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

Advances in Non-Invasive Screening Methods for Gastrointestinal Cancers: How Continued Innovation Has Revolutionized Early Cancer Detection

The early diagnosis of gastrointestinal cancers is essential for better survival and to reduce the burden of malignancies worldwide [...].

The Role of DNA Methylation in Gastrointestinal Disease: An Expanded Review of Malignant and Nonmalignant Gastrointestinal Diseases

Esophageal, colorectal, pancreatic, hepatocellular, and gastric cancer together impact millions of patients worldwide each year, with high overall mortality rates, and are increasing in incidence. Additionally, premalignant gastrointestinal diseases, such as Barrett's esophagus and inflammatory bowel disease, are also increasing in incidence. However, involvement of aberrant DNA methylation in these diseases is incompletely understood, especially given recent research advancements in this field. Here, we review knowledge of this epigenetic mechanism in gastrointestinal preneoplasia and neoplasia, considering mechanisms of action, genetic and environmental factors, and 5'-C-phosphate-G-3' island methylator phenotype. We also highlight developments in translational research, focusing on genomic-wide data, methylation-based biomarkers and diagnostic tests, machine learning, and therapeutic epigenetic strategies.

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.

Barrett's Esophagus and Associated Dysplasia

Early detection of dysplasia and effective management are critical steps in halting neoplastic progression in patients with Barrett's esophagus (BE). This review provides a contemporary overview of the BE-related dysplasia, its role in guiding surveillance and management, and discusses emerging diagnostic and therapeutic approaches that might further enhance patient management. Novel, noninvasive techniques for sampling and surveillance, adjunct biomarkers for risk assessment, and their limitations are also discussed.

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.

Population Based Time Trends in the Epidemiology and Mortality of Gastroesophageal Junction and Esophageal Adenocarcinoma

BACKGROUND

Limited data are available on the epidemiology of gastroesophageal junction adenocarcinoma (GEJAC), particularly in comparison to esophageal adenocarcinoma (EAC). With the advent of molecular non-endoscopic Barrett's esophagus (BE) detection tests which sample the esophagus and gastroesophageal junction, early detection of EAC and GEJAC has become a possibility and their epidemiology has gained importance.

AIMS

We sought to evaluate time trends in the epidemiology and survival of patients with EAC and GEJAC in a population-based cohort.

METHODS

EAC and GEJAC patients from 1976 to 2019 were identified using ICD 9 and 10 diagnostic codes from the Rochester Epidemiology Project (REP). Clinical data and survival status were abstracted. Poisson regression was used to calculate incidence rate ratios (IRR). Survival analysis and Cox proportional models were used to assess predictors of survival.

RESULTS

We included 443 patients (287 EAC,156 GEJAC). The incidence of EAC and GEJAC during 1976-2019 was 1.40 (CI 1.1-1.74) and 0.83 (CI 0.61-1.11) per 100,000 people, respectively. There was an increase in the incidence of EAC (IRR = 2.45, p = 0.011) and GEJAC (IRR = 3.17, p = 0.08) from 2000 to 2004 compared to 1995-1999, plateauing in later time periods. Most patients had associated BE and presented at advanced stages, leading to high 5-year mortality rates (66% in EAC and 59% in GEJAC). Age and stage at diagnosis were predictors of mortality.

CONCLUSION

The rising incidence of EAC/GEJAC appears to have plateaued somewhat in the last decade. However, both cancers present at advanced stages with persistently poor survival, underscoring the need for early detection.

Diagnosis and management of Barrett esophagus: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

MR1 : ESGE recommends the following standards for Barrett esophagus (BE) surveillance:- a minimum of 1-minute inspection time per cm of BE length during a surveillance endoscopy- photodocumentation of landmarks, the BE segment including one picture per cm of BE length, and the esophagogastric junction in retroflexed position, and any visible lesions- use of the Prague and (for visible lesions) Paris classification- collection of biopsies from all visible abnormalities (if present), followed by random four-quadrant biopsies for every 2-cm BE length.Strong recommendation, weak quality of evidence. MR2:  ESGE suggests varying surveillance intervals for different BE lengths. For BE with a maximum extent of ≥ 1 cm and < 3 cm, BE surveillance should be repeated every 5 years. For BE with a maximum extent of ≥ 3 cm and < 10 cm, the interval for endoscopic surveillance should be 3 years. Patients with BE with a maximum extent of ≥ 10 cm should be referred to a BE expert center for surveillance endoscopies. For patients with an irregular Z-line/columnar-lined esophagus of < 1 cm, no routine biopsies or endoscopic surveillance are advised.Weak recommendation, low quality of evidence. MR3:  ESGE suggests that, if a patient has reached 75 years of age at the time of the last surveillance endoscopy and/or the patient's life expectancy is less than 5 years, the discontinuation of further surveillance endoscopies can be considered. Weak recommendation, very low quality of evidence. MR4:  ESGE recommends offering endoscopic eradication therapy using ablation to patients with BE and low grade dysplasia (LGD) on at least two separate endoscopies, both confirmed by a second experienced pathologist.Strong recommendation, high level of evidence. MR5:  ESGE recommends endoscopic ablation treatment for BE with confirmed high grade dysplasia (HGD) without visible lesions, to prevent progression to invasive cancer.Strong recommendation, high level of evidence. MR6:  ESGE recommends offering complete eradication of all remaining Barrett epithelium by ablation after endoscopic resection of visible abnormalities containing any degree of dysplasia or esophageal adenocarcinoma (EAC).Strong recommendation, moderate quality of evidence. MR7:  ESGE recommends endoscopic resection as curative treatment for T1a Barrett's cancer with well/moderate differentiation and no signs of lymphovascular invasion.Strong recommendation, high level of evidence. MR8:  ESGE suggests that low risk submucosal (T1b) EAC (i. e. submucosal invasion depth ≤ 500 µm AND no [lympho]vascular invasion AND no poor tumor differentiation) can be treated by endoscopic resection, provided that adequate follow-up with gastroscopy, endoscopic ultrasound (EUS), and computed tomography (CT)/positrion emission tomography-computed tomography (PET-CT) is performed in expert centers.Weak recommendation, low quality of evidence. MR9:  ESGE suggests that submucosal (T1b) esophageal adenocarcinoma with deep submucosal invasion (tumor invasion > 500 µm into the submucosa), and/or (lympho)vascular invasion, and/or a poor tumor differentiation should be considered high risk. Complete staging and consideration of additional treatments (chemotherapy and/or radiotherapy and/or surgery) or strict endoscopic follow-up should be undertaken on an individual basis in a multidisciplinary discussion.Strong recommendation, low quality of evidence. MR10 A: ESGE recommends that the first endoscopic follow-up after successful endoscopic eradication therapy (EET) of BE is performed in an expert center.Strong recommendation, very low quality of evidence. B:  ESGE recommends careful inspection of the neo-squamocolumnar junction and neo-squamous epithelium with high definition white-light endoscopy and virtual chromoendoscopy during post-EET surveillance, to detect recurrent dysplasia.Strong recommendation, very low level of evidence. C:  ESGE recommends against routine four-quadrant biopsies of neo-squamous epithelium after successful EET of BE.Strong recommendation, low level of evidence. D:  ESGE suggests, after successful EET, obtaining four-quadrant random biopsies just distal to a normal-appearing neo-squamocolumnar junction to detect dysplasia in the absence of visible lesions.Weak recommendation, low level of evidence. E:  ESGE recommends targeted biopsies are obtained where there is a suspicion of recurrent BE in the tubular esophagus, or where there are visible lesions suspicious for dysplasia.Strong recommendation, very low level of evidence. MR11:  After successful EET, ESGE recommends the following surveillance intervals:- For patients with a baseline diagnosis of HGD or EAC:at 1, 2, 3, 4, 5, 7, and 10 years after last treatment, after which surveillance may be stopped.- For patients with a baseline diagnosis of LGD:at 1, 3, and 5 years after last treatment, after which surveillance may be stopped.Strong recommendation, low quality of evidence.

