Developing a nonendoscopic screening test for Barrett's esophagus

Specific DNA methylation markers in the diagnosis and prognosis of esophageal cancer

The early diagnosis and accurate prognosis prediction of esophageal cancer is an essential part of improving survival. However, these diseases lack effective and specific markers. A total of 1,744 samples of HumanMethylation450 data were integrated to identify and validate specific methylation markers for esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC) as well as for Barrett's esophagus (BE) using The Cancer Genome Atlas and the Gene Expression Omnibus. The diagnostic and prognostic methylation classifiers were constructed by moderated t-statistics and the least absolute shrinkage and selection operator method. The diagnostic methylation classifier using 12 CpG sites was constructed in training set (377 samples) that could effectively discriminate samples of BE, EAC, and ESCC from normal tissue (AUC = 0.992), which achieved highly predictive ability in both internal (187 samples, AUC = 0.990) and external validation (184 samples, AUC = 0.978). The prognostic methylation classifier with 3 CpG and 2 CpG sites for EAC and ESCC respectively, could accurately estimate the prognosis of an individual patient and improved the predictive ability of the tumor node metastasis staging system. Overall, our study systematically analyzed large-scale methylation data and provided promising markers for the diagnosis and prognosis of esophageal cancer.

Combined EsophaCap cytology and MUC2 immunohistochemistry for screening of intestinal metaplasia, dysplasia and carcinoma

Purpose: The incidence of esophageal adenocarcinoma (EAC) has increased by 700% in Western countries over the last 30 years. Although clinical guidelines call for endoscopic surveillance for EAC among high-risk populations, fewer than 5% of new EAC patients are under surveillance at the time of diagnosis. We studied the accuracy of combined cytopathology and MUC2 immunohistochemistry (IHC) for screening of Intestinal Metaplasia (IM), dysplasia and EAC, using specimens collected from the EsophaCap swallowable encapsulated cytology sponge from Canada and United States. Patients and methods: By comparing the EsophaCap cytological diagnosis with concurrent endoscopic biopsies performed on the same patients in 28 cases, we first built up the cytology diagnostic categories and criteria. Based on these criteria, 136 cases were evaluated by both cytology and MUC2 IHC with blinded to patient biopsy diagnosis. Results: We first set up categories and criteria for cytological diagnosis of EscophaCap samples. Based on these, we divided our evaluated cytological samples into two groups: non-IM group and IM or dysplasia or adenocarcinoma group. Using the biopsy as our gold standard to screen IM, dysplasia and EAC by combined cytology and MUC2 IHC, the sensitivity and specificity were 68% and 91%, respectively, which is in the range of clinically useful cytological screening tests such as the cervical Pap smear. Conclusions: Combined EsophaCap cytology and MUC2 IHC could be a good screening test for IM and Beyond.

Identifying DNA methylation biomarkers for non-endoscopic detection of Barrett's esophagus

We report a biomarker-based non-endoscopic method for detecting Barrett's esophagus (BE) based on detecting methylated DNAs retrieved via a swallowable balloon-based esophageal sampling device. BE is the precursor of, and a major recognized risk factor for, developing esophageal adenocarcinoma. Endoscopy, the current standard for BE detection, is not cost-effective for population screening. We performed genome-wide screening to ascertain regions targeted for recurrent aberrant cytosine methylation in BE, identifying high-frequency methylation within the CCNA1 locus. We tested CCNA1 DNA methylation as a BE biomarker in cytology brushings of the distal esophagus from 173 individuals with or without BE. CCNA1 DNA methylation demonstrated an area under the curve of 0.95 for discriminating BE-related metaplasia and neoplasia cases versus normal individuals, performing identically to methylation of VIM DNA, an established BE biomarker. When combined, the resulting two biomarker panel was 95% sensitive and 91% specific. These results were replicated in an independent validation cohort of 149 individuals who were assayed using the same cutoff values for test positivity established in the training population. To progress toward non-endoscopic esophageal screening, we engineered a well-tolerated, swallowable, encapsulated balloon device able to selectively sample the distal esophagus within 5 min. In balloon samples from 86 individuals, tests of CCNA1 plus VIM DNA methylation detected BE metaplasia with 90.3% sensitivity and 91.7% specificity. Combining the balloon sampling device with molecular assays of CCNA1 plus VIM DNA methylation enables an efficient, well-tolerated, sensitive, and specific method of screening at-risk populations for BE.

