carcinoma histopathology images

Whole slide imaging (WSI) of Hematoxylin and Eosin-stained biopsy specimens has been used to predict chemoradiotherapy (CRT) response and overall survival (OS) of esophageal squamous cell carcinoma (ESCC) patients. This retrospective study collected 279 specimens in 89 non-surgical ESCC patients through endoscopic biopsy between January 2010 and January 2019. These patients were divided into a CRT response group (CR + PR group) and a CRT non-response group (SD + PD group). The WSIs have segmented approximately 1,206,000 non-overlapping patches. Two experienced pathologists manually delineated the eight types of tissues on 32 WSIs, including esophagus tumor cell (TUM), cancer-associated stroma (CAS), normal epithelium layer (NEL), smooth muscle (MUS), lymphocytes (LYM), Red cells (RED), debris (DEB), uneven areas (UNE). The chemoradiotherapy response prediction models were built using maximum relevance-minimum redundancy (MRMR) feature selection and least absolute shrinkage and selection operator (LASSO) regression. However, pathological features with p < 0.1 were selected and integrated to be further screened using a LASSO Cox regression model to build a multivariate Cox proportional hazards model for predicting the OS. The testing accuracy of the tissue classification model was 91.3 %. The pathological model created using two CAS in-depth features and eight TUM in-depth features performed best for the prediction of treatment response and achieved an AUC of 0.744. For the prediction of OS, the testing AUC of this model at one year and three years were 0.675 and 0.870, respectively. The TUM model showed the highest AUC at one year (0.712). With its high accuracy rate, the deep learning model has the potential to transform from bench to bedside in clinical practice, improve patient's quality of life, and prolong the OS rate.

Extrachromosomal DNA in the cancerous transformation of Barrett's oesophagus

Oncogene amplification on extrachromosomal DNA (ecDNA) drives the evolution of tumours and their resistance to treatment, and is associated with poor outcomes for patients with cancer1-6. At present, it is unclear whether ecDNA is a later manifestation of genomic instability, or whether it can be an early event in the transition from dysplasia to cancer. Here, to better understand the development of ecDNA, we analysed whole-genome sequencing (WGS) data from patients with oesophageal adenocarcinoma (EAC) or Barrett's oesophagus. These data included 206 biopsies in Barrett's oesophagus surveillance and EAC cohorts from Cambridge University. We also analysed WGS and histology data from biopsies that were collected across multiple regions at 2 time points from 80 patients in a case-control study at the Fred Hutchinson Cancer Center. In the Cambridge cohorts, the frequency of ecDNA increased between Barrett's-oesophagus-associated early-stage (24%) and late-stage (43%) EAC, suggesting that ecDNA is formed during cancer progression. In the cohort from the Fred Hutchinson Cancer Center, 33% of patients who developed EAC had at least one oesophageal biopsy with ecDNA before or at the diagnosis of EAC. In biopsies that were collected before cancer diagnosis, higher levels of ecDNA were present in samples from patients who later developed EAC than in samples from those who did not. We found that ecDNAs contained diverse collections of oncogenes and immunomodulatory genes. Furthermore, ecDNAs showed increases in copy number and structural complexity at more advanced stages of disease. Our findings show that ecDNA can develop early in the transition from high-grade dysplasia to cancer, and that ecDNAs progressively form and evolve under positive selection.

Detection of Barrett's neoplasia with a near-infrared fluorescent heterodimeric peptide

BACKGROUND

Esophageal adenocarcinoma (EAC) is a molecularly heterogeneous disease with poor prognosis that is rising rapidly in incidence. We aimed to demonstrate specific binding by a peptide heterodimer to Barrett's neoplasia in human subjects.

METHODS

Peptide monomers specific for EGFR and ErbB2 were arranged in a heterodimer configuration and labeled with IRDye800. This near-infrared (NIR) contrast agent was topically administered to patients with Barrett's esophagus (BE) undergoing either endoscopic therapy or surveillance. Fluorescence images were collected using a flexible fiber accessory passed through the instrument channel of an upper gastrointestinal endoscope. Fluorescence images were collected from 31 BE patients. A deep learning model was used to segment the target (T) and background (B) regions.

RESULTS

The mean target-to-background (T/B) ratio was significantly greater for high grade dysplasia (HGD) and EAC versus BE, low grade dysplasia (LGD), and squamous epithelium. At a T/B ratio of 1.5, sensitivity and specificity of 94.1 % and 92.6 %, respectively, were achieved for the detection of Barrett's neoplasia with an area under the curve of 0.95. No adverse events attributed to the heterodimer were found. EGFR and ErbB2 expression were validated in the resected specimens.

CONCLUSIONS

This "first-in-human" clinical study demonstrates the feasibility of detection of early Barrett's neoplasia using a NIR-labeled peptide heterodimer.

Diagnosis and Management of Barrett's Esophagus: An Updated ACG Guideline

Barrett's esophagus (BE) is a common condition associated with chronic gastroesophageal reflux disease. BE is the only known precursor to esophageal adenocarcinoma, a highly lethal cancer with an increasing incidence over the last 5 decades. These revised guidelines implement Grading of Recommendations, Assessment, Development, and Evaluation methodology to propose recommendations for the definition and diagnosis of BE, screening for BE and esophageal adenocarcinoma, surveillance of patients with known BE, and the medical and endoscopic treatment of BE and its associated early neoplasia. Important changes since the previous iteration of this guideline include a broadening of acceptable screening modalities for BE to include nonendoscopic methods, liberalized intervals for surveillance of short-segment BE, and volume criteria for endoscopic therapy centers for BE. We recommend endoscopic eradication therapy for patients with BE and high-grade dysplasia and those with BE and low-grade dysplasia. We propose structured surveillance intervals for patients with dysplastic BE after successful ablation based on the baseline degree of dysplasia. We could not make recommendations regarding chemoprevention or use of biomarkers in routine practice due to insufficient data.

Challenges in Determining the Role of Microbiome Evolution in Barrett's Esophagus and Progression to Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) claims the lives of half of patients within the first year of diagnosis, and its incidence has rapidly increased since the 1970s despite extensive research into etiological factors. The changes in the microbiome within the distal esophagus in modern populations may help explain the growth in cases that other common EAC risk factors together cannot fully explain. The precursor to EAC is Barrett's esophagus (BE), a metaplasia adapted to a reflux-mediated microenvironment that can be challenging to diagnose in patients who do not undergo endoscopic screening. Non-invasive procedures to detect microbial communities in saliva, oral swabs and brushings from the distal esophagus allow us to characterize taxonomic differences in bacterial population abundances within patients with BE versus controls, and may provide an alternative means of BE detection. Unique microbial communities have been identified across healthy esophagus, BE, and various stages of progression to EAC, but studies determining dynamic changes in these communities, including migration from proximal stomach and oral cavity niches, and their potential causal role in cancer formation are lacking. Helicobacter pylori is negatively associated with EAC, and the absence of this species has been implicated in the evolution of chromosomal instability, a main driver of EAC, but joint analyses of microbiome and host genomes are needed. Acknowledging technical challenges, future studies on the prediction of microbial dynamics and evolution within BE and the progression to EAC will require larger esophageal microbiome datasets, improved bioinformatics pipelines, and specialized mathematical models for analysis.

Endoscopic features of buried Barrett's mucosa

BACKGROUND AND AIMS

Buried Barrett's mucosa is defined as intestinal metaplasia that is "buried" under the normal-appearing squamous epithelium. This can occur in Barrett's esophagus with or without previous endoscopic therapy. Dysplasia and neoplasia within buried Barrett's mucosa have also been reported. However, endoscopic features of buried Barrett's mucosa have not been described. At our tertiary referral center for Barrett's esophagus, several endoscopic features have been observed in patients who were found to have buried Barrett's mucosa on histology. These features are squamous epithelium which is (1) darker pink on white-light and darker brown on narrow-band imaging and/or (2) has a slightly raised or nodular appearance. It was also observed that either of these 2 features is frequently seen adjacent to a Barrett's mucosa island. This study aimed to (1) evaluate the diagnostic accuracy of these endoscopic features, and (2) evaluate the frequency of endoscopically identifiable buried Barrett's mucosa in patients with dysplastic Barrett's esophagus, before and after endoscopic eradication therapy.