AGA Clinical Practice Update on New Technology and Innovation for Surveillance and Screening in Barrett's Esophagus: Expert Review

DESCRIPTION

The purpose of this best practice advice (BPA) article from the Clinical Practice Update Committee of the American Gastroenterological Association is to provide an update on advances and innovation regarding the screening and surveillance of Barrett's esophagus.

METHODS

The BPA statements presented here were developed from expert review of existing literature combined with discussion and expert opinion to provide practical advice. Formal rating of the quality of evidence or strength of BPAs was not the intent of this clinical practice update. This expert review was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPUC and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. BEST PRACTICE ADVICE 1: Screening with standard upper endoscopy may be considered in individuals with at least 3 established risk factors for Barrett's esophagus (BE) and esophageal adenocarcinoma, including individuals who are male, non-Hispanic white, age >50 years, have a history of smoking, chronic gastroesophageal reflux disease, obesity, or a family history of BE or esophageal adenocarcinoma. BEST PRACTICE ADVICE 2: Nonendoscopic cell-collection devices may be considered as an option to screen for BE. BEST PRACTICE ADVICE 3: Screening and surveillance endoscopic examination should be performed using high-definition white light endoscopy and virtual chromoendoscopy, with endoscopists spending adequate time inspecting the Barrett's segment. BEST PRACTICE ADVICE 4: Screening and surveillance exams should define the extent of BE using a standardized grading system documenting the circumferential and maximal extent of the columnar lined esophagus (Prague classification) with a clear description of landmarks and the location and characteristics of visible lesions (nodularity, ulceration), when present. BEST PRACTICE ADVICE 5: Advanced imaging technologies such as endomicroscopy may be used as adjunctive techniques to identify dysplasia. BEST PRACTICE ADVICE 6: Sampling during screening and surveillance exams should be performed using the Seattle biopsy protocol (4-quadrant biopsies every 1-2 cm and target biopsies from any visible lesion). BEST PRACTICE ADVICE 7: Wide-area transepithelial sampling may be used as an adjunctive technique to sample the suspected or established Barrett's segment (in addition to the Seattle biopsy protocol). BEST PRACTICE ADVICE 8: Patients with erosive esophagitis should be biopsied when concern of dysplasia or malignancy exists. A repeat endoscopy should be performed after 8 weeks of twice a day proton pump inhibitor therapy. BEST PRACTICE ADVICE 9: Tissue systems pathology-based prediction assay may be utilized for risk stratification of patients with nondysplastic BE. BEST PRACTICE ADVICE 10: Risk stratification models may be utilized to selectively identify individuals at risk for Barrett's associated neoplasia. BEST PRACTICE ADVICE 11: Given the significant interobserver variability among pathologists, the diagnosis of BE-related neoplasia should be confirmed by an expert pathology review. BEST PRACTICE ADVICE 12: Patients with BE-related neoplasia should be referred to endoscopists with expertise in advanced imaging, resection, and ablation. BEST PRACTICE ADVICE 13: All patients with BE should be placed on at least daily proton pump inhibitor therapy. BEST PRACTICE ADVICE 14: Patients with nondysplastic BE should undergo surveillance endoscopy in 3 to 5 years. BEST PRACTICE ADVICE 15: In patients undergoing surveillance after endoscopic eradication therapy, random biopsies should be taken of the esophagogastric junction, gastric cardia, and the distal 2 cm of the neosquamous epithelium as well as from all visible lesions, independent of the length of the original BE segment.

Expanding beyond endoscopy: A review of non-invasive modalities in Barrett's esophagus screening and surveillance

Barrett's esophagus (BE) is a condition that results from replacement of the damaged normal squamous esophageal mucosa to intestinal columnar mucosa and is the most significant predisposing factor for development of esophageal adenocarcinoma. Current guidelines recommend endoscopic evaluation for screening and surveillance based on various risk factors which has limitations such as invasiveness, availability of a trained specialist, patient logistics and cost. Trans-nasal endoscopy is a less invasive modality but still has similar limitations such as limited availability of trained specialist and costs. Non-endoscopic modalities, in comparison, require minimal intervention, can be done in an office visit and has the potential to be a more ideal choice for mass public screening and surveillance, particularly in patents at low risk for BE. These include newer generations of esophageal capsule endoscopy which provides direct visualization of BE, and tethered capsule endomicroscopy which can obtain high-resolution images of the esophagus. Various cell collection devices coupled with biomarkers have been used for BE screening. Cytosponge, in combination with TFF3, as well as EsophaCap and EsoCheck have shown promising results in various studies when used with various biomarkers. Other modalities including circulatory microRNAs and volatile organic compounds that have demonstrated favorable outcomes. Use of these cell collection methods for BE surveillance is a potential area of future research.