A crosssectional analysis of Facebook comments to study public perception of a new diagnostic test called the Cytosponge

Social media provides a useful platform for informal discussions about healthcare. Acceptability is key to the uptake of diagnostic devices and this can be difficult to gauge from questionnaires and qualitative studies. The aim of this study is to investigate whether Facebook could be used to gauge public perception toward uptake of a new diagnostic test for Barrett's esophagus called the Cytosponge. We retrospectively reviewed Facebook comments relating to a video on the Cytosponge. We categorized comments into: (1) Positive, (2) Negative, (3) Unknown and (4) Questions. Recurring themes that arose were compared to a qualitative study on the Cytosponge. The video received 22.5 million views and 2837 comments within four months. Of these, 525 comments were positive, 215 were unknown, 179 were negative, 71 were questions, and 1847 were 'Tagged' comments. Among positive comments, recurrent themes were that it was innovative, could lead to early cancer-detection, and more favorable than endoscopy. Among negative comments, a recurring theme was concern about the risk of gagging and vomiting. Among 'questions', a recurring theme was related to the risk of Cytosponge detachment. We compared our analysis to a published qualitative study and found similar themes arose across both studies. Facebook provides a rich source of qualitative data, which could be used to augment studies to gauge public perception toward a new diagnostic test.

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.

Targeted bisulfite sequencing identified a panel of DNA methylation-based biomarkers for esophageal squamous cell carcinoma (ESCC)

Background

DNA methylation has been implicated as a promising biomarker for precise cancer diagnosis. However, limited DNA methylation-based biomarkers have been described in esophageal squamous cell carcinoma (ESCC).

Methods

A high-throughput DNA methylation dataset (100 samples) of ESCC from The Cancer Genome Atlas (TCGA) project was analyzed and validated along with another independent dataset (12 samples) from the Gene Expression Omnibus (GEO) database. The methylation status of peripheral blood mononuclear cells and peripheral blood leukocytes from healthy controls was also utilized for biomarker selection. The candidate CpG sites as well as their adjacent regions were further validated in 94 pairs of ESCC tumor and adjacent normal tissues from the Chinese Han population using the targeted bisulfite sequencing method. Logistic regression and several machine learning methods were applied for evaluation of the diagnostic ability of our panel.

Results

In the discovery stage, five hyper-methylated CpG sites were selected as candidate biomarkers for further analysis as shown below: cg15830431, P = 2.20 × 10⁻⁴; cg19396867, P = 3.60 × 10⁻⁴; cg20655070, P = 3.60 × 10⁻⁴; cg26671652, P = 5.77 × 10⁻⁴; and cg27062795, P = 3.60 × 10⁻⁴. In the validation stage, the methylation status of both the five CpG sites and their adjacent genomic regions were tested. The diagnostic model based on the combination of these five genomic regions yielded a robust performance (sensitivity = 0.75, specificity = 0.88, AUC = 0.85). Eight statistical models along with five-fold cross-validation were further applied, in which the SVM model reached the best accuracy in both training and test dataset (accuracy = 0.82 and 0.80, respectively). In addition, subgroup analyses revealed a significant difference in diagnostic performance between the alcohol use and non-alcohol use subgroups.

Conclusions

Methylation profiles of the five genomic regions covering cg15830431 (STK3), cg19396867, cg20655070, cg26671652 (ZNF418), and cg27062795 (ZNF542) can be used for effective methylation-based testing for ESCC diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s13148-017-0430-7) contains supplementary material, which is available to authorized users.

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.

