Predictive factors of coexisting cancer in Barrett's high-grade dysplasia

The role of esophagectomy in the management of Barrett's esophagus with high-grade dysplasia

Barrett's esophagus (BE) with high-grade dysplasia (HGD) has previously been a routine indication for esophagectomy. Recent advances in endoscopic therapy have resulted in a shift away from surgery. Current international guidelines recommend endoscopic therapy for BE with HGD irrespective of recurrence or progression of dysplasia. Current guidelines do not address the ongoing role of esophagectomy as an adjunct in the setting of failed endoscopic therapy. This review examines the role of esophagectomy as an adjunct to endoscopy in the management of patients with BE and HGD, with a specific focus on patients with persistent, progressive, or recurrent disease, disease resistant to endoscopic therapy, in patients with concomitant esophageal pathology, and in those patients in whom lifelong surveillance may not be possible or desired.

Mitochondrial DNA deletions in patients with esophagitis, Barrett's esophagus, esophageal adenocarcinoma and squamous cell carcinoma

Background

Esophageal cancer is the eighth most common cancer globally. Esophageal adenocarcinoma (EA) and esophageal squamous-cell carcinoma (ESCC) are the two major types of esophageal cancer with poor prognosis. The mechanisms of the progression of normal esophagus to Barrett's esophagus (BE) and EA are not fully understood. Mitochondria play a central role in generating energy, apoptosis and cell proliferation. Mutations of mitochondrial DNA (mtDNA) have been identified in many diseases including cancers. Mutations of mtDNA were investigated as a part of carcinogenesis.

Objective

Our objective is to study whether the 5 kb and 7.4 kb mtDNA deletions are important in the progression of normal esophagus to BE and EA.

Method

In this study, the frequency of the 5 kb and 7.4 kb deletions in mtDNA were studied in specimens ranging from normal esophageal tissue to BE and EA and also from ESCC. Seventy six paraffin-embedded tissue samples were studied. Four couple primers were used.

Results

Seventy-six tissue samples were analyzed total. The negative control and the positive control PCR product were detected in all analyzed samples. The fusion PCR products, which represent the presence of the deletions, were not detected in any of the samples.

Conclusion

We can say that, these deletions are not associated with progression of normal esophagus to BE and EA and they do not have an important role in detecting esophagitis, BE, EA, and ESSC.

How Should We Report Endoscopic Results in Patient's with Barrett's Esophagus?

Barrett's esophagus is the only known pre-cancerous lesion for esophageal adenocarcinoma and is diagnosed by high-definition white light endoscopy demonstrating a columnar-lined esophagus along with biopsy evidence of intestinal metaplasia. With accurate performance and reporting of the endoscopic procedure, an evidence-based management strategy can be developed for treatment of Barrett's dysplasia. However, cross-sectional data demonstrate that there is still inconsistency among gastroenterologists in performance and reporting of endoscopic findings in patients with Barrett's esophagus. Here, we present an evidence-based review of how to report endoscopic findings in Barrett's esophagus.

Diagnosis and treatment of superficial esophageal cancer

Endoscopy allows for the screening, early diagnosis, treatment and follow up of superficial esophageal cancer. Endoscopic submucosal dissection has become the gold standard for the resection of superficial squamous cell neoplasia. Combinations of endoscopic mucosal resection and radiofrequency ablation are the mainstay of the management of Barrett’s associated neoplasia. However, protruded, non-lifting or large lesions may be better managed by endoscopic submucosal dissection. Novel ablation tools, such as argon plasma coagulation with submucosal lifting and cryoablation balloons, are being developed for the treatment of residual Barrett’s esophagus, since iatrogenic strictures still hamper the development of extensive circumferential resections in the esophagus. Optimal surveillance modalities after endoscopic resection are still to be determined. The assessment of the risk of lymph-node metastases, as well as of the need for additional treatments based on qualitative and quantitative histological criteria, balanced to the patient’s condition, requires a dedicated multidisciplinary team decision process. The need for trained endoscopists, expert pathologists and surgeons, and specialized multidisciplinary meetings underlines the role of expert centers in the management of superficial esophageal cancer.

Probe confocal laser endomicroscopy in the therapeutic endoscopic management of Barrett's dysplasia

Background

Endoscopic management of Barrett’s esophagus (BE) depends on the histological stage of BE and includes the following: follow up, endotherapy with thermal ablation, and piecemeal or monobloc endoscopic resection (ER). We know that biopsies are unreliable in 20-75% of cases. The aim of our study was to evaluate the efficiency of probe confocal laser endomicroscopy (pCLE) in the diagnosis of the histological stage of BE, compared with the final histological results after ER.

Methods

This retrospective study was based on a prospective registry of patients referred for management of BE-associated dysplasia. The inclusion criteria were dysplasia associated with BE on pre-resection biopsy and endoscopic resection of the examined areas. CLE examinations (pCLEs) were performed using the Gastroflex^® probe (Maunakea company). ER was sufficient to ensure that the target area was resected. The following four potential diagnoses were considered: normal or inflammatory mucosa, metaplasia (BE), low-grade dysplasia (LGD), and high-grade dysplasia/esophageal adenocarcinoma (HGD/EAC).

Results

The sensitivity, specificity, and accuracy in the detection of HGD/EAC were 92.9%, 71.4% and 80% for pCLE, and 78.6%, 61.9%, and 68.6% for histological biopsy, respectively. The differences in favor of pCLE were not statistically significant (P=0.2); however, in 13 patients with irregularities of the mucosa without elevated or depressed lesions (2 HGD/EAC and 11 non-HGD/EAC), pCLE led to positive redirection of therapy in 70% (9/13) of cases.

Conclusion

In the absence of visible lesions, pCLE appears to lead to correct diagnoses and to aid real-time decisions regarding therapeutic management.

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.

