Recurrent columnar-lined esophageal segments--study of the phenotypic characteristics using intestinal markers

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.

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.

Dynamics of SOX2 and CDX2 Expression in Barrett's Mucosa

Barrett's esophagus (BE) is the replacement of the normal esophageal squamous epithelium by a columnar lining epithelium. It is a premalignant condition for the development of adenocarcinoma of the esophagus and esophagogastric junction. BE is associated with gastroesophageal reflux which might change the expression profile of key transcription factors involved in the establishment of tissue differentiation, namely, SOX2 (associated with esophageal and gastric differentiation) and CDX2 (associated with intestinal differentiation). Here, we sought to characterize the expression profile of SOX2 and CDX2 in the sequential alterations of the esophageal mucosa towards adenocarcinoma and compare it with the well-established gastric and intestinal mucin profiles (MUC5AC, MUC6, and MUC2). We observed that SOX2 and CDX2 expression correlates with gastric and intestinal differentiation in BE, defined by morphological parameters and mucin expression. We show the presence of a complete intestinal profile in BE, without gastric mucins and without SOX2, and we observed an evolutionary modulation of the metaplastic phenotype by SOX2 and CDX2. We observed that adenocarcinomas harbor more frequently a mixed gastric and intestinal phenotype. In conclusion, our study establishes a role for transcription factors SOX2 and CDX2 in the progression from gastric to gastrointestinal differentiation in Barrett's metaplasia.

Transcommitment: Paving the Way to Barrett's Metaplasia

Barrett's esophagus is the condition in which metaplastic columnar epithelium that predisposes to cancer development replaces stratified squamous epithelium in the distal esophagus. Potential sources for the cell or tissue of origin for metaplastic Barrett's epithelium are reviewed including native esophageal differentiated squamous cells, progenitor cells native to the esophagus located within the squamous epithelium or in the submucosal glands or ducts, circulating bone marrow-derived stem cells, and columnar progenitor cells from the squamocolumnar junction or the gastric cardia that proximally shift into the esophagus to fill voids left by damaged squamous epithelium. Wherever its source the original cell must undergo molecular reprogramming (i.e., either transdifferentiation or transcommitment) to give rise to specialized intestinal metaplasia. Transcription factors that specify squamous, columnar, intestinal, and mucus-secreting epithelial differentiation are discussed. An improved understanding of how esophageal columnar metaplasia forms could lead to development of effective treatment or prevention strategies for Barrett's esophagus. It could also more broadly inform upon normal tissue development and differentiation, wound healing, and stem cell biology.

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.

Barrett oesophagus: lessons on its origins from the lesion itself

Barrett oesophagus develops when the lower oesophageal squamous epithelium is replaced with columnar epithelium, which shows both intestinal and gastric differentiation. No consensus has been reached on the origin of Barrett oesophagus. Theories include a direct origin from the oesophageal-stratified squamous epithelium, or by proximal migration of the gastric cardiac epithelium with subsequent intestinalization. Variations of this theory suggest the origin is a distinctive cell at the squamocolumnar junction, the oesophageal gland ducts, or circulating bone-marrow-derived cells. Much of the supporting evidence comes from experimental models and not from studies of Barrett mucosa. In this Perspectives article, we look at the Barrett lesion itself: at its phenotype, its complexity, its clonal architecture and its stem cell organization. We conclude that Barrett glands are unique structures, but share many similarities with gastric glands undergoing the process of intestinal metaplasia. We conclude that current evidence most strongly supports an origin from stem cells in the cardia.

Long-term recurrence of neoplasia and Barrett's epithelium after complete endoscopic resection

BACKGROUND

Current endoscopic therapy for neoplastic Barrett's oesophagus (BO) consists of complete resection/ablation of all Barrett's tissue including neoplastic lesions. Recurrence seems to be frequent after thermal therapy, such as radiofrequency ablation.

OBJECTIVE

To analyse long-term recurrence of neoplasia and BO after successful widespread endoscopic mucosal resection (EMR).

