Comparison of cancer-associated genetic abnormalities in columnar-lined esophagus tissues with and without goblet cells. Ann Surg. 2014;260:72-80. [PMID: 24509200 DOI: 10.1097/sla.0000000000000424]

Understanding the malignant potential of gastric metaplasia of the oesophagus and its relevance to Barrett's oesophagus surveillance: individual-level data analysis

OBJECTIVE

Whether gastric metaplasia (GM) of the oesophagus should be considered as Barrett's oesophagus (BO) is controversial. Given concern intestinal metaplasia (IM) may be missed due to sampling, the UK guidelines include GM as a type of BO. Here, we investigated whether the risk of misdiagnosis and the malignant potential of GM warrant its place in the UK surveillance.

DESIGN

We performed a thorough pathology and endoscopy review to follow clinical outcomes in a novel UK cohort of 244 patients, covering 1854 person years of follow-up. We complemented this with a comparative genomic analysis of 160 GM and IM specimens, focused on early molecular hallmarks of BO and oesophageal adenocarcinoma (OAC).

RESULTS

We found that 58 of 77 short-segment (<3 cm) GM (SS-GM) cases (75%) continued to be observed as GM-only across a median of 4.4 years of follow-up. We observed that disease progression in GM-only cases and GM+IM cases (cases with reported GM on some occasions, IM on others) was significantly lower than in the IM-only cases (Kaplan-Meier, p=0.03). Genomic analysis revealed that the mutation burden in GM is significantly lower than in IM (p<0.01). Moreover, GM does not bear the mutational hallmarks of OAC, with an absence of associated signatures and driver gene mutations. Finally, we established that GM found adjacent to OAC is evolutionarily distant from cancer.

CONCLUSION

SS-GM is a distinct entity from SS-IM and the malignant potential of GM is lower than IM. It is questionable whether SS-GM warrants inclusion in BO surveillance.

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.

TUMOR CELL MALIGNANCY: A COMPLEX TRAIT BUILT THROUGH RECIPROCAL INTERACTIONS BETWEEN TUMORS AND TISSUE-BODY SYSTEM

Since the discovery of oncogenes and tumor suppressor genes in the late past century, cancer research has been overwhelmingly focused on the genetics and biology of tumor cells and hence has addressed mostly cell-autonomous processes with emphasis on traditional driver/passenger genetic models. Nevertheless, over that same period, multiple seminal observations have accumulated highlighting the role of non-cell autonomous effectors in tumor growth and metastasis. However, given that cell autonomous and non-autonomous events are observed together at the time of diagnosis, it is in fact impossible to know whether the malignant transformation is initiated by cell autonomous oncogenic events or by non-cell autonomous conditions generated by alterations of the tissue-body ecosystem. This review aims at addressing this issue by taking the option of defining malignancy as a complex genetic trait incorporating genetically determined reciprocal interactions between tumor cells and tissue-body ecosystem.

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

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

DNA methylation markers in esophageal cancer: an emerging tool for cancer surveillance and treatment

Esophageal carcinoma (EC) is one of the most pervasive cancers in the world, with upwards of 500,000 new diagnoses, annually. Despite its prominence, advancements in the detection and treatment of EC have been marginal over the past 30 years and the survival rate continues to stay below 20%. This is due to the uncommonly heterogeneous presentation of EC which presents unprecedented challenges in improving patient survival and quality of care. However, distinct epigenetic alterations to the DNA methylome may provide an avenue to drastically improve the detection and treatment of EC. Specifically, the creation of novel biomarker panels that consist of EC-specific methylation markers have shown promise as a potential alternative to the more invasive, contemporary diagnostic methods. Additionally, growing insight into the biological and clinical properties of EC-specific methylation patterns have opened a window of opportunity for enhanced treatment; of growing interest is the application of "DNMT inhibitors" - a class of drugs which inhibit excessive methylation and have been shown to re-sensitize chemoresistant tumors. Here we provide a comprehensive review of the current advancements in EC DNA methylation to underscore a potential approach to its detection and treatment.