Radiofrequency Ablation Is Associated With Decreased Neoplastic Progression in Patients With Barrett's Esophagus and Confirmed Low-Grade Dysplasia

BACKGROUND & AIMS

Barrett's esophagus (BE) with low-grade dysplasia (LGD) can progress to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC). Radiofrequency ablation (RFA) has been shown to be an effective treatment for LGD in clinical trials, but its effectiveness in clinical practice is unclear. We compared the rate of progression of LGD after RFA with endoscopic surveillance alone in routine clinical practice.

METHODS

We performed a retrospective study of patients who either underwent RFA (n = 45) or surveillance endoscopy (n = 125) for LGD, confirmed by at least 1 expert pathologist, from October 1992 through December 2013 at 3 medical centers in the United States. Cox regression analysis was used to assess the association between progression and RFA.

RESULTS

Data were collected over median follow-up periods of 889 days (interquartile range, 264-1623 days) after RFA and 848 days (interquartile range, 322-2355 days) after surveillance endoscopy (P = .32). The annual rates of progression to HGD or EAC were 6.6% in the surveillance group and 0.77% in the RFA group. The risk of progression to HGD or EAC was significantly lower among patients who underwent RFA than those who underwent surveillance (adjusted hazard ratio = 0.06; 95% confidence interval: 0.008-0.48).

CONCLUSIONS

Among patients with BE and confirmed LGD, rates of progression to a combined end point of HGD and EAC were lower among those treated with RFA than among untreated patients. Although selection bias cannot be excluded, these findings provide additional evidence for the use of endoscopic ablation therapy for LGD.

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.

Progression of Barrett oesophagus: role of endoscopic and histological predictors

Barrett oesophagus is an important precursor lesion for the development of oesophageal adenocarcinoma (OAC). Upper gastrointestinal endoscopy is the modality most widely used to visualize and biopsy the oesophagus to establish a diagnosis. Additional clues are available at the time of endoscopy that can identify high-risk features known to increase the risk of progression to OAC, such as the length of the Barrett oesophagus segment, length of hiatal hernia and the presence of nodularity or visible endoscopic lesions in this segment. Until molecular biomarkers are identified and validated as adjunctive tools for risk stratification, knowledge of endoscopic features could complement dysplasia grading for risk stratification of patients with Barrett oesophagus and identify subgroups at risk of progression to OAC. This approach would, in turn, facilitate more rational tailoring of endoscopic surveillance. This Review summarizes the current role of endoscopic and histological factors involved in neoplastic progression of Barrett oesophagus to OAC, and provides an overview of the risk-prediction models that have utilized endoscopic and histological factors for risk stratification in patients with Barrett oesophagus.

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

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

Management controversies in Barrett's oesophagus

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

Barrett's oesophagus: epidemiology, cancer risk and implications for management

Although endoscopic surveillance of patients with Barrett's oesophagus has been widely implemented, its effectiveness is debateable. The recently reported low annual oesophageal adenocarcinoma risk in population studies, the failure to identify most Barrett's patients at risk of disease progression, the poor adherence to surveillance and biopsy protocols, and the significant risk of misclassification of dysplasia all tend to undermine the effectiveness of current management, in particular, endoscopic surveillance programmes, to prevent or improve the outcomes of patients with oesophageal adenocarcinoma. The ongoing increase in incidence of Barrett's oesophagus and consequent growth of the surveillance population, together with the associated discomfort and costs of endoscopic surveillance, demand improved techniques for accurately determining individual risk of oesophageal adenocarcinoma. More accurate techniques are needed to run efficient surveillance programmes in the coming decades. In this review, we will discuss the current knowledge on the epidemiology of Barrett's oesophagus, and the challenging epidemiological dilemmas that need to be addressed when assessing the current screening and surveillance strategies.

Barrett Esophagus: Evolving Concepts in Diagnosis and Neoplastic Progression

Surgical pathologists need to answer 2 questions when evaluating biopsies from the distal esophagus or gastroesophageal junction in patients with a history of gastroesophageal reflux disease: Are the findings consistent with Barrett esophagus? and Is there any evidence of dysplasia? Pathologists should be well informed about the controversy around the definition of Barrett esophagus and the common pitfalls that lead to a false-positive diagnosis of Barrett esophagus or Barrett esophagus-associated dysplasia. A concise description of distinct morphologic types of dysplasia in Barrett esophagus and a summary of recent data on the natural history of BE are provided in this review.

Radiofrequency ablation in the management of Barrett's esophagus: present role and future perspective

Esophageal adenocarcinoma is the most rapidly increasing gastrointestinal cancer. Barrett's esophagus has been identified as a precancerous condition and major risk factor for esophageal cancer. Radiofrequency ablation has been shown to be a highly efficient in promoting remission of intestinal metaplasia. This technology has seen widespread clinical use since 2005. Radiofrequency ablation is common with all other ablative techniques; the concern that sound oncological principles are not being adhered to, that is, appropriate pathological staging, followed by appropriate definitive therapy. Endoscopic mucosal excision techniques are technically demanding; however, they are more attractive from an oncological perspective. Future research endeavors focusing on facilitation of large population screening, the identification of high risk phenotypes, endoscopic mucosal resection techniques will combat the esophageal adenocarcinoma epidemic.

Barrett's esophagus: review of diagnosis and treatment

Barrett's esophagus (BE) is an acquired condition characterized by replacement of stratified squamous epithelium by a cancer predisposing metaplastic columnar epithelium. Endoscopy with systemic biopsy protocols plays a vital role in diagnosis. Technological advancements in dysplasia detection improves outcomes in surveillance and treatment of patients with BE and dysplasia. These advances in endoscopic technology radically changed the treatment for dysplastic BE and early cancer from being surgical to organ-sparing endoscopic therapy. A multimodal treatment approach combining endoscopic resection of visible and/or raised lesions with ablation techniques for flat BE mucosa, followed by long-term surveillance improves the outcomes of BE. Safe and effective endoscopic treatment can be either tissue acquiring as in endoscopic mucosal resection and endoscopic submucosal dissection or tissue ablative as with photodynamic therapy, radiofrequency ablation and cryotherapy. Debatable issues such as durability of response, recognition and management of sub-squamous BE and optimal management strategy in patients with low-grade dysplasia and non-dysplastic BE need to be studied further. Development of safer wide field resection techniques, which would effectively remove all BE and obviate the need for long-term surveillance, is another research goal. Shared decision making between the patient and physician is important while considering treatment for dysplasia in BE.

