THE LOWER ESOPHAGUS LINED BY COLUMNAR EPITHELIUM

Porcine Esophageal Submucosal Gland Culture Model Shows Capacity for Proliferation and Differentiation

BACKGROUND & AIMS

Although cells comprising esophageal submucosal glands (ESMGs) represent a potential progenitor cell niche, new models are needed to understand their capacity to proliferate and differentiate. By histologic appearance, ESMGs have been associated with both overlying normal squamous epithelium and columnar epithelium. Our aim was to assess ESMG proliferation and differentiation in a 3-dimensional culture model.

METHODS

We evaluated proliferation in human ESMGs from normal and diseased tissue by proliferating cell nuclear antigen immunohistochemistry. Next, we compared 5-ethynyl-2'-deoxyuridine labeling in porcine ESMGs in vivo before and after esophageal injury with a novel in vitro porcine organoid ESMG model. Microarray analysis of ESMGs in culture was compared with squamous epithelium and fresh ESMGs.

RESULTS

Marked proliferation was observed in human ESMGs of diseased tissue. This activated ESMG state was recapitulated after esophageal injury in an in vivo porcine model, ESMGs assumed a ductal appearance with increased proliferation compared with control. Isolated and cultured porcine ESMGs produced buds with actively cycling cells and passaged to form epidermal growth factor-dependent spheroids. These spheroids were highly proliferative and were passaged multiple times. Two phenotypes of spheroids were identified: solid squamous (P63+) and hollow/ductal (cytokeratin 7+). Microarray analysis showed spheroids to be distinct from parent ESMGs and enriched for columnar transcripts.

CONCLUSIONS

Our results suggest that the activated ESMG state, seen in both human disease and our porcine model, may provide a source of cells to repopulate damaged epithelium in a normal manner (squamous) or abnormally (columnar epithelium). This culture model will allow the evaluation of factors that drive ESMGs in the regeneration of injured epithelium. The raw microarray data have been uploaded to the National Center for Biotechnology Information Gene Expression Omnibus (accession number: GSE100543).

Past, present and future of Barrett's oesophagus

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

Changes of microRNAs-192, 196a and 203 correlate with Barrett's esophagus diagnosis and its progression compared to normal healthy individuals

BACKGROUND

Barrett's esophagus (BE) is a disease with a rising prevalence in western countries probably due to the unhealthy lifestyle. In significant number of cases it develops to esophageal adenocarcinoma. Two decades ago, important gene regulators (microRNAs) were discovered and their attendance in the process of malignant transformation was demonstrated (e.g. miR-192, 196a, 203). Our aim was to select the patients with the increased risk of malignant transformation before the cancer develops.

METHODS

71 patients with BE disease were selected, slides from FFPE blocks were prepared, the lesions were microdissected and a qPCR relative expression analysis for selected microRNAs (generally known to be connected with malignant transformation process) was carried out.

RESULTS

We demonstrated unequivocal statistically significant upregulation of two microRNAs (miR-192, 196a) and downregulation of miR-203 and positive miR-196a correlation with progression from intestinal metaplasia to adenocarcinoma compared to normal individuals.

CONCLUSIONS

We hypothesize that there do exist changes of selected microRNAs which can undoubtedly distinguish the patients with BE from normal healthy individuals.

History, molecular mechanisms, and endoscopic treatment of Barrett's esophagus

This report is an adjunct to the American Gastroenterological Association Institute's medical position statement and technical review on the management of Barrett's esophagus, which will be published in the near future. Those documents will consider a number of broad questions on the diagnosis, clinical features, and management of patients with Barrett's esophagus, and the reader is referred to the technical review for an in-depth discussion of those topics. In this report, we review historical, molecular, and endoscopic therapeutic aspects of Barrett's esophagus that are of interest to clinicians and researchers.

Routinely diagnosed low-grade dysplasia in Barrett's oesophagus: a population-based study of natural history

AIMS

To examine the natural history of columnar-lined oesophagus with routinely diagnosed low-grade dysplasia and ascertain the risk of oesophageal adenocarcinoma development.

METHODS AND RESULTS

A multicentre retrospective cohort study of 283 patients with low-grade dysplasia. Follow-up data were obtained from examination of hospital records. One hundred and forty-four patients had biopsies prior to low-grade dysplasia diagnosis and 217 had follow-up biopsies after index low-grade dysplasia diagnosis. In these patients the incidence of high-grade dysplasia and adenocarcinoma combined was 4.6% per annum and of adenocarcinoma alone was 2.7% per annum. At most recent follow-up, 43 (19.8%) had persistent low-grade dysplasia, 37 (17.1%) had changes indefinite for dysplasia and 108 (49.8%) had non-dysplastic columnar-lined oesophagus. When prevalent cases were excluded (those occurring within 1 year of index low-grade dysplasia diagnosis), the annual incidence of high-grade dysplasia and adenocarcinoma combined was 2.2% and of adenocarcinoma alone was 1.4%. The relative risk for adenocarcinoma development in low-grade dysplasia compared with non-dysplastic columnar-lined oesophagus was 2.871 (P = 0.002).

CONCLUSIONS

Low-grade dysplasia has a threefold increased risk of progression to cancer compared with non-dysplastic epithelium, but in the majority of patients dysplasia is not subsequently detected.

The influence of symptom type and duration on the fate of the metaplastic columnar-lined Barrett's oesophagus

BACKGROUND

Prolonged gastro-oesophageal reflux resulting in columnar metaplasia of the oesophagus is the main risk factor for oesophageal adenocarcinoma.

AIM

To examine the duration of symptoms and associations of different symptoms with the development of columnar-lined oesophagus, dysplasia and adenocarcinoma.

METHODS

UK multicentre cohort study of patients with columnar-lined oesophagus whose date of symptom onset (1082 patients) and/or types of symptoms reported (1681 patients) were documented. Follow-up was examined by analysis of histological reports from the registering centers.