Gastro-esophageal reflux disease and Barrett's esophagus: an overview with an histologic diagnostic approach

The first part of this overview on non-neoplastic esophagus is focused on gastro-esophageal reflux disease (GERD) and Barrett’s esophagus. In the last 20 years much has changed in histological approach to biopsies of patients with gastro-esophageal reflux disease. In particular, elementary histologic lesions have been well defined and modality of evaluation and grade are detailed, their sensitivity and specificity has been evaluated and their use has been validated by several authors. Also if there is not a clinical indication to perform biopsies in patient with GERD, the diagnosis of microscopic esophagitis, when biopsies are provided, can be performed by following simple rules for evaluation which allow pathologists to make the diagnosis with confidence. On the other hand, biopsies are required for the diagnosis of Barrett’s esophagus. This diagnosis is the synthesis of endoscopic picture (which has to be provided with the proper description on extent and with adequate biopsies number) and histologic pattern. The current guidelines and expert opinions for the correct management of these diagnosis are detailed.

Barrett's Esophagus and Intestinal Metaplasia

Intestinal metaplasia refers to the replacement of the differentiated and mature normal mucosal epithelium outside the intestinal tract by the intestinal epithelium. This paper briefly describes the etiology and clinical significance of intestinal metaplasia in Barrett’s esophagus. This article summarizes the impact of intestinal metaplasia on the diagnosis, monitoring, and treatment of Barrett’s esophagus according to different guidelines. We also briefly explore the basis for the endoscopic diagnosis of intestinal metaplasia in Barrett’s esophagus. The identification techniques of goblet cells in Barrett’s esophagus are also elucidated by some scholars. Additionally, we further elaborate on the current treatment methods related to Barrett’s esophagus.

The complexity of cancer origins at the gastro-oesophageal junction

Chronic acid-biliary reflux and Helicobacter pylori infection are instrumental environmental drivers of cancer initiation and progression in the upper gastrointestinal tract. Remarkably, although these environmental carcinogens are quite dissimilar, the tumour progression cascade these carcinogens engender is highly comparable. For this reason, studies of malignant progression occurring at the anatomic borderland between the oesophagus and the stomach have traditionally lumped junctional adenocarcinomas with either oesophageal adenocarcinoma or gastric adenocarcinoma. Whilst studies have revealed remarkable epidemiological and genetic similarities of these cancers and their associated premalignant conditions, these works have also revealed some key differences. This highlights that further scientific effort demands a dedicated focus on the understanding of the cell-cell interaction between the epithelium and the local microenvironment in this anatomic region. We here review available evidence with regards to tumour progression occurring at the gastro-oesophageal junction and contrast it with available data on cancer evolution in the metaplastic oesophagus and distal stomach.

Recent insights into the biology of Barrett's esophagus

Barrett's esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC), an aggressive cancer with a poor prognosis. Our understanding of the pathogenesis and Barrett's metaplasia is incomplete, and this has limited the development of new therapeutic targets and agents, risk stratification ability, and management strategies. This review outlines current insights into the biology of BE and addresses controversies surrounding cell of origin, cellular reprogramming theories, updates on esophageal epithelial barrier function, and the significance of goblet cell metaplasia and its association with malignant change. Further research into the basic biology of BE is vital as it will underpin novel therapies and improve our ability to predict malignant progression and help identify the minority of patients who will develop EAC.

Challenges to diagnostic standardization of Barrett's esophagus in Asia

Barrett's esophagus (BE), a premalignant condition of the lower esophagus, is increasingly prevalent in Asia. However, endoscopic and histopathological criteria vary widely between studies across Asia, making it challenging to assess comparability between geographical regions. Furthermore, guidelines from various societies worldwide provide differing viewpoints and definitions, leading to diagnostic challenges that affect prognostication of the condition. In this review, the authors discuss the controversies surrounding the diagnosis of BE, particularly in Asia. Differences between guidelines worldwide are summarized with further discussion regarding various classifications of BE used, different definitions of gastroesophageal junction used across geographical regions and the clinical implications of intestinal metaplasia in the setting of BE. Although many guidelines recommend the Seattle protocol as the preferred approach regarding dysplasia surveillance in BE, some limitations exist, leading to poor adherence. Newer technologies, such as acetic acid-enhanced magnification endoscopy, narrow band imaging, Raman spectroscopy, molecular approaches and the use of artificial intelligence appear promising in addressing these problems, but further studies are required before implementation into routine clinical practice. The Asian Barrett's Consortium also outlines its ongoing plans to tackle the challenge of standardizing the diagnosis of BE in Asia.