DESIGN

In a retrospective analysis, all patients undergoing widespread EMR of neoplastic BO between 2002 and 2007 at two referral centres were followed for at least 3 years after completion of endotherapy. Recurrence was diagnosed if neoplasia and/or BO were detected following previous successful complete removal, defined as at least two negative endoscopies and biopsies.

RESULTS

Ninety patients undergoing widespread EMR were included (mean age 63 years; 82 male), 58% of whom underwent additional thermal ablation for minor residual disease. Complete eradication of neoplasia and Barrett's tissue was achieved in 90% of patients. On further follow-up (mean 64.8 months), recurrence of neoplastic and non-neoplastic BO was found in 6.2% and 39.5%, respectively. Recurring neoplasia (3 adenocarcinomas, 1 low-grade and 1 high-grade dysplasia) were found after a median of 44 months (range 38-85) and could be retreated endoscopically. In a multivariate analysis, Barrett's length was the only factor significantly associated with recurrence (OR 2.73).

CONCLUSIONS

Even after seemingly complete endoscopic resection, recurrence of BO is frequent and independent of additional thermal therapy. Due to the possibility of neoplasia recurrence even after long disease-free intervals, follow-up should be extended beyond 5 years.

A pSMAD/CDX2 complex is essential for the intestinalization of epithelial metaplasia

The molecular mechanisms leading to epithelial metaplasias are poorly understood. Barrett's esophagus is a premalignant metaplastic change of the esophageal epithelium into columnar epithelium, occurring in patients suffering from gastroesophageal reflux disease. Mechanisms behind the development of the intestinal subtype, which is associated with the highest cancer risk, are unclear. In humans, it has been suggested that a nonspecialized columnar metaplasia precedes the development of intestinal metaplasia. Here, we propose that a complex made up of at least two factors needs to be activated simultaneously to drive the expression of intestinal type of genes. Using unique animal models and robust in vitro assays, we show that the nonspecialized columnar metaplasia is a precursor of intestinal metaplasia and that pSMAD/CDX2 interaction is essential for the switch toward an intestinal phenotype.

Characteristics of cardiac epithelium at the esophagogastric junction of a pediatric population with gastroesophageal reflux

Cardiac mucosa (CM) of the adult, regardless its location, shares phenotypic characteristics with Barrett's epithelium, namely villin expression and a Barrett's pattern of cytokeratins 7 and 20 expression. As far as we know, the phenotypic profile of CM in children has not been studied. The objective was to evaluate the phenotypic profile of cardiac mucosa from the esophagogastric junction of children with reflux symptoms. Biopsies routinely performed at the esophagogastric junction of children submitted to upper-gastrointestinal endoscopy for complaints suggestive of reflux were retrieved from the archive and used for the purposes of this study. Biopsies were assessed for the presence of squamous epithelium, cardiac and oxyntic mucosa and intestinal metaplasia. Samples displaying both squamous and columnar epithelia were immunohistochemically evaluated for the presence of villin and sucrase-isomaltae and for the expression of cytokeratins 7 and 20. From the 42 biopsies samples retrieved, 30 had simultaneously squamous and columnar epithelia. Cardiac mucosa was present in 86.7% of the cases, and intestinal metaplasia was observed only in one (3.3%). Villin expression in cardiac mucosa was observed in 96% of the cases and a cytokeratins 7 and 20 Barrett's pattern in 73%. Sucrase-isomaltase and MUC2 were only expressed in the case with intestinal metaplasia. Cardiac mucosa was high prevalent in biopsies from the esophagogastric junction of children with reflux. As in adults, cardiac mucosa in children has an immunoprofile similar to Barrett's esophagus. For the first time, it was shown that pediatric cardiac mucosa frequently expresses villin.

Laparoscopic Nissen fundoplication in the treatment of Barrett's esophagus - 10 years of experience

Introduction

Barrett's esophagus (BE) is a state in which the distal portion of esophageal mucosa becomes lined with cylindrical epithelium as a result of adaptive remodeling. It is widely accepted that the metaplastic lesions result from chronic irritation with gastric and/or duodenal contents in the course of reflux disease. For many years, research centered on the risk factors of BE and resulting adenocarcinoma. Anti-reflux operations are the only procedures which offer the possibility of treating the cause by restoring the anatomic barrier responsible for guarding against irritating effects of gastroduodenal content on the distal esophagus. Total (i.e. 360°) laparoscopic Nissen fundoplication (LNF) is considered the most effective amongst these procedures. Still, controversies related to the indications for anti-reflux surgery are frequently encountered.