RESULTS

Symptoms of dysphagia/odynophagia and nausea/vomiting were associated with development of dysplasia. High-grade dysplasia and adenocarcinoma were associated with dysphagia/odynophagia and weight loss. Median duration from symptom onset to detection of columnar-lined oesophagus without intestinal metaplasia: 2.6 years, columnar-lined oesophagus with intestinal metaplasia: 5.0 years, indefinite changes for dysplasia: 19.3 years and low-grade dysplasia: 30.0 years. One tenth of patients had developed high-grade dysplasia at 9.6 years and one tenth had developed adenocarcinoma at 13.8 years from symptom onset.

CONCLUSIONS

In patients with columnar-lined oesophagus, symptoms of dysphagia/odynophagia and nausea/vomiting were associated with a higher risk of development of dysplasia and adenocarcinoma. There is a trend for longer duration of symptoms to the detection of dysplasia.

Update on the diagnosis and treatment of Barrett esophagus and related neoplastic precursor lesions

CONTEXT

At present, Barrett esophagus is the most common cause of esophageal adenocarcinoma. In the past 20 years, the incidence of esophageal adenocarcinoma in white males has exceeded that of tumors of the colorectum, lung, prostate, and skin.

OBJECTIVES

To (1) provide an evidence-based review of the diagnosis, classification, and histologic differentiation of Barrett esophagus from gastric carditis, (2) provide a summary of the key pathologic features of precursor lesions, such as dysplasia, and (3) evaluate adjunctive markers of dysplasia and predictive markers for the development of cancer. The natural history and risk of cancer in patients with Barrett esophagus is also reviewed.

DATA SOURCES

For this review, selected published peer reviewed articles were chosen from a search through PubMed between the years 1970 and 2007.

CONCLUSIONS

The current definition of Barrett esophagus is partially flawed because not all cases are endoscopically recognizable, nongoblet epithelium is biologically intestinalized, and determination of the presence or absence of goblet cells is susceptible to sampling error. Differentiation of ultrashort segment Barrett esophagus from chronic gastric carditis can be accomplished, in a minority of cases, by evaluating for the presence or absence of histologic features that are known to be associated with Barrett esophagus. Dysplasia in Barrett esophagus begins in the crypt bases and then extends more superficially to include the upper portions of the crypts and surface epithelium. Low- and high-grade dysplasia are distinguished by the presence of marked cytologic and/or architectural abnormalities in the latter compared with the former. There are few, if any, reliable adjunctive diagnostic techniques that can help differentiate nondysplastic from dysplastic epithelium. However, alpha-methylacyl coenzyme A racemase staining has been shown to be useful in 2 separate studies. Both low- and high-grade dysplasia are progressive lesions, and in general, the extent of dysplasia, particularly low grade, is a strong risk factor for progression to carcinoma. Of all the biologic and genetic biomarkers studied to date, evaluation of DNA content is the most reliable and specific. The management of patients with dysplasia is variable among institutions and ranges from aggressive surveillance, endoscopic mucosal resection, mucosal ablation, or total esophagectomy.

Relevance of the detection of intestinal metaplasia in non-dysplastic columnar-lined oesophagus

OBJECTIVE

In the USA, detection of intestinal metaplasia is a requirement for enrollment in surveillance programmes for dysplasia or adenocarcinoma in columnar-lined oesophagus. In the UK, it is believed that failure to detect intestinal metaplasia at index endoscopy does not imply its absence within the columnarized segment or that the tissue is not at risk of neoplastic transformation. The aim of this study was to investigate the factors predicting the probability of detection of intestinal metaplasia in the columnarized segment.

MATERIAL AND METHODS

Demonstration of intestinal metaplasia was analysed in 3568 biopsies of non-dysplastic columnar-lined oesophagus from 1751 patients from 7 centres in the UK. Development of dysplasia and adenocarcinoma was analysed in 322 patients without intestinal metaplasia and compared with that in 612 patients with intestinal metaplasia.

RESULTS

Intestinal metaplasia was more commonly detected in males than in females (odds ratio 1.244), longer segment length (10.3% increase per centimetre) and increasing number of biopsies taken (24% increase per unit increase). After 5 years of follow-up, 54.8% of patients without intestinal metaplasia at index endoscopy demonstrated intestinal metaplasia, and 90.8% after 10 years. There was no significant difference in the rate of development of dysplasia or adenocarcinoma between patients with or without intestinal metaplasia detection at index endoscopy.

CONCLUSIONS

Detection of intestinal metaplasia is subject to significant sampling error. It increases with segment length and number of biopsies taken. In the majority of patients, if sufficient biopsies are taken over time, intestinal metaplasia will be demonstrated. The decision to offer surveillance should not be based upon the presence or absence of intestinal metaplasia at index endoscopy as the risk of dysplasia and adenocarcinoma is similar in both groups.

Columnar-lined esophagus: time to drop the eponym of "Barrett": Historical review

There can be few medical conditions that have been surrounded by as much confusion about their definition or terminology as columnar-lined esophagus (CLE); approximately 30 different terms and eponyms have been used to describe this condition. The history of this condition can be divided into five stages: (i) descriptive stage, 1906-1950; (ii) "argument" stage, 1950-1963; (iii) "significant" stage, 1963-1973; (iv) surveillance stage, 1973-1990; and (v) refined research stage, 1990-present. The use of the eponym "Barrett's" to describe CLE is not justified from a historical point of view. Lining of the lower esophagus by columnar epithelium was termed "Barrett's esophagus" after the presentation by Barrett in 1957. Although this finding has been attributed to Barrett, the work of others, including Tileston, Lortat-Jacob, and Allison and Johnstone, preceded Barrett's description. The historical aspects of CLE were reviewed to show how little Norman Barrett had contributed to the core concept of this condition in comparison to the contributions of other investigators, particularly the contribution of Philip Allison. Based on many discussed historical facts, we are not in favor of retaining the term "Barrett's esophagus" and we propose that CLE be henceforth referred to as "columnar-lined esophagus".