Prevalence and risk factors for Barrett’s esophagus in Taiwan

BACKGROUND

Barrett’s esophagus (BE) is a pre-malignant condition associated with the development of esophageal adenocarcinoma. The prevalence of BE in the general populations of Asian countries ranges from 0.06% to 1%. However, with lifestyle changes in Asian countries and adoption of western customs, the prevalence of BE might have increased.

AIM

To determine the current prevalence of BE in Taiwan, and to investigate risk factors predicting the presence of BE.

METHODS

This retrospective study was conducted at the Health Evaluation Center of Kaohsiung Veterans General Hospital in Taiwan. Between January 2015 and December 2015, 3385 subjects undergoing routine esophagogastroduodenoscopy examinations as part of a health check-up at the Health Evaluation Center were included. Patient characteristics and endoscopic findings were carefully reviewed. Lesions with endoscopic findings consistent with BE awaiting histological evaluation were judged as endoscopically suspected esophageal metaplasia (ESEM). BE was defined based on extension of the columnar epithelium ≥ 1 cm above the gastroesophageal junction and was confirmed based on the presence of specialized intestinal metaplasia (IM) in the metaplastic esophageal epithelium. Clinical factors of subjects with BE and subjects without BE were compared, and the risk factors predicting BE were analyzed.

RESULTS

A total of 3385 subjects (mean age, 51.29 ± 11.42 years; 57.1% male) were included in the study, and 89 among them were confirmed to have IM and presence of goblet cells via biopsy examination. The majority of these individuals were classified as short segment BE (n = 85). The overall prevalence of BE was 2.6%. Multivariate analysis disclosed that old age [odds ratio (OR) = 1.033; 95% confidence interval (CI): 1.012-1.055; P = 0.002], male gender (OR = 2.106; 95%CI: 1.145-3.872; P = 0.017), ingestion of tea (OR = 1.695; 95%CI: 1.043-2.754; P = 0.033), and presence of hiatal hernia (OR = 3.037; 95%CI: 1.765-5.225; P < 0.001) were significant risk factors predicting BE. The independent risk factor for the presence of IM in ESEM lesions was old age alone (OR = 1.029; 95%CI: 1.006-1.053; P = 0.014).

CONCLUSION

Current prevalence of BE among the general population in Taiwan is 2.6%. Old age, male gender, ingestion of tea and hiatal hernia are significant risk factors for BE.

Is Barrett's-Associated Esophageal Adenocarcinoma a Clonal Disease?

In this study, we argue that the basic clonal unit that makes up the Barrett's segment is at the level of the gland. There is expansion of this clonal unit, the gland, by fission, and there is evidence that the Barrett's segment is itself a clonal proliferation. Barrett's esophagus arises from both goblet cell-containing metaplasia and non-goblet cell-containing metaplasia and may arise from a stable clone, but the genomic changes occurring are subject to selection, usually with little or no evolution, appearing indolent from the evolutionary perspective. Genomic changes leading to dysplastic phenotypes are selected, but without any single clone predominating within the segment.

Histology of Barrett's Metaplasia: Do Goblet Cells Matter?

This review has provided a summary of the biology of goblet cell metaplasia in CLE as it pertains to BE. Goblet cells are terminally differentiated nonproliferative cells that have many overlapping histochemical characteristics with mucinous columnar cells and pseudogoblet cells. There is an abundance of evidence that suggests that use of goblet cells as a biomarker of BE, and its progression to malignancy, is problematic. Some of these limitations include the fact that the background non-goblet epithelium in most patients with CLE is biologically intestinalized and contains molecular abnormalities similar to goblet cell CLE, goblet cells fluctuate with time and decrease in number with progression of neoplasia, and pathologists have problems with interpretation, and distinction, of goblet cells from other types of cells in the esophagus. Sampling error results in sensitivity and specificity issues that limit its positive predictive value. Goblet cells are fewest in number in the same population of patients with CLE that are hardest to detect endoscopically (i.e., those with short or ultrashort CLE). Nevertheless, the risk of cancer in patients with short-segment BE, a condition difficult to distinguish from the stomach, is very low regardless of the presence or absence of goblet cells so it is unclear what the role of goblet cells is in these patients as a biomarker. Nevertheless, if the answer to the following question, "Would you as a gastroenterologist recommend surveillance for a patient with clear endoscopic evidence of CLE, particularly if it is ≥ 3 cm in length, but in which goblet cells were not reported to be present by the pathologist," is yes, then the US requirement for goblet cells as part of the criteria for "BE" is superfluous.

