Non-endoscopic screening biomarkers for Barrett's oesophagus: from microarray analysis to the clinic

DNA methylation markers in esophageal cancer

Background

Esophageal cancer (EC) is a prevalent malignancy characterized by a low 5-year survival rate, primarily attributed to delayed diagnosis and limited therapeutic options. Currently, early detection of EC heavily relies on endoscopy and pathological examination, which pose challenges due to their invasiveness and high costs, leading to low patient compliance. The detection of DNA methylation offers a non-endoscopic, cost-effective, and secure approach that holds promising prospects for early EC detection.

Methods

To identify improved methylation markers for early EC detection, we conducted a comprehensive review of relevant literature, summarized the performance of DNA methylation markers based on different input samples and analytical methods in EC early detection and screening.

Findings

This review reveals that blood cell free DNA methylation-based method is an effective non-invasive method for early detection of EC, although there is still a need to improve its sensitivity and specificity. Another highly sensitive and specific non-endoscopic approach for early detection of EC is the esophageal exfoliated cells based-DNA methylation analysis. However, while there are substantial studies in esophageal adenocarcinoma, further more validation is required in esophageal squamous cell carcinoma.

Conclusion

In conclusion, DNA methylation detection holds significant potential as an early detection and screening technology for EC.

Non-endoscopic Screening for Esophageal Squamous Cell Carcinoma: Recent Advances

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most common tumors in the gastrointestinal tract, and China has a high incidence area with a high burden on the disease. As early symptoms of ESCC are not obvious, the mortality rate is high, and it is often diagnosed in the intermediate and advanced stages. However, early screening and treatment may reduce morbidity and mortality.

METHODS

Screening methods are divided into endoscopic and non-endoscopic screening.

RESULTS

Endoscopic screening cannot be widely used because of its invasive nature and high cost. Currently, non-endoscopic screening consists primarily of tumor biomarkers and cytology, and tumor biomarkers including autoantibodies, circulating tumor cells, circulating tumor DNA, exosomes and serum metabolomics are more likely to be effective. But the efficiency of early diagnosis of esophageal cancer is low and the accuracy of screening needs to be improved. The aim of this study is to summarize advances in non-endoscopic esophageal cancer screening and strategies to provide a scientific basis and research idea for esophageal cancer prevention and control.

CONCLUSIONS

Non-endoscopic screening is better than endoscopic screening. And the application of tumor biomarkers is much better than other non-endoscopic screening methods.

Advances in Screening for Barrett Esophagus and Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC), the primary form of esophageal cancer in the United States, is a lethal cancer with exponentially increasing incidence. Screening for Barrett esophagus (BE), the only known precursor to EAC, followed by endoscopic surveillance to detect dysplasia and early-stage EAC and subsequent endoscopic treatment (to prevent progression of dysplasia to EAC and to treat early-stage EAC effectively) is recommended by several society guidelines. Sedated endoscopy (the primary current tool for BE screening) is both invasive and expensive, limiting its widespread use. In this review, we aim to provide a comprehensive review of recent innovations in the nonendoscopic detection of BE and EAC. These include swallowable cell sampling devices combined with protein and epigenetic biomarkers (which are now guideline endorsed as alternatives to sedated endoscopy), tethered capsule endomicroscopy, emerging peripheral blood-sampled molecular biomarkers, and exhaled volatile organic compounds. We also summarize progress and challenges in assessing BE and EAC risk, which is an important complementary component of the process for the clinical implementation of these innovative nonendoscopic tools, and propose a new paradigm for the strategy to reduce EAC incidence and mortality.

Shared features of metaplasia and the development of adenocarcinoma in the stomach and esophagus

Introduction: Plasticity is an inherent property of the normal gastrointestinal tract allowing for appropriate response to injury and healing. However, the aberrancy of adaptable responses is also beginning to be recognized as a driver during cancer development and progression. Gastric and esophageal malignancies remain leading causes of cancer-related death globally as there are limited early disease diagnostic tools and paucity of new effective treatments. Gastric and esophageal adenocarcinomas share intestinal metaplasia as a key precancerous precursor lesion.

Methods: Here, we utilize an upper GI tract patient-derived tissue microarray that encompasses the sequential development of cancer from normal tissues to illustrate the expression of a set of metaplastic markers.

Results: We report that in contrast to gastric intestinal metaplasia, which has traits of both incomplete and complete intestinal metaplasia, Barrett's esophagus (i.e., esophageal intestinal metaplasia) demonstrates hallmarks of incomplete intestinal metaplasia. Specifically, this prevalent incomplete intestinal metaplasia seen in Barrett's esophagus manifests as concurrent development and expression of both gastric and intestinal traits. Additionally, many gastric and esophageal cancers display a loss of or a decrease in these characteristic differentiated cell properties, demonstrating the plasticity of molecular pathways associated with the development of these cancers.

Discussion: Further understanding of the commonalities and differences governing the development of upper GI tract intestinal metaplasias and their progression to cancer will lead to improved diagnostic and therapeutic avenues.

Quantification of TFF3 expression from a non-endoscopic device predicts clinically relevant Barrett's oesophagus by machine learning

BACKGROUND

Intestinal metaplasia (IM) is pre-neoplastic with variable cancer risk. Cytosponge-TFF3 test can detect IM. We aimed to 1) assess whether quantitative TFF3 scores can distinguish clinically relevant Barrett's oesophagus (BO) (C≥1 or M≥3) from focal IM pathologies (C<1, M<3 or IM of gastro-oesophageal junction); 2) whether TFF3 counts can be automated to inform clinical practice.

METHODS

Patients from the Barett's oEsophagus Screening Trial 2 (BEST2) case-control and BEST3 randomised trials were used. For aim 1, TFF3-positive glands were scored manually and correlated with clinical diagnosis. For aim 2, machine learning approach was used to obtain TFF3 count and logistic regression with cross-validation was trained on the BEST2 dataset (n = 529) and tested in the BEST3 dataset (n = 158).

FINDINGS

Patients with clinically relevant BO had higher mean TFF3 gland count compared to focal IM pathologies (mean difference 4.14; 95% confidence interval, CI 2.76-5.52, p < 0.001). The mean class-balanced validation accuracy was 0.84 (95% CI 0.77-0.90), and precision of 0.95 (95% CI 0.87-1.00) for detecting clinically relevant BO. Applying this model on BEST3 showed precision of 0.91 (95% CI 0.85-0.97) for focal IM pathologies with a class-balanced accuracy of 0.77 (95% CI 0.69-0.84). Using this model, 55% of patients (87/158) in BEST3 would fall below the threshold for clinically relevant BO and could avoid gastroscopy, while only missing 5.1% of patients (8/158).