Pathology of the gastroesophageal junction

The gastroesophageal junction (GEJ) is a poorly defined anatomic area that represents the junction etween the distal esophagus and the proximal stomach (cardia). The true anatomic GEJ corresponds to the most proximal aspect of the gastric folds, which represents an endoscopically apparent transition oint in most individuals. Many, if not most, adults, particularly those with either physiologic or logic GERD, have a proximally displaced Z-line indicating that the histologic squamocolumnar nction (SCJ) is located above the anatomic GEJ. The histologic characteristics of short segments of columnar mucosa located above the anatomic GEJ in these individuals are similar to the gastric cardia, ng composed of either pure mucous glands or mixed mucous glands/oxyntic glands. Although controversial, some authors believe that the cardia is normally composed, at birth, of surface mucinous columnar epithelium and underlying oxyntic glands identical to the gastric corpus, whereas others maintain that the true anatomic cardia is normally composed of mucinous columnar epithelium with underlying mucous glands or mixed mucous and oxyntic glands. However, the preponderance of evidence supports the latter theory and that the length of mucosa composed of either mucous, or mixed mucous glands/oxyntic glands, increases with age and is presumed to be related to ongoing GERD. Inflammation of the true gastric cardia (carditis), which is most often due to H. pylori infection, is difficult to distinguish from columnar metaplasia of the distal esophagus secondary to GERD. From a pathologist's perspective, the differential diagnosis of true gastric carditis from esophageal columnar metaplasia of the distal esophagus in GEJ biopsies is difficult, but a variety of clinical, pathologic, and immunohistochemical methods can be used to help separate these two disorders. Nearly one-third of patients who present for upper GI endoscopy without endoscopic evidence of BE reveal foci of intestinal metaplasia in the GEJ. There are some studies to suggest that the risk of dysplasia and cancer is different in patients with intestinal metaplasia in the cardia related to H. pylori infection versus those with metaplastic columnar epithelium in the distal esophagus related to GERD. Chronic inflammation is generally considered the predominant underlying stimulus for the development of columnar metaplasia in the GEJ, regardless of the etiology. Columnar metaplasia and intestinal metaplasia in the distal esophagus represents a squamous to columnar cell transition and there is some evidence that this occurs through an intermediate, or transitional, phase of intestinalization termed multilayered epithelium. In contrast, intestinal metaplasia that develops in the true gastric cardia secondary to H. pylori infection represents a columnar to columnar metaplastic reaction. This review will focus on the clinical, pathologic, and pathogenetic aspects of GERD and H. pylori-induced inflammation of the GEJ region.

Multistage carcinogenesis in Barrett's esophagus

The multistage carcinogenesis of esophageal adenocarcinoma is a process of clonal evolution within Barrett's esophagus neoplasms. The initiating event for Barrett's esophagus is unknown, but is associated with chronic gastric reflux which probably also promotes progression. Inactivation of both alleles of CDKN2A appear to be early events causing clonal expansion. Clones with TP53 inactivated expand if they have already inactivated CDKN2A. After TP53 has been inactivated, tetraploid and aneuploid clones tend to develop. The final events that lead to invasion and metastasis are unknown. Evolutionary biology provides important tools to understand clonal evolution in progression and cancer prevention.

Pathogenesis of columnar-lined esophagus

Since its initial description, the pathogenesis of the columnar-lined esophagus (CLE) has been surrounded by many controversies. The first controversy is related to the existence of the condition itself. The second controversy centers on whether the CLE is a congenital or an acquired condition. In this article, we review the congenital and acquired theories of development of CLE and discuss the various factors in acquisition of CLE. The bulk of evidence in the literature suggests that CLE is an acquired condition.

Unraveling the mystery of the gastroesophageal junction: a pathologist's perspective

The gastroesophageal junction (GEJ), which is defined as the point where the distal esophagus joins the proximal stomach (cardia), is a short anatomic area that is commonly exposed to the injurious effects of GERD and/or Helicobacter pylori infection. These disorders often lead to inflammation and intestinal metaplasia (IM) of this anatomic region. The true gastric cardia is an extremely short segment (<0.4 mm) of mucosa that is typically composed of pure mucous glands, or mixed mucous/oxyntic glands that are histologically indistinguishable from metaplastic mucinous columnar epithelium of the distal esophagus. In patients with GERD, whether physiologic or pathologic, the length of cardia-type epithelium increases and extends proximally above the level of the anatomic GEJ into the distal esophagus. Columnar metaplasia of the distal esophagus represents a squamous to columnar metaplastic reaction that develops from an esophageal stem cell and may pass through an intermediate phase characterized by the presence of a type of epithelium that possesses a mixture of squamous and columnar features, termed multilayered epithelium. In contrast, IM of the gastric cardia represents a columnar to columnar cell metaplastic reaction that develops from a gastric stem cell located in the deep foveolar compartment of the gastric mucosa. Intestinal metaplasia, particularly the incomplete type, is widely believed to represent the precursor lesion upon which dysplasia and cancer arises. The frequency of IM is probably greater in metaplastic columnar epithelium in the esophagus secondary to GERD, than in cases of true gastric carditis secondary to H. pylori, and may be a reason why there is a higher risk of carcinoma in the former compared to the latter. A variety of clinical, endoscopic, histologic, and histochemical methods can be used to distinguish GERD-induced columnar metaplasia of the distal esophagus from H. pylori-induced inflammation of true gastric cardia, and these are outlined in this review, but further controlled studies are needed to critically evaluate these techniques. Further prospective trials are needed to adequately evaluate the different etiologic and pathogenetic mechanisms and, most importantly, the risk of malignancy in these two conditions.

Cytokeratins 7 and 20 and mucin core protein expression in esophageal cervical inlet patch

Cervical inlet patch (CIP) is defined by the presence of gastric mucosa within the first few centimeters of the esophagus. Several endoscopic series have demonstrated a frequent association of CIP with Barrett's esophagus (BE) suggesting a pathogenetic link. A histochemical study reporting the presence of acid mucin in CIP, including sulfomucin, supports this hypothesis. We evaluated mucin core protein expression and cytokeratins 7 and 20 (CK7/CK20) pattern in biopsies of CIP, normal antrum, and BE to comment on a possible relationship of CIP with BE. We observed that both lesions have similar cytokeratin patterns with mixed CK7/CK20 reactivity on the surface and pits and lone CK7 positivity in the glands. MUC5AC was strongly expressed on the surface and pits but not in the glands of CIP and antral mucosa. Within BE, MUC5AC positivity was noted not only on the surface and pits but also in the glands. MUC6 similarly decorated the glands of CIP and BE. MUC2 was expressed rarely in CIP with goblet cells but conspicuously on the surface and pits of BE. MUC5B was seen in both CIP and BE and rarely in the antral mucosa. The similarities between CIP and BE but not with normal antral mucosa fits with the hypothesis that both lesions may originate from submucosal esophageal mucous glands. Two pathogenetic pathways can be entertained: focal upper esophageal mucosal misdevelopment in pediatric population and patchy metaplastic replacement of squamous mucosa in adults with gastroesophageal reflux disease.