Outcomes in patients who have failed endoscopic therapy for dysplastic Barrett's metaplasia or early esophageal cancer

BACKGROUND

Endoscopic therapy (ablation ± mucosal resection) for esophageal high-grade dysplasia (HGD) or intramucosal carcinoma has demonstrated promising results. Little is known about patients who have persistent or progressive disease despite endotherapy. We compared patients who had successful eradication of their disease with those in whom endotherapy failed to try to identify factors predictive of failure and outcomes after salvage therapy.

METHODS

We performed a single-institution retrospective review of patients treated with endotherapy from 2007 to 2012.

RESULTS

Thirty-eight patients underwent endotherapy: 28 had successful eradication of their disease and endotherapy failed in 10 patients. Patients in whom endotherapy failed were more likely to have high-grade dysplasia (HGD) on initial endoscopy, nodules or ulcers, multifocal dysplasia, and persistent nondysplastic Barrett's metaplasia. Patients in whom endotherapy failed also underwent significantly more endotherapy sessions. Seven patients had persistent dysplasia or progression to cancer, and 3 patients had complete eradication of HGD but presented with intramucosal carcinoma an average of 15 months after eradication. The 10 patients in whom endotherapy failed underwent salvage therapy with esophagectomy (7 patients), definitive chemoradiotherapy (1 patient), and endotherapy (2 patients). Patients treated with esophagectomy were disease free at a mean of 25 months postoperatively.

CONCLUSIONS

HGD on initial endoscopy, multifocal dysplasia, mucosal abnormalities, and failure to eradicate nondysplastic Barrett's metaplasia were associated with failure of endotherapy. Patients with these characteristics should be considered at higher risk for treatment failure, and earlier consideration should be given to esophagectomy if there is persistent, progressive, or recurrent neoplasia. Clinical outcomes are good, even after salvage therapy. Continued endoscopic surveillance is mandatory after successful endotherapy because of the risk of recurrent disease.

Endoscopic Therapy of Neoplasia Related to Barrett's Esophagus and Endoscopic Palliation of Esophageal Cancer

Background

Barrett's esophagus (BE) is the most important identifiable risk factor for the progression to esophageal adenocarcinoma.

Methods

This article reviews the current endoscopic therapies for BE with high-grade dysplasia and intramucosal cancer and briefly discusses the endoscopic palliation of advanced esophageal cancer.

Results

The diagnosis of low-grade or high-grade dysplasia (HGD) is based on several cytologic criteria that suggest neoplastic transformation of the columnar epithelium. HGD and carcinoma in situ are regarded as equivalent. The presence of dysplasia, particularly HGD, is also a risk factor for synchronous and metachronous adenocarcinoma. Dysplasia is a marker of adenocarcinoma and also has been shown to be the preinvasive lesion. Esophagectomy has been the conventional treatment for T1 esophageal cancer and, although debated, is an appropriate option in some patients with HGD due to the presence of occult cancer in over one-third of patients.

Conclusions

Endoscopic ablative modalities (eg, photodynamic therapy and cryoablation) and endoscopic resection techniques (eg, endoscopic mucosal resection) have demonstrated promising results. The significant morbidity and mortality of esophagectomy makes endoscopic treatment an attractive potential option.

[Screening for adenocarcinoma in Barrett's esophagus: yes or no, when and how?]

Barrett's esophagus (BE) is the main recognized risk factor for the development of esophageal adenocarcinoma (EAC). The incidence of this cancer and its associated mortality has increased in developed countries during the last few years. Detection of EAC at earlier stages could potentially improve survival dramatically in these patients, which is especially important as mortality from EAC remains high despite the available treatments. Therefore, endoscopic surveillance is an attractive option for patients with Barrett's esophagus. Consequently, periodic endoscopic surveillance is recommended by all the International Gastroenterology Societies in an attempt to detect EAC at an early and potentially curable stage. Currently, the frequency of endoscopic surveillance and its need in Barrett's esophagus with low-grade dysplasia or without dysplasia are under discussion. This review presents the available evidence in order to assist clinicians in the decision-making process.

Consensus statements for management of Barrett's dysplasia and early-stage esophageal adenocarcinoma, based on a Delphi process

BACKGROUND & AIMS

Esophageal adenocarcinoma (EA) is increasingly common among patients with Barrett's esophagus (BE). We aimed to provide consensus recommendations based on the medical literature that clinicians could use to manage patients with BE and low-grade dysplasia, high-grade dysplasia (HGD), or early-stage EA.

METHODS

We performed an international, multidisciplinary, systematic, evidence-based review of different management strategies for patients with BE and dysplasia or early-stage EA. We used a Delphi process to develop consensus statements. The results of literature searches were screened using a unique, interactive, Web-based data-sifting platform; we used 11,904 papers to inform the choice of statements selected. An a priori threshold of 80% agreement was used to establish consensus for each statement.

RESULTS

Eighty-one of the 91 statements achieved consensus despite generally low quality of evidence, including 8 clinical statements: (1) specimens from endoscopic resection are better than biopsies for staging lesions, (2) it is important to carefully map the size of the dysplastic areas, (3) patients that receive ablative or surgical therapy require endoscopic follow-up, (4) high-resolution endoscopy is necessary for accurate diagnosis, (5) endoscopic therapy for HGD is preferred to surveillance, (6) endoscopic therapy for HGD is preferred to surgery, (7) the combination of endoscopic resection and radiofrequency ablation is the most effective therapy, and (8) after endoscopic removal of lesions from patients with HGD, all areas of BE should be ablated.