METHODS

This was a retrospective analysis of a prospectively observed cohort of all cases of dysplastic Barrett's esophagus referred to St Vincent's Hospital, Melbourne. Endoscopy documentation software and histopathology reports of esophageal biopsy and EMR specimens between March 2013 and March 2019 were searched for terms "buried" or "subsquamous" Barrett's mucosa. Endoscopic reports, images, and histopathology reports of suspected buried Barrett's mucosa were then reviewed to apply the endoscopic features and correlate with the histologic diagnosis.

RESULTS

In a cohort of 506 patients with dysplastic Barrett's esophagus, 33 (7%) patients (73% male, median age at referral 70.5 years) had buried Barrett's mucosa on histology. Twenty-seven (82%) patients had previous treatment for dysplastic Barrett's esophagus; radiofrequency in 2 (6%), EMR in 4 (12%), and both modalities in 21 (64%). Six (18%) had no previous treatment. Histologically confirmed buried Barrett's mucosa was suspected at endoscopy in 26 patients (79%). Endoscopic features were (1) darker pink or darker brown mucosa underneath squamous epithelium (24%), (2) raised areas underneath squamous mucosa (27%), and both features present concurrently (27%). These features were associated with adjacent islands of Barrett's esophagus in 48%. Forty-four cases of buried Barrett's mucosa were suspected endoscopically, and these were sampled by biopsy (50%) and EMR (50%). Buried Barrett's mucosa was confirmed in 26 cases, with a positive predictive value of endoscopic suspicion of 59%. Eighteen cases of endoscopically suspected buried Barrett's mucosa had no buried Barrett's mucosa on histology; inflammation or reflux was identified in 12 (67%) patients. Dysplasia was identified within buried Barrett's mucosa in 12 (36%) patients; 5 intramucosal adenocarcinoma, 1 high-grade dysplasia, and 6 low-grade dysplasia. Endoscopic features of buried Barrett's mucosa were observed in 11 of 12 cases harboring dysplasia or neoplasia, compared with 15 of 21 cases of buried Barrett's mucosa without dysplasia.

CONCLUSIONS

In this retrospective analysis of prospectively observed patients with dysplastic Barrett's esophagus, buried Barrett's mucosa was identified in 7%, including treatment-naive patients. The proposed endoscopic features of buried Barrett's mucosa were seen in 79% of patients with histology confirmed disease. These endoscopic features may predict the presence of buried Barrett's mucosa, which may contain dysplasia or neoplasia. An overlap between the endoscopic features of inflammation, reflux, and buried Barrett's mucosa was observed. Future prospective studies are required to develop and validate endoscopic criteria for identifying buried Barrett's mucosa.

Optimal Timing for Cancer Screening and Adaptive Surveillance Using Mathematical Modeling

Cancer screening and early detection efforts have been partially successful in reducing incidence and mortality, but many improvements are needed. Although current medical practice is informed by epidemiologic studies and experts, the decisions for guidelines are ultimately ad hoc. We propose here that quantitative optimization of protocols can potentially increase screening success and reduce overdiagnosis. Mathematical modeling of the stochastic process of cancer evolution can be used to derive and optimize the timing of clinical screens so that the probability is maximal that a patient is screened within a certain "window of opportunity" for intervention when early cancer development may be observable. Alternative to a strictly empirical approach or microsimulations of a multitude of possible scenarios, biologically based mechanistic modeling can be used for predicting when best to screen and begin adaptive surveillance. We introduce a methodology for optimizing screening, assessing potential risks, and quantifying associated costs to healthcare using multiscale models. As a case study in Barrett's esophagus, these methods were applied for a model of esophageal adenocarcinoma that was previously calibrated to U.S. cancer registry data. Optimal screening ages for patients with symptomatic gastroesophageal reflux disease were older (58 for men and 64 for women) than what is currently recommended (age > 50 years). These ages are in a cost-effective range to start screening and were independently validated by data used in current guidelines. Collectively, our framework captures critical aspects of cancer evolution within patients with Barrett's esophagus for a more personalized screening design. SIGNIFICANCE: This study demonstrates how mathematical modeling of cancer evolution can be used to optimize screening regimes, with the added potential to improve surveillance regimes. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/4/1123/F1.large.jpg.

Is Malignant Potential of Barrett’s Esophagus Predictable by Endoscopy Findings?

Given that endoscopic findings can be used to predict the potential of neoplastic progression in Barrett’s esophagus (BE) cases, the detection rate of dysplastic Barrett’s lesions may become higher even in laborious endoscopic surveillance because a special attention is consequently paid. However, endoscopic findings for effective detection of the risk of neoplastic progression to esophageal adenocarcinoma (EAC) have not been confirmed, though some typical appearances are suggestive. In the present review, endoscopic findings that can be used predict malignant potential to EAC in BE cases are discussed. Conventional results obtained with white light endoscopy, such as length of BE, presence of esophagitis, ulceration, hiatal hernia, and nodularity, are used as indicators of a higher risk of neoplastic progression. However, there are controversies in some of those findings. Absence of palisade vessels may be also a new candidate predictor, as that reveals degree of intense inflammation and of cyclooxygenase-2 protein expression with accelerated cellular proliferation. Furthermore, an open type of mucosal pattern and enriched stromal blood vessels, which can be observed by image-enhanced endoscopy, including narrow band imaging, have been confirmed as factors useful for prediction of neoplastic progression of BE because they indicate more frequent cyclooxygenase-2 protein expression along with accelerated cellular proliferation. Should the malignant potential of BE be shown predictable by these endoscopic findings, that would simplify methods used for an effective surveillance, because patients requiring careful monitoring would be more easily identified. Development in the near future of a comprehensive scoring system for BE based on clinical factors, biomarkers and endoscopic predictors is required.

Barrett Esophagus Length, Nodularity, and Low-grade Dysplasia are Predictive of Progression to Esophageal Adenocarcinoma

GOALS

To investigate factors predictive of progression from nondysplastic Barrett esophagus (NDBE) or low-grade dysplasia (LGD) to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC) using a large, prospective cohort of patients, wherein all esophageal biopsies undergo expert gastrointestinal pathologist review.

BACKGROUND

Efficacy and cost-effectiveness of endoscopic surveillance to detect incident EAC in the setting of Barrett esophagus (BE), particularly in NDBE patients, is questioned. Previous studies have reported factors predictive of progression to EAC to guide surveillance intervals, but their strength is limited by small sample size and absence of expert gastrointestinal pathologist involvement in esophageal biopsy review.

STUDY

NDBE and LGD subjects were identified from a prospective registry in a tertiary care center. "Progressors" were BE subjects who developed HGD/EAC>12 months after the initial NDBE or LGD diagnosis. Cox proportional hazards model were used to identify predictors of progression.

RESULTS

In total, 318 with NDBE and 301 with BE-LGD (mean age, 62.6 y, 85% male) were included. The mean follow-up was 5.3 years. The 7 NDBE and 21 LGD subjects progressed to HGD/EAC. BE length [hazards ratio (HR), 1.16; 95% confidence interval (CI), 1.03-1.29], presence of nodularity (HR, 4.98; 95% CI, 1.80-11.7), and baseline LGD (HR, 2.57; 95% CI, 1.13-6.57) were significant predictors of progression on multivariate analysis.

CONCLUSIONS

In this well-defined cohort of NDBE and BE-LGD subjects, BE length, presence of LGD, and nodularity were independent predictors of progression to HGD/EAC. These factors may aid in identifying high-risk patients who may benefit from closer endoscopic surveillance/therapy.