INTERPRETATION

Automated Cytosponge-TFF3 gland quantification may enable thresholds to be set to trigger confirmatory gastroscopy to minimize overdiagnosis of focal IM pathologies with very low cancer-associated risk.

FUNDING

Cancer Research UK (12088/16893 and C14478/A21047).

Kyoto international consensus report on anatomy, pathophysiology and clinical significance of the gastro-oesophageal junction

OBJECTIVE

An international meeting was organised to develop consensus on (1) the landmarks to define the gastro-oesophageal junction (GOJ), (2) the occurrence and pathophysiological significance of the cardiac gland, (3) the definition of the gastro-oesophageal junctional zone (GOJZ) and (4) the causes of inflammation, metaplasia and neoplasia occurring in the GOJZ.

DESIGN

Clinical questions relevant to the afore-mentioned major issues were drafted for which expert panels formulated relevant statements and textural explanations.A Delphi method using an anonymous system was employed to develop the consensus, the level of which was predefined as ≥80% of agreement. Two rounds of voting and amendments were completed before the meeting at which clinical questions and consensus were finalised.

RESULTS

Twenty eight clinical questions and statements were finalised after extensive amendments. Critical consensus was achieved: (1) definition for the GOJ, (2) definition of the GOJZ spanning 1 cm proximal and distal to the GOJ as defined by the end of palisade vessels was accepted based on the anatomical distribution of cardiac type gland, (3) chemical and bacterial (Helicobacter pylori) factors as the primary causes of inflammation, metaplasia and neoplasia occurring in the GOJZ, (4) a new definition of Barrett's oesophagus (BO).

CONCLUSIONS

This international consensus on the new definitions of BO, GOJ and the GOJZ will be instrumental in future studies aiming to resolve many issues on this important anatomic area and hopefully will lead to better classification and management of the diseases surrounding the GOJ.

Acceptability and Adequacy of a Non-endoscopic Cell Collection Device for Diagnosis of Barrett's Esophagus: Lessons Learned

BACKGROUND

Endoscopic screening for Barrett's esophagus (BE) is common, costly, and underperformed in at-risk people. A non-endoscopic cell collection device can be used to collect esophageal cells, enabling BE screening.

AIMS

This study assessed the acceptability and adequacy of a commercial non-endoscopic cell collection device in a US population.

METHODS

Six sites enrolled patients with confirmed BE or heartburn/regurgitation for ≥ 6 months. Patients underwent administration of the device, consisting of a sponge encapsulated in a capsule. The capsule dwelled in the stomach for 7.5 min and was retracted via an attached suture. An adequate sample was ≥ 1 columnar cell by H&E staining. Sample quality was rated using a 0-5 scale, with 0 = no columnar cells and 5 = plentiful groups. Trefoil Factor 3 (TFF3) staining was performed. Accuracy was assessed using esophagogastroduodenoscopy (EGD)/biopsy as the gold standard.

RESULTS

Of 191 patients, 99.5% successfully swallowed the device. Overall sample adequacy was 91% (171/188), with 84% (158/188) high quality. The detachment rate was 2/190 (1%). Overall sensitivity, specificity, and accuracy of the assay with TFF3 staining were 76%, 77%, and 76%. Sensitivity, specificity, and accuracy for ≥ 3 cm BE were 86%, 77%, and 82%. Asked if willing to repeat the procedure, 93% would, and 65% indicated a preference for the device over EGD.

CONCLUSIONS

This study demonstrated a high rate of sample adequacy and promising acceptability of this non-endoscopic sampling device in a US population. Diagnostic characteristics suggest that non-endoscopic assessment of BE deserves further development as an alternative to endoscopy.

Barrett's Esophagus: Diagnosis, Management, and Key Updates

Barrett's esophagus (BE) is the precursor lesion for esophageal adenocarcinoma (EAC) development. Unfortunately, BE screening/surveillance has not provided the anticipated EAC reduction benefit. Noninvasive techniques are increasingly available or undergoing testing to screen for BE among those with/without known risk factors, and the use of artificial intelligence platforms to aid endoscopic screening and surveillance will likely become routine, minimizing missed cases or lesions. Management of high-grade dysplasia and intramucosal EAC is clear with endoscopic eradication therapy preferred to surgery. BE with low-grade dysplasia can be managed with removal of visible lesions combined with endoscopic eradication therapy or endoscopic surveillance at present.

Molecular characterization of Barrett's esophagus at single-cell resolution

Barrett’s esophagus (BE), the premalignant condition of esophageal adenocarcinoma, is categorized into different stages which correlate with the risk of developing carcinoma. We performed single-cell DNA-sequencing experiments with fresh biopsies, which revealed the appearance of a specific T > C and T > G mutational signature, known as COSMIC signature SBS17, in BE cells that are chromosomally unstable. The SBS17-specific mutations were, however, not detected in chromosomally stable BE cells. Additionally, we performed single-cell RNA sequencing experiments which identified seven genes that facilitate the distinction between different BE stages on histological sections.

Barrett’s esophagus (BE) is categorized, based on morphological appearance, into different stages, which correlate with the risk of developing esophageal adenocarcinoma. More advanced stages are more likely to acquire chromosomal instabilities, but stage-specific markers remain elusive. Here, we performed single-cell DNA-sequencing experiments (scDNAseq) with fresh BE biopsies. Dysplastic BE cells frequently contained chromosomal instability (CIN) regions, and these CIN cells carried mutations corresponding to the COSMIC mutational signature SBS17, which were not present in biopsy-matched chromosomally stable (CS) cells or patient-matched nondiseased control cells. CS cells were predominantly found in nondysplastic BE biopsies. The single-base substitution (SBS) signatures of all CS BE cells analyzed were indistinguishable from those of nondiseased esophageal or gastric cells. Single-cell RNA-sequencing (scRNAseq) experiments with BE biopsies identified two sets of marker genes which facilitate the distinction between columnar BE epithelium and nondysplastic/dysplastic stages. Moreover, histological validation confirmed a correlation between increased CLDN2 expression and the presence of dysplastic BE stages. Our scDNAseq and scRNAseq datasets, which are a useful resource for the community, provide insight into the mutational landscape and gene expression pattern at different stages of BE development.