Unravelling biology and shifting paradigms in cancer with single-cell sequencing

The fundamental operative unit of a cancer is the genetically and epigenetically innovative single cell. Whether proliferating or quiescent, in the primary tumour mass or disseminated elsewhere, single cells govern the parameters that dictate all facets of the biology of cancer. Thus, single-cell analyses provide the ultimate level of resolution in our quest for a fundamental understanding of this disease. Historically, this quest has been hampered by technological shortcomings. In this Opinion article, we argue that the rapidly evolving field of single-cell sequencing has unshackled the cancer research community of these shortcomings. From furthering an elemental understanding of intra-tumoural genetic heterogeneity and cancer genome evolution to illuminating the governing principles of disease relapse and metastasis, we posit that single-cell sequencing promises to unravel the biology of all facets of this disease.

DNA Methylation Status of PAX1 and ZNF582 in Esophageal Squamous Cell Carcinoma

Hypermethylation of specific gene promoters is an important mechanism of carcinogenesis. A high frequency of promoter methylation of PAX1 and ZNF582 genes has been detected in cervical cancer. In the present study, we investigated the methylation status of PAX1 and ZNF582 genes in esophageal squamous cell carcinoma (ESCC) tissues. Tumor and paracancerous tissues were obtained from 14 ESCC patients. Genomic DNA was extracted from both tumor and paracancerous tissues, and the concentration of DNA were determined. DNA methylation analysis of PAX1 and ZNF582 genes was carried out using quantitative methylation-specific PCR. To assess the diagnostic performance of the two methylated genes for cancer detection, receiver operating characteristic (ROC) curves were generated. Sensitivities and specificities were tested at cut-offs obtained from the ROC curves. The methylation levels of both PAX1 and ZNF582 genes were significantly higher in tumor tissues compared to non-tumor paracancerous tissues. The methylation rates of PAX1 and ZNF582 in ESCC tumor and paracancerous tissues were 100% and 21.4% (p = 0.006), 85.7% and 0% (p < 0.001), respectively. The sensitivities and specificities of PAX1 and ZNF582 methylation for the detection of cancer were 100% and 85.7%, and 78.6% and 100%, respectively. The DNA methylation levels and frequencies of PAX1 and ZNF582 genes were markedly higher in ESCC tumor tissues compared to those in paracancerous tissues. Moreover, the conclusions were verified by using The Cancer Genome Atlas (TCGA) datasets. DNA methylation status of these two genes showed a relatively good sensitivity and specificity for the detection of ESCC tumors. This data suggests that DNA methylation testing holds a great promise for ESCC screening and warrants further prospective population-based studies.

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).

Review: Surveillance of patients with Barrett oesophagus

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

Spatial predisposition of dysplasia in Barrett's esophagus segments: a pooled analysis of the SURF and AIM dysplasia trials

OBJECTIVES

Surveillance endoscopy detects dysplasia within Barrett's esophagus (BE) and dictates treatment. Current biopsy regimens recommend uniformly spaced random biopsies. We assessed the distribution of dysplasia in BE to develop evidence-based biopsy regimens.

METHODS

We performed analysis of the distribution of dysplasia within BE using pretreatment biopsy data from two randomized controlled trials (RCTs) of radiofrequency ablation for dysplastic BE: the SURF (Surveillance vs. Radiofrequency Ablation) trial and the AIM Dysplasia (Ablation of Intestinal Metaplasia (AIM) Containing Dysplasia) trial. We used generalized linear models with generalized estimating equations (GEE) to estimate prevalence differences for dysplasia depending on the standardized location of biopsies. We performed Monte Carlo simulation of biopsy regimens to estimate their yield for any dysplasia within segments.

RESULTS

Dysplasia preferentially resides in the proximal-most half of the BE segment that is almost twice as likely to demonstrate dysplasia as the distal-most quartile. In pooled analysis, compared with the distal-most quarter, the prevalence difference in the proximal-most quarter was 22.6%, in the second proximal-most quarter 23.1%, and in the second distal-most quarter 15.3%. The best performing biopsy regimen in simulation studies acquired 8 biopsies in the most proximal cm of BE, 8 biopsies in the second cm, and 2 biopsies in each cm thereafter (q1cm: 8, 8, 2, 2…). A slightly simpler q2cm (every 2 cm) regimen (q2cm: 12, 12, 4…) was nearly as effective.