Aim

Retrospective analysis of long-term treatment outcomes in patients with BE subjected to laparoscopic Nissen fundoplication.

Material and methods

The group included 42 BE patients, amongst them 30 men and 12 women. Initially, all the patients were treated conservatively for at least 1 year. The subgroup with dysplasia was subjected to preoperative argon plasma coagulation (APC). From 1 year after surgery (laparoscopic Nissen fundoplication), control biopsy specimens were obtained from the gastroesophageal junction of all the patients.

Results

None of the patients showed the development of esophageal adenocarcinoma during the follow-up period. Furthermore, no cases of dysplasia progression or de novo development of dysplasia were observed in the analyzed group. In the initial 12-24 months after surgery, complete regression of metaplasia was documented in 7 (31.8%) patients from group A, and a reduction in the area of Barrett's metaplasia was observed in another 7 patients (31.8%). Throughout the period of this study, persistent planoepithelial re-epithelialization was observed in 14 (70%) group B patients, i.e. in individuals with baseline dysplasia subjected to preoperative argon plasma ablation. In the remaining patients of this group, the developed changes of BE character were less advanced than at baseline.

Conclusions

Our opinion is that laparoscopic Nissen fundoplication, as a result of high effectiveness, represents the method of choice in the treatment of BE in the case of patients who were qualified for surgery.

Aberrant expression of Wnt and Notch signal pathways in Barrett's esophagus

BACKGROUND

Specialized intestinal metaplasia (SIM) mucosa observed in Barrett's esophagus (BE) has been a hot research topic due to the close relationship with adenocarcinoma of esophagus (ACE). Earlier studies found that SIM mucosa was similar to normal intestinal epithelium on morphology and histology. The signal pathway involved in conformation of intestinal epithelium may be a critical initiator for BE.

METHODS

The expressions of key regulators (Tcf4, Cdx2, Hes1 and Math1) in Wnt and Notch signal pathways were measured in 41 paired esophageal biopsies. Cell morphological changes in normal esophagus were compared among groups treated by acid, bile acid and the mixture of both media.

RESULTS

The expression levels of regulators (Tcf4, Cdx2, Hes1 and Math1) were found significantly increased in SIM, C ≥ 3Mn and high-grade dysplasia (HGD) groups. Distinct ultrastructure changes and highly expressed key regulators were also detected at the seventh day for group treated by 400 μmol bile acid.

CONCLUSIONS

Aberrant expressed regulators in Wnt and Notch pathways were observed in BE tissue and normal esophageal cells treated by acid, bile acid and the mixture of both media. This study provided preliminary data to understand the mechanism of BE conformation.

Columnar-lined oesophagus without intestinal metaplasia: results from a cohort with a mean follow-up of 7 years

BACKGROUND

The definition of Barrett's oesophagus lacks consensus, particularly the requirement of intestinal metaplasia for diagnosis. Scarce information exists on the prevalence and natural history of columnar-lined oesophagus without intestinal metaplasia.

AIM

To evaluate the demographics and natural history of columnar-lined oesophagus without intestinal metaplasia ≥ 2 cm in length.

METHODS

Patients with columnar-lined oesophagus ≥ 2 cm in length and no intestinal metaplasia in biopsy specimens from two consecutive endoscopies with at least a 1-year interval were prospectively followed. A cohort of Barrett's oesophagus patients was used as a control.