Signatures within the esophageal microbiome are associated with host genetics, age, and disease

BACKGROUND

The esophageal microbiome has been proposed to be involved in a range of diseases including the esophageal adenocarcinoma cascade; however, little is currently known about its function and relationship to the host. Here, the esophageal microbiomes of 106 prospectively recruited patients were assessed using 16S rRNA and 18S rRNA amplicon sequencing as well as shotgun sequencing, and associations with age, gender, proton pump inhibitor use, host genetics, and disease were tested.

RESULTS

The esophageal microbiome was found to cluster into functionally distinct community types (esotypes) defined by the relative abundances of Streptococcus and Prevotella. While age was found to be a significant factor driving microbiome composition, bacterial signatures and functions such as enrichment with Gram-negative oral-associated bacteria and microbial lactic acid production were associated with the early stages of the esophageal adenocarcinoma cascade. Non-bacterial microbes such as archaea, Candida spp., and bacteriophages were also identified in low abundance in the esophageal microbiome. Specific host SNPs in NOTCH2, STEAP2-AS1, and NREP were associated with the composition of the esophageal microbiome in our cohort.

CONCLUSIONS

This study provides the most comprehensive assessment of the esophageal microbiome to date and identifies novel signatures and host markers that can be investigated further in the context of esophageal adenocarcinoma development.

Endoscopic therapy for confirmed low-grade dysplasia in Barrett's esophagus

Barrett's esophagus (BE) is a premalignant condition characterized by replacement of the esophageal lining with metastatic columnar epithelium. To date, the management in case of confirmed low-grade dysplasia (LGD) remains controversial. In this article we summarize the available endoscopic options and their results in terms of efficacy and safety in the treatment of confirmed LGD in BE.

How Should We Report Endoscopic Results in Patient's with Barrett's Esophagus?

Barrett's esophagus is the only known pre-cancerous lesion for esophageal adenocarcinoma and is diagnosed by high-definition white light endoscopy demonstrating a columnar-lined esophagus along with biopsy evidence of intestinal metaplasia. With accurate performance and reporting of the endoscopic procedure, an evidence-based management strategy can be developed for treatment of Barrett's dysplasia. However, cross-sectional data demonstrate that there is still inconsistency among gastroenterologists in performance and reporting of endoscopic findings in patients with Barrett's esophagus. Here, we present an evidence-based review of how to report endoscopic findings in Barrett's esophagus.

Longitudinal outcomes of radiofrequency ablation versus surveillance endoscopy for Barrett's esophagus with low-grade dysplasia

Radiofrequency ablation of Barrett's esophagus with low-grade dysplasia is recommended in recent American College of Gastroenterology guidelines, with endoscopic surveillance considered a reasonable alternative. Few studies have directly compared outcomes of radiofrequency ablation to surveillance and those that have are limited by short duration of follow-up. This study aims to compare the long-term effectiveness of radiofrequency ablation versus endoscopic surveillance in a large, longitudinal cohort of patients with Barrett's esophagus, and low-grade dysplasia.We conducted a retrospective analysis of patients with confirmed low-grade dysplasia at a single academic medical center from 1991 to 2014. Patients progressing to high-grade dysplasia or esophageal adenocarcinoma within one year of index LGD endoscopy were defined as missed dysplasia and excluded. Risk factors for progression were assessed via Cox proportional hazards model. Comparison of progression risk was conducted using a Kaplan-Meier analysis. Subset analyses were conducted to examine the effect of reintroducing early progressors and excluding patients diagnosed prior to the advent of ablative therapy. Of 173 total patients, 79 (45.7%) underwent radiofrequency ablation while 94 (54.3%) were untreated, with median follow up of 90 months. Seven (8.9%) patients progressed to high-grade dysplasia or adenocarcinoma despite ablation, compared with 14 (14.9%) undergoing surveillance (P = 0.44). This effect was preserved when patients diagnosed prior to the introduction of radiofrequency ablation were excluded (8.9% vs 13%, P = 0.68). Reintroduction of patients progressing within the first year of follow-up resulted in a trend toward significance for ablation versus surveillance (11.1% vs 23.8%, P = 0.053).In conclusion, progression to high-grade dysplasia or adenocarcinoma was not significantly reduced in the radiofrequency ablation cohort when compared to surveillance. Despite recent studies suggesting the superiority of radiofrequency ablation in reducing progression, diligent endoscopic surveillance may provide similar long-term outcomes.

Genome-Wide Analysis of Barrett's Adenocarcinoma. A First Step Towards Identifying Patients at Risk and Developing Therapeutic Paths

BACKGROUND: Barrett's esophagus metaplasia is the key precursor lesion of esophageal adenocarcinoma. The aim of this study was to find a subset of markers that may allow the identification of patients at risk for esophageal adenocarcinoma, and to determine genes differentially expressed in esophageal squamous cell carcinoma. METHODS: Laser capture microdissection technique was applied to procure cells from defined regions. Genome-wide RNA profiling was performed on esophageal adenocarcinoma (n = 21), Barrett's esophagus (n = 20), esophageal squamous carcinoma (n = 9) and healthy esophageal biopsies (n = 18) using the Affymetrix Human Genome U133plus 2.0 array. Microarray results were validated by quantitative real-time polymerase chain reaction in a second and independent cohort and by immunohistochemistry of two putative markers in a third independent cohort. RESULTS: Through unsupervised hierarchical clustering and principal component analysis, samples were separated into four distinct groups that match perfectly with histology. Many genes down-regulated in esophageal cancers belong to the epidermal differentiation complex or the related GO-group “cornified envelope” of terminally differentiated keratinocytes. Similarly, retinol metabolism was strongly down-regulated. Genes showing strong overexpression in esophageal carcinomas belong to the GO groups extracellular region /matrix such as MMP1, CTHRC1, and INHBA. According to an analysis of genes strongly up-regulated in both esophageal adenocarcinoma and Barrett's esophagus, REG4 might be of particular interest as an early marker for esophageal adenocarcinoma. CONCLUSIONS: Our study provides high quality data, which could serve for identification of potential biomarkers of Barrett's esophagus at risk of esophageal adenocarcinoma progression.

Diagnosis and Endoscopic Management of Barrett's Esophagus: an Italian Experts' Opinion based document

BACKGROUND

Barrett's esophagus (BE) is recognized as a risk factor for esophageal adenocarcinoma. An expert panel was organized in Italy with the aim of drafting a series of statements on BE to guide diagnosis and management of patients with BE.

METHODS

The working Group Coordinators worked on a literature search to identify key topics regarding critical steps of the endoscopic approach to BE. Based on the search and their expert opinion, a list of most meaningful questions was prepared and emailed to all members who were asked to vote the questions. When the survey was completed a consensus meeting was organized. According to the survey results, Group Coordinators proposed a draft statement that was voted. By definition, the statement was formulated when there was an agreement of ≥50% among participants.

RESULTS

Twenty nine participants deliberated 18 questions. The agreement was reached for 16 questions for which a recommendation was formulated.

CONCLUSION

The generated statements highlight the Italian contribution to the European Position Statement of the European Society of Gastrointestinal Endoscopy. The Italian statements preserve peculiarities when dealing with the endoscopic management of BE and wishes to be considered as a contribution for the care of BE patients even with a low risk of progression to esophageal neoplasia.

The virtual esophagus: investigating esophageal functions in silico

Esophageal and gastroesophageal junction (GEJ) diseases are highly prevalent worldwide and are a significant socioeconomic burden. Recently, applications of multiscale mathematical models of the upper gastrointestinal tract have gained attention. These in silico investigations can contribute to the development of a virtual esophagus modeling framework as part of the larger GIome and Physiome initiatives. There are also other modeling investigations that have potential screening and treatment applications. These models incorporate detailed anatomical models of the esophagus and GEJ, tissue biomechanical properties and bolus transport, sensory properties, and, potentially, bioelectrical models of the neural and myogenic pathways of esophageal and GEJ functions. A next step is to improve the integration between the different components of the virtual esophagus, encoding standards, and simulation environments to perform more realistic simulations of normal and pathophysiological functions. Ultimately, the models will be validated and will provide predictive evaluations of the effects of novel endoscopic, surgical, and pharmaceutical treatment options and will facilitate the clinical translation of these treatments.