CONCLUSIONS

The post hoc analysis of two RCTs reveals a substantially increased prevalence of dysplasia proximally in BE segments. Our simulations suggest an altered biopsy regimen could increase sensitivity of biopsies in short-segment BE by >30%.

Inter-Observer Agreement among Pathologists Using Wide-Area Transepithelial Sampling With Computer-Assisted Analysis in Patients With Barrett's Esophagus

OBJECTIVES

The histopathological diagnosis of Barrett's esophagus (BE)-associated dysplasia has poor inter-observer agreement. The wide-area transepithelial sampling (WATS) procedure uses a minimally invasive brush biopsy technique for acquiring wide-area sampling of BE tissue followed by computer-assisted analysis. In this study, our aim was to assess inter-observer agreement among pathologists in the diagnosis of Barrett's-associated dysplasia using the WATS computer-assisted analysis technique.

METHODS

WATS slides with varying degrees of BE dysplasia were randomly selected and distributed to four pathologists. Each pathologist graded the slides as nondysplastic, low-grade dysplasia (LGD), or high-grade dysplasia/esophageal adenocarcinoma (HGD/EAC) and completed a standardized case report form (CRF) for each slide.

RESULTS

In all, 149 BE slides were evaluated in a blinded manner by 4 pathologists. The slides included the following: no dysplasia (n=109), LGD, and HGD/EAC (n=40). The overall mean kappa value for all 3 diagnoses for the 4 observers was calculated at 0.86 (95% confidence interval (CI) 0.75-0.97). The kappa values (95% CI) for HGD/EAC, IND/LGD, and no dysplasia were 0.95 (0.88-0.99), 0.74 (0.61-0.85), and 0.88 (0.81-0.94), respectively.

CONCLUSIONS

The diagnosis of BE and associated dysplasia using the WATS technique has very high inter-observer agreement. This appears to be significantly higher as compared with previously published data using standard histopathology.

Personalized targeted therapy for esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma continues to heavily burden clinicians worldwide. Researchers have discovered the genomic landscape of esophageal squamous cell carcinoma, which holds promise for an era of personalized oncology care. One of the most pressing problems facing this issue is to improve the understanding of the newly available genomic data, and identify the driver-gene mutations, pathways, and networks. The emergence of a legion of novel targeted agents has generated much hope and hype regarding more potent treatment regimens, but the accuracy of drug selection is still arguable. Other problems, such as cancer heterogeneity, drug resistance, exceptional responders, and side effects, have to be surmounted. Evolving topics in personalized oncology, such as interpretation of genomics data, issues in targeted therapy, research approaches for targeted therapy, and future perspectives, will be discussed in this editorial.

Cost considerations in implementing a screening and surveillance strategy for Barrett's oesophagus

There is increasing concern over the rising costs of healthcare leading to debate regarding the use of resources to implement preventive strategies. Oesophageal adenocarcinoma and its precursor, Barrett's oesophagus provides an excellent opportunity to highlight this issue since cancer is uncommon even among individuals with documented Barrett's oesophagus. This review provides a brief introduction to economic analysis in healthcare and summarizes published studies of the cost-effectiveness of strategies to reduce mortality from cancer. Current best estimates highlight the cost-effectiveness of endoscopic ablation among patients with Barrett's oesophagus and high-grade dysplasia and the low cost-effectiveness of ablation among patients without dysplasia. The cost-effectiveness of ablation among patients with Barrett's and low-grade dysplasia is poorly defined due to the ambiguity of diagnosing dysplasia, the unknown risk of cancer among patients with low-grade dysplasia, and the uncertain durability of ablation to maintain remission from metaplasia and dysplasia and prevent cancer.

