The use of cytokeratin stain to distinguish Barrett's esophagus from contiguous tissues: a systematic review

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.

Intermediate filament proteins of digestive organs: physiology and pathophysiology

Intermediate filament proteins (IFs), such as cytoplasmic keratins in epithelial cells and vimentin in mesenchymal cells and the nuclear lamins, make up one of the three major cytoskeletal protein families. Whether in digestive organs or other tissues, IFs share several unique features including stress-inducible overexpression, abundance, cell-selective and differentiation state expression, and association with >80 human diseases when mutated. Whereas most IF mutations cause disease, mutations in simple epithelial keratins 8, 18, or 19 or in lamin A/C predispose to liver disease with or without other tissue manifestations. Keratins serve major functions including protection from apoptosis, providing cellular and subcellular mechanical integrity, protein targeting to subcellular compartments, and scaffolding and regulation of cell-signaling processes. Keratins are essential for Mallory-Denk body aggregate formation that occurs in association with several liver diseases, whereas an alternate type of keratin and lamin aggregation occurs upon liver involvement in porphyria. IF-associated diseases have no known directed therapy, but high-throughput drug screening to identify potential therapies is an appealing ongoing approach. Despite the extensive current knowledge base, much remains to be discovered regarding IF physiology and pathophysiology in digestive and nondigestive organs.

SOX15 governs transcription in human stratified epithelia and a subset of esophageal adenocarcinomas

BACKGROUND & AIMS

Intestinal metaplasia (Barrett's esophagus, BE) is the principal risk factor for esophageal adenocarcinoma (EAC). Study of the basis for BE has centered on intestinal factors, but loss of esophageal identity likely also reflects absence of key squamous-cell factors. As few determinants of stratified epithelial cell-specific gene expression are characterized, it is important to identify the necessary transcription factors.

METHODS

We tested regional expression of mRNAs for all putative DNA-binding proteins in the mouse digestive tract and verified esophagus-specific factors in human tissues and cell lines. Integration of diverse data defined a human squamous esophagus-specific transcriptome. We used chromatin immunoprecipitation (ChIP-seq) to locate transcription factor binding sites, computational approaches to profile transcripts in cancer datasets, and immunohistochemistry to reveal protein expression.

RESULTS

The transcription factor SOX15 is restricted to esophageal and other murine and human stratified epithelia. SOX15 mRNA levels are attenuated in BE and its depletion in human esophageal cells reduced esophageal transcripts significantly and specifically. SOX15 binding is highly enriched near esophagus-expressed genes, indicating direct transcriptional control. SOX15 and hundreds of genes co-expressed in squamous cells are reactivated in up to 30% of EAC specimens. Genes normally confined to the esophagus or intestine appear in different cells within the same malignant glands.

CONCLUSIONS

These data identify a novel transcriptional regulator of stratified epithelial cells and a subtype of EAC with bi-lineage gene expression. Broad activation of squamous-cell genes may shed light on whether EACs arise in the native stratified epithelium or in ectopic columnar cells.

The dose of omeprazole required to achieve adequate intraesophageal acid suppression in patients with gastroesophageal junction specialized intestinal metaplasia and Barrett's esophagus

BACKGROUND

The mainstay of medical therapy for Barrett's esophagus is normalization of esophageal acid exposure with proton pump inhibitors (PPIs). However, the optimal dose and whether once daily or twice daily is required for acid suppression is unknown.

AIM

The purpose of this study was to assess whether adequate intra-esophageal acid suppression could be achieved with once daily versus twice daily omeprazole in patients with gastroesophageal specialized intestinal metaplasia (GEJSIM), short-segment (SSBE) and long-segment Barrett's esophagus (LSBE).

METHODS

Patients with GEJSIM and Barrett's esophagus underwent upper endoscopy with 48-h wireless pH capsule while on once daily 20 mg omeprazole for at least 1 week. If intra-esophageal acid was not adequately controlled, defined as pH value <4 for greater than 4.2 % of the time during the second 24-h period, omeprazole was increased to twice daily for 1 week and upper endoscopy with wireless pH capsule was repeated.