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.

A Molecular Clock Infers Heterogeneous Tissue Age Among Patients with Barrett's Esophagus

Biomarkers that drift differentially with age between normal and premalignant tissues, such as Barrett’s esophagus (BE), have the potential to improve the assessment of a patient’s cancer risk by providing quantitative information about how long a patient has lived with the precursor (i.e., dwell time). In the case of BE, which is a metaplastic precursor to esophageal adenocarcinoma (EAC), such biomarkers would be particularly useful because EAC risk may change with BE dwell time and it is generally not known how long a patient has lived with BE when a patient is first diagnosed with this condition. In this study we first describe a statistical analysis of DNA methylation data (both cross-sectional and longitudinal) derived from tissue samples from 50 BE patients to identify and validate a set of 67 CpG dinucleotides in 51 CpG islands that undergo age-related methylomic drift. Next, we describe how this information can be used to estimate a patient’s BE dwell time. We introduce a Bayesian model that incorporates longitudinal methylomic drift rates, patient age, and methylation data from individually paired BE and normal squamous tissue samples to estimate patient-specific BE onset times. Our application of the model to 30 sporadic BE patients’ methylomic profiles first exposes a wide heterogeneity in patient-specific BE onset times. Furthermore, independent application of this method to a cohort of 22 familial BE (FBE) patients reveals significantly earlier mean BE onset times. Our analysis supports the conjecture that differential methylomic drift occurs in BE (relative to normal squamous tissue) and hence allows quantitative estimation of the time that a BE patient has lived with BE.

Barrett’s Esophagus (BE) is a metaplastic precursor to esophageal adenocarcinoma (EAC). When a patient is diagnosed with BE, it is generally not known how long he/she has had this condition because BE is asymptomatic. While the question of how long a premalignant tissue or lesion has been resident in an organ (dwell time) may not be of importance for cases where curative interventions are readily available (such as adenomas in the colon), for BE, curative interventions are either costly or carry patient risks. Knowledge of a precursor’s dwell time may therefore be advantageous in determining the cancer risk due to the stepwise accumulation of critical mutations in the precursor. In this study, we create a molecular clock model that infers patient-specific BE onsets from DNA methylation data. We show that there is considerable variation in the predicted BE onset times which translates, using mathematical modeling of EAC, into large variation in individual EAC risks. We make the case that, notwithstanding other known risk factors such as chronological age, gender, reflux status, etc., knowledge of biological tissue age can provide valuable patient-specific risk information when a patient is first diagnosed with BE.

A Systematic Review of Esophageal MicroRNA Markers for Diagnosis and Monitoring of Barrett's Esophagus

BACKGROUND

Esophageal epithelial microRNAs may be used to diagnose Barrett's esophagus (BE) and possibly monitor its progression to esophageal adenocarcinoma (EAC).

AIMS

We reviewed studies that have investigated this to identify microRNAs with high biomarker potential for screening and disease monitoring in BE.

METHODS

PubMed and EMBASE databases were searched for studies that quantified esophageal epithelial microRNAs. Publications reporting microRNA comparisons of normal, non-dysplastic BE, BE with high-grade dysplasia (HGD), and EAC tissues using both unbiased discovery and independent validation phases were reviewed.

RESULTS

Eleven studies on microRNA expression differences between normal epithelium and non-dysplastic BE (seven studies), HGD (4) or EAC (7), or between non-dysplastic BE and HGD (3) or EAC (6) were identified, and the findings of their validation phase were analyzed. Increased miR-192, -194, and -215, and reduced miR-203 and -205 expression in BE compared to normal was noticed by all 4-6 of the seven studies that examined these microRNAs. In heterogeneity tests of the reported fold-change values, the I (2) statistics were 7.9-17.1 % (all P < 0.05). Elevated miR-192, -194, and -215, and diminished miR-203 and -205 levels were also noted for comparisons of HGD or EAC against normal. In contrast, a consistent microRNA expression difference was absent for the comparisons of HGD or EAC against BE.

CONCLUSIONS

MicroRNAs miR-192, -194, -203, -205, and -215 are promising tissue biomarkers for diagnosing BE. Cross-sectional data suggest that microRNAs may have a limited role in separating BE from HGD/EAC epithelia but need further testing in longitudinal follow-up studies.

Disintegrin and metalloproteinases (ADAMs) expression in gastroesophageal reflux disease and in esophageal adenocarcinoma

BACKGROUND

Clinically useful marker molecules for the progression of gastroesophageal reflux disease and Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC) are lacking. Many adenocarcinomas and inflammatory conditions exhibit increased expression of ADAMs, 'a disintegrin and metalloproteinases'.

METHODS

We assessed the expression of five ADAMs (9, 10, 12, 17, 19) in three esophageal cell lines (Het-1A, OE19, OE33) by RT-PCR and Western blotting, and in human samples of normal esophagus, esophagitis, BE, Barrett's dysplasia, and EAC by RT-PCR, and in selected samples by immunohistochemistry.

RESULTS

EAC patients showed increased mRNA expression of ADAMs 9, 12, 17 and 19, as compared to controls. At immunohistochemistry, ADAM9 and ADAM10 proteins were increased in EAC. Patient samples also showed increased mRNA expression of ADAM12 in esophagitis, of ADAM9 in BE, and of ADAMs 9, 12 and 19 in Barrett's dysplasia, as compared to controls. Two EAC cell lines showed increased ADAM9 mRNA.

CONCLUSIONS

ADAM9 expression is increased in EAC. Its predecessors show increased ADAM9 mRNA expression. The importance of the alterations in ADAM expression for the development of EAC, and their use as marker molecules, warrant further studies.

The impact of lifestyle on Barrett's Esophagus: A precursor to esophageal adenocarcinoma

BACKGROUND

Barrett's Esophagus (BE), particularly long-segment Barrett's Esophagus, and the age of onset of Barrett's Esophagus are risk factors for esophageal adenocarcinoma. However, it is unknown if lifestyle factors such as alcohol abuse, tobacco use, weight gains that increase the risk of developing BE and esophageal adenocarcinoma affect its length or age at diagnosis.

METHODS

In a retrospective, cross-sectional analysis, we analyzed 158 newly diagnosed adult BE patients at a 600-bed tertiary care center in the United States from 1999 to 2008. We constructed generalized linear models for the outcomes of BE length and age at diagnosis. Predictors of interest included current or prior alcohol abuse, tobacco use, weight gain over the last 5 years, and body mass index (BMI).

RESULTS

71 (45%) had length ≥ 3 cm. Barrett's Esophagus length was positively correlated with hiatal hernia length (r=0.67, p<0.001) and heartburn duration (r=0.36, p<0.001). Multivariate results showed no significant relationship between alcohol abuse, tobacco use, weight gain or BMI and BE length. Patients with weight gain, current tobacco use, and male gender were diagnosed at a significantly younger age than their peers (for example, the adjusted mean age at diagnosis for current tobacco users vs. non-smokers was 49.2 years vs. 54.7 years, p=0.029).

CONCLUSIONS

Lifestyle factors did not appear to affect Barrett's Esophagus length but weight gains, smoking, and male gender were associated with a diagnosis at a significantly younger age.

Low risk of adenocarcinoma and high-grade dysplasia in patients with non-dysplastic Barrett's esophagus: Results from a cohort from a country with low esophageal adenocarcinoma incidence

BACKGROUND

The risk of esophageal adenocarcinoma (EAC) in non-dysplastic Barrett's esophagus (NDBE) is considered to be approximately 0.3% per year or even lower, according to population-based studies. Data from countries with low EAC incidence are scarce. Our principal aim was to determine the incidence of high-grade dysplasia (HGD) and EAC in NDBE. Our secondary aims were to identify the predictors of progression and to calculate the incidence of HGD/EAC, by using the calculation method for surveillance time in population-based studies.