Somatic DNA Copy-Number Alterations Detection for Esophageal Adenocarcinoma Using Digital Polymerase Chain Reaction

Somatic copy-number alterations are commonly found in cancer and play key roles in activating oncogenes and deactivating tumor suppressor genes. Digital polymerase chain reaction is an effective way to detect the changes in copy number. In esophageal adenocarcinoma, detection of somatic copy-number alterations could predict the prognosis of patients as well as the response to therapy. This chapter will review the methods involved in digital polymerase chain reaction for the research or potential clinical applications in esophageal adenocarcinoma.

From Heartburn to Barrett's Esophagus, and Beyond

BACKGROUND

Gastroesophageal reflux disease (GERD) affects an estimated 20% of the population in the USA, and its prevalence is increasing worldwide. About 10-15% of patients with GERD will develop Barrett's esophagus (BE).

AIMS

The aims of this study were to review the available evidence of the pathophysiology of BE and the role of anti-reflux surgery in the treatment of this disease.

RESULTS

The transformation of the squamous epithelium into columnar epithelium with goblet cells is due to the chronic injury produced by repeated reflux episodes. It involves genetic mutations that in some patients may lead to high-grade dysplasia and cancer. There is no strong evidence that anti-reflux surgery is associated with resolution or improvement in BE, and its indications should be the same as for other GERD patients without BE.

CONCLUSIONS

Patients with BE without dysplasia require endoscopic surveillance, while those with low- or high-grade dysplasia should have consideration of endoscopic eradication therapy followed by surveillance. New endoscopic treatment modalities are being developed, which hold the promise to improve the management of patients with BE.

Current Concepts in Treatment of Barrett's Esophagus With and Without Dysplasia

BACKGROUND

Around 10-15% of patients with gastroesophageal reflux disease will develop Barrett's esophagus (BE). The development of novel endoscopic modalities has changed the management of BE in the last decade.

AIM

The aim of this study was to review the current evidence for the treatment of BE with and without dysplasia.

RESULTS

In patients with BE without dysplasia, antireflux surgery should not be suggested as a modality to prevent the malignant transformation of BE, but its indications should be the same as for other patients with gastroesophageal reflux. Endoscopic surveillance at intervals of 3-5 years is recommended for these patients. For patients with BE with low-grade dysplasia, radiofrequency ablation (RFA) is the preferred treatment modality, while endoscopic surveillance every 12 months is an acceptable alternative in patients with life-limiting comorbidities. For most patients with BE and high-grade dysplasia, RFA is the preferred treatment strategy. Patients with intramucosal adenocarcinoma (T1a), should be treated with EMR followed by ablative therapy, in order to eradicate the remaining intestinal metaplasia. Endoscopic resection may be suitable for low-risk T1b tumors (well-differentiated, without lymphovascular invasion, and with superficial submucosal invasion); however, further data are necessary to better risk stratify this group.

CONCLUSIONS

Patients with BE without dysplasia should undergo endoscopic surveillance every 3-5 years. Endoscopic ablative therapy (RFA) is the preferred treatment modality for dysplastic BE. Patients with T1a adenocarcinoma should be treated with EMR followed by ablative therapy. Low-risk T1b tumors may be suitable for endoscopic resection.

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.

Past, present and future of Barrett's oesophagus

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

Who Deserves Endoscopic Screening for Esophageal Neoplasia?

Despite the availability of safe and effective endoscopic treatment of Barrett's esophagus (BE)-related dysplasia and neoplasia, the incidence and mortality from esophageal adenocarcinoma (EAC) have continued to increase. This likely stems from the large population of patients that develop EAC outside of a BE screening and surveillance program. Identification of BE with screening followed by enrollment in an appropriate surveillance/risk stratification program could be a strategy to address both the incidence of and mortality from EAC. This article summarizes the rationale and challenges for BE screening, the risk factors for BE, and the currently described BE risk assessment tools.