RESULTS

A total of 36 patients completed the study (10 patients had GEJSIM, 16 patients had SSBE, and 10 patients had LSBE). Normalization of intraesophageal pH was achieved in 28 patients (78 %) with once daily PPI and eight patients required twice daily PPI. There was no significant difference between the three groups in the proportion of patients requiring high dose PPI (GEJSIM 10 %, SSBE 25 %, LSBE 30 %, p = 0.526).

CONCLUSIONS

The majority of patients with Barrett's esophagus were controlled with once daily low dose PPI and only a minority required twice daily dosing, regardless of the length of Barrett's mucosa.

Evaluation of Barrett's esophagus with CK7, CK20, p53, Ki67, and COX2 expressions using chromoendoscopical examination

Barrett's esophagus (BE) is a complication of chronic gastroesophageal reflux disease and can be diagnosed when there is an endoscopically irregular Z-line and intestinal metaplasia (IM) in a biopsy obtained lower esophagus. It is still not clear whether IM in the gastric cardia or columnar mucosa without IM in the lower esophagus have any significance as BE, which is considered as preneoplastic. The aim of the study was to determine the immunohistochemical features of BE and columnar mucosa in the distal esophagus and also to evaluate the value of chromoendoscopy in the diagnosis of BE in a prospective manner. A total of 12 chromoendoscopic biopsies (six from normal-looking unstained esophagus and six from esophageal mucosa stained with methyl blue suspicious of BE) were taken from 111 cases who underwent endoscopy because of a variety of upper gastrointestinal symptoms. Immunohistochemical analysis was performed using CK7, CK20, p53, Ki67, and cyclooxygenase 2 (COX2). Of the 111 cases, 19 cases with carcinoma (nine adeno, six squamous, four undifferentiated carcinomas) and 17 cases with normal squamous epithelium were excluded, while 75 cases showing columnar epithelium, including 46 (61.3%) with IM and 29 (38,7%) without IM, were further evaluated immunohistochemically. CK7 was observed in surface, crypt, and glandular epithelium, whereas CK20 was expressed in surface and superficial crypt epithelium. No significant difference was observed between the Barrett and non-Barrett type of CK7/20 staining pattern (P > 0,05). Expression of p53 did not show any difference between BE and columnar mucosa without IM, whereas COX2 expression was significantly increased in BE (P < 0.05) in comparison with columnar mucosa without IM. Ki67 expression was significiantly higher both in upper and lower crypts in BE (P < 0.05). The present study showed that a Barrett pattern does not seem to exist; however, the analysis of COX2 expression and the Ki67 proliferation fraction by immunohistochemistry can be used to separate BE from non-Barrett's metaplasia of the distal esophagus. In our point of view, the immunohistochemical detection of p53 expression in Barrett's metaplasia stage is useless as a marker for early detection of high-risk patients.

Development and characterization of an organotypic model of Barrett's esophagus

Understanding the molecular and cellular processes underlying the development, maintenance, and progression of Barrett's esophagus (BE) presents an empirical challenge because there are no simple animal models and standard 2D cell culture can distort cellular processes. Here we describe a three-dimensional (3D) cell culture system to study BE. BE cell lines (CP-A, CP-B, CP-C, and CP-D) and esophageal squamous keratinocytes (EPC2) were cultured on a matrix consisting of esophageal fibroblasts and collagen. Comparison of growth and cytokeratin expression in the presence of all-trans retinoic acid or hydrochloric acid was made by immunohistochemistry and Alcian Blue staining to determine which treatments produced a BE phenotype of columnar cytokeratin expression in 3D culture. All-trans retinoic acid differentially affected the growth of BE cell lines in 3D culture. Notably, the non-dyplastic metaplasia-derived cell line (CP-A) expressed reduced squamous cytokeratins and enhanced columnar cytokeratins upon ATRA treatment. ATRA altered the EPC2 squamous cytokeratin profile towards a more columnar expression pattern. Cell lines derived from patients with high-grade dysplasia already expressed columnar cytokeratins and therefore did not show a systematic shift toward a more columnar phenotype with ATRA treatment. ATRA treatment, however, did reduce the squamoid-like multilayer stratification observed in all cell lines. As the first study to demonstrate long-term 3D growth of BE cell lines, we have determined that BE cells can be cultured for at least 3 weeks on a fibroblast/collagen matrix and that the use of ATRA causes a general reduction in squamous-like multilayered growth and an increase in columnar phenotype with the specific effects cell-line dependent.