MATERIALS AND METHODS

A cohort of NDBE patients was prospectively followed up. Cases of HGD and EAC (study end points) diagnosed during the first year of follow-up were considered as prevalent. Only cases with an endoscopic surveillance time > 1 year were included in our analysis.

RESULTS

We enrolled 331 patients (251 men) in the surveillance program. Their median age was 59 years (interquartile range (IQR): 47-67 years). Their median NDBE length was 3 cm (IQR: 2-4 cm). Of these patients, 80 died during the follow-up (one from EAC) and two were lost to follow-up. After 2284 patient-years of endoscopic follow-up (median surveillance time, 5 years (IQR: 2-10 years)), we found that five cases of HGD and two cases of EAC were diagnosed. The incidence of HGD/EAC was 3.1 cases per 1000 patient-years (95% CI: 1.3-6.0) and that of EAC was 0.9 (95% CI: 0.2-2.9). The incidence of HGD/EAC in short segments (≤ 3 cm) was 0.7 cases per 1000 patient-years (95% CI: 0.3-3.4). The sole variable that we found associated with progression was NDBE length. If the total surveillance time was considered (3537 patient-years), the incidence of HGD and EAC was only slight lower.

CONCLUSIONS

The incidence of HGD and EAC was very low in NDBE. Therefore, current surveillance guidelines must be reassessed, at least for short-segment BE.

Radiofrequency Ablation Is Associated With Decreased Neoplastic Progression in Patients With Barrett's Esophagus and Confirmed Low-Grade Dysplasia

BACKGROUND & AIMS

Barrett's esophagus (BE) with low-grade dysplasia (LGD) can progress to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC). Radiofrequency ablation (RFA) has been shown to be an effective treatment for LGD in clinical trials, but its effectiveness in clinical practice is unclear. We compared the rate of progression of LGD after RFA with endoscopic surveillance alone in routine clinical practice.

METHODS

We performed a retrospective study of patients who either underwent RFA (n = 45) or surveillance endoscopy (n = 125) for LGD, confirmed by at least 1 expert pathologist, from October 1992 through December 2013 at 3 medical centers in the United States. Cox regression analysis was used to assess the association between progression and RFA.

RESULTS

Data were collected over median follow-up periods of 889 days (interquartile range, 264-1623 days) after RFA and 848 days (interquartile range, 322-2355 days) after surveillance endoscopy (P = .32). The annual rates of progression to HGD or EAC were 6.6% in the surveillance group and 0.77% in the RFA group. The risk of progression to HGD or EAC was significantly lower among patients who underwent RFA than those who underwent surveillance (adjusted hazard ratio = 0.06; 95% confidence interval: 0.008-0.48).

CONCLUSIONS

Among patients with BE and confirmed LGD, rates of progression to a combined end point of HGD and EAC were lower among those treated with RFA than among untreated patients. Although selection bias cannot be excluded, these findings provide additional evidence for the use of endoscopic ablation therapy for LGD.

Barrett esophagus

Although there are many unanswered questions with Barrett esophagus, we can safely say that the incidence is increasing, chemoprevention strategies for the prevention of Barrett metaplasia and its progression to adenocarcinoma may be in the offing, surveillance should be considered for all patients who are discovered to have Barrett esophagus, RFA is the treatment of choice for those with HGD and strongly considered in those with LGD, EMR should be the treatment of choice for patients with nodular high-grade Barrett esophagus, and, finally, vagal-sparing esophagectomy reserved for patients with persistent HGD or a strong suspicion of carcinoma, with consideration of a concomitant fundoplication.

Recent developments in pathogenesis, diagnosis and therapy of Barrett's esophagus

The burden of illness from esophageal adenocarcinoma continues to rise in the Western world, and overall prognosis is poor. Given that Barrett’s esophagus (BE), a metaplastic change in the esophageal lining is a known cancer precursor, an opportunity to decrease disease development by screening and surveillance might exist. This review examines recent updates in the pathogenesis of BE and comprehensively discusses known risk factors. Diagnostic definitions and challenges are outlined, coupled with an in-depth review of management. Current challenges and potential solutions related to screening and surveillance are discussed. The effectiveness of currently available endoscopic treatment techniques, particularly with regards to recurrence following successful endotherapy and potential chemopreventative agents are also highlighted. The field of BE is rapidly evolving and improved understanding of pathophysiology, combined with emerging methods for screening and surveillance offer hope for future disease burden reduction.

Ablative Endoscopic Therapies for Barrett's-Esophagus-Related Neoplasia

Barrett's esophagus (BE) is more common in developed countries. Endoscopic therapy is an effective treatment method in management of dysplastic BE. Ablation by thermal energy, freezing, or photochemical injury completely eradicates dysplasia and specialized intestinal metaplasia resulting in neosquamation of esophagus. Among the ablative modalities, radiofrequency ablation (RFA) is the most studied with safe, effective, and durable long-term outcomes. Cryotherapy, argon plasma coagulation, and photodynamic therapy can be offered in select patients when RFA is unavailable, has failed, or is contraindicated. Future research on natural disease progression, biomarkers, advanced imaging, and application of endoscopic techniques will lead to better clinical outcomes for BE-associated neoplasia.

Surveillance in Barrett's Esophagus: Utility and Current Recommendations

Surveillance of Barrett's esophagus for preventing death from esophageal adenocarcinoma is attractive and widely practiced. However, empirical evidence supporting its effectiveness is weak. Longer intervals between surveillance examinations are being recommended, supported by computer simulation analyses. If surveillance is performed, an adequate number of biopsies should be performed or the effect of surveillance would be squandered.

Screening for Barrett's Esophagus

There is substantial interest in identifying patients with premalignant conditions such as Barrett's esophagus (BE), to improve outcomes of subjects with esophageal adenocarcinoma. However, there is limited consensus on the rationale for screening, the appropriate target population, and optimal screening modality. Recent progress in the development and validation of minimally invasive tools for BE screening has reinvigorated interest in BE screening. BE risk scores combining clinical, anthropometric, and laboratory variables are being developed that may allow more precise targeting of screening to high-risk individuals. This article reviews and summarizes data on recent progress and challenges in screening for BE.

Biomarkers in Barrett's Esophagus: Role in Diagnosis, Risk Stratification, and Prediction of Response to Therapy

Esophageal adenocarcinoma (EAC) has increased dramatically in the past 3 decades, making its precursor lesion Barrett's esophagus (BE) an important clinical problem. Effective interventions are available, but overall outcomes remain unchanged. Most of the BE population remains undiagnosed; most EACs are diagnosed late, and most BE patients will never progress to cancer. These epidemiologic factors make upper endoscopy an inefficient and ineffective strategy for BE diagnosis and risk stratification. In the current review, biomarkers for diagnosis, risk stratification, and predictors of response to therapy in BE are discussed.

A Multiscale Model Evaluates Screening for Neoplasia in Barrett's Esophagus

Barrett’s esophagus (BE) patients are routinely screened for high grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) through endoscopic screening, during which multiple esophageal tissue samples are removed for histological analysis. We propose a computational method called the multistage clonal expansion for EAC (MSCE-EAC) screening model that is used for screening BE patients in silico to evaluate the effects of biopsy sampling, diagnostic sensitivity, and treatment on disease burden. Our framework seamlessly integrates relevant cell-level processes during EAC development with a spatial screening process to provide a clinically relevant model for detecting dysplastic and malignant clones within the crypt-structured BE tissue. With this computational approach, we retain spatio-temporal information about small, unobserved tissue lesions in BE that may remain undetected during biopsy-based screening but could be detected with high-resolution imaging. This allows evaluation of the efficacy and sensitivity of current screening protocols to detect neoplasia (dysplasia and early preclinical EAC) in the esophageal lining. We demonstrate the clinical utility of this model by predicting three important clinical outcomes: (1) the probability that small cancers are missed during biopsy-based screening, (2) the potential gains in neoplasia detection probabilities if screening occurred via high-resolution tomographic imaging, and (3) the efficacy of ablative treatments that result in the curative depletion of metaplastic and neoplastic cell populations in BE in terms of the long-term impact on reducing EAC incidence.