Accuracy of liquid cytology in the diagnosis and monitoring of eosinophilic oesophagitis

BACKGROUND

Oesophagoscopy with biopsy is considered the gold standard for diagnosing and monitoring eosinophilic oesophagitis (EoE). Therefore is important to discover less-invasive diagnostic methods.

METHODS

Cytology specimens were obtained in patients with active EoE (AEoE) (≥15 eos/hpf) and EoE in remission (EoER) (<15 eos/hpf). The samples were assessed by two independent pathologists and were compared with biopsy samples. EoE cytology specimens were compared with specimens obtained from patients with GERD.

RESULTS

Specimens of 36 patients (69.4% male, mean age 30.88 years) were included. AEoE (17, 47.2%), EoER (11, 30.5%) and GERD (22.2%). eos/hpf in cytology (AEoE 9.23 vs. EoER 1.54 vs. GERD 2, p = 0.01). Linear correlation between eos/hpf average biopsy and cytology eos/hpf: r = 0.57, p < 0.001. For diagnosis of EoE ≥3 eos/hpf in cytology obtained a sensitivity of 70%, specificity 81%, PPV 86% and NPV 60% (AUC = 0.81, p = 0.01). For detection of AEoE, ≥3 eos/hpf in LBC obtained a sensitivity of 70%, specificity 82%, PPV 81% and NPV 66% (AUC = 0.87, p = 0.001).

CONCLUSIONS

LBC in oesophageal aspirate seems to be effective for the diagnosis and monitoring activity in EoE. These results support the usefulness of non-invasive methods for the diagnosis and monitoring of EoE.

Comparison of cancer-associated genetic abnormalities in columnar-lined esophagus tissues with and without goblet cells

OBJECTIVE

To determine and compare the frequency of cancer-associated genetic abnormalities in esophageal metaplasia biopsies with and without goblet cells.

BACKGROUND

Barrett's esophagus is associated with increased risk of esophageal adenocarcinoma (EAC), but the appropriate histologic definition of Barrett's esophagus is debated. Intestinal metaplasia (IM) is defined by the presence of goblet cells whereas nongoblet cell metaplasia (NGM) lacks goblet cells. Both have been implicated in EAC risk but this is controversial. Although IM is known to harbor genetic changes associated with EAC, little is known about NGM. We hypothesized that if NGM and IM infer similar EAC risk, then they would harbor similar genetic aberrations in genes associated with EAC.

METHODS

Ninety frozen NGM, IM, and normal tissues from 45 subjects were studied. DNA copy number abnormalities were identified using microarrays and fluorescence in situ hybridization. Targeted sequencing of all exons from 20 EAC-associated genes was performed on metaplasia biopsies using Ion AmpliSeq DNA sequencing.

RESULTS

Frequent copy number abnormalities targeting cancer-associated genes were found in IM whereas no such changes were observed in NGM. In 1 subject, fluorescence in situ hybridization confirmed loss of CDKN2A and amplification of chromosome 8 in IM but not in a nearby NGM biopsy. Targeted sequencing revealed 11 nonsynonymous mutations in 16 IM samples and 2 mutations in 19 NGM samples.

CONCLUSIONS

This study reports the largest and most comprehensive comparison of DNA aberrations in IM and NGM genomes. Our results show that IM has a much higher frequency of cancer-associated mutations than NGM.

Screening for Barrett's esophagus: results from a population-based survey

BACKGROUND

Screening for Barrett's esophagus (BE) and adenocarcinoma (EAC) is controversial, but interest remains in finding the optimal method. Attitudes on screening within the community are unknown. We aimed to assess these attitudes via a survey.

STUDY

A mixed-mode survey was conducted in adults >50 years to assess awareness regarding BE, willingness to participate in screening, and preferences regarding method of screening. Methods evaluated were sedated endoscopy (sEGD), unsedated transnasal endoscopy (uTNE) and video capsule (VCE).

RESULTS

A total of 136 from 413 (33%) adults responded [47% males, mean (SD) age 63 (10.2) years], and 26% of responders knew of BE at baseline. After reading the information on BE, 72% were interested in screening. A history of undergoing screening tests and GI symptoms were predictive of interest. Unsedated techniques were preferred by 64% (VCE: 56% and uTNE: 8%) versus sEGD (36%).