Comparison of intestinal metaplasia in gastric cardia and Barrett's esophagus

OBJECTIVE

To evaluate and compare the pathological features and immunostaining pattern (cytokeratin 7 (CK-7), mucin core peptide 1 (Muc-1)) in Barrett's esophagus (BE) and cardiac intestinal metaplasia (CIM).

METHODS

According to endoscopic diagnosis, patients with gastric cardiac inflammation and BE were selected from March 2008 to February 2009 in Renji Hospital, Shanghai Jiaotong University School of Medicine. Those patients who had histological findings of intestinal metaplasia (82 cases of CIM and 64 special type BE) were enrolled in our study. Hematoxylin-eosin, periodic acid-Schiff and Alcian blue staining and an immunohistochemical examination (CK-7, Muc-1) were undertaken in all of them.

RESULTS

Squamous mucosa overlying the columnar crypts with intestinal metaplasia, also called buried metaplasia, was often found in the BE group (56.2%), mainly as an incomplete type (85.9%). Inflammation in the gastric antrum was more severe in the CIM group (45.1% vs 26.6%), in contrast, esophagitis was more severe in the BE group (53.1% vs 35.4%). CK-7 was highly expressed in the BE group (84.4%) in contrast to the CIM group (37.8%). There was no difference in the expression of Muc-1 in these two kinds of intestinal metaplasia (14.1% vs 19.5%).

CONCLUSIONS

Buried intestinal metaplasia, mainly as an incomplete type, is the major predominant type of BE. The degree of inflammation in the gastric antrum and esophagus can differentiate BE from CIM to some extent. CK-7 immunohistochemical staining can help identify BE and CIM but Muc-1 cannot.

Epidemiology and natural history of intestinal metaplasia of the gastroesophageal junction and Barrett's esophagus: a population-based study

OBJECTIVES

Population-based data on the epidemiology and outcomes of subjects with intestinal metaplasia of the gastroesophageal junction (IMGEJ) and Barrett's esophagus (BE) are limited. The objectives of this study were to (i) estimate the incidence of IMGEJ and BE diagnosed from clinically indicated endoscopy in Olmsted County, MN, over three decades (1976-2006) and prevalence as of 1 January 2007, (ii) compare baseline characteristics of subjects with IMGEJ and BE, and (iii) study the natural history and survival of both cohorts.

METHODS

This was a population-based cohort study. The study setting was Olmsted County, MN. Patients with BE (columnar segment >1 cm with intestinal metaplasia) and IMGEJ (intestinal metaplasia in biopsies from the gastroesophageal junction) from 1976 to 2006 in Olmsted County, MN, were identified using Rochester Epidemiology Project resources. Demographic and clinical data were abstracted from medical records and pathology confirmed by gastrointestinal pathologists. The association of baseline characteristics with overall and progression-free survival was assessed using proportional hazards regression models. Outcome measures were baseline characteristics and overall survival of subjects with IMGEJ compared to those with BE.

RESULTS

In all, 487 patients (401 with BE and 86 with IMGEJ) were identified and followed for a median interval of 7 (BE subjects) to 8 (IMGEJ subjects) years. Subjects with BE were older, heavier, reported reflux symptoms more often, and had higher prevalence of advanced neoplasia than those with IMGEJ. No patient with IMGEJ progressed to esophageal adenocarcinoma (EAC) in contrast to BE subjects who had a cumulative risk of progression of 7% at 10 years and increased risk of death from EAC (standardized mortality ratio 9.62). The overall survival of subjects with BE and IMGEJ did not differ from that expected in similar age- and sex-distributed white Minnesota populations.

CONCLUSIONS

Subjects with IMGEJ appear to have distinct clinical characteristics and substantially lower cancer progression risk compared to those with BE.