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.

Unsedated transnasal endoscopy for the detection of Barrett's esophagus: systematic review and meta-analysis

Conventional esophagogastroduodenoscopy (cEGD) is currently the gold standard endoscopic procedure for diagnosis and surveillance of Barrett's esophagus (BE). This procedure is however less suitable for widespread screening because of its invasiveness and costs. An alternative endoscopic procedure is unsedated transnasal endoscopy (uTNE). We performed a systematic review and meta-analysis to evaluate the diagnostic accuracy, patient tolerability, technical success rate, and safety of uTNE compared with cEGD for detecting BE and related neoplasia. PubMed, EMBASE, and Cochrane Library were searched for studies that reported the diagnostic accuracy of uTNE compared with cEGD for detecting BE and related neoplasia. Eight prospective studies were included, in which 623 patients underwent both uTNE and cEGD. Pooled sensitivity and specificity of uTNE for detecting columnar epithelium were 98% (95% CI 83-100%) and 99% (95% CI 82-100%), respectively. Pooled sensitivity and specificity of uTNE for detecting intestinal metaplasia in biopsies were 89% (95% CI 78-95%) and 93% (95% CI 71-98%), respectively. In three of the six studies that reported patient tolerability, a higher patient tolerability of uTNE compared with cEGD was reported. The technical success rate of uTNE ranged from 89% to 100% and no (serious) adverse events were reported. This systematic review and meta-analysis provides evidence that uTNE is an accurate, safe, and well-tolerated procedure for the detection of columnar epithelium and can be considered as screening modality for BE.

Feasibility and Safety of Tethered Capsule Endomicroscopy in Patients With Barrett's Esophagus in a Multi-Center Study

BACKGROUND & AIMS

Tethered capsule endomicroscopy (TCE) involves swallowing a small tethered pill that implements optical coherence tomography (OCT) imaging, procuring high resolution images of the whole esophagus. Here, we demonstrate and evaluate the feasibility and safety of TCE and a portable OCT imaging system in patients with Barrett's esophagus (BE) in a multi-center (5-site) clinical study.

METHODS

Untreated patients with BE as per endoscopic biopsy diagnosis were eligible to participate in the study. TCE procedures were performed in unsedated patients by either doctors or nurses. After the capsule was swallowed, the device continuously obtained 10-μm-resolution cross-sectional images as it traversed the esophagus. Following imaging, the device was withdrawn through mouth, and disinfected for subsequent reuse. BE lengths were compared to endoscopy findings when available. OCT-TCE images were compared to volumetric laser endomicroscopy (VLE) images from a patient who had undergone VLE on the same day as TCE.

RESULTS

147 patients with BE were enrolled across all sites. 116 swallowed the capsule (79%), 95/114 (83.3%) men and 21/33 (63.6%) women (P = .01). High-quality OCT images were obtained in 104/111 swallowers (93.7%) who completed the procedure. The average imaging duration was 5.55 ± 1.92 minutes. The mean length of esophagus imaged per patient was 21.69 ± 5.90 cm. A blinded comparison of maximum extent of BE measured by OCT-TCE and EGD showed a strong correlation (r = 0.77-0.79). OCT-TCE images were of similar quality to those obtained by OCT-VLE.

CONCLUSIONS

The capabilities of TCE to be used across multiple sites, be administered to unsedated patients by either physicians or nurses who are not expert in OCT-TCE, and to rapidly and safely evaluate the microscopic structure of the esophagus make it an emerging tool for screening and surveillance of BE patients. Clinical trial registry website and trial number: NCT02994693 and NCT03459339.

Feasibility of using P16 methylation as a cytologic marker for esophageal squamous cell carcinoma screening: A pilot study

BACKGROUND

Early diagnosis and treatment of esophageal squamous cell dysplasia (ESCdys) and esophageal squamous cell carcinoma (ESCC) could significantly reduce the incidence and mortality of ESCC. This pilot study aimed to investigate whether P16/CDKN2A methylation could serve as a cytologic biomarker for early detection of ESCdys and ESCC.

METHODS

Paired esophageal biopsy and cytology specimens (exfoliated cells) were obtained from subjects at different stages of ESCC development. The methylation status of P16 gene in these two specimen types was determined using a 115-bp MethyLight assay. Categorical data were compared by the Chi-square test. Logistic regression was performed to assess adjusted odds ratios of P16 methylation associated with ESCC and ESCdys. Prediction models for identifying individuals at risk of ESCC and high-grade ESCdys (high-grade intraepithelial neoplasia, HGIN) were developed by multivariable logistic regression. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis. Internal validation of the prediction models was performed using the 1000-bootstrap resample.

RESULTS

A total of 105 subjects with diagnoses ranging from normal mucosa through ESCC were included in this study. An increase in P16 methylation frequency was observed with increasing severity of esophageal lesions (p for trend <0.001). In the adjusted logistic regression models, P16 methylation in cytology specimens was positively associated with ESCC and ESCdys risk, whereas P16 methylation in biopsy specimens was only associated with a higher risk of developing ESCC. The predictive capacity of base model I (AUC, 0.816) for ESCC and HGIN was significantly increased by adding P16 methylation in cytology specimens (model III; AUC, 0.882; p = 0.043), but not P16 methylation in biopsy specimens (model II; AUC, 0.850; p = 0.225). Bootstrap validation showed optimism-corrected AUC of 0.789 for model I, 0.822 for model II, and 0.854 for model III.

CONCLUSION

P16 methylation as a cytologic marker was associated with the ESCC development and has the potential for application in minimally invasive ESCC screening.