CONCLUSIONS

The majority of adults were willing to undergo screening for BE/EAC, with a preference for unsedated techniques.

The use of imaging and biomarkers in diagnosing Barrett's esophagus and predicting the risk of neoplastic progression

Long-standing gastroesophageal reflux disease can result in transformation of the normal squamous lining of the esophagus into columnar epithelium (with goblet cells). This condition, Barrett's esophagus (BE), is considered a risk factor for esophageal cancer (EAC) and may be the cause of the increased incidence of EAC over the last few decades. Currently, endoscopy with biopsies revealing dysplasia is the best predictor for neoplastic progression in patients with BE. However, the use of more sophisticated imaging techniques and biomarkers with or without histological assessment may be helpful in more accurate prediction of malignant transformation in these patients. New approaches to the evaluation of BE such as epigenetics, miRNA analysis, detection of DNA content abnormalities and loss of heterozygosity have great potential to shed light on the complex gastroesophageal reflux disease -BE-EAC sequence.

Unmet diagnostic needs in eosinophilic esophagitis

The description of eosinophilic esophagitis (EoE) from a clinical, endoscopic, histologic and mechanistic perspective has emerged at a rapid pace. Nevertheless, there are many key areas of diagnosis which remain problematic. The first area is trying to identify a gold standard for EoE, particularly in its differentiation from gastroesophageal reflux disease. As a result, many of the consensus guidelines advise expensive and cumbersome steps with endoscopy and empiric courses of medication that would not be needed should a completely accurate method for identifying EoE be developed. We also grapple with the lack of an accurate test short of endoscopy and biopsy to diagnose and monitor treatment response in EoE. This is particularly problematic in food elimination diets where patients may require up to ten endoscopies to determine precise food avoidance. Finally, it is imperative that we diagnose factors that predict severity and phenotype of the disease. This will yield far clearer guidance concerning the level and duration of therapy needed on EoE patients.

Management controversies in Barrett's oesophagus

The management of Barrett's oesophagus and associated neoplasia has evolved considerably in recent years. Modern endoscopic strategies including endoscopic resection and mucosal ablation can eradicate dysplastic Barrett's and prevent progression to invasive oesophageal cancer. However, several aspects of Barrett's management remain controversial including the stage in the disease process at which to intervene, and the choice of endoscopic or surgical therapy. A review of articles pertaining to the management of Barrett's oesophagus with or without associated neoplasia, was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, Embase and Cochrane databases were searched to identify literature relevant to eight pre-defined areas of clinical controversy. The following search terms were used: Barrett's oesophagus; dysplasia; intramucosal carcinoma; endotherapy; endoscopic resection; ablation; oesophagectomy. A significant body of evidence exists to support early endoscopic therapy for high-grade dysplasia (HGD). Although not supported by randomised controlled trial evidence, endoscopic therapy is now favoured ahead of oesophagectomy for most patients with HGD. Focal intramucosal (T1a) carcinomas can be managed effectively using endoscopic and surgical therapy, however surgery should be considered the first line therapy where there is submucosal invasion (T1b). Treatment of low grade dysplasia is not supported at present due to widespread over-reporting of the disease. The role of surveillance endoscopy in non-dysplastic Barrett's remains controversial.