Advances in research on Barrett's esophagus

Over the past 20 years, the incidence of esophageal adenocarcinoma has increased dramatically. Barrett's esophagus is an acquired premalignant condition in which an abnormal columnar epithelium replaces the stratified squamous epithelium that normally lines the distal esophagus. Barrett's esophagus is often associated with long-standing gastroesophageal reflux disease. Gastric and/or bile contents may contribute to the development and malignant progression of Barrett's esophagus. At present, the uniform histopathologic definitions and diagnostic criteria for Barrett's esophagus, intestinal metaplasia at the gastroesophageal junction and cardiac metaplasia have not been established, and the correlation between Helicobactor pylori infection and gastroesophageal reflux disease is still a matter of ongoing debate. Recent studies have suggested that esophageal injury in Barrett's esophagus heals through the proliferation and differentiation of muti-potential progenitor cells derived from the bone marrow rather than from the injured organ itself. MicroRNAs (miRNAs) are potentially useful for development of biomarkers for evaluation of the prognosis of Barrett's esophagus and for early detection, chemoprevention, and treatment of esophageal cancer.

Differences in the molecular biology of adenocarcinoma of the esophagus, gastric cardia, and upper gastric third

Adenocarcinoma of the distal esophagus, gastric cardia, and upper gastric third are grouped in type I-III by the Siewert classification. This classification is based on the endoscopic localisation of the tumor center, and is the most important diagnostic tool to group these tumors. On a molecular level, there is currently no marker that would allow to differentiate the three different types. Furthermore, the Siewert classification was not uniformly used in the recent literature, making interpretation and generalization of these results difficult. However, several potential targets have been identified that may help to separate these tumors by molecular markers, and are summarized in this chapter.

Toward unraveling the complexity of simple epithelial keratins in human disease

Simple epithelial keratins (SEKs) are found primarily in single-layered simple epithelia and include keratin 7 (K7), K8, K18-K20, and K23. Genetically engineered mice that lack SEKs or overexpress mutant SEKs have helped illuminate several keratin functions and served as important disease models. Insight into the contribution of SEKs to human disease has indicated that K8 and K18 are the major constituents of Mallory-Denk bodies, hepatic inclusions associated with several liver diseases, and are essential for inclusion formation. Furthermore, mutations in the genes encoding K8, K18, and K19 predispose individuals to a variety of liver diseases. Hence, as we discuss here, the SEK cytoskeleton is involved in the orchestration of several important cellular functions and contributes to the pathogenesis of human liver disease.

Diagnosing Barrett's esophagus: reliability of clinical and pathologic diagnoses

BACKGROUND

The accuracy of a Barrett's esophagus diagnosis is not well studied.

OBJECTIVE

Our purpose was to evaluate the accuracy of a clinical Barrett's esophagus diagnosis and the reproducibility of an esophageal intestinal metaplasia diagnosis.

METHODS

All patients with a Barrett's esophagus diagnosis between 1994 and 2005 were identified by use of International Classification of Disease (ICD) and Systematized Nomenclature of Medicine (SNOMED) coding. Subsets received manual record review (endoscopy/pathology reports), slide review by a referral pathologist (interrater reliability), and 2 blinded reviews by the same pathologist (intrarater reliability).

SETTING

An integrated health services delivery system.

MAIN OUTCOME MEASUREMENTS

Accuracy of electronic clinical diagnosis and reproducibility of esophageal intestinal metaplasia diagnosis.

RESULTS

A total of 2470 patients coded with Barrett's esophagus underwent record review; a subgroup (616) received manual pathology slide review. Review confirmed a Barrett's esophagus diagnosis for 1533 (61.9%) patients: 437 of 798 subjects (54.8%) with a SNOMED diagnosis alone, 153 of 671 subjects (26.8%) with an ICD diagnosis alone, and 940 of 1101 subjects (85%) who had both a SNOMED and an ICD diagnosis. The same metaplasia diagnosis occurred with 88.3% of subjects (original vs referral pathologist, interrater reliability; kappa = .42, 95% CI, 0.34-0.48). The referral pathologist made the same metaplasia diagnosis twice for a given patient for 88.6% of subjects (intrarater reliability, 2 reviews by same pathologist; kappa = 0.65, 95% CI, 0.35-0.93).

