Acetic acid chromoendoscopy in Barrett's esophagus surveillance is superior to the standardized random biopsy protocol: results from a large cohort study (with video)

Dedicated service for Barrett's oesophagus surveillance endoscopy yields higher dysplasia detection and guideline adherence in a non-tertiary setting in the UK: a 5-year comparative cohort study

Objective

Barrett's oesophagus (BO) endoscopic surveillance is performed to varying quality, dedicated services may offer improved outcomes. This study compares a dedicated BO service to standard care, specifically dysplasia detection rate (DDR), guideline adherence and use of advanced imaging modalities in a non-tertiary setting.

Design/method

5-year retrospective comparative cohort study comparing a dedicated BO endoscopy service with surveillance performed on non-dedicated slots at a non-tertiary centre in the UK. All adult patients undergoing BO surveillance between 1 March 2016 and 1 March 2021 were reviewed and those who underwent endoscopy on a dedicated BO service run by endoscopists with training in BO was compared with patients receiving their BO surveillance on any other endoscopy list. Endoscopy reports, histology results and clinic letters were reviewed for DDR and British society of gastroenterology guideline adherence.

Results

921 BO procedures were included (678 patients). 574 (62%) endoscopies were on a dedicated BO list vs 348 (38%) on non-dedicated.DDR was significantly higher in the dedicated cohort 6.3% (36/568) vs 2.7% (9/337) (p=0.014). Significance was sustained when cases with indefinite for dysplasia were excluded: 4.9% 27/533 vs 0.9% 3/329 (p=0.002). Guideline adherence was significantly better on the dedicated endoscopy lists.Factors associated with dysplasia detection in regression analysis included visible lesion documentation (p=0.036), use of targeted biopsies (p=<0.001), number of biopsies obtained (p≤0.001).

Conclusions

A dedicated Barrett's service showed higher DDR and guideline adherence than standard care and may be beneficial pending randomised trial data.

Effect of biopsy protocol adherence vs non-adherence on dysplasia detection rates in Barrett's esophagus surveillance endoscopies: a systematic review and meta-analysis

Background  Barrett's esophagus (BE) surveillance endoscopies are advised for early diagnosis of esophageal adenocarcinoma (EAC). Current guidelines recommend obtaining four-quadrant random biopsies every 2 centimeters of BE length alongside with targeted biopsies if visible lesions are present. Low adherence rates for this random biopsy protocol are widely reported. The aim of this systematic review and meta-analysis was to assess the effect of adherence versus non-adherence to the four-quadrant biopsy protocol on detection of dysplasia in BE patients. Methods  We searched for studies that reported effects of adherence and non-adherence to the four-quadrant biopsy protocol on dysplasia detection rates in BE patients. Adherence was defined as taking a minimum of 4 quadrant random biopsies per 2 cm of BE segment. Studies with low risk of bias and without applicability concerns were included in a good quality synthesis. Pooled relative risks (RRs) with 95% confidence interval (CI) of dysplasia detection rates were calculated. Results  A total of 1,570 studies were screened and 8 studies were included. Four studies were included in the good quality synthesis. In the pooled good quality analysis, four-quadrant biopsy protocol adherence significantly increased detection of dysplasia compared to non-adherence (RR 1.90, 95 % CI = 1.36-2.64; I2 = 45 %). Pooled RRs for LGD and HGD/EAC were 2.00 (95 % CI = 1.49-2.69; I2 = 0 %) and 2.03 (95 % CI = 0.98-4.24; I2 = 28 %), respectively. Conclusion  This systematic review and meta-analysis demonstrates that four-quadrant biopsy protocol adherence is associated with increased detection of dysplasia in BE patients. Efforts should be made to increase biopsy protocol adherence rates.

Role of artificial intelligence in diagnosing Barrett's esophagus-related neoplasia

Barrett's esophagus is associated with an increased risk of adenocarcinoma. Thorough screening during endoscopic surveillance is crucial to improve patient prognosis. Detecting and characterizing dysplastic or neoplastic Barrett's esophagus during routine endoscopy are challenging, even for expert endoscopists. Artificial intelligence-based clinical decision support systems have been developed to provide additional assistance to physicians performing diagnostic and therapeutic gastrointestinal endoscopy. In this article, we review the current role of artificial intelligence in the management of Barrett's esophagus and elaborate on potential artificial intelligence in the future.

Current status of surveillance for Barrett's esophagus in Japan and the West

Prospective studies in western countries have shown that the obvious risk factors for Barrett's esophageal cancer are male sex, smoking habit, a longer length of Barrett's esophagus, and low‐grade dysplasia. However, few reports have prospectively examined risk factors for adenocarcinoma development from Barrett's esophagus in Japan. In the West, where adenocarcinoma is common among esophageal cancer, endoscopic surveillance of Barrett's esophagus every 2–5 years is recommended for early detection of adenocarcinoma. However, there is no established surveillance method in Japan. In recent years, the incidence of adenocarcinoma from long‐segment Barrett's esophagus and short‐segment Barrett's esophagus longer than 2 cm in Japan has been reported to be similar to the West. For surveillance of adenocarcinoma arising from Barrett's esophagus, recognizing the characteristics of superficial adenocarcinoma and carefully observing the entire Barrett's esophagus are needed. It has been reported that representative characteristics of Barrett's adenocarcinoma are a reddish area or a lesion located on the anterior to the right sidewall. It is necessary to establish surveillance methods for Barrett's esophagus sooner in Japan.