Computational pathology aids derivation of microRNA biomarker signals from Cytosponge samples

BACKGROUND

Non-endoscopic cell collection devices combined with biomarkers can detect Barrett's intestinal metaplasia and early oesophageal cancer. However, assays performed on multi-cellular samples lose information about the cell source of the biomarker signal. This cross-sectional study examines whether a bespoke artificial intelligence-based computational pathology tool could ascertain the cellular origin of microRNA biomarkers, to inform interpretation of the disease pathology, and confirm biomarker validity.

METHODS

The microRNA expression profiles of 110 targets were assessed with a custom multiplexed panel in a cohort of 117 individuals with reflux that took a Cytosponge test. A computational pathology tool quantified the amount of columnar epithelium present in pathology slides, and results were correlated with microRNA signals. An independent cohort of 139 Cytosponges, each from an individual patient, was used to validate the findings via qPCR.

FINDINGS

Seventeen microRNAs are upregulated in BE compared to healthy squamous epithelia, of which 13 remain upregulated in dysplasia. A pathway enrichment analysis confirmed association to neoplastic and cell cycle regulation processes. Ten microRNAs positively correlated with columnar epithelium content, with miRNA-192-5p and -194-5p accurately detecting the presence of gastric cells (AUC 0.97 and 0.95). In contrast, miR-196a-5p is confirmed as a specific BE marker.

INTERPRETATION

Computational pathology tools aid accurate cellular attribution of molecular signals. This innovative design with multiplex microRNA coupled with artificial intelligence has led to discovery of a quality control metric suitable for large scale application of the Cytosponge. Similar approaches could aid optimal interpretation of biomarkers for clinical use.

FUNDING

Funded by the NIHR Cambridge Biomedical Research Centre, the Medical Research Council, the Rosetrees and Stoneygate Trusts, and CRUK core grants.

Evolutionary dynamics in Barrett oesophagus: implications for surveillance, risk stratification and therapy

Cancer development is a dynamic evolutionary process characterized by marked intratumoural heterogeneity at the genetic, epigenetic and phenotypic levels. Barrett oesophagus, the pre-malignant condition to oesophageal adenocarcinoma (EAC), is an exemplary system to longitudinally study the evolution of malignancy. Evidence has emerged of Barrett oesophagus lesions pre-programmed for progression to EAC many years before clinical detection, indicating a considerable window for therapeutic intervention. In this Review, we explore the mechanisms underlying clonal expansion and contraction that establish the Barrett oesophagus clonal mosaicism over time and space and discuss intrinsic genotypic and extrinsic environmental drivers that direct the evolutionary trajectory of Barrett oesophagus towards a malignant phenotype. We propose that understanding and exploiting the evolutionary dynamics of Barrett oesophagus will identify novel therapeutic targets, improve prognostic tools and offer the opportunity for personalized surveillance programmes geared to prevent progression to EAC.

Innovations in Screening Tools for Barrett's Esophagus and Esophageal Adenocarcinoma

PURPOSE OF REVIEW

Esophageal adenocarcinoma (EAC) is a lethal disease with rapidly rising incidence. Screening for EAC and its metaplastic precursor, Barrett's esophagus (BE), followed by endoscopic surveillance and endoscopic treatment of dysplasia or early EAC are promising approaches to decreasing EAC incidence and EAC mortality. Historically, screening for EAC has been completed with a traditional per-oral esophagogastroduodenoscopy (EGD); however, this method has limitations including cost, tolerability, and accessibility. For this reason, much effort has been put forward to develop more effective, minimally invasive, and accessible BE and EAC screening tools. The purpose of this review is to describe recent developments of these novel tools.

RECENT FINDINGS

While endoscopic alternatives such as transnasal endoscopy are cheaper and well tolerated, they have not gained acceptance. Non-endoscopic modalities namely, swallowable cell collection devices coupled with biomarker analysis have been found to have excellent performance characteristics, tolerability, and cost effectiveness. In this article, we provide an update on innovative developments in EAC/BE screening modalities including transnasal endoscopy, capsule endomicroscopy, swallowable cell collection devices, and exhaled volatile organic compound analyses.

Validation of a methylated DNA marker panel for the nonendoscopic detection of Barrett's esophagus in a multisite case-control study

BACKGROUND AND AIMS

We previously identified a 5 methylated DNA marker (MDM) panel for the detection of nonendoscopic Barrett's esophagus (BE). In this study, we aimed to recalibrate the performance of the 5 MDM panel using a simplified assay in a training cohort, validate the panel in an independent test cohort, and explore the accuracy of an MDM panel with only 3 markers.

METHODS

Participants were recruited from 3 medical centers. The sponge on a string device (EsophaCap; CapNostics, Concord, NC, USA) was swallowed and withdrawn, followed by endoscopy, in BE cases and control subjects. A 5 MDM panel was blindly assayed using a simplified assay. Random forest modeling analysis was performed, in silico cross-validated in the training set, and then locked down, before test set analysis.

RESULTS

The training set had 199 patients: 110 BE cases and 89 control subjects, and the test set had 89 patients: 60 BE cases and 29 control subjects. Sensitivity of the 5 MDM panel for BE diagnosis was 93% at 90% specificity in the training set and 93% at 93% specificity in the test set. Areas under the receiver operating characteristic curves were .96 and .97 in the training and test sets, respectively. Model accuracy was not influenced by age, sex, or smoking history. Multiple 3 MDM panels achieved similar accuracy.

CONCLUSIONS

A 5 MDM panel for BE is highly accurate in training and test sets in a blinded multisite case-control analysis using a simplified assay. This panel may be reduced to only 3 MDMs in the future. (Clinical trial registration number: NCT02560623.).