Medical management of Barrett's esophagus

Barrett's metaplasia of some extent is found commonly in patients with GERD. Detection is possible only by endoscopy and biopsy of the columnar appearing mucosa; no symptoms or signs distinguish patients with Barrett's metaplasia from those without. The management goals in patients with Barrett's are to alleviate reflux symptoms and to control the risk of adenocarcinoma. Symptom control is achieved primarily with PPIs. Acid inhibition does not, however, cause regression of Barrett's metaplasia and has not been shown to reduce the risk of esophageal adenocarcinoma. The risk of adenocarcinoma is managed by surveillance with endoscopy and biopsy searching for dysplastic change. LGD merits more intense surveillance. The optimal management of HGD, however, remains controversial, as evidenced by the multitude of ablation therapies that have been introduced recently. These techniques will be discussed in depth in subsequent articles in this volume.

Changing role of in vivo models in columnar-lined lower esophagus

Columnar-lined lower esophagus (CLE) or Barrett's esophagus (BE) is caused by chronic reflux of the gastrointestinal tract and can progress to invasive adenocarcinoma. However, the pathophysiology, cell of origin, and management of this condition is incompletely understood. This review evaluates the role of in vivo models in resolving these debates. A search was performed on the Ovid and Pub Medline for 1964-2001 and Cochrane Collaboration. The keywords used were adenocarcinoma, animal model, Barrett's esophagus, columnar-lined esophagus, esophageal neoplasms, and esophageal carcinogenesis. All relevant papers were scrutinized and an attempt at tabulation was made. In vivo models have been used at several stages of debate on the pathophysiology of BE. They provide conclusive evidence for its acquired nature secondary to duodenogastroesophageal reflux. The cell of origin of experimental BE may arise from adjacent columnar epithelium, basal layer multipotent cells, or esophageal glands. Experimental work on BE is lacking in assessing therapeutic modalities.

Prospective evaluation of multilayered epithelium in Barrett's esophagus

OBJECTIVE

We recently identified a distinctive type of multilayered epithelium in two patients with Barrett's esophagus, which shows morphological characteristics of both squamous and columnar epithelium. This study was performed to prospectively evaluate the prevalence of multilayered epithelium in patients with Barrett's esophagus.

METHODS

Mucosal biopsies were obtained from the squamocolumnar junction (Z-line) of 58 patients with endoscopic evidence of esophageal columnar epithelium and from the gastroesophageal junction in 21 patients without endoscopic evidence of esophageal columnar epithelium. Specimens were evaluated for the presence of multilayered epithelium and goblet cells.

RESULTS

Twenty-four of 58 (41%) of the patients with endoscopic evidence of esophageal columnar epithelium had multilayered epithelium compared with only one of 21 patients (5%) in the control group (p = 0.005). Of the 58 patients in the study group, 43 had goblet cell metaplasia and 15 did not (p < 0.001). Only patients with goblet cell metaplasia had multilayered epithelium. Shorter lengths of columnar epithelium were noted in the 24 patients with goblet cells and multilayered epithelium compared with the 19 patients with goblet cells and no multilayered epithelium (p < 0.05).

CONCLUSIONS

Multilayered epithelium is strongly associated with goblet cell metaplasia in patients with endoscopic evidence of esophageal columnar epithelium. These data support the hypothesis that multilayered epithelium may represent a transitional stage in the development of Barrett's esophagus.

Expression of p53-related protein p63 in the gastrointestinal tract and in esophageal metaplastic and neoplastic disorders

p63 is a p53-related DNA-binding protein that helps regulate differentiation and proliferation in epithelial progenitor cells. Its expression has never been evaluated in the human gastrointestinal tract. The aim of this study was to evaluate the expression of p63 in the esophagus and related metaplastic and neoplastic disorders to gain insight into the pathogenesis of these processes. Of particular interest was the expression of p63 in Barrett esophagus (BE) and in BE-associated multilayered epithelium. Multilayered epithelium has been postulated to represent an early precursor to the development of BE primarily because it shares morphologic and immunophenotypic features of both squamous and columnar epithelium, and has been shown prospectively to be highly associated with BE. Routinely processed mucosal biopsy or resection specimens that contained normal esophageal squamous epithelium (n = 20), squamous dysplasia (n = 4), squamous cell carcinoma (n = 7), BE (n = 10), BE-associated multilayered epithelium (n = 13), esophageal mucosal gland ducts (n = 10), BE-associated dysplasia (n = 12), and BE-associated adenocarcinoma (n = 7) were immunostained for p63 to determine the extent and location of staining. p63 staining was compared with the staining patterns observed for p53, Ki 67 (proliferation marker), and cytokeratins (CKs) 13 (squamous marker), 14 (basal squamous marker), 8/18 (columnar marker), and 19 (basal/columnar marker). Expression of p63 messenger RNA (mRNA) isoforms was also analyzed by reverse-transcription polymerase chain reaction of freshly isolated tissues. In the normal esophagus, p63 was expressed in the basal and suprabasal layers of the squamous epithelium and in basal cells that line the mucosal gland ducts but was negative in all other epithelia of the gastrointestinal tract, including the stomach, small intestine, and colon. Similarly, p63 was not expressed in BE, but it, was present in the basal layer of multilayered epithelium in 9 of 13 cases (69%). p63-positive cells in multilayered epithelium and in the mucosal gland duct epithelium were positive for CK8/18 (100%) and CK13 (67% and 30%, respectively) and negative for CK14 (0%), in contrast to p63-positive cells in squamous epithelium, which were positive for CK14 and CK13 (100%) but negative for CK8/18. In neoplastic tissues, p63 was diffusely expressed in all cases of esophageal squamous cell dysplasia and carcinoma but was negative in all cases of esophageal and colorectal adenocarcinoma. The DeltaN isoform of p63 mRNA predominated in all benign and neoplastic squamous tissues examined. p63 may represent a marker of 2 distinct epithelial progenitor cells (basal squamous epithelium and gland duct epithelium) in the esophagus. P63 is upregulated in squamous neoplastic conditions and in this manner may play a role in squamous carcinogenesis. These data also indicate that multilayered epithelium is phenotypically similar to, and may share a lineage relationship with, mucosal gland duct epithelium.