Developing patient-orientated Barrett's oesophagus services: the role of dedicated services

Introduction

Barrett’s oesophagus (BO) is common and is a precursor to oesophageal adenocarcinoma with a 0.33% per annum risk of progression. Surveillance and follow-up services for BO have been shown to be lacking, with studies showing inadequate adherence to guidelines and patients reporting a need for greater disease-specific knowledge. This review explores the emerging role of dedicated services for patients with BO.

Methods

A literature search of PubMed, MEDLINE, Embase, Emcare, HMIC, BNI, CiNAHL, AMED and PsycINFO in regard to dedicated BO care pathways was undertaken.

Results

Prospective multicentre and randomised trials were lacking. Published cohort data are encouraging with improvements in guideline adherence with dedicated services, with one published study showing significant improvements in dysplasia detection rates. Accuracy of allocation to surveillance endoscopy has been shown to hold cost savings, and a study of a dedicated clinic showed increased discharges from unnecessary surveillance. Training modalities for BO surveillance and dysplasia detection exist, which could be used to educate a BO workforce. Qualitative and quantitative studies have shown patients report high levels of cancer worry and poor disease-specific knowledge, but few studies have explored follow-up care models despite being a patient and clinician priority for research.

Conclusions

Cost–benefit analysis for dedicated services, considering both financial and environmental impacts, and more robust clinical data must be obtained to support this model of care in the wider health service. Greater understanding is needed of the root causes for poor guideline adherence, and disease-specific models of care should be designed around clinical and patient-reported outcomes to address the unmet needs of patients with BO.

Barrett's esophagus: The pathomorphological and molecular genetic keystones of neoplastic progression

Barrett's esophagus is a widespread chronically progressing disease of heterogeneous nature. A life threatening complication of this condition is neoplastic transformation, which is often overlooked due to lack of standardized approaches in diagnosis, preventative measures and treatment. In this essay, we aim to stratify existing data to show specific associations between neoplastic transformation and the underlying processes which predate cancerous transition. We discuss pathomorphological, genetic, epigenetic, molecular and immunohistochemical methods related to neoplasia detection on the basis of Barrett's esophagus. Our review sheds light on pathways of such neoplastic progression in the distal esophagus, providing valuable insight into progression assessment, preventative targets and treatment modalities. Our results suggest that molecular, genetic and epigenetic alterations in the esophagus arise earlier than cancerous transformation, meaning the discussed targets can help form preventative strategies in at-risk patient groups.

Current Status of Image-Enhanced Endoscopy for Early Identification of Esophageal Neoplasms

Advanced esophageal cancer is known to have a poor prognosis. The early detection of esophageal neoplasms, including esophageal dysplasia and early esophageal cancer, is highly important for the accurate treatment of the disease. However, esophageal dysplasia and early esophageal cancer are usually subtle and can be easily missed. In addition to the early detection, proper pretreatment evaluation of the depth of invasion of esophageal cancer is very important for curative treatment. The progression of non-invasive diagnosis via image-enhanced endoscopy techniques has been shown to aid the early detection and estimate the depth of invasion of early esophageal cancer and, as a result, may provide additional opportunities for curative treatment. Here, we review the advancement of image-enhanced endoscopy-related technologies and their role in the early identification of esophageal neoplasms.

Modern Diagnosis of Early Esophageal Cancer: From Blood Biomarkers to Advanced Endoscopy and Artificial Intelligence

Simple Summary

Esophageal cancer (EC) has a poor prognosis when the diagnosis is delayed, but curative treatment is possible if the diagnosis is timely. The disease subtly progresses before symptoms prompt patients to seek medical attention. Effective pre-symptomatic screening strategies may improve the outcome of the disease. Recent evidence provided insights into early diagnosis of EC via blood tests, advanced endoscopic imaging, and artificial intelligence. Accordingly, we reviewed available strategies to diagnose early EC.

Abstract

Esophageal cancer (EC) is the seventh most common cancer and the sixth cause of cancer death worldwide. Histologically, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) account for up to 90% and 20% of all ECs, respectively. Clinical symptoms such as dysphagia, odynophagia, and bolus impaction occur late in the natural history of the disease, and the diagnosis is often delayed. The prognosis of ESCC and EAC is poor in advanced stages, being survival rates less than 20% at five years. However, when the diagnosis is achieved early, curative treatment is possible, and survival exceeds 80%. For these reasons, mass screening strategies for EC are highly desirable, and several options are currently under investigation. Blood biomarkers offer an inexpensive, non-invasive screening strategy for cancers, and novel technologies have allowed the identification of candidate markers for EC. The esophagus is easily accessible via endoscopy, and endoscopic imaging represents the gold standard for cancer surveillance. However, lesion recognition during endoscopic procedures is hampered by interobserver variability. To fill this gap, artificial intelligence (AI) has recently been explored and provided encouraging results. In this review, we provide a summary of currently available options to achieve early diagnosis of EC, focusing on blood biomarkers, advanced endoscopy, and AI.