Current state of prognostication, therapy and prospective innovations for Barrett's-related esophageal adenocarcinoma: a literature review

Objective

Barrett's esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC), which has one of the lowest 5-year survival rates in oncology. The reasons for poor survival are twofold: the large majority of diagnoses are in advanced stages (~80%) and limited treatment options, with a deficit of biology-guided therapies. As a rapidly growing public health concern with poor prognosis, research into the molecular progression for BE and novel therapeutics for EAC currently has high clinical utility. Review of the literature reveals that innovative analysis of metaplastic progression from BE to EAC at a molecular level can shed light on the underlying transformative probabilities of BE into malignant pathologies and may impact current of future therapeutic modalities for management of these diseases.

Background

EAC is the fastest increasing cancer in the United States with a 600% increase over the past 25 years. This cancer arises from dysplastic tissue of BE, a complication of gastroesophageal reflux disease (GERD). Chronic acid and bile reflux in the distal esophagus initiates a metaplastic conversion of normal squamous epithelium to premalignant intestinalized columnar epithelium. Patients with BE have a 125-fold higher risk of cancer compared to the general population.

Methods

We critically reviewed the current status of BE monitoring, and subsequent therapeutic strategies being used in patients who have progressed to cancer. Also, new diagnostic tools and therapeutic candidates for BE-related EAC are discussed. Highly-targeted searches of databases containing recent original peer-reviewed papers were utilized for this review.

Conclusions

Novel and well-described biomarkers analyzed in the patient's diseased tissue will provide for more powerful diagnostics, but also possess the potential to develop strategies for personalized management and identify targets for intervention to either cease disease progression or treat BE and/or EAC. Since millions of Americans develop BE without progressing to cancer, there is a critical need to identify the small percentage of Barrett's patients who possess hallmarks of disease progression or carcinogenesis with novel screening techniques. Incorporation of such tools into standard screening protocols for BE surveillance and/or therapy would be critical to detect malignant transformations before clinically obvious cancer ever develops.

Functionality and Acceptance of the EsoCap System-A Novel Film-Based Drug Delivery Technology: Results of an In Vivo Study

There are no methods for specific local application of active substances to the mucosa of the esophagus to treat eosinophilic esophagitis or other esophageal diseases. This publication describes the principal in vivo functionality and acceptance of a novel modular drug delivery concept, called EsoCap system, by 12 healthy volunteers. For the first time, the EsoCap system enables targeted placement on the esophageal mucosa of a mucoadhesive polymer film. Acceptance was determined by means of a standardized questionnaire after administration and functionality of the device by MRI scans. Two different setups of the EsoCap system were tested: one setup with a density of 0.4 g/cm³ and one with a density of 1.0 g/cm³. Acceptability of the dosage form was also confirmed in addition to functionality, by measuring the applied film length. It was found that acceptance of the variant with the higher density was significantly better. This novel drug delivery technology could enable a targeted, local and long-lasting therapy of the esophagus for the first time, depending on the polymer film used.

Triage-driven diagnosis of Barrett's esophagus for early detection of esophageal adenocarcinoma using deep learning

Deep learning methods have been shown to achieve excellent performance on diagnostic tasks, but how to optimally combine them with expert knowledge and existing clinical decision pathways is still an open challenge. This question is particularly important for the early detection of cancer, where high-volume workflows may benefit from (semi-)automated analysis. Here we present a deep learning framework to analyze samples of the Cytosponge-TFF3 test, a minimally invasive alternative to endoscopy, for detecting Barrett's esophagus, which is the main precursor of esophageal adenocarcinoma. We trained and independently validated the framework on data from two clinical trials, analyzing a combined total of 4,662 pathology slides from 2,331 patients. Our approach exploits decision patterns of gastrointestinal pathologists to define eight triage classes of varying priority for manual expert review. By substituting manual review with automated review in low-priority classes, we can reduce pathologist workload by 57% while matching the diagnostic performance of experienced pathologists.

Minimally invasive esophageal sponge cytology sampling is feasible in a Tanzanian community setting

Esophageal sponge cytology is an endoscopy alternative well accepted by patients with extensive data for accuracy in the context of adenocarcinoma. Few studies have assessed its feasibility in asymptomatic community members, and fewer still in East Africa, where esophageal squamous cell carcinoma (ESCC) rates are high. We aimed to assess the feasibility of a capsule-based diagnosis of esophageal squamous dysplasia (ESD), an ESCC precursor, which may benefit epidemiological and early detection research. We collected Cytosponge collections in 102 asymptomatic adults from Kilimanjaro, Tanzania. Uptake, acceptability and safety were assessed. Participants scored acceptability immediately following the procedure and 7 days later on a scale of 0 (least) to 10 (most acceptable). Slides from paraffin-embedded cell clots were read by two pathologists for ESD and other pathologies. All participants (52 men, 50 women, aged 30-77) swallowed the device at first attempt, 100 (98%) of which gave slides of adequate cellularity. Acceptability scores were 10 (53%), 9 (24%), 8 (21%), 7 (2%) and 6 (1%), with no differences by age, sex or time of asking. Cytological findings were esophageal inflammation (4%), atypical squamous cells of uncertain significance (1%), low-grade dysplasia (1%), gastritis (22%) and suspected intestinal metaplasia (6%). Setting-specific logistical and ethical considerations of study implementation are discussed. We demonstrate the safety, acceptability and feasibility of Cytosponge sampling in this setting, paving the way for innovative etiology and early-detection research. Targeted sampling strategies and biomarker development will underpin the success of such initiatives. The study protocol is registered on ClinicalTrials.gov (NCT04090554).

Epigenetic Alterations in the Gastrointestinal Tract: Current and Emerging Use for Biomarkers of Cancer

Colorectal cancer, liver cancer, stomach cancer, pancreatic cancer, and esophageal cancer are leading causes of cancer-related deaths worldwide. A fundamental trait of virtually all gastrointestinal cancers is genomic and epigenomic DNA alterations. Cancer cells acquire genetic and epigenetic alterations that drive the initiation and progression of the cancers by altering the molecular and cell biological processes of the cells. These alterations, as well as other host and microenvironment factors, ultimately mediate the clinical behavior of the precancers and cancers and can be used as biomarkers for cancer risk determination, early detection of cancer and precancer, determination of the prognosis of cancer and prediction of the response to therapy. Epigenetic alterations have emerged as one of most robust classes of biomarkers and are the basis for a growing number of clinical tests for cancer screening and surveillance.

Alteration of protein expression and spliceosome pathway activity during Barrett's carcinogenesis

BACKGROUND

Barrett's esophagus (BE) is a known precursor lesion and the strongest risk factor for esophageal adenocarcinoma (EAC), a common and lethal type of cancer. Prediction of risk, the basis for efficient intervention, is commonly solely based on histologic examination. This approach is challenged by problems such as inter-observer variability in the face of the high heterogeneity of dysplastic tissue. Molecular markers might offer an additional way to understand the carcinogenesis and improve the diagnosis-and eventually treatment. In this study, we probed significant proteomic changes during dysplastic progression from BE into EAC.