LIMITATIONS

The accuracy of a Barrett's esophagus diagnosis likely represents the minimum number, given the strict criteria.

CONCLUSIONS

A community pathologist's diagnosis of esophageal intestinal metaplasia is likely to be confirmed by a referral pathologist. Electronic diagnoses of Barrett's esophagus overestimate the prevalence, although they are usually confirmed in patients with both a SNOMED and ICD diagnosis of Barrett's esophagus.

Gene expression in Barrett's esophagus: laser capture versus whole tissue

OBJECTIVE

Diagnosis of Barrett's esophagus (BE) is typically done through morphologic analysis of esophageal tissue biopsy. Such samples contain several cell types. Laser capture microdissection (LCM) allows the isolation of specific cells from heterogeneous cell populations. The purpose of this study was to determine the degree of overlap of the two sample types and to define a set of genes that might serve as biochemical markers for BE.

MATERIAL AND METHODS

Biopsies were obtained from regions of the glandular tissue of BE and normal esophagus from 9 subjects with BE. Samples from 5 subjects were examined as whole tissue (BE [whole]; E [whole]), and in 4 subjects the glandular epithelium of BE was isolated using LCM (BE [LCM]) and compared with the averaged values (E [LCM]) for both basal cell (B [LCM]) and squamous cell (S [LCM]) epithelium.

RESULTS

Gene expression revealed 1797 probe sets between BE [whole] and E [whole] (fold change > 2.0; p<0.001). Most of these genes (74%) were also differentially expressed between BE [LCM] and E [LCM], showing that there was high concordance between the two sampling methods. LCM provided a great deal of additional information (2113 genes) about the alterations in gene expression that may represent the BE phenotype.

CONCLUSIONS

There are differences in gene expression profiles depending on whether specimens are whole tissue biopsies or LCM dissected. Whole tissue biopsies should prove satisfactory for diagnostic purposes. Because the data from LCM samples delineated many more Barrett's-specific genes, this procedure might provide more information regarding pathogenesis than would whole tissue material.

Histological assessment of oesophageal columnar mucosa

This review presents the pathological features of Barrett's oesophagus, with an emphasis on the role of pathologists in the diagnosis, surveillance and treatment of the disease. The diagnosis of Barrett's oesophagus is based both on endoscopy and histology. The surveillance of patients relies on systematic biopsy sampling, looking for dysplasia - intraepithelial neoplasia. Well established classifications of dysplasia are now used by pathologists, but there remain problems with this marker. Therefore, many alternative biomarkers have been proposed, that remain of limited interest in daily practice, including DNA-ploidy, proliferation markers, and p53 abnormalities. Endoscopic improvements already allow a better selection of biopsies, and it may be that new technologies will allow 'virtual biopsies'. The role of pathologists is now extended to the evaluation of new therapeutic modalities of early neoplastic lesions in Barrett's oesophagus, especially endoscopic mucosal resection.

Columnar lined (Barrett's) esophagus: future perspectives

Columnar lined esophagus (CLE) or Barrett's esophagus is the precursor for esophageal adenocarcinoma. Future advances in understanding and management of this condition as well as improving the quality of care of CLE patients depends on answering essential questions. It is important to standardize the criteria for CLE definition. The rapid increase in incidence of CLE and adenocarcinoma raises serious concerns that the current management of gastroesophageal reflux disease (GERD) needs reassessment. The risk factors that determine who will and will not develop CLE are as yet undetermined. There is a need to develop a clinical risk stratification tool, which will help in determining who should be screened. The impact of elimination of GERD on the natural history of CLE is one important area for future research. The benefit of surveillance strategies remains unproven and the ideal endoscopic frequency, protocols and markers of cancer risk are unknown. Dysplasia may not provide the gold standard marker of cancer risk because of some inherited problems. A better technique than the current endoscopic pinch biopsy protocol is needed. To overcome the limitations of histological markers, many other markers of cancer risk needs to be developed and validated. The key question as to whether cancer risk is actually reduced by the new ablation modalities remains unanswered. The natural history of dysplasia and its management needs to be clarified. Although many questions have to be answered, it seems, however, that at least some answers exist, and these and proposals for answering some of these questions are underlined throughout this review.