Spectral Endoscopy Enhances Contrast for Neoplasia in Surveillance of Barrett's Esophagus

Early detection of esophageal neoplasia enables curative endoscopic therapy, but the current diagnostic standard of care has low sensitivity because early neoplasia is often inconspicuous with conventional white-light endoscopy. Here, we hypothesized that spectral endoscopy could enhance contrast for neoplasia in surveillance of patients with Barrett's esophagus. A custom spectral endoscope was deployed in a pilot clinical study of 20 patients to capture 715 in vivo tissue spectra matched with gold standard diagnosis from histopathology. Spectral endoscopy was sensitive to changes in neovascularization during the progression of disease; both non-dysplastic and neoplastic Barrett's esophagus showed higher blood volume relative to healthy squamous tissue (P = 0.001 and 0.02, respectively), and vessel radius appeared larger in neoplasia relative to non-dysplastic Barrett's esophagus (P = 0.06). We further developed a deep learning algorithm capable of classifying spectra of neoplasia versus non-dysplastic Barrett's esophagus with high accuracy (84.8% accuracy, 83.7% sensitivity, 85.5% specificity, 78.3% positive predictive value, and 89.4% negative predictive value). Exploiting the newly acquired library of labeled spectra to model custom color filter sets identified a potential 12-fold enhancement in contrast between neoplasia and non-dysplastic Barrett's esophagus using application-specific color filters compared with standard-of-care white-light imaging (perceptible color difference = 32.4 and 2.7, respectively). This work demonstrates the potential of endoscopic spectral imaging to extract vascular properties in Barrett's esophagus, to classify disease stages using deep learning, and to enable high-contrast endoscopy. SIGNIFICANCE: The results of this pilot first-in-human clinical trial demonstrate the potential of spectral endoscopy to reveal disease-associated vascular changes and to provide high-contrast delineation of neoplasia in the esophagus. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/12/3415/F1.large.jpg.

Curriculum for optical diagnosis training in Europe: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

This manuscript represents an official Position Statement of the European Society of Gastrointestinal Endoscopy (ESGE) aiming to guide general gastroenterologists to develop and maintain skills in optical diagnosis during endoscopy. In general, this requires additional training beyond the core curriculum currently provided in each country. In this context, ESGE have developed a European core curriculum for optical diagnosis practice across Europe for high quality optical diagnosis training. 1:  ESGE suggests that every endoscopist should have achieved general competence in upper and/or lower gastrointestinal (UGI/LGI) endoscopy before commencing training in optical diagnosis of the UGI/LGI tract, meaning personal experience of at least 300 UGI and/or 300 LGI endoscopies and meeting the ESGE quality measures for UGI/LGI endoscopy. ESGE suggests that every endoscopist should be able and competent to perform UGI/LGI endoscopy with high definition white light combined with virtual and/or dye-based chromoendoscopy before commencing training in optical diagnosis. 2:  ESGE suggests competency in optical diagnosis can be learned by attending a validated optical diagnosis training course based on a validated classification, and self-learning with a minimum number of lesions. If no validated training course is available, optical diagnosis can only be learned by attending a non-validated onsite training course and self-learning with a minimum number of lesions. 3:  ESGE suggests endoscopists are competent in optical diagnosis after meeting the pre-adoption and learning criteria, and meeting competence thresholds by assessing a minimum number of lesions prospectively during real-time endoscopy. ESGE suggests ongoing in vivo practice by endoscopists to maintain competence in optical diagnosis. If a competent endoscopist does not perform in vivo optical diagnosis on a regular basis, ESGE suggests repeating the learning and competence phases to maintain competence.Key areas of interest were optical diagnosis training in Barrett's esophagus, esophageal squamous cell carcinoma, early gastric cancer, diminutive colorectal lesions, early colorectal cancer, and neoplasia in inflammatory bowel disease. Condition-specific recommendations are provided in the main document.

Chromoendoscopy: role in modern endoscopic imaging

Detection of early gastrointestinal tract malignancy can be challenging on white light endoscopy especially as lesions can be subtle and inconspicuous. With the advent of electronic chromoendoscopy technologies, lesions which have already been detected can be quickly and "conveniently" characterised. This review will discuss some of the indications and modern applications of chromoendoscopy in various conditions including Barrett's oesophagus, oesophageal squamous cell carcinoma, early gastric cancer, inflammatory bowel disease and neoplastic colonic lesions. In carefully selected situations, chromoendoscopy could still be a useful adjunct to white light endoscopy in day-to-day clinical practice.

Quality indicators in diagnostic upper gastrointestinal endoscopy

Upper gastrointestinal (UGI) endoscopy contributes a major clinical service with consistently growing demand around the world. Its utility corresponds to varying epidemiological issues throughout the globe, with cancer screening and surveillance being of the utmost priority. Despite high accuracy in neoplasia detection, UGI endoscopy remains a highly operator-dependent procedure, characterized by a substantial rate of missed pathology. Despite an overall lack of high-quality performance measures, there is an increased level of awareness about the need for quality control of this procedure, which is reflected in several guidelines and position statements published in recent years. It is widely recognized that quality assessment should go beyond mere technical aspects of the examination, and include both pre- and post-procedural factors. By this means, quality control encompasses the entire patient experience with the health care provider, from appropriate indication and physical assessment, through high-quality endoscopy service, to appropriate follow up and patient satisfaction. This article aims to review the available and emerging quality metrics for UGI endoscopy, taken mostly from Western endoscopy societies, with references to Asian recommendations where appropriate. The paper is limited solely to diagnostic UGI endoscopy and does not include performance measures for therapeutic procedures.

A roadmap for the clinical implementation of optical-imaging biomarkers

Clinical workflows for the non-invasive detection and characterization of disease states could benefit from optical-imaging biomarkers. In this Perspective, we discuss opportunities and challenges towards the clinical implementation of optical-imaging biomarkers for the early detection of cancer by analysing two case studies: the assessment of skin lesions in primary care, and the surveillance of patients with Barrett's oesophagus in specialist care. We stress the importance of technical and biological validations and clinical-utility assessments, and the need to address implementation bottlenecks. In addition, we define a translational roadmap for the widespread clinical implementation of optical-imaging technologies.