Endoscopic surveillance of columnar-lined esophagus: frequency of intestinal metaplasia detection and impact of antireflux surgery

OBJECTIVE

To quantify the occurrence of intestinal metaplasia in columnar-lined esophagus (CLE) during endoscopic surveillance and to evaluate the impact of antireflux surgery on the development of intestinal metaplasia.

SUMMARY BACKGROUND DATA

The malignant potential in segments of CLE is mainly restricted to those containing intestinal metaplasia. Patients with segments of CLE in which no intestinal metaplasia can be detected are rarely enrolled in a surveillance program but may still be at increased risk of developing esophageal adenocarcinoma because intestinal metaplasia may be missed or may develop with time.

METHODS

The occurrence of intestinal metaplasia on biopsy samples was determined on repeated endoscopies in 177 patients enrolled in a surveillance program for CLE. The incidence of intestinal metaplasia in patients with no evidence of intestinal metaplasia on the two first endoscopies was evaluated on the subsequent endoscopies and compared in patients with medically and surgically treated gastroesophageal reflux disease.

RESULTS

Intestinal metaplasia was found in 53% of the patients (94/177) on their first surveillance endoscopy and was more prevalent in long segments of CLE. The prevalence of intestinal metaplasia increased markedly with increasing number of surveillance endoscopies. Intestinal metaplasia tended to be detected early in patients with long segments of CLE; in patients with shorter segments, intestinal metaplasia was also detected late in the course of endoscopic surveillance. Patients with surgically treated reflux disease were 10.3 times less likely to develop intestinal metaplasia compared with a group receiving standard medical therapy.

CONCLUSION

Biopsy samples from a single endoscopy, despite an adequate biopsy protocol, are insufficient to rule out the presence of intestinal metaplasia. Patients in whom biopsy specimens from a segment of CLE show no intestinal metaplasia have a significant risk of having undetected intestinal metaplasia or of developing intestinal metaplasia with time. Sampling error is probably the reason for the absence of intestinal metaplasia in segments of CLE longer than 4 cm, whereas development of intestinal metaplasia is common in patients with shorter segments of CLE. Antireflux surgery protects against the development of intestinal metaplasia, possibly by better control of reflux of gastric contents.

Extent of high-grade dysplasia in Barrett's esophagus correlates with risk of adenocarcinoma

BACKGROUND & AIMS

The identification of any high-grade dysplasia (HGD) in Barrett's esophagus has been considered to be an indication for esophagectomy because of the increased risk of cancer. The aim of this study was to determine if a limited extent of HGD has the same potential for cancer as diffuse HGD.

METHODS

A retrospective cohort study was performed to assess the risk of developing adenocarcinoma in relationship to the extent of HGD found on endoscopic surveillance. The extent of HGD was defined as focal if cytologic and/or architectural changes of HGD were limited to a single focus of 5 or fewer crypts and diffuse if more than 5 crypts were involved in a single biopsy specimen or if HGD involved more than one biopsy fragment. The relative risk of cancer was assessed using a Cox proportional hazard model, and cancer-free survival was determined using survival curves.

RESULTS

Sixty-seven patients with diffuse HGD and 33 with focal HGD satisfied selection criteria. Cancer-free survival rates at 1 and 3 years were 93% and 86% for focal HGD compared with 62% and 44% for diffuse HGD (P < 0.001). On univariate analysis, extent of HGD (relative risk, 5.36; 95% confidence interval, 1.84-15.56), nodularity on endoscopy (relative risk, 3.98; 95% confidence interval, 1.97-8.04), and lack of acid suppression (relative risk, 2.48; 95% confidence interval, 1.16-5.28) were associated with an increased risk of esophageal adenocarcinoma. Diffuse HGD had a 3.7-fold increase in the risk of esophageal cancer compared with focal HGD (P = 0.02) on multivariate analysis.

CONCLUSIONS

Patients with focal HGD are less likely to have cancer during the first year after diagnosis or on subsequent follow-up compared with diffuse HGD.

Phenotypic characteristics of a distinctive multilayered epithelium suggests that it is a precursor in the development of Barrett's esophagus

A distinctive type of multilayered epithelium (ME) has been described at the neo-squamocolumnar junction and within columnar mucosa in patients with Barrett's esophagus (BE). This epithelium has morphologic and ultrastructural features of both squamous and columnar epithelium. Multilayered epithelium may represent an early or intermediate stage of columnar metaplasia; therefore, we performed this study to determine the morphologic and biologic characteristics of this epithelium and to gain insight into its derivation. Esophageal mucosal biopsies containing ME from 17 patients with BE were evaluated morphologically, stained with a variety of mucin histochemical stains; and also immunostained with antibodies against cytokeratins (CK) 13 (squamous epithelium marker); 14 (basal squamous epithelium marker) 7, 8/18, 19, and 20 (columnar epithelium markers), MIB-1 (proliferation marker); villin (intestinal brush border protein); and TGFalpha, EGFR, pS2, and hSP (enteric proliferation/differentiation regulatory peptides). The results were compared with normal esophageal squamous epithelium, normal gastric cardia epithelium, specialized-type intestinal epithelium (BE), and esophageal mucosal and submucosal gland duct epithelium. Multilayered epithelium expressed a pattern of mucin production (neutral mucin, sialomucin, and sulfomucin in 88%, 100%, and 71% of cases, respectively) and cytokeratin expression (CK 13 and 19 in the basal "squamoid" cells, CK 7, 8/18, 19, and 20 in the superficial "columnar" cells) similar to that of columnar epithelium in BE, and showed a high capacity for cellular proliferation (Ki-67-positive in 88% of cases) and differentiation (TGFalpha, EGFR, pS2 and villin-positive in 100%, 100%, 93%, and 66% of cases, respectively). The mucosal gland duct epithelium showed a similar phenotypic pattern and, in one case, was seen to give rise to ME at the surface of the mucosa. These data provide evidence in support of the hypothesis that ME represents an early or intermediate stage in the development of esophageal columnar metaplasia (BE). The mucosal gland duct epithelium may contain progenitor cells that can give rise to ME.