Follow-Up Study Confirms the Presence of Gastric Cancer DNA Methylation Hallmarks in High-Risk Precursor Lesions

To adopt prevention strategies in gastric cancer, it is imperative to develop robust biomarkers with acceptable costs and feasibility in clinical practice to stratified populations according to risk scores. With this aim, we applied an unbiased genome-wide CpG methylation approach to a discovery cohort composed of gastric cancer (n = 24), and non-malignant precursor lesions (n = 64). Then, candidate-methylation approaches were performed in a validation cohort of precursor lesions obtained from an observational longitudinal study (n = 264), with a 12-year follow-up to identify repression or progression cases. H. pylori stratification and histology were considered to determine their influence on the methylation dynamics. As a result, we ascertained that intestinal metaplasia partially recapitulates patterns of aberrant methylation of intestinal type of gastric cancer, independently of the H. pylori status. Two epigenetically regulated genes in cancer, RPRM and ZNF793, consistently showed increased methylation in intestinal metaplasia with respect to earlier precursor lesions. In summary, our result supports the need to investigate the practical utilities of the quantification of DNA methylation in candidate genes as a marker for disease progression. In addition, the H. pylori-dependent methylation in intestinal metaplasia suggests that pharmacological treatments aimed at H. pylori eradication in the late stages of precursor lesions do not prevent epigenome reprogramming toward a cancer signature.

Screening for Barrett's Oesophagus: Are We Ready for it?

Purpose of review

The targeted approach adopted for Barrett’s oesophagus (BO) screening is sub-optimal considering the large proportion of BO cases that are currently missed. We reviewed the literature highlighting recent technological advancements in efforts to counteract this challenge. We also provided insights into strategies that can improve the outcomes from current BO screening practises.

Recent findings

The standard method for BO detection, endoscopy, is invasive and expensive and therefore inappropriate for mass screening. On the other hand, endoscopy is more cost-effective for screening a high-risk population. A consensus has however not been reached on who should be screened. Risk prediction algorithms have been tested as an enrichment pre-screening tool reporting modest AUC’s but require more prospective evaluation studies. Less invasive endoscopy methods like trans-nasal endoscopy, oesophageal capsule endsocopy and non-endoscopic cell collection devices like the Cytosponge coupled with biomarker analysis have shown promise in BO detection with randomised clinical trial evidence.

Summary

A three-tier precision cancer programme whereby risk prediction algorithms and non-endoscopic minimally invasive cell collection devices are used to triage test a wider pool of individuals may improve the detection rate of current screening practises with minimal cost implications.

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.

Endoscopic Screening for Barrett's Esophagus and Esophageal Adenocarcinoma: Rationale, Candidates, and Challenges

Barrett's esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC), a cancer with increasing incidence and poor survival. Risk of EAC in patients with BE is higher compared with the general population. Endoscopic screening for BE is performed to identify patients earlier in the metaplasia-dysplasia-carcinoma sequence from BE to EAC to enable eradication therapy. BE screening should be considered in individuals with multiple risk factors for BE and EAC. Challenges to BE screening include the absence of a cost-effective, widely applicable minimally invasive screening tool, gastroesophageal reflux disease centric screening recommendations, and limitations of current endoscopic surveillance practice.

DIAGNOSIS, TREATMENT AND FOLLOW-UP OF BARRETT'S ESOPHAGUS: A SYSTEMATIC REVIEW

BACKGROUND

Barrett's esophagus (BE) is a premalignant condition that raises controversy among general practitioners and specialists, especially regarding its diagnosis, treatment, and follow-up protocols.

OBJECTIVE

This systematic review aims to present the particularities and to clarify controversies related to the diagnosis, treatment and surveillance of BE.

METHODS

A systematic review was conducted on PubMed, Cochrane, and SciELO based on articles published in the last 10 years. PRISMA guidelines were followed and the search was made using MeSH and non-MeSH terms "Barrett" and "diagnosis or treatment or therapy or surveillance". We searched for complete randomized controlled clinical trials or Phase IV studies, carried out with individuals over 18 years old.

RESULTS

A total of 42 randomized controlled trials were selected after applying all inclusion and exclusion criteria. A growing trend of alternative and safer techniques to traditional upper gastrointestinal endoscopy were identified, which could improve the detection of BE and patient acceptance. The use of chromoendoscopy-guided biopsy protocols significantly reduced the number of biopsies required to maintain similar BE detection rates. Furthermore, the value of BE chemoprophylaxis with esomeprazole and acetylsalicylic acid was relevant, as well as the establishment of protocols for the follow-up and endoscopic surveillance of patients with BE based predominantly on the presence and degree of dysplasia, as well as on the length of the follow-up affected by BE.

CONCLUSION

Although further studies regarding the diagnosis, treatment and follow-up of BE are warranted, in light of the best evidence presented in the last decade, there is a trend towards electronic chromoendoscopy-guided biopsies for the diagnosis of BE, while treatment should encompass endoscopic techniques such as radiofrequency ablation. Risks of ablative endoscopic methods should be weighted against those of resective surgery. It is also important to consider lifetime endoscopic follow-up for both short and long term BE patients, with consideration to limitations imposed by a range of comorbidities. Unfortunately, there are no randomized controlled trials that have evaluated which is the best recommendation for BE follow-up and endoscopic surveillance (>1 cm) protocols, however, based on current International Guidelines, it is recommended esophagogastroduodenoscopy (EGD) every 5 years in BE without dysplasia with 1 up to 3 cm of extension; every 3 years in BE without dysplasia with >3 up to 10 cm of extension, every 6 to 12 months in BE with low grade dysplasia and, finally, EGD every 3 months after ablative endoscopic therapy in cases of BE with high grade dysplasia.

A narrative review of Barrett's esophagus in 2020, molecular and clinical update

Barrett’s esophagus (BE) is a condition resulting from an acquired metaplastic epithelial change in the esophagus in response to gastroesophageal reflux. BE is the only known precursor lesion to esophageal adenocarcinoma, and can progress from non-dysplastic BE (NDBE) to low grade dysplasia (LGD) and high grade dysplasia (HGD), and ultimately invasive carcinoma. Although the risk of developing esophageal adenocarcinoma (EAC) in NBDE is less than 0.5% per year, there has been a rising incidence of EAC in Western countries, which continue to drive efforts to optimize screening and surveillance methods. The current gold standard for diagnosis is esophagogastroduodenoscopy (EGD), and there has been significant interest in alternative, minimally invasive methods for screening which would be more readily accessible in the primary care setting. Surveillance endoscopy in 3–5 years is recommended for NDBE given the low progression to EAC. The mainstay of treatment for LGD and HGD is endoscopic eradication therapy (EET). Visible lesions are treated with endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). Radiofrequency ablation (RFA) is considered first line therapy for flat dysplastic BE and cryotherapy has shown promising results as an alternate form of treatment for of dysplasia. The molecular progression of BE to EAC is a complex process involving multiple pathways involving genetic and epigenetic modifications. Genomic studies have further led to the understanding of the complex molecular landscape that occurs early and late in the disease process. Promising biomarker panels have been investigated to help with the diagnosis of BE as well as aid in the risk stratification of BE during surveillance. In addition, clinical prediction models have been developed to categorize BE patients in low, intermediate, and high risk for progression to HGD and EAC. Further clinical and translational research is needed to help refine markers and techniques in diagnosis, screening, and surveillance.