Optimizing the diagnosis and therapy of Barrett's esophagus

The incidence of Barrett's esophagus (BE) in the Western world has increased over the last decades. BE is considered a premalignant lesion that can progress to esophageal adenocarcinoma (EAC), a highly aggressive malignancy with poor survival rates. The close association between BE and EAC highlights the need for an early diagnosis in order to improve survival and outcomes in this group of patients. Although the evidence for BE screening with conventional endoscopy is controversial and limited by cost-effectiveness studies, screening can be suggested in patients with chronic gastroesophageal reflux disease (GERD) and two or more risk factors for EAC. Less invasive techniques with lower costs and higher acceptability by the patients may be useful for screening in the general population. Several novel techniques have been described to aid in the early diagnosis and management of BE and dysplasia. However, these techniques have shown variable results with higher costs, the need of specific training, and variable inter-observer imaging interpretation, making its widespread implementation problematic. High-definition/high-resolution white-light endoscopy (WLE) continues to be a well-accepted technique for the evaluation and surveillance of patients with BE. Further studies are required in order to establish the efficacy of less invasive methods that can be performed in an outpatient setting for BE screening in higher risk individuals.

The characterization of an intestine-like genomic signature maintained during Barrett's-associated adenocarcinogenesis reveals an NR5A2-mediated promotion of cancer cell survival

Barrett’s oesophagus (BO), an intestinal-type metaplasia (IM), typically arising in conjunction with gastro-oesophageal reflux disease, is a prominent risk factor for the development of oesophageal adenocarcinoma (OAC). The molecular similarities between IM and normal intestinal tissues are ill-defined. Consequently, the contribution of intestine-enriched factors expressed within BO to oncogenesis is unclear. Herein, using transcriptomics we define the intestine-enriched genes expressed in meta-profiles of BO and OAC. Interestingly, 77% of the genes differentially expressed in a meta-profile of BO were similarly expressed in intestinal tissues. Furthermore, 85% of this intestine-like signature was maintained upon transition to OAC. Gene networking analysis of transcription factors within this signature revealed a network centred upon NR5A2, GATA6 and FOXA2, whose over-expression was determined in a cohort of BO and OAC patients. Simulated acid reflux was observed to induce the expression of both NR5A2 and GATA6. Using siRNA-mediated silencing and an NR5A2 antagonist we demonstrate that NR5A2-mediated cancer cell survival is facilitated through augmentation of GATA6 and anti-apoptotic factor BCL-XL levels. Abrogation of NR5A2-GATA6 expression in conjunction with BCL-XL co-silencing resulted in synergistically increased sensitivity to chemotherapeutics and photo-dynamic therapeutics. These findings characterize the intestine-like signature associated with IM which may have important consequences to adenocarcinogenesis.

Barrett's Esophagus: A Comprehensive and Contemporary Review for Pathologists

This review provides a summary of our current understanding of, and the controversies surrounding, the diagnosis, pathogenesis, histopathology, and molecular biology of Barrett's esophagus (BE) and associated neoplasia. BE is defined as columnar metaplasia of the esophagus. There is worldwide controversy regarding the diagnostic criteria of BE, mainly with regard to the requirement to histologically identify goblet cells in biopsies. Patients with BE are at increased risk for adenocarcinoma, which develops in a metaplasia-dysplasia-carcinoma sequence. Surveillance of patients with BE relies heavily on the presence and grade of dysplasia. However, there are significant pathologic limitations and diagnostic variability in evaluating dysplasia, particularly with regard to the more recently recognized unconventional variants. Identification of non-morphology-based biomarkers may help risk stratification of BE patients, and this is a subject of ongoing research. Because of recent achievements in endoscopic therapy, there has been a major shift in the treatment of BE patients with dysplasia or intramucosal cancer away from esophagectomy and toward endoscopic mucosal resection and ablation. The pathologic issues related to treatment and its complications are also discussed in this review article.

Overview of major molecular alterations during progression from Barrett's esophagus to esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) develops in the sequential transformation of normal epithelium into metaplastic epithelium, called Barrett's esophagus (BE), then to dysplasia, and finally cancer. BE is a common condition in which normal stratified squamous epithelium of the esophagus is replaced with an intestine-like columnar epithelium, and it is the most prominent risk factor for EAC. This review aims to impartially systemize the knowledge from a large number of publications that describe the molecular and biochemical alterations occurring over this progression sequence. In order to provide an unbiased extraction of the knowledge from the literature, a text-mining methodology was used to select genes that are involved in the BE progression, with the top candidate genes found to be TP53, CDKN2A, CTNNB1, CDH1, GPX3, and NOX5. In addition, sample frequencies across analyzed patient cohorts at each stage of disease progression are summarized. All six genes are altered in the majority of EAC patients, and accumulation of alterations correlates well with the sequential progression of BE to cancer, indicating that the text-mining method is a valid approach for gene prioritization. This review discusses how, besides being cancer drivers, these genes are functionally interconnected and might collectively be considered a central hub of BE progression.