The diagnosis of low-grade dysplasia in Barrett's esophagus and its implications for disease progression

OBJECTIVE

The reported risk of progression from low-grade dysplasia (LGD) to high-grade dysplasia (HGD) or carcinoma (CA) in Barrett's esophagus varies. However, the validity of a diagnosis of LGD may be questioned because of interobserver variability.

METHODS

A search of the Cleveland Clinic Foundation surgical pathology files between 1986 and 1997 yielded biopsy specimens from 43 patients with Barrett's esophagus diagnosed and coded as LGD. Patients with concurrent or prior diagnoses of HGD or carcinoma were excluded. The LGD cases were randomized and blindly reviewed by three gastrointestinal (GI) pathologists along with cases originally diagnosed as Barrett's esophagus without dysplasia (ND; n = 28), indefinite for dysplasia (IND; n = 14), or HGD (n = 15). Each pathologist classified every biopsy specimen as ND, IND, LGD, or HGD, and interobserver agreements were determined by kappa statistics (K). Follow-up data were available on 25 patients originally diagnosed with LGD. Progression was defined as a subsequent diagnosis of HGD or CA on esophageal biopsy or resection specimens.

RESULTS

Agreement between two GI pathologists for a diagnosis of LGD was fair (K = 0.28) and poor (K = 0.21 and -0.04). Individual GI pathologists agreed with the original diagnosis of LGD in 70%, 56%, and 16% of cases. The 25 patients with follow-up included 21 men and four women (mean age, 67 yr) with a mean follow-up of 26 months (range: 2-84 months). Seven patients (28%) with follow-up developed HGD (five patients) or CA (two patients), 2-43 months (median: 11 months) after a diagnosis of LGD. The individual GI pathologists' diagnosis did not correlate with progression. However, when at least two GI pathologists agreed on LGD, there was a significant association with progression (seven of 17 patients, 41%, p = 0.04). When all three GI pathologists agreed on a diagnosis of LGD, four of five patients progressed (p = 0.012). In contrast, of the eight patients with follow-up and no agreement among GI pathologists for a diagnosis of LGD, none progressed.

CONCLUSIONS

A high degree of interobserver variability is seen in the histological diagnosis of Barrett's esophagus-related LGD. Although the number of observations is low, a consensus diagnosis of LGD among GI pathologists suggests an increased risk of progression from LGD to HGD or carcinoma.

The histopathology and biologic prognostic factors of Barrett's esophagus: a review

In Barrett's esophagus, stratified squamous mucosa of the lower third of the esophagus is replaced by columnar mucosa, as a complication of chronic gastroesophageal reflux. The presence of Barrett's esophagus appears to be a major factor in the progression to adenocarcinoma of the lower third of the esophagus. Therefore it is crucial to identify the subset of patients at risk for the development of adenocarcinoma. Dysplasia is an important histologic feature to evaluate because it identifies those patients who require follow-up. The diagnosis of biopsies with lesser degrees of abnormalities, however, makes microscopic evaluation less helpful in identifying patients who need more frequent endoscopic biopsy surveillance. DNA ploidy and the use of monoclonal antibodies, such as suppressor gene product p53, oncogene cerbB-2, and Ki-67, have added dramatically to our understanding of the biology of Barrett's metaplasia and have given us objective indicators to predict the presence of an increased risk of developing cancer.

The columnar-lined esophagus. History, terminology, and clinical issues

Recently, there has been intense controversy regarding diagnostic criteria for Barrett's esophagus. Some authorities have defined the condition according to an arbitrary extent of esophageal columnar lining, whereas others have felt that the presence of specialized intestinal metaplasia anywhere in the esophagus establishes the diagnosis. This article discusses the problems that arise when either of these diagnostic approaches are used and proposes an alternative classification system for the columnar-lined esophagus.

Risk factors for the development of an adenocarcinoma in columnar-lined (Barrett) esophagus. The Rotterdam Esophageal Tumor Study Group

BACKGROUND

To evaluate the importance of the length of columnar-lined esophagus, sex, age, smoking, and drinking habits as risk factors for malignant degeneration, the authors performed a retrospective case-control study comparing patients with and without adenocarcinoma in Barrett esophagus.

METHODS

The records of 96 patients (53 male and 43 female; mean age, 61 years) with a benign columnar-lined esophagus and 62 patients (47 male and 15 female; mean age, 62 years) with an adenocarcinoma in columnar-lined esophagus referred to the Rotterdam Esophageal Tumor Study Group, diagnosed over the same period (1978-1985), were reviewed. A frequency distribution of the length of columnar-lined esophagus in both groups was made. Statistical analysis was performed with multivariate methods.

RESULTS

The length of columnar-lined esophagus was related significantly to carcinoma: a doubling of the length resulted in a 1.7 times increased risk. Smokers had a 2.3-fold increased risk as compared with nonsmokers. Male sex as a risk factor approached statistical significance (P = 0.06). Adjusted for these risk factors, no relation between carcinoma and age or alcohol consumption was found.

CONCLUSIONS

The risk of development of an adenocarcinoma in Barrett esophagus increased with the length of Barrett epithelium. Smoking and possibly male sex were also risk factors. The identification of these risk factors may help in developing more efficient screening programs for patients with Barrett esophagus.