Enhancing the Detection of Barrett Esophagus

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

How to get the most out of costly Barrett's oesophagus surveillance

Current endoscopic surveillance protocols for Barrett's oesophagus have several limitations, mainly the poor cost-effectiveness and high miss rate. However, there is sufficient evidence that patients enrolled in a surveillance program have better survival chances of oesophageal cancer due to earlier tumor stages at diagnosis compared to patients with de novo diagnosed oesophagus cancer. Risk stratifications aim to identify patients at highest risk of developing adenocarcinoma of the oesophagus; most of them base on the length of the Barrett's segment and the presence of dysplasia. This review discusses prognostic factors and provides practical guidance on how to improve the efficacy and outcome in Barrett's surveillance programs.

Machine Learning Creates a Simple Endoscopic Classification System that Improves Dysplasia Detection in Barrett's Oesophagus amongst Non-expert Endoscopists

Introduction

Barrett's oesophagus (BE) is a precursor to oesophageal adenocarcinoma (OAC). Endoscopic surveillance is performed to detect dysplasia arising in BE as it is likely to be amenable to curative treatment. At present, there are no guidelines on who should perform surveillance endoscopy in BE. Machine learning (ML) is a branch of artificial intelligence (AI) that generates simple rules, known as decision trees (DTs). We hypothesised that a DT generated from recognised expert endoscopists could be used to improve dysplasia detection in non-expert endoscopists. To our knowledge, ML has never been applied in this manner.

Methods

Video recordings were collected from patients with non-dysplastic (ND-BE) and dysplastic Barrett's oesophagus (D-BE) undergoing high-definition endoscopy with i-Scan enhancement (PENTAX®). A strict protocol was used to record areas of interest after which a corresponding biopsy was taken to confirm the histological diagnosis. In a blinded manner, videos were shown to 3 experts who were asked to interpret them based on their mucosal and microvasculature patterns and presence of nodularity and ulceration as well as overall suspected diagnosis. Data generated were entered into the WEKA package to construct a DT for dysplasia prediction. Non-expert endoscopists (gastroenterology specialist registrars in training with variable experience and undergraduate medical students with no experience) were asked to score these same videos both before and after web-based training using the DT constructed from the expert opinion. Accuracy, sensitivity, and specificity values were calculated before and after training where p < 0.05 was statistically significant.

Results

Videos from 40 patients were collected including 12 both before and after acetic acid (ACA) application. Experts' average accuracy for dysplasia prediction was 88%. When experts' answers were entered into a DT, the resultant decision model had a 92% accuracy with a mean sensitivity and specificity of 97% and 88%, respectively. Addition of ACA did not improve dysplasia detection. Untrained medical students tended to have a high sensitivity but poor specificity as they "overcalled" normal areas. Gastroenterology trainees did the opposite with overall low sensitivity but high specificity. Detection improved significantly and accuracy rose in both groups after formal web-based training although it did it reach the accuracy generated by experts. For trainees, sensitivity rose significantly from 71% to 83% with minimal loss of specificity. Specificity rose sharply in students from 31% to 49% with no loss of sensitivity.

Conclusion

ML is able to define rules learnt from expert opinion. These generate a simple algorithm to accurately predict dysplasia. Once taught to non-experts, the algorithm significantly improves their rate of dysplasia detection. This opens the door to standardised training and assessment of competence for those who perform endoscopy in BE. It may shorten the learning curve and might also be used to compare competence of trainees with recognised experts as part of their accreditation process.

Impact of advanced endoscopic imaging on Barrett's esophagus in daily clinical practice

BACKGROUND AND AIMS

Several advanced imaging techniques have been proposed to improve the visualization of dysplastic regions within Barrett's epithelium, with some evidence for the use of narrow-band imaging (NBI) and acetic acid chromoendoscopy (AAC).

METHODS

We retrospectively analyzed consecutive cases of Barrett's esophagus, diagnosed using white-light endoscopy and confirmed histologically by the presence of intestinal metaplasia, between April 2007 and April 2010 in a large community hospital. A change in practice was then instituted, whereby a Barrett's team consisting of specialist endoscopists was formed in an attempt to standardize and improve the quality of surveillance. Barrett's epithelium was inspected with both white-light imaging and NBI in all patients. Where the length of Barrett's epithelium was 3 cm or more, AAC was also used. One and a half percent acetic acid was sprayed onto the Barrett's segment and loss of aceto-whitening observed after a 2-minute period. Any abnormal areas noted during advanced imaging underwent target biopsy sampling. We subsequently compared the dysplasia detection rate in Barrett's epithelium identified between April 2011 and April 2014 after these changes. Observed differences between the cohorts were analyzed with the Fisher exact test and the Student t test.