CONCLUSIONS

We developed a data-sifting platform and used the Delphi process to create evidence-based consensus statements for the management of patients with BE and early-stage EA. This approach identified important clinical features of the diseases and areas for future studies.

Endotherapy for Barrett's esophagus

Endotherapy is now the mainstay of therapy for Barrett's associated neoplasia. The approach should begin with confirmation of neoplasia by a gastrointestinal pathologist, patient counseling, and appropriate endoscopic work up. Detailed examination with high-resolution white light endoscopy is the most important tool for detection of neoplasia. Further validation studies are needed for many enhanced imaging modalities before being recommended as part of the standard work up and assessment of patients with Barrett's esophagus (BE). Endoscopic mucosal resection is required for any visible lesion in the setting of dysplasia for accurate histological diagnosis. The remainder of the epithelium may be treated with resection or ablative therapy, followed by adequate surveillance. Patients with nondysplastic Barrett's require further risk stratification before incorporation of ablative therapy for this population. The future will fortify the endoscopic role in Barrett's with validation trials for endoscopic assessment, further long-term results for each of the treatment modalities, potential risk stratification for patients with BE, and improved guidelines for surveillance after therapy.

Columnar-lined esophagus without intestinal metaplasia has no proven risk of adenocarcinoma

Intestinal metaplasia in the columnar-lined esophagus (CLE) has long been recognized as the most significant histologic risk indicator for esophageal adenocarcinoma. Recent concern has been expressed, however, that nonintestinalized metaplastic columnar epithelia (cardiac epithelium in the esophagus) may also indicate risk. Of 2586 consecutive patients undergoing endoscopy and biopsy in the Foregut Surgery Department, we selected (a) 214 patients with a visible CLE who had systemic 4-quadrant biopsies at 1 to 2 cm intervals, with the most proximal biopsy straddling the squamocolumnar junction, and (b) 109 patients without systematic biopsy who had dysplasia or adenocarcinoma. In the first group, 187 (87.4%) patients had intestinal metaplasia, and 27 (12.6%) had cardiac epithelium. Dysplasia or adenocarcinoma was present in 55 patients, all with intestinal metaplasia; its presence was significantly higher than in the cardiac epithelium group, none of whom had dysplasia or adenocarcinoma (P=0.01). In the second group with limited sampling, 49 had only tumor tissue in the biopsy. Of 60 patients with nontumor epithelium, only 34 (56.7%) had residual intestinal metaplasia. We conclude that systematic biopsies of CLE as described in this study separate patients into those with and without intestinal metaplasia in such a manner as to remove the possibility of false-negative diagnosis of intestinal metaplasia. When intestinal metaplasia is absent using this biopsy protocol, the patient is at no or extremely low risk for dysplasia and cancer. When biopsies have a lower level of sampling of the segment of CLE, the absence of intestinal metaplasia cannot be interpreted as a true negative for intestinal metaplasia. Inadequate sampling is a powerful reason why the near absolute association between intestinal metaplasia and adenocarcinoma is not seen in some studies.

Endoscopic management of Barrett esophagus

Endoscopy has a vital role in the diagnosis, screening, surveillance and treatment of Barrett esophagus. Over the past few decades, tremendous advances have been made in endoscopic technology, and the management of dysplasia and early cancer in Barrett esophagus has changed radically from being surgical to organ-sparing endoscopic therapy. Proper endoscopic techniques and systematic biopsy protocols improve dysplasia detection, and endoscopic surveillance improves outcomes in patients with Barrett esophagus and dysplasia. Endoscopic treatment can be tissue acquiring (as in endoscopic mucosal resection and endoscopic submucosal dissection) or ablative (as with photodynamic therapy, radiofrequency ablation and cryotherapy). Treatment is usually multimodal, combining endoscopic resection of visible lesions with one or more mucosal ablation techniques, followed by long-term surveillance. Such treatment is safe and effective. Shared decision-making between the patient and physician is important while considering treatment for dysplasia in Barrett esophagus. Issues such as durability of response, importance of subsquamous Barrett epithelium and the optimal management strategy in patients with low-grade dysplasia and nondysplastic Barrett esophagus need to be studied further. Development of safer wide-field resection techniques, which would effectively remove all Barrett esophagus and obviate the need for long-term surveillance, is needed.

Endotherapy for Barrett's esophagus: Which, how, when, and who?

Recent developments in endoscopic therapeutic options for Barrett's esophagus (BE) early neoplasia have resulted in a dramatic paradigm shift in its clinical management. With multiple endoscopic choices available, it is important to discern subtle differences between these approaches based on the available current data and known limitations of each modality. The goals of endoscopic therapy of Barrett's neoplasia are to preserve the esophagus while ablating or removing the entire BE segment. This article reviews the currently available BE endoscopic treatments with emphasis on appropriate selection of patients, indications and timing of use, and clinical management considerations.

Barrett's esophagus surveillance: When, how often, does it work?

Barrett's esophagus is a well-known risk factor for the development of esophageal adenocarcinoma. Current practice guidelines recommend endoscopic surveillance of patients with Barrett's esophagus in an attempt to detect cancer at an early and potentially curable stage. This review addresses the rationale behind surveillance and criteria for inclusion of patients in surveillance programs as well as the appropriate technique and intervals that should be used. This work addresses other key topics in Barrett's esophagus surveillance, including the efficacy of surveillance programs, physician compliance with surveillance guidelines, cost-effectiveness of surveillance programs, and areas for future research.

Diagnostic challenges in the pathologic evaluation of Barrett esophagus

CONTEXT

Barrett esophagus represents an unstable epithelium resulting from chronic gastroesophageal reflux disease. Patients with Barrett esophagus routinely undergo endoscopic examination to detect dysplasia and early carcinoma. Although appropriate classification of Barrett esophagus and neoplasia is usually straightforward, persistent esophageal inflammation may induce epithelial changes that mimic, or mask, dysplasia. Recent data also indicate that specific molecular changes occur in nondysplastic Barrett mucosa and herald the development of dysplasia and/or carcinoma.