Endoscopic screening for detecting cancer and cancer precursors in Barrett’s esophagus (BE) is currently informed by repeated systematic biopsying of the metaplastic BE tissue. Here we present a comprehensive multiscale model of the natural history of esophageal adenocarcinoma (EAC), which describes the entire multistage process beginning with the conversion event of normal squamous esophageal tissue to BE metaplasia, the spatio-temporal formation of independent dysplastic and malignant clones at the cell level, and finally the appearance of symptomatic EAC in BE. This model lends itself to a systematic exploration of the efficacy and sensitivity of current biopsy-based screening methods to detect neoplasia in BE patients, as well as alternative screening techniques based on high-resolution imaging of the BE tissue. Moreover, the model can also be used to predict the impact of ablative treatments on the risk of occurrence or recurrence of dysplasia or cancer. Due to the lack of studies that attempt to explicitly model the physical and biological dimensions of the screening process itself, our computational model provides a unique, publicly-available tool to improve understanding of factors that limit the efficacy of current screening protocols for BE patients.

Is Campylobacter to esophageal adenocarcinoma as Helicobacter is to gastric adenocarcinoma?

Esophageal adenocarcinoma develops through a cascade of cellular changes that shares similarities to the etiology of Helicobacter pylori-associated intestinal-type gastric adenocarcinoma. While host genetics and immune response have been implicated in the progression to esophageal adenocarcinoma, studies investigating esophageal microbial communities suggest that bacteria may also play an important role in driving the inflammation that leads to disease. Of these, emerging Campylobacter species have been found to be more prevalent and abundant in patients progressing through the esophageal adenocarcinoma cascade compared to controls. Given that these bacteria possess several virulence mechanisms such as toxin production, cellular invasion, and intracellular survival, emerging Campylobacter species should be investigated as etiological agents of the chronic esophageal inflammation that leads to cancer.

A cross sectional study of p504s, CD133, and Twist expression in the esophageal metaplasia dysplasia adenocarcinoma sequence

The incidence of esophageal adenocarcinoma has increased dramatically over recent years and Barrett's esophagus is considered the most established risk factor for its development. Endoscopic surveillance of Barrett's esophagus is therefore recommended but hinges on histological interpretation of randomly taken biopsies which is poorly reproducible. The use of biomarkers presents an opportunity to improve our ability to risk-stratify these patients.We examined three biomarkers namely p504s, CD133, and Twist in the setting of Barrett's esophagus, low-grade dysplasia, and esophageal adenocarcinoma to evaluate differential expression between benign, dysplastic, and malignant Barrett's tissue in an exploratory cross-sectional study. Twenty-five cases each of Barrett's esophagus, low-grade dysplasia, and esophageal adenocarcinoma were included along-with 25 cases of esophagectomy resections for Barrett's adenocarcinoma. The biomarkers were immunostained on automated Ventana(®) immunostainer. The biopsies were assessed for biomarker expression by two independent observers. Granular cytoplasmic staining of p504s was observed in dysplastic Barrett's biopsies and esophageal adenocarcinoma but not in Barrett's esophagus. Apical and membranous CD133 expression was also observed in dysplastic Barrett's and esophageal adenocarcinoma. Nuclear Twist expression was seen predominantly in stromal cells. There was increased p504s expression in dysplastic Barrett's esophagus and esophageal adenocarcinoma compared with controls. CD133 expression was detected for the first time in esophageal adenocarcinoma and dysplastic Barrett's esophagus. Twist expression was not convincing enough to be labeled as Barrett's biomarker. p504s and CD133 have the potential to differentiate benign from malignant Barrett's tissue in this exploratory study. Their validity should be established in prospective longitudinal studies.

Aberrant TP53 detected by combining immunohistochemistry and DNA-FISH improves Barrett's esophagus progression prediction: a prospective follow-up study

Barrett's esophagus (BE) goes through a sequence of low grade dysplasia (LGD) and high grade dysplasia (HGD) to esophageal adenocarcinoma (EAC). The current gold standard for BE outcome prediction, histopathological staging, can be unreliable. TP53 abnormalities may serve as prognostic biomarkers. TP53 protein accumulation detected by immunohistochemistry (IHC) indirectly assesses TP53 mutations. DNA fluorescent in situ hybridization (FISH) on brush cytology specimens directly evaluates gene locus loss. We evaluated if IHC and FISH are complementary tools to assess TP53 abnormalities and tested their prognostic value in a long-term prospective follow-up of a BE cohort. TP53 IHC on tissue sections and FISH on brush cytology specimens were evaluated for 116 BE patients with respect to the different histological stages. The TP53 abnormalities were further studied in a panel of cell lines representative of the Barrett's carcinogenic sequence. For 91patients, the predictive value of TP53 abnormalities with respect to progression to HGD/EAC was tested after long term follow-up. The frequency of IHC and FISH TP53 abnormalities increased significantly with increasing histological stage (P < 0.001, Chi(2) -test). Combining the techniques detected TP53 abnormalities in 100% of patients with LGD, HGD, and EAC. Multivariate analysis showed that IHC (hazard ratio: 17, 95% CI: 3.2-96, P = 0.001) and FISH (hazard ratio: 7.3, 95% CI: 1.3-41, P = 0.02) were both independent significant predictors of progression. Combining FISH and IHC in assessing TP53 abnormalities leads to an increased detection rate of TP53 aberrations and improved accuracy for predicting BE progression.

Progression of Barrett oesophagus: role of endoscopic and histological predictors

Barrett oesophagus is an important precursor lesion for the development of oesophageal adenocarcinoma (OAC). Upper gastrointestinal endoscopy is the modality most widely used to visualize and biopsy the oesophagus to establish a diagnosis. Additional clues are available at the time of endoscopy that can identify high-risk features known to increase the risk of progression to OAC, such as the length of the Barrett oesophagus segment, length of hiatal hernia and the presence of nodularity or visible endoscopic lesions in this segment. Until molecular biomarkers are identified and validated as adjunctive tools for risk stratification, knowledge of endoscopic features could complement dysplasia grading for risk stratification of patients with Barrett oesophagus and identify subgroups at risk of progression to OAC. This approach would, in turn, facilitate more rational tailoring of endoscopic surveillance. This Review summarizes the current role of endoscopic and histological factors involved in neoplastic progression of Barrett oesophagus to OAC, and provides an overview of the risk-prediction models that have utilized endoscopic and histological factors for risk stratification in patients with Barrett oesophagus.

Evaluation of a 4-protein serum biomarker panel-biglycan, annexin-A6, myeloperoxidase, and protein S100-A9 (B-AMP)-for the detection of esophageal adenocarcinoma

BACKGROUND

Esophageal adenocarcinoma (EAC) is associated with a dismal prognosis. The identification of cancer biomarkers can advance the possibility for early detection and better monitoring of tumor progression and/or response to therapy. The authors present results from the development of a serum-based, 4-protein (biglycan, myeloperoxidase, annexin-A6, and protein S100-A9) biomarker panel for EAC.

METHODS

A vertically integrated, proteomics-based biomarker discovery approach was used to identify candidate serum biomarkers for the detection of EAC. Liquid chromatography-tandem mass spectrometry analysis was performed on formalin-fixed, paraffin-embedded tissue samples that were collected from across the Barrett esophagus (BE)-EAC disease spectrum. The mass spectrometry-based spectral count data were used to guide the selection of candidate serum biomarkers. Then, the serum enzyme-linked immunosorbent assay data were validated in an independent cohort and were used to develop a multiparametric risk-assessment model to predict the presence of disease.