Evolution of oesophageal adenocarcinoma from metaplastic columnar epithelium without goblet cells in Barrett's oesophagus

OBJECTIVE

Barrett's oesophagus commonly presents as a patchwork of columnar metaplasia with and without goblet cells in the distal oesophagus. The presence of metaplastic columnar epithelium with goblet cells on oesophageal biopsy is a marker of cancer progression risk, but it is unclear whether clonal expansion and progression in Barrett's oesophagus is exclusive to columnar epithelium with goblet cells.

DESIGN

We developed a novel method to trace the clonal ancestry of an oesophageal adenocarcinoma across an entire Barrett's segment. Clonal expansions in Barrett's mucosa were identified using cytochrome c oxidase enzyme histochemistry. Somatic mutations were identified through mitochondrial DNA sequencing and single gland whole exome sequencing.

RESULTS

By tracing the clonal origin of an oesophageal adenocarcinoma across an entire Barrett's segment through a combination of histopathological spatial mapping and clonal ordering, we find that this cancer developed from a premalignant clonal expansion in non-dysplastic ('cardia-type') columnar metaplasia without goblet cells.

CONCLUSION

Our data demonstrate the premalignant potential of metaplastic columnar epithelium without goblet cells in the context of Barrett's oesophagus.

Endoscopic Surveillance After Repair of Oesophageal Atresia: Longitudinal Study in 209 Patients

AIM

After repair of oesophageal atresia (OA), the need for endoscopic follow-up (EFU) remains unclear. To end this, we assessed the trends of oesophageal mucosal changes in successive follow-up biopsies.

METHODS

EFU records of 264 patients including histological grades of oesophagitis (from 0 to III), gastric (GM) or intestinal (IM) metaplasia and dysplasia (mild to severe) at 1, 3, 5 10, 15, and >15 years after repair of OA were reviewed.

RESULTS

Included were 209 patients with 616 biopsies. A total of 60 patients had undergone antireflux surgery and 24 had long-gap OA (LG). Median follow-up was 12 (range 1-17) years with 3 (1-6) endoscopies per patient. Highest grade of oesophagitis was Gr 0 (no oesophagitis) in 47%, Gr I in 37%, and Gr II or III in 16%. Metaplasia, GM (n = 31), IM (n = 4), occurred in 17% of patients and reached 15% prevalence by 15 years. Dysplasia and cancer were not found. From 1 to 15 years after repair grade of histological oesophagitis often fluctuated between Gr 0 and Gr I, but further progression was unlikely, hazard ratio = 0.2-3.4 (95% confidence interval 0.0-29), P = 0.06-0.87. LG and antireflux surgery predicted early detection of metaplasia (P < 0.001). Only 9% of patients with metaplasia and 32% with Gr II oesophagitis were symptomatic. A total of 6 (3%) patients had a symptomatic anastomotic stenosis at 1 year.

CONCLUSIONS

EFU revealed frequent oesophagitis and metaplasia, but no dysplasia or cancer. Routine endoscopic surveillance had limited benefit and seems unnecessary during childhood after repair of OA.

ACG Clinical Guideline: Diagnosis and Management of Barrett's Esophagus

Barrett's esophagus (BE) is among the most common conditions encountered by the gastroenterologist. In this document, the American College of Gastroenterology updates its guidance for the best practices in caring for these patients. These guidelines continue to endorse screening of high-risk patients for BE; however, routine screening is limited to men with reflux symptoms and multiple other risk factors. Acknowledging recent data on the low risk of malignant progression in patients with nondysplastic BE, endoscopic surveillance intervals are attenuated in this population; patients with nondysplastic BE should undergo endoscopic surveillance no more frequently than every 3-5 years. Neither routine use of biomarker panels nor advanced endoscopic imaging techniques (beyond high-definition endoscopy) is recommended at this time. Endoscopic ablative therapy is recommended for patients with BE and high-grade dysplasia, as well as T1a esophageal adenocarcinoma. Based on recent level 1 evidence, endoscopic ablative therapy is also recommended for patients with BE and low-grade dysplasia, although endoscopic surveillance continues to be an acceptable alternative. Given the relatively common recurrence of BE after ablation, we suggest postablation endoscopic surveillance intervals. Although many of the recommendations provided are based on weak evidence or expert opinion, this document provides a pragmatic framework for the care of the patient with BE.