METHODS

During endoscopic mucosa resection, epithelial and stromal tissue samples were collected by laser capture microdissection from 10 patients with normal BE and 13 patients with high-grade dysplastic/EAC. Samples were analyzed by mass spectrometry-based proteomic analysis. Expressed proteins were determined by label-free quantitation, and gene set enrichment was used to find differentially expressed pathways. The results were validated by immunohistochemistry for two selected key proteins (MSH6 and XPO5).

RESULTS

Comparing dysplastic/EAC to non-dysplastic BE, we found in equal volumes of epithelial tissue an overall up-regulation in terms of protein abundance and diversity, and determined a set of 226 differentially expressed proteins. Significantly higher expressions of MSH6 and XPO5 were validated orthogonally and confirmed by immunohistochemistry.

CONCLUSIONS

Our results demonstrate that disease-related proteomic alterations can be determined by analyzing minute amounts of cell-type-specific collected tissue. Further analysis indicated that alterations of certain pathways associated with carcinogenesis, such as micro-RNA trafficking, DNA damage repair, and spliceosome activity, exist in dysplastic/EAC.

Progress in Screening for Barrett's Esophagus: Beyond Standard Upper Endoscopy

The rapid increase in the incidence of esophageal adenocarcinoma in Western populations over the past 4 decades and its associated poor prognosis, unless detected early has generated great interest in screening for the precursor lesion Barrett's esophagus (BE). Recently, there have been significant developments in imaging-based modalities and esophageal cell-sampling devices coupled with biomarker assays. In this review, the authors discuss the rationale for screening for BE and the factors to consider for targeting the at-risk population. They also explore future avenues for research in this area.

Barrett's Esophagus and Esophageal Adenocarcinoma Biomarkers

Esophageal adenocarcinoma is a major cause of cancer-related morbidity and mortality in Western countries. The incidences of esophageal adenocarcinoma and its precursor Barrett's esophagus have increased substantially in the last four decades. Current care guidelines recommend that endoscopy be used for the early detection and monitoring of patients with Barrett's esophagus; however, the efficacy of this approach is unclear. To prevent the increasing morbidity and mortality from esophageal adenocarcinoma, there is a tremendous need for early detection and surveillance biomarker assays that are accurate, low-cost, and clinically feasible to implement. The last decade has seen remarkable advances in the development of minimally invasive molecular biomarkers, an effort led in large part by the Early Detection Research Network (EDRN). Advances in multi-omics analysis, the development of swallowable cytology collection devices, and emerging technology have led to promising assays that are likely to be implemented into clinical care in the next decade. In this review, an updated overview of the molecular pathology of Barrett's esophagus and esophageal adenocarcinoma and emerging molecular biomarker assays, as well as the role of EDRN in biomarker discovery and validation, will be discussed.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

The EsoCap-system - An innovative platform to drug targeting in the esophagus

For the therapy of esophageal diseases such as eosinophilic esophagitis, there are no possibilities of local targeted therapy. This publication describes a novel, innovative drug delivery concept, that enables a targeted, long-lasting administration of drug substances to the esophageal mucosa. In addition to a comprehensive in-vitro characterization of the dosage form, this work includes a proof-of-concept study with healthy volunteers, which shows the functionality and acceptance of this novel drug delivery concept. This novel drug delivery technology enables for the first time a targeted, local and long-lasting therapy of the esophagus.

Aneuploidy in targeted endoscopic biopsies outperforms other tissue biomarkers in the prediction of histologic progression of Barrett's oesophagus: A multi-centre prospective cohort study

Background

The cancer risk in Barrett's oesophagus (BO) is difficult to estimate. Histologic dysplasia has strong predictive power, but can be missed by random biopsies. Other clinical parameters have limited utility for risk stratification. We aimed to assess whether a molecular biomarker panel on targeted biopsies can predict neoplastic progression of BO.

Methods

203 patients with BO were tested at index endoscopy for 9 biomarkers (p53 and cyclin A expression; aneuploidy and tetraploidy; CDKN2A (p16), RUNX3 and HPP1 hypermethylation; 9p and 17p loss of heterozygosity) on autofluorescence-targeted biopsies and followed-up prospectively. Data comparing progressors to non-progressors were evaluated by univariate and multivariate analyses using survival curves, Cox-proportional hazards and logistic regression models.

Findings

127 patients without high-grade dysplasia (HGD) or oesophageal adenocarcinoma (OAC) at index endoscopy were included, of which 42 had evidence of any histologic progression over time. Aneuploidy was the only predictor of progression from non-dysplastic BO (NDBO) to any grade of neoplasia (p = 0.013) and HGD/OAC (p = 0.002). Aberrant p53 expression correlated with risk of short-term progression within 12 months, with an odds ratio of 6.0 (95% CI: 3.1–11.2). A panel comprising aneuploidy and p53 had an area under the receiving operator characteristics curve of 0.68 (95% CI: 0.59–0.77) for prediction of any progression.

Interpretation

Aneuploidy is the only biomarker that predicts neoplastic progression of NDBO. Aberrant p53 expression suggests prevalent dysplasia, which might have been missed by random biopsies, and warrants early follow up.

Role of TFF3 as an adjunct in the diagnosis of Barrett's esophagus using a minimally invasive esophageal sampling device-The CytospongeTM

The incidence of esophageal carcinoma continues to increase whilst its prognosis remains poor. The most dramatic reduction in mortality is likely to follow early diagnosis of the preinvasive precursor lesion, Barrett's esophagus (BE), coupled with treatment of dysplastic lesions. The major risk factor for BE is gastroesophageal reflux disease, however this is highly prevalent and only a small proportion of individuals have BE, therefore an endoscopy-based screening strategy to detect BE is unfeasible. Minimally invasive esophageal sampling devices offer an alternative, cost-effective strategy which can be deployed within an at-risk population in a primary care setting to identify individuals with probable BE who can then be referred for endoscopic confirmation. The device that has currently progressed furthest in clinical trials is the Cytosponge^TM which collects cells from the gastric cardia, gastroesophageal junction and along the whole esophageal length. The cell sample is processed into a formalin-fixed paraffin-embedded block and sections assessed for the presence of intestinal metaplasia. TFF3 immunohistochemistry has consistently been shown to be a valuable adjunct that increases the accuracy of the Cytosponge^TM test by highlighting early goblet cells which may be missed on morphological assessment and by allowing pseudogoblet cells to be differentiated from true goblet cells.