RESULTS

Columnar-lined oesophagus without intestinal metaplasia (n = 15) had a similar gender distribution, reflux symptoms prevalence and length as those of Barrett's oesophagus (n = 205). Patients were significantly younger (28.6 vs. 60 years, P < 0.0001) and accounted for 48% of patients aged <40 years in the two cohorts, but only 1% of those aged >40 years (P < 0.001). Patient distribution in both cohorts in 5 age brackets (0-19, 20-29, 30-39, 40-49, and >50 years) was significantly different, except for patients aged 40-49 years. Intestinal metaplasia was documented in 60% of the cohort after a mean follow-up of 7.1 years.

CONCLUSIONS

Columnar-lined oesophagus without intestinal metaplasia ≥ 2 cm is infrequent in the setting of a systematic biopsy protocol, is associated with a younger age in comparison with Barrett's oesophagus, and appears to be an intermediate step between squamous and intestinal lining of the oesophagus.

Intestinal differentiation in metaplastic, nongoblet columnar epithelium in the esophagus

Barrett esophagus (BE) is defined by the presence of metaplastic esophageal columnar epithelium with goblet cells within endoscopically recognizable areas of the esophagus. However, some carcinomas in BE, or from the gastroesophageal junction region, develop within mucosa devoid of goblet cells. However, the biologic properties, pathogenesis, and risk of malignancy of metaplastic, esophageal nongoblet columnar epithelium, is, essentially, unknown. In this study, 89 patients with metaplastic esophageal columnar epithelium were evaluated immunohistochemically for markers of intestinal differentiation, such as MUC2, DAS-1, Villin, and CDX2, a marker of gastric differentiation (MUC5AC), and Ki67, a marker of cell proliferation. Of the 89 patients, 59 had columnar metaplasia with goblet cells (BE), which were further separated into low-density goblet cell and high-density goblet cell groups based on the percentage of crypts with goblet cells, and 30 patients had columnar metaplasia of the esophagus without goblet cells. As controls, gastric biopsies from 19 age and sex matched patients without esophageal or gastric pathology were used. The rate of positivity of the markers and the location of Ki67 staining was evaluated only in non-goblet columnar epithelium from all patient groups. Patients with metaplastic esophageal columnar epithelium without goblet cells showed positivity for MUC5AC, MUC2, DAS-1, Villin, and CDX2 in 100%, 0%, 30%, 17%, and 43% of cases, respectively. 17% of cases showed aberrant surface Ki67 positivity. These values were significantly higher than gastric controls, which showed absence of staining for all markers except MUC5AC (100%). In patients with metaplastic esophageal columnar epithelium with goblet cells (BE) a significant increased rate of staining was observed for all markers, except MUC5AC. In addition, both MUC2 and surface Ki67 staining were significantly increased in BE patients with high-density goblet cells versus those with low-density goblet cells. In a separate analysis in which metaplastic esophageal nongoblet epithelium was evaluated in areas of mucosa devoid of goblet cells compared with areas of mucosa with goblet cells, from patients who had goblet cells elsewhere in the mucosa (N=59), no significant differences were observed with regard to the percentage of cases that stained with any of the markers in the nongoblet epithelium in areas devoid of goblet cells, similar to the patient group with metaplastic esophageal epithelium without goblet cells (N=30). Similar to above, in all cases, expression of intestinal markers increased in areas of mucosa adjacent to goblet cells. This study provides evidence that metaplastic esophageal columnar epithelium without goblet cells shows phenotypic evidence of intestinal differentiation and supports the theory that squamous epithelium converts initially to nongoblet columnar epithelium before goblet cell metaplasia. Further prospective studies are needed to evaluate the pathogenetic sequence, natural history, and risk of malignancy of metaplastic esophageal nongoblet epithelium.

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.

Treatment of Barrett's esophagus with high-grade dysplasia or cancer: predictors of surgical versus endoscopic therapy

BACKGROUND & AIMS

Patients with Barrett's esophagus and high-grade dysplasia or intramucosal carcinoma are at risk of progression to invasive carcinoma. Both esophagectomy and endoscopic ablation are treatment options. The aim of this study was to identify predictors of surgical versus endoscopic therapy at a tertiary center.

METHODS

An institutional database identified patients with Barrett's esophagus between 2003 and 2007. Demographic data and International Classification of Diseases-9th revision codes for esophagectomy, endoscopic ablation, as well as selected medical comorbidities were retrieved. Individual endoscopy, surgical, and pathology reports were reviewed.