OBJECTIVE

To describe problematic aspects of biopsy interpretation in tissue samples of the gastroesophageal junction and distal esophagus, including the diagnostic criteria for Barrett esophagus, the importance of the gastric cardia, and pitfalls to the diagnosis of dysplasia. Ancillary studies that have recently emerged as potential adjuncts to the evaluation of patients with Barrett esophagus will be briefly discussed.

DATA SOURCES

A comprehensive review of the relevant literature indexed in PubMed (National Library of Medicine) was performed.

CONCLUSIONS

Barrett esophagus is currently defined as the presence of intestinal metaplasia in samples obtained from an endoscopically evident abnormality in the distal esophagus. Diagnosis and grading of dysplasia in mucosal biopsies remain the most reliable method to assess risk for neoplastic progression, but its classification may be hindered by superimposed inflammatory changes and suffers from considerable interobserver variability. Therefore, immunohistochemical studies and molecular assessment for TP53, CDKN2A , and DNA content abnormalities have emerged as potential adjuncts to the detection of dysplasia.

Association of adenocarcinomas of the distal esophagus, "gastroesophageal junction," and "gastric cardia" with gastric pathology

Controversy exists as to whether adenocarcinomas occurring in the gastroesophageal junctional region and gastric cardia originate in the esophagus or the stomach. Esophageal adenocarcinoma is known to be strongly associated with gastroesophageal reflux disease; gastric adenocarcinoma with Helicobacter pylori gastritis, and gastric intestinal metaplasia. This study evaluates the association of these tumors with pathologic findings in the biopsies of the gastric body and the antrum. It is hypothesized that if these malignancies are esophageal, they should have little or no significant association with gastric pathology; if they are gastric, these patients should have a high prevalence of gastric pathology. Between 2004 and 2008, 234 patients were diagnosed with high-grade dysplasia (HGD) and/or adenocarcinoma; 107 were distal esophageal, 79 straddled the distal end of the tubular esophagus, and 48 were in the "gastric cardia." Simultaneous biopsies of the distal body and antrum were present in 185 patients; 49 had biopsy of either antrum or body. Gastric biopsies were assessed for inflammation, H. pylori infection, and intestinal metaplasia. During this period, 2146 patients had nonmalignant columnar epithelia in the esophagus with similar assessment of the stomach; these acted as a control group. The gastric biopsy was normal in 201/234 (85.9%) patients and showed significant inflammation, H. pylori infection, and/or gastric intestinal metaplasia in 33/234 (14.1%) patients. There was no gastritis, H. pylori infection, or intestinal metaplasia in 88/107 (82.2%) of the patients with distal esophageal HGD and/or adenocarcinoma, 70/79 (88.6%) with junctional HGD and/or adenocarcinoma, and 43/48 (85.9%) with "gastric cardiac" HGD and/or adenocarcinoma. The incidence of gastritis was significantly higher in the patients with HGD and/or adenocarcinoma (33/234 or 14.1%) than in the control population (146/2146 or 9.0%; P=0.01). This difference was largely the result of a higher incidence of gastritis in patients with HGD and/or adenocarcinoma in the distal third of the esophagus (19/107 or 17.8%) versus the control population (146/2146 or 9.0%; P=0.01). The incidence of H. pylori positivity was also significantly higher in the patients with HGD and/or adenocarcinoma in the distal third of the esophagus (13/107 or 12.2%) than in the control population (117/2146 or 5.5%; P=0.01). There was no significant difference between the control group and the patients with junctional and gastric cardiac HGD and/or adenocarcinoma for gastritis, H. pylori infection, or the gastric intestinal metaplasia. The absence of gastritis, H. pylori, and the gastric intestinal metaplasia in 85.9% of the patients with HGD and/or adenocarcinoma of the gastroesophageal junctional region strongly suggest that most of these originate in the esophagus. In the small minority of patients whose HGD and/or adenocarcinoma were associated with gastric pathology, the incidence of gastritis and H. pylori infection was significantly higher in patients with HGD and/or adenocarcinoma in the distal third of the esophagus and not in the junctional and "gastric cardiac" tumors. This suggests that the reflux of the gastric juice whose composition has been altered by gastritis and H. pylori infection may be associated with an increased tendency to HGD and/or adenocarcinoma in the distal third of the esophagus.

Esophageal resection for high-grade dysplasia and intramucosal carcinoma: When and how?

High-grade dysplasia (HGD) and intramucosal carcinoma (IMC) in the setting of Barrett’s esophagus have traditionally been treated with esophagectomy. However, with the advent of endoscopic mucosal resection and endoscopic ablative therapies, endoscopic therapy at centers with expertise is now an established treatment of Barrett’s-esophagus-related neoplasia, including HGD and IMC. Esophagectomy is today reserved for more selected cases with submucosal invasion, evidence for lymph node metastasis, or unsuccessful endoscopic therapy.

Predictors of progression in Barrett's esophagus: current knowledge and future directions

Barrett's esophagus (BE) is the strongest risk factor for esophageal adenocarcinoma (EAC), a malignancy with persistently poor long-term outcomes. EAC is thought to develop through progression of metaplasia to dysplasia to invasive carcinoma. Identification of factors predicting progression to EAC would help in focusing surveillance, chemoprevention, or ablation for those deemed to be at highest risk of progression. We performed a comprehensive review of the literature and summarized current evidence on risk factors for progression in subjects with known BE. Clinical and demographic factors (age, male gender, length of BE segment) are associated with modestly increased odds of progression to EAC in some studies. Biomarkers such as aneuploidy and p53 loss of heterozygosity have been associated with increased risk of progression to high-grade dysplasia and/or EAC in single-center prospective cohort studies. Promising newer techniques and markers have been recently reported with the potential to help risk stratify BE subjects. Development of a comprehensive BE risk progression score comprised of both clinical and biomarker variables should be the ultimate goal and can be achieved by multicenter prospective collaborative efforts. Although it would be challenging, creation of such a score has the potential to improve outcomes and make the management of patients with BE more cost-effective.