RESULTS

From 2007 to 2010 Barrett's esophagus was identified during 560 gastroscopies in 392 individual patients. The mean maximal Barrett's esophagus recorded length was 4.4 cm (range, 1-10), with an average of 4.7 esophageal biopsy specimens taken per endoscopy. In comparison, from 2011 to 2014 Barrett's esophagus was identified during 856 endoscopies in 630 patients. From 2011 to 2014 the Barrett's team performed 85% of all procedures using the aforementioned techniques. The mean maximal Barrett's esophagus length was 3.8 cm (range, 1-16), with an increased average of 5.8 biopsy specimens per endoscopy taken (P < .01). Both cohorts were comparable in age and gender distribution. Our data demonstrated no significant difference in the relative frequencies of occurrence of dysplasia detected between both cohorts of patients. From 2007 to 2010 dysplasia was detected in 11.0% (n = 43) of patients. This consisted of low-grade dysplasia in 7.7% of patients and high-grade dysplasia or cancer 3.3%. From 2011 to 2014 this compared with dysplasia in 11.3% (n = 71) of patients, with low-grade dysplasia in 9.4% and high-grade dysplasia or cancer in 1.9%.

CONCLUSIONS

Our data show that the use of NBI and AAC in the imaging of Barrett's esophagus did not result in an increased detection rate of dysplasia in routine clinical practice. These findings concur with the recommendations of existing Barrett's esophagus surveillance guidelines, which advocate the continued use of quadratic biopsy sampling within general surveillance programs.

Circular stripes were more common in Barrett's esophagus after acetic acid staining

BACKGROUND

The diagnosis of Barrett's esophagus (BE) is disturbed by numerous factors, including correct gastroesophageal junction judgment, the initial location of the Z-line and the biopsy result above it. The acetic acid (AA) could help to diagnose BE better than high resolution imaging technology or magnifying endoscopy, by providing enhanced contrast of different epithelium. We have noticed AA could produce multiple white circular lines, forming circular stripes (CS), at lower esophagus, which hasn't been reported by others. This study aimed to investigate whether the CS is a special marker in BE patients.

METHODS

A total of 47 BE patients and 63 healthy people were enrolled from March 2016 to October 2016, and 2% AA staining had been operated routinely at lower esophagus under high resolution gastroscopy. We observed whether there were CS after AA staining and the images were compared between the two groups.

RESULTS

CS were confirmed in 42 patients (89.36%) in the BE group and 5 (7.94) in the control group ((χ2 = 72.931, P < 0.001)). The average width of CS was 0.76 ± 0.25 cm in BE group, which was similar to that in the control group (0.88 ± 0.11 cm). Villous or punctate or reticular pattern usually existed above or below the CS.

CONCLUSIONS

CS could be found at lower esophagus in most BE patients with AA staining, and this special feature might be valuable in diagnosing, evaluating and following up of BE patients.

Acetic acid-guided biopsies in Barrett's surveillance for neoplasia detection versus non-targeted biopsies (Seattle protocol): A feasibility study for a randomized tandem endoscopy trial. The ABBA study

BACKGROUND AND STUDY AIMS

Barrett's esophagus is a potentially pre-cancerous condition, affecting 375,000 people in the UK. Patients receive a 2-yearly endoscopy to detect cancerous changes, as early detection and treatment results in better outcomes. Current treatment requires random mapping biopsies along the length of Barrett's, in addition to biopsy of visible abnormalities. As only 13 % of pre-cancerous changes appear as visible nodules or abnormalities, areas of dysplasia are often missed. Acetic acid chromoendoscopy (AAC) has been shown to improve detection of pre-cancerous and cancerous tissue in observational studies, but no randomized controlled trials (RCTs) have been performed to date.

PATIENTS AND METHODS

A "tandem" endoscopy cross-over design. Participants will be randomized to endoscopy using mapping biopsies or AAC, in which dilute acetic acid is sprayed onto the surface of the esophagus, highlighting tissue through an whitening reaction and enhancing visibility of areas with cellular changes for biopsy. After 4 to 10 weeks, participants will undergo a repeat endoscopy, using the second method. Rates of recruitment and retention will be assessed, in addition to the estimated dysplasia detection rate, effectiveness of the endoscopist training program, and rates of adverse events (AEs). Qualitative interviews will explore participant and endoscopist acceptability of study design and delivery, and the acceptability of switching endoscopic techniques for Barrett's surveillance.

RESULTS

Endoscopists' ability to diagnose dysplasia in Barrett's esophagus can be improved. AAC may offer a simple, universally applicable, easily-acquired technique to improve detection, affording patients earlier diagnosis and treatment, reducing endoscopy time and pathology costs. The ABBA study will determine whether a crossover "tandem" endoscopy design is feasible and acceptable to patients and clinicians and gather outcome data to power a definitive trial.

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

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

Barrett’s oesophagus: Current controversies

Oesophageal adenocarcinoma is rapidly increasing in Western countries. This tumour frequently presents late in its course with metastatic disease and has a very poor prognosis. Barrett’s oesophagus is an acquired condition whereby the native squamous mucosa of the lower oesophagus is replaced by columnar epithelium following prolonged gastro-oesophageal reflux and is the recognised precursor lesion for oesophageal adenocarcinoma. There are multiple national and society guidelines regarding screening, surveillance and management of Barrett’s oesophagus, however all are limited regarding a clear evidence base for a well-demonstrated benefit and cost-effectiveness of surveillance, and robust risk stratification for patients to best use resources. Currently the accepted risk factors upon which surveillance intervals and interventions are based are Barrett’s segment length and histological interpretation of the systematic biopsies. Further patient risk factors including other demographic features, smoking, gender, obesity, ethnicity, patient age, biomarkers and endoscopic adjuncts remain under consideration and are discussed in full. Recent evidence has been published to support earlier endoscopic intervention by means of ablation of the metaplastic Barrett’s segment when the earliest signs of dysplasia are detected. Further work should concentrate on establishing better risk stratification and primary and secondary preventative strategies to reduce the risk of adenocarcinoma of the oesophagus.