RESULTS

Among 2107 individuals with Barrett's esophagus, 79 underwent esophagectomy and 80 underwent endoscopic ablation. The mean age was 63.1 +/- 10.6 years in the surgical group and 69.7 +/- 9.4 years in the ablation group (P < .0001). Among high-grade dysplasia/intramucosal carcinoma patients, 9 of 76 (12%) first seen by a gastroenterologist underwent esophagectomy, whereas 18 of 21 (86%) first seen by a surgeon underwent esophagectomy. In a logistic regression model, factors associated independently with esophagectomy were as follows: patient age of 60 or younger (odds ratio [OR], 4.95; 95% confidence interval [CI], 1.65-14.9), cancer stage T1sm or greater (OR, 16.0; 95% CI, 5.60-45.6), and initial consultation performed by a surgeon (vs gastroenterologist) (OR, 35.1; 95% CI, 9.58-129).

CONCLUSIONS

Patient age and cancer stage predict treatment modality for Barrett's esophagus with neoplasia. Treatment choice is influenced further by whether the initial evaluation is performed by a gastroenterologist or a surgeon.

Pathologic Risk Factors of Adenocarcinoma of the Gastric Cardia and Gastroesophageal Junction

Available evidence supports the existence of two major pathways of neoplastic development in the gastroesophageal region: the Barrett pathway, related to gastroesophageal reflux disease, and the gastric pathway, related to Helicobacter pylori infection. The existence of an independent junctional pathway is questionable, and gastroesophageal junction adenocarcinomas share features of esophageal and gastric adenocarcinomas. It has been impossible to accommodate all data that are provided by different levels and tools of observation in tumors that develop in the gastroesophageal region in a single, coherent classification. That is why the stratification of pathologic risk in such tumors, and their respective precursors, incorporates features from topography, histology, immunohistochemistry, and molecular pathology.

Expression of CDX2 and MUC2 in Barrett's mucosa

Barrett's mucosa is a risk factor for esophageal adenocarcinoma and should be detected at an early stage. It is defined by the presence of columnar epithelium with goblet cells in the lower esophagus, but histologic diagnosis can be uncertain in the absence of distinct goblet cells. We investigated 55 biopsies from 48 patients with endoscopically plain Barrett's esophagus and performed immunohistochemistry for CDX2 and MUC2. In addition, alcian blue (pH 2,5)/PAS staining was done. In histologically unequivocal Barrett's mucosa, nuclear expression of CDX2 in goblet cells and many columnar cells, as well as cytoplasmic positivity for MUC2 in goblet cells, could be observed. Alcian blue (pH 2,5)/PAS stained acidic mucins in goblet cells and in some non-goblet columnar cells. In six cases, no definite Barrett's mucosa was present, and no expression of MUC2 could be observed. In these biopsies, there was granular cytoplasmic and/or focal nuclear staining for CDX2 in non-goblet columnar epithelial cells, indicating their intestinal differentiation. We suggest that this peculiar mucosa is the precursor of unequivocal Barrett's mucosa and would designate it early Barrett's mucosa. Alcian blue for acidic mucins is inconsistent in this epithelium and does not reliably indicate early intestinal differentiation.

Small-bowel metaplasia arising in the remnant esophagus after esophagojejunostomy--a [corrected] prospective study in patients with a history of total gastrectomy

OBJECTIVES

The pathogenesis of Barrett's mucosa is incompletely understood. Acidic gastro-esophageal reflux is considered an essential causative factor. The aim of this study was to detect esophageal columnar metaplasia after total gastrectomy with esophagojejunostomy, a condition of enteric, but nonacidic reflux.

METHODS

In a prospective study, patients with a history of total gastrectomy and esophagojejunostomy were investigated for the presence of columnar metaplasia in the remnant esophagus. Patients with such history, who were now referred for esophagogastroduodenoscopy, were included during a 2-yr period. Biopsies for histopathology were taken from the anastomosis and any columnar metaplasia of the esophagus.