Feasibility of combined screening for upper gastrointestinal adenocarcinoma risk by serology and Cytosponge testing: the SUGAR study

AIMS

Aim was to assess the feasibility of serum markers to identify individuals at risk for gastro-oesophageal adenocarcinoma to reduce the number of individuals requiring invasive assessment by endoscopy.

METHODS

Blood samples from 56 patients with Barrett's oesophagus and 202 non-Barrett controls who previously took part in a trial assessing the accuracy of the Cytosponge for Barrett's oesophagus were assessed for serum pepsinogen (PG) 1 and 2, gastrin-17, trefoil factor 3 (TFF3) and Helicobacter pylori infection.

RESULTS

PG1 was pathological (<50 ng/mL) in 26 patients (10.1%), none of whom had Barrett's oesophagus (p<0.001). Smoking and drinking had no influence on these results. Pathological PG1 was associated with stomach pain (p=0.029), disruption of sleep (p=0.027) and disruption of diet by symptoms (p=0.019). Serum TFF3 was not associated with any clinical parameter.

CONCLUSIONS

Assessment of serum PG1 could be combined with a test for Barrett's oesophagus to identify additional patients requiring endoscopy.

Advances in the diagnosis and surveillance of Barrett's esophagus (with videos)

BACKGROUND AND AIMS

Most patients diagnosed with esophageal adenocarcinoma do not carry a known diagnosis of Barrett's esophagus (BE), suggesting that an improved approach to screening may potentially be of benefit. The use of dysplasia as a biomarker and random biopsy protocols for its detection has limitations. In addition, detecting and appropriately classifying dysplasia in patients with known BE can be difficult.

METHODS

This document reviews several technologies with a recently established or potential role in the diagnosis and/or surveillance of BE as well as risk stratification for progression to esophageal adenocarcinoma.

RESULTS

Two technologies were reviewed for imaging or tissue sampling: (1) wide-area transepithelial sampling and (2) volumetric laser endomicroscopy. Four technologies were reviewed for molecular and biomarker technologies for diagnosis and risk stratification: (1) Cytosponge, (2) mutational load, (3) fluorescence in situ hybridization, and (4) immunohistochemistry.

CONCLUSION

Several technologies discussed in this document may improve dysplasia detection in BE in a wide-field manner. Moreover, the addition of different biomarkers may aid in enhanced risk stratification to optimize approaches to surveillance or treatment for patients with BE.

Early detection and therapeutics

Early detection, including cancer screening and surveillance, is emerging as one of the most important topics in modern oncology. Because symptomatic presentation remains the predominant route to cancer diagnosis, there is a growing interest in developing techniques to detect the disease at an early, curative stage. Moreover, growing understanding of cancer biology has paved the way for prevention studies with the focus on therapeutic interventions for premalignant conditions. Where there is a recognisable precursor stage, such as a colorectal adenoma or Barrett's metaplasia, the removal of abnormal tissue prevents the development of cancer and enables stratification of the patient to a high-risk group requiring further surveillance. Here, we provide a review of the available technologies for early diagnosis and minimally-invasive treatment.

Enhancing the Detection of Barrett Esophagus

In Western countries, the incidence of esophageal adenocarcinoma has increased rapidly in parallel with its premalignant condition, Barrett esophagus (BE). Unlike colonoscopy, endoscopic screening for BE is not currently recommended for all patients; however, surveillance endoscopy is advocated for patients with established BE. Novel imaging and sampling techniques have been developed and investigated for the purpose of improving the detection of Barrett esophagus, dysplasia, and neoplasia. This article discusses several screening and surveillance techniques, including Seattle protocol, chromoendoscopy, electronic chromoendoscopy, wide area transepithelial sampling with 3-dimensional analysis, nonendoscopic sampling devices, and transnasal endoscopy.

Safety and efficacy of a minimally invasive cell sampling device ('Cytosponge') in the diagnosis of esophageal pathology: a systematic review

Esophageal adenocarcinoma is an increasingly common cause of morbidity and mortality in developed countries. Most cases are considered the consequence of chronic gastroesophageal reflux disease, with subsequent Barrett's metaplasia and dysplasia. Because progression from Barrett's metaplasia to cancer occurs over many years, endoscopic screening and surveillance programs have been established, albeit with little or no consideration for cost-effectiveness. As an alternative to the expensive and resource-demanding endoscopic surveillance, the Cytosponge has been developed to sample the esophageal mucosa efficiently. The device is a compressed mesh sponge encapsulated in an ingestible gelatin pill attached to a string. After swallowing, the capsule dissolves allowing the sponge to expand in the stomach. As it is pulled out, cells are collected from the esophagogastric junction and throughout the esophagus. The cellular samples can be analyzed by cytology, immunohistochemistry, and molecular markers. We conducted a systematic review of all recent relevant studies to help define the role of this novel technology, including studies of screening and surveillance of Barrett's esophagus, esophageal squamous dysplasia detection, detection of eosinophilic esophagitis, and evaluation of benign esophageal diseases. With the major limitation that most studies were performed by a single investigative group that developed the technology, the device yielded overall impressive results against the endoscopy/biopsy gold standard. Patient acceptability was high. If these promising early results are validated by other investigators in other populations, the Cytosponge represents an important new advance in the detection of esophageal pathology that could potentially decrease the burden of endoscopic esophageal sampling.

Biomarkers for Barrett's esophagus - a contemporary review

INTRODUCTION

Esophageal adenocarcinoma (EAC) has a poor 5-year survival rate (10%-18%), and incidence has increased dramatically in the past three decades. Barrett's esophagus (BE) is the precursor lesion to EAC and is the replacement of the normally squamous lined esophagus with columnar cells that develop an intestinal phenotype characterized by the presence of goblet cells. Given the known precursor state, EAC is amenable to screening and surveillance strategies (analogous to colon cancer). However, unlike from colon cancer screening, BE poses challenges that make effective screening difficult. Robust and concerted effort is under way to find biomarkers of BE. Areas covered: This review summarizes current known biomarkers for BE. These include dysplasia, genomic markers, and gene expression alterations that occur early in the dysplasia/carcinoma sequence. Expert commentary: Despite the tremendous breadth of work in studying molecular advances, the ideal biomarker for BE has not yet been discerned. This review comments on innovations in the field of BE research that combine state-of-the-art molecular advances with simple technologies.