Emerging endoscopic techniques for the identification of esophageal disease

Esophageal diseases, both benign and malignant, impose an increasing burden to global health. In the West, gastroesophageal reflux disease (GERD) and Barrett's esophagus are increasing in prevalence and impact. In the East, squamous esophageal cancer remains a large burden, but increasingly, precancerous lesions related to GERD are recognized. We review the various advanced endoscopic techniques that have been developed to improve the accuracy of endoscopic identification of esophageal disease. These techniques are designed to increase the sensitivity of detecting disease and high-risk lesions, enable targeted biopsies, decrease total number of biopsies and costs for surveillance, but also guide therapy in real-time. After proper clinical validation, the widespread use of these technologies will lead to improved outcomes, mostly in cancer prevention.

Role of endoscopy in early oesophageal cancer

Incidence of oesophageal adenocarcinoma has increased exponentially in the West over the past few decades. Following detection of advanced cancers, 5-year survival rates remain bleak, making identification of early neoplasia, which has a better outcome, important. Detection of subtle oesophageal lesions during endoscopy can be challenging, and advanced imaging techniques might improve their detection. High-definition endoscopy has become a standard in most endoscopy centres, and this technology probably provides better delineation of mucosal features than standard-definition endoscopy. Various image enhancement techniques are now available with the development of new electronics and software systems. Image enhancement with chromoendoscopy using dyes has been a cost-effective option for many years, yet these techniques have been replaced in some contexts by electronic chromoendoscopy, which can be used with the press of a button. However, Lugol's chromoendoscopy remains the gold standard to identify squamous dysplasia. Identification and characterization of subtle neoplastic lesions could help to target biopsies and perform endoscopic resection for better local staging and definitive therapy. In vivo histology with techniques such as confocal endomicroscopy could make endotherapy feasible within a shorter timescale than when relying on histology on tissue samples. Once early neoplasia is identified, treatments include endoscopic resection, endoscopic submucosal dissection or various ablative techniques. Endotherapy has the advantage of being a less invasive technique than oesophagectomy, and is associated with lower mortality and morbidity. Endoscopic ablation therapies have evolved over the past few years, with radiofrequency ablation showing the best results in terms of success rates and complications in Barrett dysplasia.

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.

Advances in the Endoscopic Diagnosis of Barrett Esophagus

BACKGROUND

Barrett esophagus (BE) continues to be a major risk factor for developing esophageal adenocarcinoma.

METHODS

We review the risk factors, diagnosis, and management of BE, with an emphasis on the most current endoscopic diagnostic modalities for BE.

RESULTS

Novel diagnostic modalities have emerged to address the inadequacies of standard, untargeted biopsies, such as dye-based and virtual chromoendoscopy, endoscopic mucosal resection, molecular biomarkers, optical coherence tomography, confocal laser endomicroscopy, volumetric laser endomicroscopy, and endocytoscopy. Treatment of BE depends on the presence of intramucosal cancer or dysplasia, particularly high-grade dysplasia with or without visible mucosal lesions.

CONCLUSIONS

Recent advances in endoscopic diagnostic tools demonstrate promising results and help to mitigate the shortcomings of the Seattle protocol. Future research as well as refining these tools may help aid them in replacing standard untargeted biopsies.

Barrett's esophagus: lessons from recent clinical trials

Data from recent studies cast doubt on former recommendations on diagnosis and management of Barrett’s esophagus. Based on latest research findings several Gastroenterological Associations actualized their guidelines and international experts compiled consensus statements as practical help for clinicians. In this review we discuss recent trials and their impact on clinical practice, current recommendations and persisting controversies in Barrett’s esophagus.

Monitoring the premalignant potential of Barrett's oesophagus'

The landscape for patients with Barrett's oesophagus (BE) has changed significantly in the last decade. Research and new guidelines have helped gastroenterologists to better identify those patients with BE who are particularly at risk of developing oesophageal adenocarcinoma. In parallel, developments in endoscopic image enhancement technology and optical biopsy techniques have improved our ability to detect high-risk lesions. Once these lesions have been identified, the improvements in minimally invasive endoscopic therapies has meant that these patients can potentially be cured of early cancer and high-risk dysplastic lesions without the need for surgery, which still has a significant morbidity and mortality. The importance of reaching an accurate diagnosis of BE remains of paramount importance. More work is needed, however. The vast majority of those undergoing surveillance for their BE do not progress towards cancer and thus undergo a regular invasive procedure, which may impact on their psychological and physical well-being while incurring significant cost to the health service. New work that explores cheaper endoscopic or non-invasive ways to identify the at-risk individual provides exciting avenues for research. In future, the diagnosis and monitoring of patients with BE could move away from hospitals and into primary care.