RESULTS

In 8 of 25 patients (32%) with a history of gastrectomy, columnar metaplasia was found in the remnant esophagus, mostly in shape of tongues, partly associated with erosive reflux esophagitis. Histopathology showed a typical small-bowel mucosa, but with some villous atrophy. In a resection specimen, a double-layered muscularis mucosa was present, which proved the metaplastic nature of the intestinal mucosa. Length of the columnar metaplasia correlated with the time interval since surgery.

CONCLUSIONS

Esophageal mucosa, if exposed long term to an enteric, but nongastric refluxate, can evolve into a highly differentiated intestinal metaplasia, which resembles small-bowel mucosa. This proves that complete-type intestinal metaplasia may arise not only in the stomach, but also in the esophagus. Esophageal intestinalization seems to reflect adaptation to enteric reflux.

Dedifferentiation precedes invasion in the progression from Barrett's metaplasia to esophageal adenocarcinoma

PURPOSE

Adenocarcinoma arises in Barrett's esophagus by progression from metaplasia to cancer through grades of dysplasia. Our aim in this exploratory study was to characterize the broad changes in gene expression that underlie this histologic progression to cancer and assess the potential for using these gene expression changes as a marker predictive of malignant progression in Barrett's epithelium.

EXPERIMENTAL DESIGN

Microarray analysis was used to obtain individual gene expression profiles from endoscopic biopsies of nine esophageal adenocarcinomas and the Barrett's epithelia from which three of the cancers had arisen. Pooled samples from the Barrett's epithelia of six patients without cancer or dysplasia served as a reference.

RESULTS

Barrett's epithelia from which cancer had arisen differed from the reference Barrett's epithelia primarily by underexpression of genes, many of which function in governing cell differentiation. These changes in gene expression were found even in those specimens of Barrett's epithelia from which cancer had arisen that lacked dysplasia. Each cancer differed from the Barrett's epithelium from which it had arisen primarily by an overexpression of genes, many of which were associated with tissue remodeling and invasiveness. Cancers without identifiable Barrett's epithelium differed from cancers that had arisen from a Barrett's epithelium by having an even greater number of these overexpressed genes.

CONCLUSIONS

Histologic progression from Barrett's epithelium to cancer is associated with a gradient of increasing changes in gene expression characterized by an early loss of gene function governing differentiation that begins before histologic change; gain in function of genes related to remodeling and invasiveness follows later. This correlation of histologic progression with increasing changes in gene expression suggests that gene expression changes in biopsies taken from Barrett's epithelium potentially could serve as a marker for neoplastic progression that could be used to predict risk for developing cancer.

Cardia-type metaplasia arising in the remnant esophagus after cardia resection

BACKGROUND

Specialized intestinalized metaplasia in the distal esophagus (Barrett's esophagus) is a recognized precursor of esophageal adenocarcinoma, but its pathogenesis is incompletely understood. The aim of this study was to investigate the mucosal effects of esophagogastrostomy, an artificial interface between esophageal squamous and gastric oxyntic epithelium.

METHODS

EGD was performed in 14 consecutive patients (median age 63 years, range 26-71 years) who had undergone esophagogastrostomy from 3 to 88 months earlier. Biopsy specimens were obtained in 13 patients from the anastomosis and, when present, columnar epithelium in the remnant esophagus.

RESULTS

In 10 patients, EGD demonstrated tongue-shaped segments of columnar epithelium extending from 0.3 to 7 cm into the remnant esophagus. Biopsy specimens revealed cardia-type mucosa in all patients, whether at the anastomosis or proximally in esophageal segments of columnar epithelium. Magnification endoscopy of cardia-type mucosa visualized a long-oval, tubular, or ridged surface pattern. In 3 cases, complete intestinal metaplasia was observed within the cardia-type mucosa.

CONCLUSIONS

The frequent transformation of squamous epithelium into cardia-type mucosa in the distal remnant esophagus after esophagogastrostomy supports the concept that cardia-type mucosa is a reflux-induced metaplasia that may give rise to the subsequent development of specialized intestinalized metaplasia.