Endoscopic techniques for recognizing neoplasia in Barrett's esophagus: which should the clinician use?

PURPOSE OF REVIEW

The key to prevention and cure of esophageal adenocarcinoma is the detection and eradication of neoplasia in patients with Barrett's esophagus. Multiple tools and technologies are emerging for this purpose.

RECENT FINDINGS

A detailed white light examination with high-resolution endoscopy and recognition of lesions is paramount. A variety of imaging modalities are being studied for the detection of neoplasia in Barrett's esophagus. Chromoendoscopy, narrow band imaging, and autofluorescence provide a way to target suspicious areas. Confocal endomicroscopy and optical coherence tomography are means to pinpoint imaging to obtain information about the tissue microarchitecture.

SUMMARY

The key to detection of neoplasia is a careful white light examination with high-resolution endoscopy and recognition of lesion characteristics. Additional imaging modalities may enhance targeting of lesions or provide more information at a focused level. Many of these modalities have yet to be validated in prospective randomized, multicenter trials.

Risk factors for esophageal cancer development

The incidence of esophageal adenocarcinoma is increasing at a rate greater than that of any other cancer in the Western world today. Barrett's esophagus is a clearly recognized risk factor for the development of esophageal adenocarcinoma, but the overwhelming majority of patients with Barrett's esophagus will never develop esophageal cancer. To date, dysplasia remains the only factor useful for identifying patients at increased risk for the development of esophageal adenocarcinoma in clinical practice. Other epidemiologic risk factors include aging, gender, race, obesity, reflux symptoms, smoking, and diet. Factors that may protect against the development of adenocarcinoma include infection with Helicobacter pylori, a diet rich in fruits and vegetables, and consumption of aspirin and NSAIDs.

Mucosal ablation of Barrett esophagus

The management of Barrett esophagus is evolving with the emergence of new endoscopic technologies. Traditionally, patients with high-grade dysplasia or cancer were referred for esophagectomy. However, with the advent of endoscopic ablative therapies for Barrett esophagus, the treatment paradigm has shifted. Patients with high-grade dysplasia and intramucosal carcinoma are increasingly offered esophagus-sparing therapies. Endoscopic ablative therapies can be categorized into tissue-acquiring and non-tissue-acquiring modalities. Visible lesions in the setting of dysplasia should be treated with a tissue-acquiring modality to stage and resect the lesion appropriately. One or more modalities may be used to eradicate the entire region of affected esophagus totally. Total eradication treats all of the at-risk epithelium and, therefore, treats any metachronous or synchronous lesions. Success of treatment may be gauged by complete remission of cancer, dysplasia, or Barrett esophagus. In addition to procedure-related complications, the risk of residual Barrett esophagus or subsquamous Barrett esophagus remains to be addressed. Endoscopic surveillance and acid suppression is still currently required after ablation.

The Society of Thoracic Surgeons practice guideline series: guidelines for the management of Barrett's esophagus with high-grade dysplasia

The management of Barrett's esophagus with high-grade dysplasia is controversial. The standard of care has traditionally been esophagectomy. However, a number of treatment options aimed at esophageal preservation are increasingly being utilized by many centers. These esophageal-sparing approaches include endoscopic surveillance, mucosal ablation, and endoscopic mucosal resection. In this guideline we review the best evidence supporting these commonly used strategies for high-grade dysplasia to better define management and guide future investigation.

The Seattle protocol does not more reliably predict the detection of cancer at the time of esophagectomy than a less intensive surveillance protocol

BACKGROUND & AIMS

The optimal management of high-grade dysplasia in Barrett's esophagus remains controversial. A biopsy protocol consisting of 4 quadrant jumbo biopsies (every 1 cm) with biopsies of mucosal abnormalities (the Seattle protocol) is considered to be the optimal method for detecting early cancers in patients with high-grade dysplasia, although it has never been validated. This study aimed to determine the frequency of unsuspected carcinoma at esophagectomy in Barrett's esophagus patients with high-grade dysplasia who underwent the Seattle protocol and to compare the findings with those of a less rigorous biopsy protocol.

METHODS

Thirty-three patients with high-grade dysplasia underwent esophagectomy. None had obvious mass lesions at preoperative endoscopy. Patients were divided into group 1 (preoperative surveillance biopsies according to Seattle protocol) and group 2 (4 quadrant biopsies every 2 cm). Preoperative and postoperative diagnoses were confirmed by 2 expert gastrointestinal pathologists.

RESULTS

Unsuspected intramucosal cancer was found in 8 of 20 (40%) patients in group 1 versus 4 of 13 (30%) in group 2 (P = .6). Preoperative mucosal nodularity was observed in 4 of 8 (50%) postoperative intramucosal cancers from group 1 versus 3 of 4 (75%) from group 2. Multifocal high-grade dysplasia was seen preoperatively in 7 of 8 (87.5%) postoperative intramucosal cancers in group 1 versus 2 of 4 (50%) in group 2. No patient had submucosal cancer or lymph node metastases at surgery.

CONCLUSIONS

Intense preoperative biopsy sampling by the Seattle protocol does not more reliably predict the detection of cancer at the time of esophagectomy than a less intensive surveillance protocol. This calls into question the concept that extensive sampling with the Seattle protocol consistently detects early cancers arising in Barrett's esophagus patients with high-grade dysplasia.