Design and validation of a near-infrared fluorescence endoscope for detection of early esophageal malignancy

Barrett’s esophagus is a known precursor lesion to esophageal adenocarcinoma. In these patients, early detection of premalignant disease, known as dysplasia, allows curative minimally invasive endoscopic therapy, but is confounded by a lack of contrast in white light endoscopy. Imaging fluorescently labeled lectins applied topically to the tissue has the potential to more accurately delineate dysplasia, but tissue autofluorescence limits both sensitivity and contrast when operating in the visible region. To overcome this challenge, we synthesized near-infrared (NIR) fluorescent wheat germ agglutinin (WGA-IR800CW) and constructed a clinically translatable bimodal NIR and white light endoscope. Images of NIR and white light with a field of view of 63 deg and an image resolution of 182  μm are coregistered and the honeycomb artifact arising from the fiber bundle is removed. A minimum detectable concentration of 110 nM was determined using a dilution series of WGA-IR800CW. We demonstrated ex vivo that this system can distinguish between gastric and squamous tissue types in mouse stomachs (p=0.0005) and accurately detect WGA-IR800CW fluorescence in human esophageal resections (compared with a gold standard imaging system, rs>0.90). Based on these findings, future work will optimize the bimodal endoscopic system for clinical trials in Barrett’s surveillance.

Acetic acid chromoendoscopy: Improving neoplasia detection in Barrett's esophagus

Barrett’s esophagus (BE) is an important condition given its significant premalignant potential and dismal five-year survival outcomes of advanced esophageal adenocarcinoma. It is therefore suggested that patients with a diagnosis of BE undergo regular surveillance in order to pick up dysplasia at an earlier stage to improve survival. Current “gold-standard” surveillance protocols suggest targeted biopsy of visible lesions followed by four quadrant random biopsies every 2 cm. However, this method of Barrett’s surveillance is fraught with poor endoscopist compliance as the procedures are time consuming and poorly tolerated by patients. There are also significant miss-rates with this technique for the detection of neoplasia as only 13% of early neoplastic lesions appear as visible nodules. Despite improvements in endoscope resolution these problems persist. Chromoendoscopy is an extremely useful adjunct to enhance mucosal visualization and characterization of Barrett’s mucosa. Acetic acid chromoendoscopy (AAC) is a simple, non-proprietary technique that can significantly improve neoplasia detection rates. This topic highlight summarizes the current evidence base behind AAC for the detection of neoplasia in BE and provides an insight into the direction of travel for further research in this area.

Endoscopic imaging of Barrett’s esophagus

The incidence of esophageal adenocarcinoma (EAC) has dramatically increased in the United States as well as Western European countries. The majority of esophageal adenocarcinomas arise from a backdrop of Barrett’s esophagus (BE), a premalignant lesion that can lead to dysplasia and cancer. Because of the increased risk of EAC, GI society guidelines recommend endoscopic surveillance of patients with BE. The emphasis on early detection of dysplasia in BE through surveillance endoscopy has led to the development of advanced endoscopic imaging technologies. These techniques have the potential to both improve mucosal visualization and characterization and to detect small mucosal abnormalities which are difficult to identify with standard endoscopy. This review summarizes the advanced imaging technologies used in evaluation of BE.

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

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

Oesophageal biopsies are insufficient to predict final histology after endoscopic resection in early Barrett's neoplasia

BACKGROUND

Endoscopic resection (ER) with or without ablation is the first choice treatment for early Barrett's neoplasia. Adequate staging is important to assure a good oncological outcome.

OBJECTIVE

The purpose of this study was to investigate the diagnostic accuracy of pre-operative biopsies in patients who undergo ER for high-grade dysplasia (HGD) or early adenocarcinoma (EAC) in Barrett's oesophagus (BE) and the cardia.

METHODS

Between November 2005-May 2012, 142 ERs performed in 137 patients were obtained. Worst pre-ER and ER histology were compared. Upgrading/downgrading was defined as any more/less severe histological grading on the ER specimen.

RESULTS

The accuracy of pre-ER biopsies in predicting final histology was 61%. ER changed the pre-treatment diagnosis in 55 of the 142 procedures (39%) with downgrading in 23 cases (16%) and upgrading from HGD to T1a or T1b in 32 cases (23%). In the majority of upgraded cases, a visible lesion according to the Paris classification could be detected (26/32, 81%).

CONCLUSION

The diagnostic accuracy of oesophageal biopsies alone in predicting final pathology in Barrett's dysplasia is only 61%. The majority of upgraded lesions are detectable. When ablative therapy is considered in HGD Barrett's dysplasia a meticulous inspection for and removal of all small visible lesions is mandatory.

Endoscopic modalities for the diagnosis of Barrett's oesophagus

Barrett's oesophagus is a pre-malignant condition associated with the development of oesophageal adenocarcinoma. Currently white light endoscopy and biopsy is the mainstay diagnostic tool. Yet this approach is troubled by issues related to cumbersome biopsy sampling, biopsy sampling errors and cost. Therefore in order to overcome such adversity, there needs to be evolutionary advancement in terms of diagnosis, which should address these concerns and ideally enhance risk stratification in order to provide timely management in real time. This review highlights the current endoscopic tools aimed to enhance the diagnosis of Barrett's oesophagus and its subsequent progression.

Emerging optical methods for surveillance of Barrett's oesophagus

The rapid rise in incidence of oesophageal adenocarcinoma has motivated the need for improved methods for surveillance of Barrett's oesophagus. Early neoplasia is flat in morphology and patchy in distribution and is difficult to detect with conventional white light endoscopy (WLE). Light offers numerous advantages for rapidly visualising the oesophagus, and advanced optical methods are being developed for wide-field and cross-sectional imaging to guide tissue biopsy and stage early neoplasia, respectively. We review key features of these promising methods and address their potential to improve detection of Barrett's neoplasia. The clinical performance of key advanced imaging technologies is reviewed, including (1) wide-field methods, such as high-definition WLE, chromoendoscopy, narrow-band imaging, autofluorescence and trimodal imaging and (2) cross-sectional techniques, such as optical coherence tomography, optical frequency domain imaging and confocal laser endomicroscopy. Some of these instruments are being adapted for molecular imaging to detect specific biological targets that are overexpressed in Barrett's neoplasia. Gene expression profiles are being used to identify early targets that appear before morphological changes can be visualised with white light. These targets are detected in vivo using exogenous probes, such as lectins, peptides, antibodies, affibodies and activatable enzymes that are labelled with fluorescence dyes to produce high contrast images. This emerging approach has potential to provide a 'red flag' to identify regions of premalignant mucosa, outline disease margins and guide therapy based on the underlying molecular mechanisms of cancer progression.