Barrett's oESophagus trial 3 (BEST3): study protocol for a randomised controlled trial comparing the Cytosponge-TFF3 test with usual care to facilitate the diagnosis of oesophageal pre-cancer in primary care patients with chronic acid reflux

BACKGROUND

Early detection of oesophageal cancer improves outcomes; however, the optimal strategy for identifying patients at increased risk from the pre-cancerous lesion Barrett's oesophagus (BE) is not clear. The Cytosponge, a novel non-endoscopic sponge device, combined with the biomarker Trefoil Factor 3 (TFF3) has been tested in four clinical studies. It was found to be safe, accurate and acceptable to patients. The aim of the BEST3 trial is to evaluate if the offer of a Cytosponge-TFF3 test in primary care for patients on long term acid suppressants leads to an increase in the number of patients diagnosed with BE.

METHODS

The BEST3 trial is a pragmatic multi-site cluster-randomised controlled trial set in primary care in England. Approximately 120 practices will be randomised 1:1 to either the intervention arm, invitation to a Cytosponge-TFF3 test, or the control arm usual care. Inclusion criteria are men and women aged 50 or over with records of at least 6 months of prescriptions for acid-suppressants in the last year. Patients in the intervention arm will receive an invitation to have a Cytosponge-TFF3 test in their general practice. Patients with a positive TFF3 test will receive an invitation for an upper gastro-intestinal endoscopy at their local hospital-based endoscopy clinic to test for BE. The primary objective is to compare histologically confirmed BE diagnosis between the intervention and control arms to determine whether the offer of the Cytosponge-TFF3 test in primary care results in an increase in BE diagnosis within 12 months of study entry.

DISCUSSION

The BEST3 trial is a well-powered pragmatic trial testing the use of the Cytosponge-TFF3 test in the same population that we envisage it being used in clinical practice. The data generated from this trial will enable NICE and other clinical bodies to decide whether this test is suitable for routine clinical use.

TRIAL REGISTRATION

This trial was prospectively registered with the ISRCTN Registry on 19/01/2017, trial number ISRCTN68382401 .

Highly Discriminant Methylated DNA Markers for the Non-endoscopic Detection of Barrett's Esophagus

BACKGROUND

Minimally invasive methods have been described to detect Barrett's esophagus (BE), but are limited by subjectivity and suboptimal accuracy. We identified methylated DNA markers (MDMs) for BE in tissue and assessed their accuracy on whole esophagus brushings and capsule sponge samples.

METHODS

Step 1: Unbiased whole methylome sequencing was performed on DNA from BE and normal squamous esophagus (SE) tissue. Discriminant MDM candidates were validated on an independent patient cohort (62 BE cases, 30 controls) by quantitative methylation specific PCR (qMSP). Step 2: Selected MDMs were further evaluated on whole esophageal brushings (49 BE cases, 36 controls). 35 previously sequenced esophageal adenocarcinoma (EAC) MDMs were also evaluated. Step 3: 20 BE cases and 20 controls were randomized to swallow capsules sponges (25 mm, 10 pores or 20 pores per inch (ppi)) followed endoscopy. DNA yield, tolerability, and mucosal injury were compared. Best MDM assays were performed on this cohort.

RESULTS

Step 1: 19 MDMs with areas under the ROC curve (AUCs) >0.85 were carried forward. Step 2: On whole esophageal brushings, 80% of individual MDM candidates showed high accuracy for BE (AUCs 0.84-0.94). Step 3: The capsule sponge was swallowed and withdrawn in 98% of subjects. Tolerability was superior with the 10 ppi sponge with minimal mucosal injury and abundant DNA yield. A 2-marker panel (VAV3 + ZNF682) yielded excellent BE discrimination (AUC = 1).

CONCLUSIONS

Identified MDMs discriminate BE with high accuracy. BE detection appears safe and feasible with a capsule sponge. Corroboration in larger studies is warranted. ClinicalTrials.gov number NCT02560623.

Endoscopic Management of Early Adenocarcinoma and Squamous Cell Carcinoma of the Esophagus: Screening, Diagnosis, and Therapy

Because the esophagus is easily accessible with endoscopy, early diagnosis and curative treatment of esophageal cancer is possible. However, diagnosis is often delayed because symptoms are not specific during early stages of tumor development. The onset of dysphagia is associated with advanced disease, which has a survival at 5 years lower than 15%. Population screening by endoscopy is not cost-effective, but a number of alternative imaging and cell analysis technologies are under investigation. The ideal screening test should be inexpensive, well tolerated, and applicable to primary care. Over the past 10 years, significant progress has been made in endoscopic diagnosis and treatment of dysplasia (squamous and Barrett's), and early esophageal cancer using resection and ablation technologies supported by evidence from randomized controlled trials. We review the state-of-the-art technologies for early diagnosis and minimally invasive treatment, which together could reduce the burden of disease.

Cost Effectiveness of Screening Patients With Gastroesophageal Reflux Disease for Barrett's Esophagus With a Minimally Invasive Cell Sampling Device

BACKGROUND & AIMS

It is important to identify patients with Barrett's esophagus (BE), the precursor to esophageal adenocarcinoma (EAC). Patients with BE usually are identified by endoscopy, which is expensive. The Cytosponge, which collects tissue from the esophagus noninvasively, could be a cost-effective tool for screening individuals with gastroesophageal reflux disease (GERD) who are at increased risk for BE. We developed a model to analyze the cost effectiveness of using the Cytosponge in first-line screening of patients with GERD for BE with endoscopic confirmation, compared with endoscopy screening only.

METHODS

We incorporated data from a large clinical trial of Cytosponge performance into 2 validated microsimulation models of EAC progression (the esophageal adenocarcinoma model from Massachusetts General Hospital and the microsimulation screening analysis model from Erasmus University Medical Center). The models were calibrated for US Surveillance, Epidemiology and End Results data on EAC incidence and mortality. In each model, we simulated the effect of a 1-time screen for BE in male patients with GERD, 60 years of age, using endoscopy alone or Cytosponge collection of tissue, and analysis for the level of trefoil factor 3 with endoscopic confirmation of positive results. For each strategy we recorded the number of cases of EAC that developed, the number of EAC cases detected with screening by Cytosponge only or by subsequent targeted surveillance, and the number of endoscopies needed. In addition, we recorded the cumulative costs (including indirect costs) incurred and quality-adjusted years of life lived within each strategy, discounted at a rate of 3% per year, and computed incremental cost-effectiveness ratios (ICERs) among the 3 strategies.

RESULTS

According to the models, screening patients with GERD by Cytosponge with follow-up confirmation of positive results by endoscopy would reduce the cost of screening by 27% to 29% compared with screening by endoscopy, but led to 1.8 to 5.5 (per 1000 patients) fewer quality-adjusted life years. The ICERs for Cytosponge screening compared with no screening ranged from $26,358 to $33,307. For screening patients by endoscopy compared with Cytosponge the ICERs ranged from $107,583 to $330,361. These results were sensitive to Cytosponge cost within a plausible range of values.