Barrett's esophagus: pathogenesis, epidemiology, functional abnormalities, malignant degeneration, and surgical management

Barrett's esophagus (i.e. columnar epithelial metaplasia in the distal esophagus) is an acquired condition that in most patients results from chronic gastroesophageal reflux. It is a disorder of the white male in the Western world with a prevalence of about 1/400 population. Due to the decreased sensitivity of the columnar epithelium to symptoms, Barrett's esophagus remains undiagnosed in the majority of patients. Gastroesophageal reflux disease in patients with Barrett's esophagus has a more severe character and is more frequently associated with complications as compared with reflux patients without columnar mucosa. This appears to be due to a combination of a mechanically defective lower esophageal sphincter, inefficient esophageal clearance function, and gastric acid hypersecretion. Excessive reflux of alkaline duodenal contents may be responsible for the development of complications (i.e., stricture, ulcer, and dysplasia). Therapy of benign Barrett's esophagus is directed towards treatment of the underlying reflux disease. Barrett's esophagus is associated with a 30- to 125-fold increased risk for adenocarcinoma of the esophagus. The reasons for the dramatic rise in the incidence of esophageal adenocarcinoma, which occurred during the past years, are unknown. High grade dysplasia in a patient with columnar mucosa is an ominous sign for malignant degeneration. Whether an esophagectomy should be performed in patients with high grade dysplasia remains controversial. Complete resection of the tumor and its lymphatic drainage is the procedure of choice in all patients with a resectable carcinoma who are fit for surgery. In patients with tumors located in the distal esophagus, this can be achieved by a transhiatal en-bloc esophagectomy and proximal gastrectomy. Early adenocarcinoma can be cured by this approach. The value of multimodality therapy in patients with advanced tumors needs to be shown in randomized prospective trials.

Barrett's esophagus in a newborn

We describe Barrett's esophagus occurring in a 3-week-old male. The finding of columnar cell-lined lower esophageal epithelium in the presence of gastroesophageal reflux supports the theory of an acquired phenomenon and suggests that the metaplastic process may have begun in the perinatal period.

Collis gastroplasty: origin and evolution

In 1957 J. Leigh Collis published his innovative operation for treating the difficult problem of the irreducible hiatal hernia, esophagitis, and stricture. The design of the operation was based on the relatively primitive understanding of hiatal hernia and the newly emerging concept of reflux esophagitis. A variety of antireflux operations by different surgeons emerged over the years to follow. The original Collis gastroplasty has been subsequently modified with the addition of both partial and complete fundoplication procedures. The place of the modified Collis gastroplasty-fundoplication operations in today's approach to the problems of hiatal hernia and gastroesophageal reflux disease remains unsettled.

Evaluation of the magnitude of gastro-oesophageal reflux in Barrett's oesophagus

A manometric study to determine the role of gastro-oesophageal reflux in Barrett's oesophagus was performed on 20 patients with Barrett's oesophagus and 53 patients with reflux oesophagitis without Barrett's oesophagus (25 with mild oesophagitis and 28 with severe oesophagitis). For the same reason, the 20 patients with Barrett's oesophagus also underwent 24 hour continuous oesophageal pH monitoring, and the results obtained were compared with those of 20 oesophagitis patients without Barrett's oesophagus (10 with mild oesophagitis and 10 with severe oesophagitis). The manometric results show that the motor changes found in the Barrett's group are specific but similar to the motor dysfunction associated with reflux oesophagitis. Motor anomalies are probably related more to the inflammatory process in the oesophageal wall than to the metaplastic changes themselves. The pH monitoring results show that while reflux in the Barrett's oesophagus patients was greater overall than in the oesophagitis group without Barrett's oesophagus, the changes are similar when the results are compared with the severe oesophagitis group. In conclusion there are other factors besides gastro-oesophageal reflux involved in the pathogenesis of Barrett's oesophagus.

Barrett's esophagus: a model premalignant lesion for adenocarcinoma

Barrett's esophagus is a condition in which the lower esophagus is lined with metaplastic columnar epithelium rather than normal stratified squamous epithelium. It is associated with an increased risk of cancer. Cancers developing in Barrett's epithelium are adenocarcinomas rather than the usual squamous cell esophageal cancers. Barrett's is somewhat unique among premalignant lesions, since it represents an entirely different epithelium from the normal and can therefore be histologically identified with certainty. The abnormal mucosa can be safely accessed repeatedly and its extent quantitated by endoscopy, thereby allowing serial follow-up studies and intervention trials. We are studying Barrett's esophagus as a model premalignant lesion for adenocarcinoma. Ornithine decarboxylase activity was increased in this lesion especially when dysplastic changes were present. Interestingly there was no relationship between polyamine levels and the increased ODC activity. Flow cytometric abnormalities have been demonstrated in Barrett's mucosa. Their significance remains to be determined. Epithelial cells from this lesion have been cultured and characterized. Clonal cytogenetic abnormalities were detected in some specimens. The cultured cells were used to test the effect of drugs on their growth. The ornithine decarboxylase inhibitor, alpha-difluoromethylornithine, significantly inhibited growth even at low concentrations. A clinical intervention trial using 13-cis-retinoic acid has produced no change in the extent of the lesion in 11 evaluable patients. Nevertheless, the successful performance of this clinical study confirms that this lesion can be used for intervention trials aimed at reversing premalignant lesions.

[Barrett syndrome: clinical and practical consequences]

The Barrett-esophagus develops as a consequence of chronic reflux disease. Though the columnar epithelium is a self-protection against gastric fluid nearly all complications of reflux-disease are combined with an endobrachyesophagus. The different types of columnar-epithelium require careful primary diagnosis. The treatment of symptomatic patients consists in an adequate therapy of the reflux disease. Long-term endoscopic and histologic controls are necessary in every case of Barrett's syndrome.

Barrett's esophagus. A prevalent, occult complication of gastroesophageal reflux disease

A prospective study of patients with symptoms of gastroesophageal reflux was undertaken to determine the prevalence of Barrett's esophagus and reevaluate the diagnostic approach necessary to detect this complication. Endoscopy with mucosal biopsy was performed in 97 subjects. Twelve (12.4%) were found to have Barrett's esophagus. The sensitivity and specificity of the endoscopic and radiologic examinations for Barrett's esophagus were prospectively evaluated. Endoscopy (92%) was significantly more sensitive than radiology (24%) in detecting Barrett's esophagus (p less than 0.001). The frequency and severity of reflux symptoms among patients determined to have Barrett's esophagus, reflux esophagitis, or normal esophageal biopsies were quantitatively similar in all three groups, except for significantly greater daytime heartburn in those with reflux esophagitis (p less than 0.01). These data indicate that Barrett's esophagus complicates gastroesophageal reflux more often than previously believed.