Accurate Nonendoscopic Detection of Barrett's Esophagus by Methylated DNA Markers: A Multisite Case Control Study

INTRODUCTION

Nonendoscopic Barrett's esophagus (BE) screening may help improve esophageal adenocarcinoma outcomes. We previously demonstrated promising accuracy of methylated DNA markers (MDMs) for the nonendoscopic diagnosis of BE using samples obtained from a capsule sponge-on-string (SOS) device. We aimed to assess the accuracy of these MDMs in an independent cohort using a commercial grade assay.

METHODS

BE cases had ≥ 1 cm of circumferential BE with intestinal metaplasia; controls had no endoscopic evidence of BE. The SOS device was withdrawn 8 minutes after swallowing, followed by endoscopy (the criterion standard). Highest performing MDMs from a previous study were blindly assessed on extracted bisulfite-converted DNA by target enrichment long-probe quantitative amplified signal (TELQAS) assays. Optimal MDM combinations were selected and analyzed using random forest modeling with in silico cross-validation.

RESULTS

Of 295 patients consented, 268 (91%) swallowed the SOS device; 112 cases and 89 controls met the pre-established inclusion criteria. The median BE length was 6 cm (interquartile range 4-9), and 50% had no dysplasia. The cross-validated sensitivity and specificity of a 5 MDM random forest model were 92% (95% confidence interval 85%-96%) and 94% (95% confidence interval 87%-98%), respectively. Model performance was not affected by age, gender, or smoking history but was influenced by the BE segment length. SOS administration was well tolerated (median [interquartile range] tolerability 2 [0, 4] on 10 scale grading), and 95% preferred SOS over endoscopy.

DISCUSSION

Using a minimally invasive molecular approach, MDMs assayed from SOS samples show promise as a safe and accurate nonendoscopic test for BE prediction.

Predicting Progression in Barrett's Esophagus: Is the Holy Grail Within Reach?

Risk stratification in Barrett's esophagus may allow aggressive management of those at "high risk" and reduction in surveillance in at "low" risk. Davison et al. report the results of the independent validation of a multibiomarker panel (TissueCypher assay) performed on biopsy tissue, in a case control study. "High-risk" patients progressed 5 times more than those at "low risk." Sensitivity and specificity for "high-risk" patients were 29% and 86% with a positive predictive value of 23%. A negative predictive value of a "low-risk" score was 96%. These findings may allow more intensive surveillance in those at "high risk." Despite some limitations, this assay is a potentially major advance in the management of Barrett's esophagus patients without dysplasia.

Approach to the Post-Ablation Barrett's Esophagus Patient

Because of the rising incidence and lethality of esophageal adenocarcinoma, Barrett's esophagus (BE) is an increasingly important premalignant target for cancer prevention. BE-associated neoplasia can be safely and effectively treated with endoscopic eradication therapy (EET), incorporating tissue resection and ablation. Because EET has proliferated, managing patients after complete eradication of intestinal metaplasia has taken on increasing importance. Recurrence after complete eradication of intestinal metaplasia occurs in 8%-10% of the patients yearly, and the incidence may remain constant over time. Most recurrences occur at the gastroesophageal junction, whereas those in the tubular esophagus are endoscopically visible and distally located. A simplified biopsy protocol limited to the distal aspect of the BE segment, in addition to gastroesophageal junction sampling, may enhance efficiency and cost without significantly reducing recurrence detection. Similarly, research suggests that current surveillance intervals may be excessively frequent, failing to reflect the cancer risk reduction of EET. If validated, longer surveillance intervals could reduce the burden of resource-intensive endoscopic surveillance. Several important questions in post-EET management remain unanswered, including surveillance duration, the significance of gastric cardia intestinal metaplasia, and the role of advanced imaging and nonendoscopic sampling techniques in detecting recurrence. These merit further research to enhance quality of care and promote a more evidence-based approach.

Methylated DNA in Pancreatic Juice Distinguishes Patients With Pancreatic Cancer From Controls

BACKGROUND & AIMS

Precursors of pancreatic cancer arise in the ductal epithelium; markers exfoliated into pancreatic juice might be used to detect high-grade dysplasia (HGD) and cancer. Specific methylated DNA sequences in pancreatic tissue have been associated with adenocarcinoma. We analyzed these methylated DNA markers (MDMs) in pancreatic juice samples from patients with pancreatic ductal adenocarcinomas (PDACs) or intraductal papillary mucinous neoplasms (IPMNs) with HGD (cases), and assessed their ability to discriminate these patients from individuals without dysplasia or with IPMNs with low-grade dysplasia (controls).

METHODS

We obtained pancreatic juice samples from 38 patients (35 with biopsy-proven PDAC or pancreatic cystic lesions with invasive cancer and 3 with HGD) and 73 controls (32 with normal pancreas and 41 with benign disease), collected endoscopically from the duodenum after secretin administration from February 2015 through November 2016 at 3 medical centers. Samples were analyzed for the presence of 14 MDMs (in the genes NDRG4, BMP3, TBX15, C13orf18, PRKCB, CLEC11A, CD1D, ELMO1, IGF2BP1, RYR2, ADCY1, FER1L4, EMX1, and LRRC4), by quantitative allele-specific real-time target and signal amplification. We performed area under the receiver operating characteristic curve analyses to determine the ability of each marker, and panels of markers, to distinguish patients with HGD and cancer from controls. MDMs were combined to form a panel for detection using recursive partition trees.