[Surgical treatment for early Barrett cancer]

Adenocarcinomas in Barrett's oesophagus are more commonly diagnosed at an early stage due to effective surveillance programmes. Subtotal oesophagectomy with extended lymphadenectomy is considered the best curative treatment for patients with early adenocarcinoma of the oesophagus. However, such treatment carries substantial morbidity and compromises quality of life. Limited resection, minimal invasive surgical procedures or endoscopic mucosal ablation have been proposed as less invasive alternatives. A comparison of treatment associated morbidity, recurrence rate, long-term survival and functional outcome suggests that none of these alternative methods can be universally recommended. An individualized strategy should be employed based on staging (tumour penetration into the mucosa/submucosa, presence of lymph node metastasis), multicentricity, length of the underlying Barrett mucosa and risk factors of the patient. Surgical resection (radical or limited) remains the treatment of choice for tumours invading the submucosa, or multicentric and recurrent tumours after endoscopic mucosectomy.

Low prevalence of submucosal invasive carcinoma at esophagectomy for high-grade dysplasia or intramucosal adenocarcinoma in Barrett's esophagus: a 20-year experience

BACKGROUND

The rate of occult adenocarcinoma at esophagectomy in patients with Barrett's esophagus (BE) and high-grade dysplasia (HGD) has been reported to be approximately 40%. Recently, it has been suggested that this risk may be overestimated.

OBJECTIVE

Our purpose was to determine the rate of submucosal invasive adenocarcinoma in patients undergoing esophagectomy for BE after biopsy diagnosis of HGD or intramucosal carcinoma (IMC). A secondary aim was to identify clinical risk factors for submucosal invasive adenocarcinoma in these patients.

DESIGN

A retrospective study.

SETTING

Tertiary referral center.

PATIENTS

All patients with preoperative BE with HGD or IMC treated with esophagectomy over a 20 year period.

INTERVENTIONS

Esophagectomy.

MAIN OUTCOME MEASUREMENTS

Submucosal invasive adenocarcinoma at esophagectomy.

RESULTS

Sixty patients were included (41 with preoperative HGD, 19 with preoperative IMC). The overall rate of submucosal invasive carcinoma was 6.7% (95% CI, 1.8%-16.2%) (n = 4), with a 5% rate of submucosal invasion in patients with preoperative HGD and 11% for patients with preoperative IMC. All 4 patients with submucosal invasion at esophagectomy had either nodular or ulcerated mucosa on preoperative endoscopy. The 1-year and 5-year all-cause risks of death for the entire cohort were 1.9% and 10.9%, respectively.

LIMITATIONS

Retrospective study.

CONCLUSIONS

The rate of submucosal invasive adenocarcinoma at esophagectomy in BE patients with HGD or IMC on biopsy is much lower than 40%. After adequate sampling and staging, patients with BE with HGD and IMC, especially those without endoscopically visible lesions, can potentially be treated by nonsurgical (local) therapies.

Frequency of the mitochondrial DNA 4977bp deletion in oesophageal mucosa during the progression of Barrett's oesophagus

PURPOSE

The mechanisms of the progression of Barrett's oesophagus (BO) to oesophageal adenocarcinoma (OA) are poorly understood. The frequency of the 4977bp deletion in mitochondrial DNA (mtDNA) was investigated in specimens ranging from normal oesophageal tissue to OA in order to investigate whether this deletion represents a useful biomarker of disease progression.

METHODS

The presence of the 4977bp deletion was screened by PCR amplification from 70 specimens in total.

RESULTS

The frequency of specimens with the 4977bp deletion increased in relation to the degree of dysplasia (8.3% in normal squamous epithelium; 15.4% in BO; 40% in low grade dysplasia (LGD); 69.2% in high-grade dysplasia and 90% in para-tumoural tissue). However, the frequency of the deletion reduced sharply in OA specimens (16.7%; p<0.001).

CONCLUSION

The mtDNA 4977bp deletion may be useful as a biomarker to detect the severity of dysplasia but not the presence of OA.

Patient predictors of histopathologic response after photodynamic therapy of Barrett's esophagus with high-grade dysplasia or intramucosal carcinoma

BACKGROUND

Photodynamic therapy (PDT) has been used extensively for endoscopic ablation of Barrett's esophagus with high-grade dysplasia (HGD) or intramucosal carcinoma.

OBJECTIVE

To identify patient variables that influence the likelihood of response to PDT.

DESIGN

A retrospective cohort study.

SETTING

Tertiary-referral center.

PATIENTS

A total of 116 patients with Barrett's esophagus and with HGD, intramucosal carcinoma, or T1 cancer.

INTERVENTIONS

PDT with porfimer sodium.

MAIN OUTCOME MEASUREMENTS

(1) Ablation of HGD and/or intramucosal carcinoma and (2) eradication of all Barrett's epithelium.

RESULTS

Of the patients, 51% underwent treatment for HGD and 49% of patients had intramucosal carcinoma or T1 cancer. At 12-month follow-up, ablation of HGD and/or cancer was observed in 70% of patients, and ablation of all Barrett's epithelium was observed in 39%. In multivariate analysis, the pretreatment length of Barrett's esophagus was inversely correlated with successful ablation of all Barrett's epithelium. Patients with Barrett's esophagus length more than 3 cm were less likely to experience complete ablation compared with patients with Barrett's esophagus length 3 cm or less (odds ratio [OR] 0.15 [95% CI, 0.04-0.50]). Patients with intramucosal carcinoma were not significantly less likely to experience elimination of HGD and/or cancer (OR 0.77 [95% CI, 0.30-2.00]) or ablation of all Barrett's epithelium (OR 0.82 [95% CI, 0.32-2.07]) compared with patients with HGD alone.

LIMITATIONS

Retrospective study, limited sample size without a control group for comparison.

CONCLUSIONS

PDT of Barrett's esophagus with HGD, intramucosal carcinoma, or T1 cancer can result in ablation of dysplasia and/or eradication of all Barrett's epithelium. Factors associated with the likelihood of response include length of Barrett's esophagus. The presence of intramucosal carcinoma or T1 cancer was not associated with higher likelihood of treatment failure.