Histological and histochemical changes in the columnar lined (Barrett's) oesophagus

Multiple endoscopic specimens were obtained from 58 patients with a columnar lined gesophagus to study the histological and histochemical features of this metaplastic epithelium. Five patients (8.6%) had presented with a primary oesophageal adenocarcinoma. Three different epithelial types, junctional, atrophic fundic and intestinal were identified. Twenty two (38%) patients had just one type of epithelium present, the other 36 (62%) having a combination of two or three different types. Intestinal type of epithelium, either alone or in combination with gastric type epithelium was present in 48 (83%) patients. In every case this intestinal type epithelium took the form of an incompletely differentiated variant of intestinal metaplasia, although complete intestinal metaplasia as a focal change was also present in 14 of these patients. Histochemically, sulphomucins were present in the biopsies of 43 (74%) of the patients studied. They were seen in both goblet and columnar mucous cells with almost equal frequency. Incomplete intestinal metaplasia with sulphomucin production was present in four of the five patients with an oesophageal adenocarcinoma. In the columnar lined oesophagus sulphomucin production is common and its presence does not help to identify those individuals at particular risk of developing an adenocarcinoma.

Comparative features of esophageal and gastric adenocarcinomas: recent changes in type and frequency

One hundred sixty consecutive cases of esophageal and gastric carcinoma were reviewed to evaluate the impression of recent changes in their types and characteristics. Esophageal adenocarcinomas accounted for 34 per cent of all esophageal cancers and 60 per cent of tumors confined to the lower third of the esophagus; all but one were associated with Barrett's epithelium. Among the gastric cancers, previous observations of an increased prevalence of neoplasms confined to the cardia were extended. Proximal adenocarcinomas (arising from the esophagus, gastroesophageal junction, and cardia) constituted 34 per cent of all adenocarcinomas in this series and appeared to be a distinctive group with common features. Compared with other gastric cancers, the proximal carcinomas were associated with a lower mean age (65 years), higher male-to-female ratio (3.3:1), greater frequency of hiatal hernia (40 per cent), greater incidence of smoking and alcohol use, and lower prevalence of tumors composed predominantly of signet ring cells. Thus, proximal adenocarcinomas may form a specific category etiologically different from distal gastric cancers.

Radiologic diagnosis of Barrett's esophagus: critical analysis of 65 cases

A recent increase in the number of Barrett's esophagus being diagnosed is probably directly related to a proportional increase in endoscopic biopsies of the esophagus and awareness of premalignant potential of Barrett's mucosa. While the endoscopist can detect Barrett's mucosa with fair degree of accuracy, the radiologic diagnosis of Barrett's esophagus still remains a diagnostic challenge despite several well established radiologic features. We reviewed 65 patients with pathologically proven Barrett's esophagus and found a wide spectrum of radiologic features. These include hiatus hernia in 49, gastroesophageal reflux in 38, strictures in 32, esophagitis in 20, and characteristic Barrett's ulcer in 12. In addition ascending or migrating strictures were found in 10, mucosal pattern simulating areae gastricae in 5, cricopharyngeal dysfunction in 4, and fixed spiral folds in 3 patients. This constellation of radiologic features, some of which have not been previously emphasized, should further assist radiologists in suggesting the diagnosis of Barrett's esophagus.

Barrett's esophagus: its prevalence and association with adenocarcinoma in patients with symptoms of gastroesophageal reflux

The pathologic reports of all 1,020 esophageal biopsy specimens obtained between 1975 and 1981 in patients with symptoms of gastroesophageal reflux were reviewed. Barrett's esophagus was identified in 84 patients (8 percent). The 362 patients seen between 1980 and 1981 were reviewed in detail. The symptoms in patients with Barrett's esophagus differed from those of the patients without Barrett's esophagus. Dysphagia was more often present in the former group (34 percent versus 16 percent, p less than 0.05) and epigastric distress was less frequent (11 percent versus 27 percent, p less than 0.05). Objective findings of hiatal hernia, esophageal stricture, and esophageal ulcers occurred more commonly in patients with Barrett's esophagus than in those without Barrett's esophagus (70 percent versus 48 percent, 31 percent versus 4 percent, and 14 percent versus 6 percent, respectively, p less than 0.05). Mid esophageal strictures were associated almost exclusively with Barrett's esophagus (five of six patients). At esophagoscopy, erythema was seen more commonly with Barrett's esophagus. The diagnosis was suspected by the endoscopist in only 34 percent of patients subsequently demonstrated histopathologically to have Barrett's esophagus. There was no significant difference in the prevalence of a positive Bernstein test result or gastroesophageal reflux on upper gastrointestinal series in patients with and without Barrett's esophagus. However, a hypotensive lower esophageal sphincter was found more commonly in patients with Barrett's esophagus (100 percent versus 53 percent, p less than 0.05). Thirteen of the 84 patients with Barrett's esophagus (15 percent) had a coexistent adenocarcinoma arising from Barrett's mucosa. These patients, when compared with the patients with Barrett's esophagus without carcinoma, were more often male (77 percent versus 51 percent, p = 0.1), more often had dysphagia (69 percent versus 34 percent, p less than 0.05), and more frequently had a comparatively short duration of symptoms (67 percent versus 36 percent, p less than 0.05). Our findings suggest that patients with Barrett's esophagus have a high risk of development of carcinoma. Because the entity is often not recognized at endoscopy, routine esophageal biopsy should be performed on all patients undergoing esophagoscopy for symptoms of gastroesophageal reflux. Patients with known Barrett's esophagus should be followed closely with repeated endoscopy and biopsy.

Barrett's esophagus: current views of etiology and treatment

Barrett's esophagus is now thought to be an acquired condition rather than a congenital condition. It has a dangerous potential for malignancy; yet, aggressive medical management, antireflux procedures, and diligent follow-up may reduce the incidence of malignancy in this condition.