RESULTS

With a minimum threshold of 10 spectral counts, 351 proteins were identified as differentially abundant along the spectrum of Barrett esophagus, high-grade dysplasia, and EAC (P<.05). Eleven proteins from this data set were then tested using enzyme-linked immunosorbent assays in serum samples, of which 5 proteins were significantly elevated in abundance among patients who had EAC compared with normal controls, which mirrored trends across the disease spectrum present in the tissue data. By using serum data, a Bayesian rule-learning predictive model with 4 biomarkers was developed to accurately classify disease class; the cross-validation results for the merged data set yielded accuracy of 87% and an area under the receiver operating characteristic curve of 93%.

CONCLUSIONS

Serum biomarkers hold significant promise for the early, noninvasive detection of EAC.

Dysplasia detection rate of confirmatory EGD in nondysplastic Barrett's esophagus

Current guidelines for endoscopic surveillance of Barrett's esophagus (BE) recommend that patients with newly diagnosed BE undergo confirmatory esophagogastroduodenoscopy (EGD) to exclude the presence of dysplasia. The extent to which confirmatory endoscopy alters management and detects missed dysplasia in newly diagnosed BE has not been reported. The frequency with which confirmatory endoscopy changed surveillance management in patients with newly diagnosed BE was assessed. A two center cohort analysis was conducted on patients newly diagnosed with BE. The rate of dysplasia on confirmatory endoscopy for patients who had nondysplastic BE was obtained. Demographic and endoscopic variables were assessed for association with dysplasia detection using Firth logistic regression model. Out of the 146 patients newly diagnosed with BE and initially determined to be without dysplasia, 12 had dysplasia on the confirmatory second EGD (8.2%). Eleven of 12 cases with dysplasia on confirmatory endoscopy had long-segment BE (LSBE). Among all the LSBE cases in our cohort, 11 had newly diagnosed dysplasia on confirmatory EGD, 29.7% (11/37). The average number of biopsies obtained from the 11 LSBE cases with dysplasia was comparable with the rest of the LSBE cases without dysplasia (6.73 and 5.42, respectively, P-value 0.205). The rate of dysplasia detection in short-segment BE (SSBE) was much lower, 0.95% (1 out of 105). There were no cases of high-grade dysplasia (HGD) or cancer detected in any SSBE case. HGD was detected on confirmatory EGD in two cases, both were LSBE. Segment length was the only statistically significant factor to predict the presence of dysplasia on confirmatory endoscopy (odds ratio 9.158, P. 0.008). Confirmatory EGD in newly diagnosed LSBE had significant rate of dysplasia detection (29.7%) in this cohort. Among patients with SSBE, there was a low rate of dysplasia detection with confirmatory EGD, less than 1% of cases. No additional cases of HGD or esophageal carcinoma in SSBE cases were detected. This suggests that the yield of confirmatory EGD is greater in patients with LSBE.

Surveillance for low-grade dysplastic Barrett's oesophagus: one size fits all?

This paper reviews the role of low-grade dysplasia (LGD) as a marker of progression in Barrett's oesophagus (BO). Albeit with its limits due to the difficulty of its diagnosis and the low agreement among pathologists, LGD remains the most relevant single prognostic factor of progression, and, when the diagnosis is confirmed by two or three pathologists, the chances of progression to high-grade dysplasia or invasive adenocarcinoma are as high as 40%. On the other hand, BO patients who remain dysplasia free at several follow-up examinations seem to have a very low likelihood of progression. The diagnosis of LGD should be confirmed by two pathologists, and surveillance programs should be tailored depending on the presence or persistent absence of LGD. Ablative therapy should be also considered for cases where LGD persists in a series of follow-ups.

Low grade dysplasia in Barrett’s esophagus: Should we worry?

The optimal management for low-grade dysplasia (LGD) in Barrett’s esophagus is unclear. In this article the importance of LGD is discussed, including the significant risk of progression to esophageal adenocarcinoma. Endoscopic surveillance is a management option but is plagued by sampling error and issues of suboptimal endoscopy. Furthermore endoscopic surveillance has not been demonstrated to be cost-effective or to reduce cancer mortality. The emergence of endoluminal therapy over the past decade has resulted in a paradigm shift in the management of LGD. Ablative therapy, including radiofrequency ablation, has demonstrated promising results in the management of LGD with regards to safety, cost-effectiveness, durability and reduction in cancer risk. It is, however, vital that a shared-decision making process occurs between the physician and the patient as to the preferred management of LGD. As such the management of LGD should be “individualised.”

Symptoms and endoscopic features at barrett's esophagus diagnosis: implications for neoplastic progression risk

OBJECTIVES

Risk stratification of Barrett's esophagus (BE) patients based on clinical and endoscopic features may help to optimize surveillance practice for esophageal adenocarcinoma (EAC) development. The aim of this study was to investigate patient symptoms and endoscopic features at index endoscopy and risk of neoplastic progression in a large population-based cohort of BE patients.

METHODS

A retrospective review of hospital records relating to incident BE diagnosis was conducted in a subset of patients with specialized intestinal metaplasia from the Northern Ireland BE register. Patients were matched to the Northern Ireland Cancer Registry to identify progressors to EAC or esophageal high-grade dysplasia (HGD). Cox proportional hazards models were applied to evaluate the association between endoscopic features, symptoms, and neoplastic progression risk.

RESULTS

During 27,997 person-years of follow-up, 128 of 3,148 BE patients progressed to develop HGD/EAC. Ulceration within the Barrett's segment, but not elsewhere in the esophagus, was associated with an increased risk of progression (hazard ratio (HR) 1.72; 95% confidence interval (CI): 1.08-2.76). Long-segment BE carried a significant sevenfold increased risk of progression compared with short-segment BE; none of the latter group developed EAC during the study period. Conversely, the absence of reflux symptoms was associated with an increased risk of cancer progression (HR 1.61; 95% CI: 1.05-2.46).

CONCLUSIONS

BE patients presenting with a long-segment BE or Barrett's ulcer have an increased risk of progressing to HGD/EAC and should be considered for more intense surveillance. The absence of reflux symptoms at BE diagnosis is not associated with a reduced risk of malignant progression, and may carry an increased risk of progression.

Barrett's oesophagus: epidemiology, cancer risk and implications for management

Although endoscopic surveillance of patients with Barrett's oesophagus has been widely implemented, its effectiveness is debateable. The recently reported low annual oesophageal adenocarcinoma risk in population studies, the failure to identify most Barrett's patients at risk of disease progression, the poor adherence to surveillance and biopsy protocols, and the significant risk of misclassification of dysplasia all tend to undermine the effectiveness of current management, in particular, endoscopic surveillance programmes, to prevent or improve the outcomes of patients with oesophageal adenocarcinoma. The ongoing increase in incidence of Barrett's oesophagus and consequent growth of the surveillance population, together with the associated discomfort and costs of endoscopic surveillance, demand improved techniques for accurately determining individual risk of oesophageal adenocarcinoma. More accurate techniques are needed to run efficient surveillance programmes in the coming decades. In this review, we will discuss the current knowledge on the epidemiology of Barrett's oesophagus, and the challenging epidemiological dilemmas that need to be addressed when assessing the current screening and surveillance strategies.

The '-omics' revolution and oesophageal adenocarcinoma

Oesophageal adenocarcinoma (OAC) is the eighth most common cancer type worldwide with a dismal 5-year survival. Barrett oesophagus, the replacement of the normal squamous epithelia with glandular cells, is the first step in the pathway towards OAC. Although most patients with OAC present de novo, the presence of the easily detectable OAC precursor lesion, Barrett oesophagus, enables the possibility of early detection of high-risk patients who are more likely to progress. Currently, identification of high-risk patients depends on histopathological assessment of dysplasia with no regards to molecular pathogenesis. In the future, screening and risk stratification initiatives for Barrett oesophagus that incorporate molecular profiles might permit improved early diagnosis and intervention strategies with the possibility of preventing OAC. For the majority of patients presenting de novo at an advanced stage, combining so-called -omics datasets with current clinical staging algorithms might enable OACs to be better classified according to distinct molecular programmes, thereby leading to better targeted treatment strategies as well as cancer monitoring regimes. This Review discusses how the latest advances in -omics technologies have improved our understanding of the development and biology of OAC, and how this development might alter patient management in the future.