Management of high-grade dysplasia

High-grade dysplasia is the last stage before the development of adenocarcinoma. Despite the fact that the lesion is not yet invasive, it has tremendous potential to become malignant. The approach to the disease has clinicians divided between immediate intervention with surgical resection or continued endoscopic surveillance proof of the unclear natural history. Much knowledge has been acquired recently regarding application of surveillance and outcomes of esophageal resection. Also, many endoscopic techniques for treating high-grade dysplasia have been studied in depth. Results on their safety, efficacy, and complication rates have recently become available. This review analyzes the progress in the understanding and treatment of high-grade dysplasia during the past 24 to 36 months and examines how this new information plays a role in the disease's treatment algorithm.

The incidence of esophageal cancer and high-grade dysplasia in Barrett's esophagus: a systematic review and meta-analysis

Barrett's esophagus is a well-recognized precursor of esophageal adenocarcinoma. Surveillance of Barrett's esophagus patients is recommended to detect high-grade dysplasia (HGD) or early cancer. Because of wide variation in the published cancer incidence in Barrett's esophagus, the authors undertook a systematic review and meta-analysis of cancer and HGD incidence in Barrett's esophagus. Ovid Medline (Ovid Technologies, Inc., New York, New York) and EMBASE (Elsevier, Amsterdam, the Netherlands) databases were searched for papers published between 1950 and 2006 that reported the cancer/HGD risk in Barrett's esophagus. Where possible, early incident cancers/HGD were excluded, as were patients with HGD at baseline. Forty-seven studies were included in the main analysis, and the pooled estimate for cancer incidence in Barrett's esophagus was 6.1/1,000 person-years, 5.3/1,000 person-years when early incident cancers were excluded, and 4.1/1,000 person-years when both early incident cancer and HGD at baseline were excluded. Corresponding figures for combined HGD/cancer incidence were 10.0 person-years, 9.3 person-years, and 9.1/1,000 person-years. Compared with women, men progressed to cancer at twice the rate. Cancer or HGD/cancer incidences were lower when only high-quality studies were analyzed (3.9/1,000 person-years and 7.7/1,000 person-years, respectively). The pooled estimates of cancer and HGD incidence were low, suggesting that the cost-effectiveness of surveillance is questionable unless it can be targeted to those with the highest cancer risk.

Is the risk of concomitant invasive esophageal cancer in high-grade dysplasia in Barrett's esophagus overestimated?

BACKGROUND & AIMS

Recent studies have claimed long neoplasia-free survival rates with endoscopic mucosal resection of high-grade dysplasia (HGD) in Barrett's esophagus (BE). However, reports have contended that approximately 40% of patients who have esophagectomy for HGD have occult invasive cancer. The aim of this study was to use explicit criteria to determine the true prevalence of invasive adenocarcinoma in reports of patients who had esophagectomy for HGD in BE.

METHODS

Studies reporting rates of esophageal cancer in patients who underwent esophagectomy for HGD in BE were gathered using MEDLINE and PUBMED. We defined invasive esophageal adenocarcinoma (IEAC) as tumor with submucosal invasion or beyond. Intramucosal carcinoma (IMC) was not considered IEAC.

RESULTS

Twenty-three articles were selected for analysis. Most investigators reported rates of invasive cancer in the esophagectomy specimen, and the pooled average was 39.9% among the 441 patients who underwent an esophagectomy for HGD. Reported rates varied from 0% to 73%. A total of 267 patients had American Joint Committee on Cancer stage 0 postoperatively, 132 patients had stage I, 23 patients had stage IIa, 10 patients had stage IIb, and 9 patients had stage III. Fourteen studies provided differentiation between intramucosal and submucosal invasion. Among 213 patients, only 12.7% had IEAC, whereas 87.3% had HGD or IMC. The IEAC rate of 11% among patients with visible lesions is greater than the rate of 3% among patients with no visible lesion.

CONCLUSIONS

By using strict pathologic definitions of invasive disease, the present study indicates the true prevalence of IEAC in BE and HGD may have been overestimated significantly. Separating IMC from IEAC is clinically relevant because endoscopic techniques potentially may treat IMC.

MicroRNA expression profiles of esophageal cancer

OBJECTIVE

Expression of microRNAs by array analysis provides unique profiles for classifying tissues and tumors. The purpose of our study was to examine microRNA expression in Barrett esophagus and esophageal cancer to identify potential markers for disease progression.

METHODS

MicroRNA was isolated from 35 frozen specimens (10 adenocarcinoma, 10 squamous cell carcinoma, 9 normal epithelium, 5 Barrett esophagus, and 1 high-grade dysplasia). MicroRNA expression was analyzed with Ambion bioarrays (Ambion, Austin, Tex) containing 328 human microRNA probes.

RESULTS

Unsupervised hierarchic clustering resulted in four major branches corresponding with four histologic groups. One branch consisted of 7 normal epithelium samples and 1 squamous cell carcinoma sample. The second branch consisted of 7 squamous cell carcinoma samples and 1 normal epithelium sample. The third branch contained 4 Barrett esophagus samples and 1 squamous cell carcinoma sample. The fourth contained all the adenocarcinoma samples and 1 sample each of Barrett esophagus, normal epithelium, squamous cell carcinoma, and high-grade dysplasia. Supervised classification with principal component analysis determined that the normal epithelium samples were more similar to the squamous cell carcinoma tumors, whereas the Barrett esophagus samples were more similar to adenocarcinoma. Pairwise comparisons between sample types revealed microRNAs that may be markers of tumor progression. Both mir_203 and mir_205 were expressed 2- to 10-fold lower in squamous cell carcinoma and adenocarcinomas than in normal epithelium. The mir_21 expression was 3- to 5-fold higher in both tumors than in normal epithelium. Prediction analysis of microarray classified 3 Barrett esophagus samples as Barrett esophagus, 1 as adenocarcinoma, and 1 as normal epithelium.

CONCLUSION

Expression profiles of miRNA distinguish esophageal tumor histology and can discriminate normal tissue from tumor. MicroRNA expression may prove useful for identifying patients with Barrett esophagus at high risk for progression to adenocarcinoma.