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

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

Red flag imaging in Barrett's esophagus: does it help to find the needle in the haystack?

Esophageal Adenocarcinoma (EAC) has suffered a sharp increase on its incidence for the last decades, and it is associated with a poor prognosis. Barrett's Esophagus (BE) is the most important identifiable risk factor for the progression to esophageal adenocarcinoma. The key to prevent and provide a curative treatment of esophageal adenocarcinoma is the detection and eradication of early neoplasia in patients with esophagus. Endoscopic surveillance is evolving from a blind or random four quadrant biopsies protocol (Seattle protocol) to a more targeted approach. A detailed white light examination with high-resolution endoscopy is the cornerstone for recognition of early neoplastic lesions in BE. Additional imaging modalities may enhance targeting of lesions or provide more information at a focused level. There are emerging data that some of these new modalities can increase the yield of detecting dysplasia, although its routine use has yet to be validated.

Advanced Imaging in Barrett's Esophagus

Barrett's esophagus (BE) is present in up to 5.6% of the US population and is the precursor lesion for esophageal adenocarcinoma. Surveillance endoscopy is the primary management approach for BE. However, standard protocol biopsies have been associated with significant miss rates of dysplastic lesions in patients with BE. Thus, a variety of methods to optimize the imaging of BE have been developed to improve the efficiency and diagnostic yield of surveillance endoscopy in detecting early neoplasia. These techniques use changes that occur at macroscopic, microscopic, and subcellular levels in early neoplasia and are the focus of this article.

The role of acetic acid in the management of Barrett's oesophagus

Barrett's oesophagus is of significant importance due to its premalignant potential. Acetic acid chromoendoscopy is a simple technique that can be used with any endoscope system. It has been utilised for the identification of Barrett's intestinal metaplasia; and more importantly, for the localisation of early neoplasia within Barrett's, which is often focal, subtle and very easy to miss by random quadrantic biopsies alone. Acetic acid is routinely utilised in specialised centres and its use is expanding. This article examines the evidence base behind acetic acid chromoendoscopy and looks at where further research needs to be directed.

Pathophysiology of Barrett's esophagus-associated neoplasia: circumferential spatial predilection

The prevalence rates of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) arising from BE show striking geographic patterns as they are much more common in Western as compared with Asian countries. However, recent epidemiological studies indicate that the number of patients with BE and EAC are gradually increasing in Asia including Japan, corresponding to the increase in prevalence of gastroesophageal reflux disease (GERD). Because the prognosis of patients with advanced-stage EAC remains poor, early detection of neoplastic lesion in those with BE has led to recent interest in effective treatment. Several promising studies have revealed that early neoplasia in BE is mainly located in the right anterior wall of the distal esophagus. Interestingly, this endoscopic characteristic has been found in both Western and Japanese populations. Potential pathophysiologic explanations underlying the circumferential distribution of neoplasia in BE include a nonuniform asymmetric distribution of esophageal acid exposure, with a tendency toward mucosal acid-related injury on the right side of the esophageal wall in patients with GERD, and the functional structure of the lower esophageal sphincter. Findings of the present study should improve lesion detection and aid in developing a target biopsy protocol for surveillance of BE.

BOB CAT: A Large-Scale Review and Delphi Consensus for Management of Barrett's Esophagus With No Dysplasia, Indefinite for, or Low-Grade Dysplasia

OBJECTIVES

Barrett's esophagus (BE) is a common premalignant lesion for which surveillance is recommended. This strategy is limited by considerable variations in clinical practice. We conducted an international, multidisciplinary, systematic search and evidence-based review of BE and provided consensus recommendations for clinical use in patients with nondysplastic, indefinite, and low-grade dysplasia (LGD).

METHODS

We defined the scope, proposed statements, and searched electronic databases, yielding 20,558 publications that were screened, selected online, and formed the evidence base. We used a Delphi consensus process, with an 80% agreement threshold, using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to categorize the quality of evidence and strength of recommendations.

RESULTS

In total, 80% of respondents agreed with 55 of 127 statements in the final voting rounds. Population endoscopic screening is not recommended and screening should target only very high-risk cases of males aged over 60 years with chronic uncontrolled reflux. A new international definition of BE was agreed upon. For any degree of dysplasia, at least two specialist gastrointestinal (GI) pathologists are required. Risk factors for cancer include male gender, length of BE, and central obesity. Endoscopic resection should be used for visible, nodular areas. Surveillance is not recommended for <5 years of life expectancy. Management strategies for indefinite dysplasia (IND) and LGD were identified, including a de-escalation strategy for lower-risk patients and escalation to intervention with follow-up for higher-risk patients.

CONCLUSIONS

In this uniquely large consensus process in gastroenterology, we made key clinical recommendations for the escalation/de-escalation of BE in clinical practice. We made strong recommendations for the prioritization of future research.