RESULTS

We identified a group of 3 MDMs (at C13orf18, FER1L4, and BMP3) in pancreatic juice that distinguished cases from controls with an area under the receiver operating characteristic value of 0.90 (95% CI, 0.83-0.97). Using a specificity cut-off value of 86%, this group of MDMs distinguished patients with any stage of pancreatic cancer from controls with 83% sensitivity (95% CI, 66%-93%) and identified patients with stage I or II PDAC or IPMN with HGD with 80% sensitivity (95% CI, 56%-95%).

CONCLUSIONS

We identified a group of 3 MDMs in pancreatic juice that identify patients with pancreatic cancer with an area under the receiver operating characteristic value of 0.90, including patients with early stage disease or advanced precancer. These DNA methylation patterns might be included in algorithms for early detection of pancreatic cancer, especially in high-risk cohorts. Further optimization and clinical studies are needed.

Discovery, Validation, and Application of Novel Methylated DNA Markers for Detection of Esophageal Cancer in Plasma

PURPOSE

The burden of esophageal cancer continues to rise, and noninvasive screening tools are needed. Methylated DNA markers (MDM) assayed from plasma show promise in detection of other cancers. For esophageal cancer detection, we aimed to discover and validate MDMs in tissue, and determine their feasibility when assayed from plasma.

EXPERIMENTAL DESIGN

Whole-methylome sequencing was performed on DNA extracted from 37 tissues (28 EC; 9 normal esophagus) and 8 buffy coat samples. Top MDMs were validated by methylation specific PCR on tissue from 76 EC (41 adeno, 35 squamous cell) and 17 normal esophagus. Quantitative allele-specific real-time target and signal amplification was used to assay MDMs in plasma from 183 patients (85 EC, 98 controls). Recursive partitioning (rPART) identified MDM combinations predictive of esophageal cancer. Validation was performed in silico by bootstrapping.

RESULTS

From discovery, 23 candidate MDMs were selected for independent tissue validation; median area under the receiver operating curve (AUC) for individual MDMs was 0.93. Among 12 MDMs advanced to plasma testing, rPART modeling selected a 5 MDM panel (FER1L4, ZNF671, ST8SIA1, TBX15, ARHGEF4) which achieved an AUC of 0.93 (95% CI, 0.89-0.96) on best-fit and 0.81 (95% CI, 0.75-0.88) on cross-validation. At 91% specificity, the panel detected 74% of esophageal cancer overall, and 43%, 64%, 77%, and 92% of stages I, II, III, and IV, respectively. Discrimination was not affected by age, sex, smoking, or body mass index.

CONCLUSIONS

Novel MDMs assayed from plasma detect esophageal cancer with moderate accuracy. Further optimization and clinical testing are warranted.

Use of the Electronic Health Record to Target Patients for Non-endoscopic Barrett's Esophagus Screening

BACKGROUND

Clinical prediction models targeting patients for Barrett's esophagus (BE) screening include data obtained by interview, questionnaire, and body measurements. A tool based on electronic health records (EHR) data could reduce cost and enhance usability, particularly if combined with non-endoscopic BE screening methods.

AIMS

To determine whether EHR-based data can identify BE patients.

METHODS

We performed a retrospective review of patients ages 50-75 who underwent a first-time esophagogastroduodenoscopy. Data extracted from the EHR included demographics and BE risk factors. Endoscopy and pathology reports were reviewed for histologically confirmed BE. Screening criteria modified from clinical guidelines were assessed for association with BE. Subsequently, a score based on multivariate logistic regression was developed and assessed for its ability to identify BE subjects.

RESULTS

A total of 2931 patients were assessed, and BE was found in 1.9%. Subjects who met screening criteria were more likely to have BE (3.3% vs. 1.1%, p = 0.001), and the criteria predicted BE with an AUROC of 0.65 (95% CI 0.59-0.71). A score based on logistic regression modeling included gastroesophageal reflux disease, sex, body mass index, and ever-smoker status and identified BE subjects with an AUROC of 0.71 (95% CI 0.64-0.77). Both prediction tools produced higher AUROCs in women than in men.

CONCLUSIONS

EHR-based BE risk prediction tools identify BE patients with fair accuracy. While these tools may improve the efficiency of patient targeting for BE screening in the primary care setting, challenges remain to identify high-risk patients for non-invasive BE screening in clinical practice.

Barrett Esophagus

Barrett esophagus is a metaplastic change in the lining of the distal esophageal epithelium, characterized by replacement of the normal squamous epithelium by specialized intestinal metaplasia. The presence of Barrett esophagus increases the risk of esophageal adenocarcinoma several-fold. Esophageal adenocarcinoma is a malignancy with rapidly rising incidence and persistently poor outcomes when diagnosed after the onset of symptoms. Risk factors for Barrett esophagus include chronic gastroesophageal reflux, central obesity, white race, male gender, older age, smoking, and a family history of Barrett esophagus or esophageal adenocarcinoma. Screening for Barrett esophagus in those with several risk factors followed by endoscopic surveillance to detect dysplasia or adenocarcinoma is currently recommended by society guidelines. Minimally invasive nonendoscopic tools for the early detection of Barrett esophagus are currently being developed. Multimodality endoscopic therapy-using a combination of endoscopic resection and ablation techniques-for the treatment of dysplasia and early adenocarcinoma is successful in eliminating intestinal metaplasia and preventing progression to adenocarcinoma, with outcomes comparable to those after esophagectomy. Risk stratification of those diagnosed with Barrett esophagus is a challenge at present, with active research focused on identifying clinical and biomarker panels to identify those with low and high risk of progression. This narrative review highlights some of the challenges and recent progress in this field.

Novel Methylated DNA Markers Discriminate Advanced Neoplasia in Pancreatic Cysts: Marker Discovery, Tissue Validation, and Cyst Fluid Testing

OBJECTIVES

Pancreatic cystic lesions (PCLs) may be precancerous. Those likely to harbor high-grade dysplasia (HGD) or pancreatic cancer (PC) are targets for surgical resection. Current algorithms to predict advanced neoplasia (HGD/PC) in PCLs lack diagnostic accuracy. In pancreatic tissue and cyst fluid (CF) from PCLs, we sought to identify and validate novel methylated DNA markers (MDMs) that discriminate HGD/PC from low-grade dysplasia (LGD) or no dysplasia (ND).