Biomarkers and molecular imaging in gastrointestinal cancers

The best means to improve gastrointestinal cancer survival is screening and treatment of early lesions. In esophageal adenocarcinoma, it is believed that low-grade dysplasia and perhaps even high-risk Barrett's esophagus represent the most attractive targets for achieving a cure. An issue with Barrett's esophagus is that endoscopy alone cannot distinguish Barrett's esophagus from columnar-lined epithelium or from areas of low-grade dysplasia. Much effort, therefore, has been devoted to discover molecular biomarkers of high-risk states and to develop imaging tools for detecting these biomarkers in a manner that could assist real-time in vivo targeting of sites for biopsy. The strategy we have used is to generate stem cell clones from Barrett's esophagus biopsy specimens and to compare their gene expression profiles with patient-matched stem cell clones of the esophageal squamous epithelia and gastric cardia. It is anticipated that by mining the expression data sets of these Barrett's stem cell clones, we will be able to identify unique cell surface markers of the Barrett's stem cells against which cytotoxic antibodies or aptamers can be developed and used to aid the endoscopist in identifying regions of atypia for biopsy, perform a real-time diagnosis, stratify patients during the examination, and, ultimately, direct therapy in a preemptive manner.

Review on novel concepts of columnar lined esophagus

BACKGROUND

Columnar lined esophagus (CLE) is a marker for gastroesophageal reflux and associates with an increased cancer risk among those with Barrett's esophagus. Recent studies fostered the development of integrated CLE concepts.

METHODS

Using PubMed, we conducted a review of studies on novel histopathological concepts of nondysplastic CLE.

RESULTS

Two histopathological concepts-the squamo-oxyntic gap (SOG) and the dilated distal esophagus (DDE), currently model our novel understanding of CLE. As a consequence of reflux, SOG interposes between the squamous lined esophagus and the oxyntic mucosa of the proximal stomach. Thus the SOG describes the histopathology of CLE within the tubular esophagus and the DDE, which is known to develop at the cost of a shortened lower esophageal sphincter and foster increased acid gastric reflux. Histopathological studies of the lower end of the esophagus indicate, that the DDE is reflux damaged, dilated, gastric type folds forming esophagus and cannot be differentiated from proximal stomach by endoscopy. While the endoscopically visible squamocolumnar junction (SCJ) defines the proximal limit of the SOG, the assessment of the distal limit requires the histopathology of measured multilevel biopsies. Within the SOG, CLE types distribute along a distinct zonation with intestinal metaplasia (IM; Barrett's esophagus) and/or cardiac mucosa (CM) at the SCJ and oxyntocardiac mucosa (OCM) within the distal portion of the SOG. The zonation follows the pH-gradient across the distal esophagus. Diagnosis of SOG and DDE includes endoscopy, histopathology of measured multi-level biopsies from the distal esophagus, function, and radiologic tests. CM and OCM do not require treatment and are surveilled in 5 year intervals, unless they associate with life quality impairing symptoms, which demand medical or surgical therapy. In the presence of an increased cancer risk profile, it is justified to consider radiofrequency ablation (RFA) of IM within clinical studies in order to prevent the progression to dysplasia and cancer. Dysplasia justifies RFA ± endoscopic resection.

CONCLUSIONS

SOG and DDE represent novel concepts fusing the morphological and functional aspects of CLE. Future studies should examine the impact of SOG and DDE for monitoring and management of gastroesophageal reflux disease (GERD).

Early diagnostic biomarkers for esophageal adenocarcinoma--the current state of play

Esophageal adenocarcinoma (EAC) is one of the two most common types of esophageal cancer with alarming increase in incidence and very poor prognosis. Aiming to detect EAC early, currently high-risk patients are monitored using an endoscopic-biopsy approach. However, this approach is prone to sampling error and interobserver variability. Diagnostic tissue biomarkers related to genomic and cell-cycle abnormalities have shown promising results, although with current technology these tests are difficult to implement in the screening of high-risk patients for early neoplastic changes. Differential miRNA profiles and aberrant protein glycosylation in tissue samples have been reported to improve performance of existing tissue-based diagnostic biomarkers. In contrast to tissue biomarkers, circulating biomarkers are more amenable to population-screening strategies, due to the ease and low cost of testing. Studies have already shown altered circulating glycans and DNA methylation in BE/EAC, whereas disease-associated changes in circulating miRNA remain to be determined. Future research should focus on identification and validation of these circulating biomarkers in large-scale trials to develop in vitro diagnostic tools to screen population at risk for EAC development.