CONCLUSIONS

In a comparative modeling analysis of screening strategies for BE in patients with GERD, we found Cytosponge screening with endoscopic confirmation to be a cost-effective strategy. The greatest benefit was achieved by endoscopic screening, but with an unfavorable cost margin.

Alternatives to Traditional Per-Oral Endoscopy for Screening

Barrett's esophagus (BE) predisposes patients to esophageal adenocarcinoma. 3 to 6% of individuals with gastro-esophageal reflux disease are estimated to have BE but only 20 to 25% of BE patients are currently diagnosed. The current gold standard for diagnosis of BE is per-oral upper GI endoscopy. As this is not suitable for large-scale screening, a number of alternative methods are currently being investigated: transnasal and video capsule endoscopy, endomicroscopy, cell collection devices like the cytosponge and biomarkers. Some of these are promising, however, well powered studies carried out in relevant screening populations are needed.

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.

Past, present and future of Barrett's oesophagus

Barrett's oesophagus is a condition which predisposes towards development of oesophageal adenocarcinoma, a highly lethal tumour which has been increasing in incidence in the Western world over the past three decades. There have been tremendous advances in the field of Barrett's oesophagus, not only in diagnostic modalities, but also in therapeutic strategies available to treat this premalignant disease. In this review, we discuss the past, present and future of Barrett's oesophagus. We describe the historical and new evolving diagnostic criteria of Barrett's oesophagus, while also comparing and contrasting the British Society of Gastroenterology guidelines, American College of Gastroenterology guidelines and International Benign Barrett's and CAncer Taskforce (BOBCAT) for Barrett's oesophagus. Advances in endoscopic modalities such as confocal and volumetric laser endomicroscopy, and a non-endoscopic sampling device, the Cytosponge, are described which could aid in identification of Barrett's oesophagus. With regards to therapy we review the evidence for the utility of endoscopic mucosal resection and radiofrequency ablation when coupled with better characterization of dysplasia. These endoscopic advances have transformed the management of Barrett's oesophagus from a primarily surgical disease into an endoscopically managed condition.

Range of pathologies diagnosed using a minimally invasive capsule sponge to evaluate patients with reflux symptoms

AIMS

Reflux symptoms are highly prevalent and non-specific; hence, in the absence of alarm symptoms, endoscopy referral decisions are challenging. This study evaluated whether a non-endoscopic Cytosponge could detect benign oesophageal pathologies and thus have future potential in triaging patients with persistent symptoms.

METHODS AND RESULTS

Two complementary cohorts were recruited: (i) patients with reflux symptoms and no prior endoscopy (n = 409), and (ii) patients with reflux symptoms referred for endoscopy (n = 411). All patients were investigated using the Cytosponge and endoscopy. Significant epithelial inflammation was present in 130 (16%) Cytosponge samples, 32 of which had ulcer slough. Candida and significant inflammation was detected in a further 22 (2.3%) cases; epithelial infiltration with >15 eosinophils/high-power field reflecting possible eosinophilic oesophagitis (EOE) in five (0.6%); and viral inclusions suggestive of herpes oesophagitis in one (0.1%). No significant pathology was detected in the majority, 662 (81%), of Cytosponge samples. Cytosponge and endoscopy findings were in agreement in 574 (70%) cases, in 165 (67%) of the discordant cases one investigation showed mild inflammation while the other was negative, with an additional 22 (8.9%) differing on the extent of inflammation. Eighteen cases with severe inflammation, six with candida and two with EOE were detected only at endoscopy, while 18 with candida and significant inflammation, 13 with ulcer slough, one probable EOE and one viral oesophagitis were identified on the Cytosponge only.

CONCLUSIONS

The Cytosponge detects a range of benign oesophageal pathologies, and therefore has potential clinical utility in the triaging of patients with troublesome reflux symptoms. This warrants further investigation.

Accuracy and Safety of the Cytosponge for Assessing Histologic Activity in Eosinophilic Esophagitis: A Two-Center Study

OBJECTIVES

Management of eosinophilic esophagitis (EoE) requires repeated endoscopic mucosal sampling to assess disease activity. A less invasive and expensive means of monitoring of EoE is required. The objective of this study was to assess the accuracy, safety, and tolerability of the cytosponge compared to endoscopy and biopsy for histologic assessment of EoE.

METHODS

In this prospective two-center cross-sectional study, patients with known EoE underwent cytosponge sampling followed by endoscopy and biopsy. Sample adequacy and eosinophil counts (eos/HPF) were determined for both cytosponge and endoscopic samples. The cytosponge was assessed for diagnostic accuracy, safety, and patient preference as compared to endoscopy.

RESULTS

Six patients (7%) failed to swallow the sponge. One hundred and five procedures were successfully performed in 80 patients (66% male, 100% white, 19% stricture). The cytosponge sample was adequate in 102 and the biopsy in 104; 101 procedures had adequate samples by both techniques. Fifty-seven biopsies were graded as active EoE with ≥15 eos/HPF as the gold standard. Eosinophil counts highly correlated between the biopsy and cytosponge (r=0.78, P<0.0001). Using a cutoff of ≤15 eos/HPF for inactive disease, the sensitivity and specificity of the cytosponge was 75% and 86%, respectively. Six patients had active EoE on cytosponge not found on biopsy. For biopsies with inactive EoE, the cytosponge identified 38/44. No complications occurred, and cytosponge endoscopic abrasion scores were low (0.34/4). Patients preferred cytosponge to endoscopy with higher rating scores (7.27 vs. 6.11, P=0.002).

CONCLUSIONS

Compared to endoscopy with biopsy, cytosponge provided a minimally invasive, safe, well tolerated, and accurate method to assess EoE histologic activity. (ClinicalTrial.gov number NCT01585103).

Barrett’s esophagus in 2016: From pathophysiology to treatment

Esophageal complications caused by gastroesophageal reflux disease (GERD) include reflux esophagitis and Barrett’s esophagus (BE). BE is a premalignant condition with an increased risk of developing esophageal adenocarcinoma (EAC). The carcinogenic sequence may progress through several steps, from normal esophageal mucosa through BE to EAC. A recent advent of functional esophageal testing (particularly multichannel intraluminal impedance and pH monitoring) has helped to improve our knowledge about GERD pathophysiology, including its complications. Those findings (when properly confirmed) might help to predict BE neoplastic progression. Over the last few decades, the incidence of EAC has continued to rise in Western populations. However, only a minority of BE patients develop EAC, opening the debate regarding the cost-effectiveness of current screening/surveillance strategies. Thus, major efforts in clinical and research practice are focused on new methods for optimal risk assessment that can stratify BE patients at low or high risk of developing EAC, which should improve the cost effectiveness of screening/surveillance programs and consequently significantly affect health-care costs. Furthermore, the area of BE therapeutic management is rapidly evolving. Endoscopic eradication therapies have been shown to be effective, and new therapeutic options for BE and EAC have emerged. The aim of the present review article is to highlight the status of screening/surveillance programs and the current progress of BE therapy. Moreover, we discuss the recent introduction of novel esophageal pathophysiological exams that have improved the knowledge of the mechanisms linking GERD to BE.