METHODS

From an unbiased whole-methylome discovery approach using predefined selection criteria followed by multistep validation on case (HGD or PC) and control (ND or LGD) tissues, we identified discriminant MDMs. Top candidate MDMs were then assayed by quantitative methylation-specific polymerase chain reaction on archival CF from surgically resected PCLs.

RESULTS

Of 25 discriminant MDMs identified in tissue, 13 were selected for validation in 134 CF samples (21 cases [8 HGD, 13 PC], 113 controls [45 ND, 68 LGD]). A tree-based algorithm using 2 CF-MDMs (TBX15, BMP3) achieved sensitivity and specificity above 90%. Discrimination was significantly better by this CF-MDM panel than by mutant KRAS or carcinoembryonic antigen, with areas under the receiver operating characteristic curve of 0.93 (95% confidence interval: 0.86-0.99), 0.71 (0.57-0.85), and 0.72 (0.60-0.84), respectively. Cutoffs for the MDM panel applied to an independent CF validation set (31 cases, 56 controls) yielded similarly high discrimination, areas under the receiver operating characteristic curve = 0.86 (95% confidence interval: 0.77-0.94, P = 0.2).

DISCUSSION

Novel MDMs discovered and validated in tissue accurately identify PCLs harboring HGD/PC. A panel of 2 MDMs assayed in CF yielded results with potential to enhance current risk prediction algorithms. Prospective studies are indicated to optimize and further evaluate CF-MDMs for clinical use.

Novel Screening Tests for Barrett's Esophagus

PURPOSE OF REVIEW

There has been an exponential increase in the incidence of esophageal adenocarcinoma (EAC) over the last half century. Barrett's esophagus (BE) is the only known precursor lesion of EAC. Screening for BE in high-risk populations has been advocated with the aim of identifying BE, followed by endoscopic surveillance to detect dysplasia and early stage cancer, with the intent that treatment can improve outcomes. We aimed to review BE screening methodologies currently recommended and in development.

RECENT FINDINGS

Unsedated transnasal endoscopy allows for visualization of the distal esophagus, with potential for biopsy acquisition, and can be done in the office setting. Non-endoscopic screening methods being developed couple the use of swallowable esophageal cell sampling devices with BE specific biomarkers, as well as trefoil factor 3, methylated DNA markers, and microRNAs. This approach has promising accuracy. Circulating and exhaled volatile organic compounds and the foregut microbiome are also being explored as means of detecting EAC and BE in a non-invasive manner. Non-invasive diagnostic techniques have shown promise in the detection of BE and may be effective methods of screening high-risk patients.

Gastrointestinal Endoscopy Editorial Board top 10 topics: advances in GI endoscopy in 2018

The American Society for Gastrointestinal Endoscopy's Gastrointestinal Endoscopy Editorial Board reviewed original endoscopy-related articles published during 2018 in Gastrointestinal Endoscopy and 10 other leading medical and gastroenterology journals. Votes from each individual member were tallied to identify a consensus list of 10 topic areas of major advances in GI endoscopy. Individual board members summarized important findings published in these 10 areas of adenoma detection, bariatric endoscopy, EMR/submucosal dissection/full-thickness resection, artificial intelligence, expandable metal stents for palliation of biliary obstruction, pancreatic therapy with lumen-apposing metal stents, endoscope reprocessing, Barrett's esophagus, interventional EUS, and GI bleeding. This document summarizes these "Top 10" endoscopic advances of 2018.

Barrett oesophagus

Barrett oesophagus (BE), the only known histological precursor of oesophageal adenocarcinoma (EAC), is a condition in which the squamous epithelium of the oesophagus is replaced by columnar epithelium as an adaptive response to gastro-oesophageal reflux. EAC has one of the fastest rising incidences of cancers in Western countries and has a dismal prognosis. BE is usually detected during endoscopic examination, and diagnosis is confirmed by the histological presence of intestinal metaplasia. Advances in genomics and transcriptomics have improved our understanding of the pathogenesis and malignant progression of intestinal metaplasia. As the majority of EAC cases are diagnosed in individuals without a known history of BE, screening for BE could potentially decrease disease-related mortality. Owing to the pre-malignant nature of BE, endoscopic surveillance of patients with BE is imperative for early detection and treatment of dysplasia to prevent further progression to invasive EAC. Developments in endoscopic therapy have resulted in a major shift in the treatment of patients with BE who have dysplasia or early EAC, from surgical resection to endoscopic resection and ablation. In addition to symptom control by optimization of lifestyle and pharmacological therapy with proton pump inhibitors, chemopreventive strategies based on NSAIDs and statins are currently being investigated for BE management.

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

PURPOSE

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

EXPERIMENTAL DESIGN

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

RESULTS

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

CONCLUSIONS

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

Barrett's esophagus: novel strategies for screening and surveillance

Barrett’s esophagus is the precursor lesion for esophageal adenocarcinoma. Screening and surveillance of Barrett’s esophagus are undertaken with the goal of earlier detection and lowering the mortality from esophageal adenocarcinoma. The widely used technique is standard esophagogastroduodenoscopy with biopsies per the Seattle protocol for screening and surveillance of Barrett’s esophagus. Surveillance intervals vary depending on the degree of dysplasia with endoscopic eradication therapy confined to patients with Barrett’s esophagus and confirmed dysplasia. In this review, we present various novel techniques for screening of Barrett’s esophagus such as unsedated transnasal endoscopy, cytosponge with trefoil factor-3, balloon cytology, esophageal capsule endoscopy, liquid biopsy, electronic nose, and oral microbiome. In addition, advanced imaging techniques such as narrow band imaging, dye-based chromoendoscopy, confocal laser endomicroscopy, volumetric laser endomicroscopy, and wide-area transepithelial sampling with computer-assisted three-dimensional analysis developed for better detection of dysplasia are also reviewed.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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