Screening and risk stratification for Barrett's esophagus: how to limit the clinical impact of the increasing incidence of esophageal adenocarcinoma

Barrett's esophagus (BE) and gastroesophageal reflux disease are the strongest risk factors for esophageal adenocarcinoma. To reduce the clinical impact of this disease, endoscopic screening to detect BE has been proposed and nonendoscopic diagnostic techniques are under investigation. Because screening would result in new diagnoses of BE and additional costs related to endoscopic surveillance, novel tools for risk stratification are also warranted. Dysplasia is the gold standard for risk stratification. Molecular biomarkers may provide a more objective and reproducible estimation of the individual risk, and further prospective studies are required as a prelude to introducing biomarkers into routine clinical practice.

Aberrant vimentin methylation is characteristic of upper gastrointestinal pathologies

BACKGROUND

We have previously established aberrant DNA methylation of vimentin exon-1 (VIM methylation) as a common epigenetic event in colon cancer and as a biomarker for detecting colon neoplasia. We now examine vimentin methylation in neoplasia of the upper gastrointestinal tract.

METHODS

Using a quantitative real-time methylation-specific PCR assay, we tested for vimentin methylation in archival specimens of esophageal and gastric neoplasia.

RESULTS

We find that acquisition of aberrant vimentin methylation is highly common in these neoplasms, but largely absent in controls. The highest frequency of vimentin methylation was detected in lesions of the distal esophagus, including 91% of Barrett's esophagus (n = 11), 100% of high-grade dysplasia (HGD, n = 5), and 81% of esophageal adenocarcinoma (EAC, n = 26) but absent in controls (n = 9). Vimentin methylation similarly was detected in 87% of signet ring (n = 15) and 53% of intestinal type gastric cancers (n = 17). Moreover, in tests of cytology brushings vimentin methylation proved detectable in 100% of Barrett's esophagus cases (n = 7), 100% of HGD cases (n = 4), and 83% of EAC cases (n = 18) but was absent in all controls (n = 5).

CONCLUSIONS

These findings establish aberrant vimentin methylation as a highly common epigenetic alteration in neoplasia of the upper gastrointestinal tract and show that Barrett's esophagus, even without dysplasia, already contains epigenetic alterations characteristic of adenocarcinoma.

IMPACT

These findings suggest vimentin methylation as a biomarker of upper gastrointestinal neoplasia with potential for development as molecular cytology in esophageal screening.

Modeling the risk of esophageal squamous cell carcinoma and squamous dysplasia in a high risk area in Iran

BACKGROUND

Identifying people at higher risk of having squamous dysplasia, the precursor lesion for esophageal squamous cell carcinoma (ESCC), would allow targeted endoscopic screening.

METHODS

We used multivariate logistic regression models to predict ESCC and dysplasia as outcomes. The ESCC model was based on data from the Golestan Case-Control Study (total n = 871; cases = 300), and the dysplasia model was based on data from a cohort of subjects from a gastroenterology clinic in Northeast Iran (total n = 724; cases = 26). In each of these analyses, we fit a model including all risk factors known in this region to be associated with ESCC. Individual risks were calculated using the linear combination of estimated regression coefficients and individual-specific values for covariates. We used cross-validation to determine the area under the curve (AUC) and to find the optimal cut points for each of the models.

RESULTS

The model had an area under the curve of 0.77 (95% CI: 0.74-0.80) to predict ESCC with 74% sensitivity and 70.4% specificity for the optimum cut point. The area under the curve was 0.71 (95% CI: 0.64-0.79) for dysplasia diagnosis, and the classification table optimized at 61.5% sensitivity and 69.5% specificity. In this population, the positive and negative predictive values for diagnosis of dysplasia were 6.8% and 97.8%, respectively.

CONCLUSION

Our models were able to discriminate between ESCC cases and controls in about 77%, and between individuals with and without squamous dysplasia in about 70% of the cases. Using risk factors to predict individual risk of ESCC or squamous dysplasia still has limited application in clinical practice, but such models may be suitable for selecting high risk individuals in research studies, or increasing the pretest probability for other screening strategies.