Surveillance in Barrett esophagus

The only known precursor of the esophageal adenocarcinoma (EAC) is represented by the Barrett's esophagus (BE). EAC incidence has increased sharply in the last 4 decades. The annual conversion rate of BE to cancer is small but significant; therefore the identification of patients at a higher risk of cancer represents a dilemma. The endoscopic surveillance of BE aims to detect dysplasia and in particular high-grade dysplasia and intramucosal cancers that can be endoscopically treated before progressing to invasive cancer with lymph node metastases. Using standard white light endoscopy (WLE), these high-risk lesions are often subtle and hard to detect. In addition to high-definition standard endoscopy, chromoendoscopy (CE), virtual chromoendoscopy (e.g. narrow band imaging), and confocal laser endomicroscopy might increase the diagnostic efficiency for the detection of dysplastic lesions and can also increase the diagnostic efficiency for the detection of BE dysplasia or cancer. This ability to detect subtle mucosal abnormalities that harbor high-grade dysplasia (HGD) or intramucosal carcinoma might enable endoscopists skilled in the assessment of BE to perform targeted rather than random biopsies. The standard protocol will remain the careful examination by using conventional high-resolution endoscopes, combined with a longer inspection time, which is associated with an increased detection of dysplasia until these modalities have been demonstrated to enhance efficiency or be cost effective. Many of the limitations of the current clinical standard may be overcome in the future by the use of multi-modal imaging combined with molecular information.

Mitigating fluorescence spectral overlap in wide-field endoscopic imaging

The number of molecular species suitable for multispectral fluorescence imaging is limited due to the overlap of the emission spectra of indicator fluorophores, e.g., dyes and nanoparticles. To remove fluorophore emission cross-talk in wide-field multispectral fluorescence molecular imaging, we evaluate three different solutions: (1) image stitching, (2) concurrent imaging with cross-talk ratio subtraction algorithm, and (3) frame-sequential imaging. A phantom with fluorophore emission cross-talk is fabricated, and a 1.2-mm ultrathin scanning fiber endoscope (SFE) is used to test and compare these approaches. Results show that fluorophore emission cross-talk could be successfully avoided or significantly reduced. Near term, the concurrent imaging method of wide-field multispectral fluorescence SFE is viable for early stage cancer detection and localization in vivo. Furthermore, a means to enhance exogenous fluorescence target-to-background ratio by the reduction of tissue autofluorescence background is demonstrated.

Recurrence of esophageal intestinal metaplasia after endoscopic mucosal resection and radiofrequency ablation of Barrett's esophagus: results from a US Multicenter Consortium

BACKGROUND & AIMS

Radiofrequency ablation (RFA) is an established treatment for dysplastic Barrett's esophagus (BE). Although short-term end points of ablation have been ascertained, there have been concerns about recurrence of intestinal metaplasia (IM) after ablation. We aimed to estimate the incidence and identify factors that predicted the recurrence of IM after successful RFA.

METHODS

We analyzed data from 592 patients with BE treated with RFA from 2003 through 2011 at 3 tertiary referral centers. Complete remission of intestinal metaplasia (CRIM) was defined as eradication of IM (in esophageal and gastroesophageal junction biopsy specimens), documented by 2 consecutive endoscopies. Recurrence was defined as the presence of IM or dysplasia after CRIM in surveillance biopsies. Two experienced gastrointestinal pathologists confirmed pathology findings.

RESULTS

Based on histology analysis, before RFA, 71% of patients had high-grade dysplasia or esophageal adenocarcinoma, 15% had low-grade dysplasia, and 14% had nondysplastic BE. Of patients treated, 448 (76%) were assessed after RFA. Fifty-five percent of patients underwent endoscopic mucosal resection before RFA. The median time to CRIM was 22 months, with 56% of patients in CRIM by 24 months. Increasing age and length of BE segment were associated with longer times to CRIM. Twenty-four months after CRIM, the incidence of recurrence was 33%; 22% of all recurrences observed were dysplastic BE. There were no demographic or endoscopic factors associated with recurrence. Complications developed in 6.5% of subjects treated with RFA; strictures were the most common complication.

CONCLUSIONS

Of patients with BE treated by RFA, 56% were in complete remission after 24 months. However, 33% of these patients had disease recurrence within the next 2 years. Most recurrences were nondysplastic and endoscopically manageable, but continued surveillance after RFA is essential.

Occupational exposure and the risk of Barrett's esophagus: a case-control study

BACKGROUND

Case-control studies in the United States and Europe have linked occupational exposure to volatile sulfur compounds, solvents, and pesticide to increased risk of esophageal adenocarcinoma. However, the association between occupational exposures and the risk of Barrett's esophagus (BE) is unclear given the absence of studies in this area.

METHODS

This is a case-control study in patients undergoing endoscopy who were either referred directly or were eligible for screening colonoscopy and recruited from primary care clinics. All participants completed a survey on (1) self-reported occupational exposures to asbestos, metal dust, organic solvents, and pesticides, and (2) self reported longest held job and job-related activities. The latter were assigned by an industrial hygienist who was blinded to the case and control status into one of 99 standard occupational categories used by the US Department of Labor. Each occupational category was then assigned an expected level of exposure to the same four classes of agents in addition to radiation. We compared the self-reported exposure and the expected occupational exposure based on the self-reported occupation between cases with definitive BE and controls without BE. We examined the associations adjusting for age, sex, race, and patient recruitment source in a multivariable logistic regression analysis.

RESULTS

We examined 226 cases of definitive BE and 1,424 controls without BE. There was a greater proportion of patients with self-reported asbestos exposure in cases than controls (16.2 % vs. 12.0 %; p = 0.08) but no significant differences in metal dust, organic solvents, or pesticides. The multivariate model did not show an independent association between self-reported asbestos exposure and BE. For the calculated occupational exposure, there were no significant differences between cases and controls for asbestos (29.6 % vs. 27.5 %; p = 0.5), metal dust, organic solvents, pesticides, or radiation exposure. Among commonly reported occupation, there were significantly greater proportion of retail sales workers in BE cases than controls (10.8 % vs. 4.9 %; p = 0.01).

CONCLUSIONS

Exposure to asbestos and sedentary jobs may be risk factors for Barrett's esophagus. Further studies are needed to confirm this finding.

Recent developments in esophageal adenocarcinoma

Answer questions and earn CME/CNE Esophageal adenocarcinoma (EAC) is characterized by 6 striking features: increasing incidence, male predominance, lack of preventive measures, opportunities for early detection, demanding surgical therapy and care, and poor prognosis. Reasons for its rapidly increasing incidence include the rising prevalence of gastroesophageal reflux and obesity, combined with the decreasing prevalence of Helicobacter pylori infection. The strong male predominance remains unexplained, but hormonal influence might play an important role. Future prevention might include the treatment of reflux or obesity or chemoprevention with nonsteroidal antiinflammatory drugs or statins, but no evidence-based preventive measures are currently available. Likely future developments include endoscopic screening of better defined high-risk groups for EAC. Individuals with Barrett esophagus might benefit from surveillance, at least those with dysplasia, but screening and surveillance strategies need careful evaluation to be feasible and cost-effective. The surgery for EAC is more extensive than virtually any other standard procedure, and postoperative survival, health-related quality of life, and nutrition need to be improved (eg, by improved treatment, better decision-making, and more individually tailored follow-up). Promising clinical developments include increased survival after preoperative chemoradiotherapy, the potentially reduced impact on health-related quality of life after minimally invasive surgery, and the new endoscopic therapies for dysplastic Barrett esophagus or early EAC. The overall survival rates are improving slightly, but poor prognosis remains a challenge.