Barrett's oesophagus diagnostic criteria: endoscopy and histology

This review summarizes the endoscopic and histologic features of Barrett's oesophagus(BO) as well as some of the recent advancements and controversies. BO represents metaplastic conversion of normal squamous epithelium of tubular oesophagus to columnar epithelium. The diagnosis of BO requires a combination of endoscopic and histopathologic findings. There is worldwide controversy regarding the exact definition of BO, particularly with regard to the requirement to histologically identify goblet cells in biopsies. The presence and detectability of goblet cells might vary depending on a variety of factors and is subject to sampling error. Therefore, a systematic biopsy sampling with sufficient number of biopsies is currently recommended to limit the likelihood of a false negative result for detection of goblet cells. There are both endoscopic and pathologic challenges in evaluating gastro-oesophageal junction biopsies in patients with irregular Z lines to determine the exact location of the sample (i.e., oesophagus versus stomach). Recently, several novel endoscopic techniques have been developed to improve BO detection. However, none have been validated yet in clinical practice. The surveillance of patients with BO relies on histologic evaluation of dysplasia. However, there are significant pathologic limitations and diagnostic variability in evaluating the presence and grading of BO dysplasia, particularly with regard to the more recently recognized non-intestinal types of dysplasia. All BO dysplasia samples should be reviewed by an expert gastrointestinal pathologist to confirm the diagnosis. Finally, it is important to emphasize that close interaction between gastroenterologists and pathologists is essential to ensure proper evaluation of endoscopic biopsies in order to optimize the surveillance and clinical management of patients with BO.

Barrett's oesophagus: frequency and prediction of dysplasia and cancer

The incidence of oesophageal adenocarcinoma is continuing to increase at an alarming rate in the Western world today. Barrett's oesophagus is a clearly recognized risk factor for the development of oesophageal adenocarcinoma, but the overwhelming majority of patients with Barrett's oesophagus will never develop oesophageal cancer. A number of endoscopic, histologic and epidemiologic risk factors identify Barrett's oesophagus patients at increased risk for progression to high-grade dysplasia and oesophageal adenocarcinoma. Endoscopic factors include segment length, mucosal abnormalities as seemingly trivial as oesophagitis and the 12 to 6 o'clock hemisphere of the oesophagus. Both intestinal metaplasia and low grade dysplasia, the latter only if confirmed by a pathologist with expertise in Barrett's oesophagus pathologic interpretation are the histologic risk factors for progression. Epidemiologic risk factors include ageing, male gender, obesity, and smoking. Factors that may protect against the development of adenocarcinoma include a diet rich in fruits and vegetables, and the use of proton pump inhibitors, aspirin/NSAIDs and statins.

The Barrett's Gland in Phenotype Space

Barrett's esophagus is characterized by the erosive replacement of esophageal squamous epithelium by a range of metaplastic glandular phenotypes. These glandular phenotypes likely change over time, and their distribution varies along the Barrett's segment. Although much recent work has addressed Barrett's esophagus from the genomic viewpoint-its genotype space-the fact that the phenotype of Barrett's esophagus is nonstatic points to conversion between phenotypes and suggests that Barrett's esophagus also exists in phenotype space. Here we explore this latter concept, investigating the scope of glandular phenotypes in Barrett's esophagus and how they exist in physical and temporal space as well as their evolution and their life history. We conclude that individual Barrett's glands are clonal units; because of this important fact, we propose that it is the Barrett's gland that is the unit of selection in phenotypic and indeed neoplastic progression. Transition between metaplastic phenotypes may be governed by neutral drift akin to niche turnover in normal and dysplastic niches. In consequence, the phenotype of Barrett's glands assumes considerable importance, and we make a strong plea for the integration of the Barrett's gland in both genotype and phenotype space in future work.