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.

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.

Genomics of Esophageal Cancer and Biomarkers for Early Detection

In-depth molecular characterization of esophageal oncogenesis has improved over the recent years. Advancement in molecular biology and bioinformatics has led to better understanding of its genomic landscape. More specifically, analysis of its pathogenesis at the genetic level has uncovered the involvement of a number of tumor suppressor genes, cell cycle regulators, and receptor tyrosine kinases. Due to its poor prognosis, the development of clinically applicable biomarkers for diagnosis, progression, and treatment has been the focus of many research studies concentrating on upper gastrointestinal malignancies. As in other cancers, early detection and subsequent intervention of the preneoplastic condition significantly improves patient outcomes. Currently, clinically approved surveillance practices heavily depend on expensive, invasive, and sampling-error-prone endoscopic procedures. There is, therefore, a great demand to establish clearly reliable biomarkers that could identify those patients at higher risk of neoplastic progression and hence would greatly benefit from further monitoring and/or intervention. This chapter will present the most recent advances in the analysis of the esophageal cancer genome serving as basis for biomarker development.

Advances in the management of Barrett's esophagus and early esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has markedly increased in the United States over the last few decades. Barrett’s esophagus (BE) is the most significant known risk factor for this malignancy. Theoretically, screening and treating early BE should help prevent EAC but the exact incidence of BE and its progression to EAC is not entirely known and cost-effectiveness studies for Barrett’s screening are lacking. Over the last few years, there have been major advances in our understanding of the epidemiology, pathogenesis and endoscopic management of BE. These developments focus on early recognition of advanced histology and endoscopic treatment of high-grade dysplasia. Advanced resection techniques now enable us to endoscopically treat early esophageal cancer. In this review, we will discuss these recent advances in diagnosis and treatment of Barrett’s esophagus and early esophageal adenocarcinoma.

Golgi phosphoprotein 2 (GOLPH2) is a novel bile acid-responsive modulator of oesophageal cell migration and invasion

BACKGROUND

The aetiology of Barrett's oesophagus (BO) and oesophageal cancer is poorly understood. We previously demonstrated that Golgi structure and function is altered in oesophageal cancer cells. A Golgi-associated protein, GOLPH2, was previously established as a tissue biomarker for BO. Cellular functions for GOLPH2 are currently unknown, therefore in this study we sought to investigate functional roles for this Golgi-associated protein in oesophageal disease.

METHODS

Expression, intracellular localisation and secretion of GOLPH2 were identified by immunofluorescence, immunohistochemistry and western blot. GOLPH2 expression constructs and siRNA were used to identify cellular functions for GOLPH2.

RESULTS

We demonstrate that the structure of the Golgi is fragmented and the intracellular localisation of GOLPH2 is altered in BO and oesophageal adenocarcinoma tissue. GOLPH2 is secreted by oesophageal cancer cells and GOLPH2 expression, cleavage and secretion facilitate cell migration and invasion. Furthermore, exposure of cells to DCA, a bile acid component of gastric refluxate and known tumour promoter for oesophageal cancer, causes disassembly of the Golgi structure into ministacks, resulting in cleavage and secretion of GOLPH2.

CONCLUSIONS

This study demonstrates that GOLPH2 may be a useful tissue biomarker for oesophageal disease. We provide a novel mechanistic insight into the aetiology of oesophageal cancer and reveal novel functions for GOLPH2 in regulating tumour cell migration and invasion, important functions for the metastatic process in oesophageal cancer.

Serum Glycoprotein Biomarker Discovery and Qualification Pipeline Reveals Novel Diagnostic Biomarker Candidates for Esophageal Adenocarcinoma

We report an integrated pipeline for efficient serum glycoprotein biomarker candidate discovery and qualification that may be used to facilitate cancer diagnosis and management. The discovery phase used semi-automated lectin magnetic bead array (LeMBA)-coupled tandem mass spectrometry with a dedicated data-housing and analysis pipeline; GlycoSelector (http://glycoselector.di.uq.edu.au). The qualification phase used lectin magnetic bead array-multiple reaction monitoring-mass spectrometry incorporating an interactive web-interface, Shiny mixOmics (http://mixomics-projects.di.uq.edu.au/Shiny), for univariate and multivariate statistical analysis. Relative quantitation was performed by referencing to a spiked-in glycoprotein, chicken ovalbumin. We applied this workflow to identify diagnostic biomarkers for esophageal adenocarcinoma (EAC), a life threatening malignancy with poor prognosis in the advanced setting. EAC develops from metaplastic condition Barrett's esophagus (BE). Currently diagnosis and monitoring of at-risk patients is through endoscopy and biopsy, which is expensive and requires hospital admission. Hence there is a clinical need for a noninvasive diagnostic biomarker of EAC. In total 89 patient samples from healthy controls, and patients with BE or EAC were screened in discovery and qualification stages. Of the 246 glycoforms measured in the qualification stage, 40 glycoforms (as measured by lectin affinity) qualified as candidate serum markers. The top candidate for distinguishing healthy from BE patients' group was Narcissus pseudonarcissus lectin (NPL)-reactive Apolipoprotein B-100 (p value = 0.0231; AUROC = 0.71); BE versus EAC, Aleuria aurantia lectin (AAL)-reactive complement component C9 (p value = 0.0001; AUROC = 0.85); healthy versus EAC, Erythroagglutinin Phaseolus vulgaris (EPHA)-reactive gelsolin (p value = 0.0014; AUROC = 0.80). A panel of 8 glycoforms showed an improved AUROC of 0.94 to discriminate EAC from BE. Two biomarker candidates were independently verified by lectin magnetic bead array-immunoblotting, confirming the validity of the relative quantitation approach. Thus, we have identified candidate biomarkers, which, following large-scale clinical evaluation, can be developed into diagnostic blood tests. A key feature of the pipeline is the potential for rapid translation of the candidate biomarkers to lectin-immunoassays.

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.