Dysplasia in Barrett's esophagus

Which factors make Barrett's esophagus lesions difficult to diagnose?

Background and study aims  Although the Japan Esophageal Society's magnifying endoscopic classification for Barrett's epithelium (JES-BE) offers high diagnostic accuracy, some cases are challenging to diagnose as dysplastic or non-dysplastic in daily clinical practice. Therefore, we investigated the diagnostic accuracy of this classification and the clinicopathological features of Barrett's esophagus cases that are difficult to diagnose correctly. Patients and methods  Five endoscopists with experience with fewer than 10 cases of magnifying observation for superficial Barrett's esophageal carcinoma reviewed 132 images of Barrett's mucosa or carcinoma (75 dysplastic and 57 non-dysplastic cases) obtained using high-definition magnification endoscopy with narrow-band imaging (ME-NBI). They diagnosed each image as dysplastic or non-dysplastic according to the JES-BE classification, and the diagnostic accuracy was calculated. To identify risk factors for misdiagnosed images, images with a correct rate of less than 40 % were defined as difficult-to-diagnose, and those with 60 % or more were defined as easy-to-diagnose. Logistic regression analysis was performed to identify risk factors for difficult-to-diagnose images. Results  The sensitivity, specificity and overall accuracy were 67 %, 80 % and 73 %, respectively. Of the 132 ME-NBI images, 34 (26 %) were difficult-to-diagnose and 99 (74 %) were easy-to-diagnose. Logistic regression analysis showed low-grade dysplasia (LGD) and high-power magnification images were each significant risk factors for difficult-to-diagnose images (OR: 6.80, P  = 0.0017 and OR: 3.31, P  = 0.0125, respectively). Conclusions  This image assessment study suggested feasibility of the JES-BE classification for diagnosis of Barrett's esophagus by non-expert endoscopists and risk factors for difficult diagnosis as high-power magnification and LGD histology. For non-experts, high-power magnification images are better evaluated in combination with low-power magnification images.

Utility of ancillary studies in the diagnosis and risk assessment of Barrett's esophagus and dysplasia

Barrett's esophagus (BE) is a major risk factor for the development of esophageal adenocarcinoma (EAC). BE patients undergo periodic endoscopic surveillance with biopsies to detect dysplasia and EAC, but this strategy is imperfect owing to sampling error and inconsistencies in the diagnosis and grading of dysplasia, which may result in an inaccurate diagnosis or risk assessment for progression to EAC. The desire for more accurate diagnosis and better risk stratification has prompted the investigation and development of potential biomarkers that might assist pathologists and clinicians in the management of BE patients, allowing more aggressive endoscopic surveillance and treatment options to be targeted to high-risk individuals, while avoiding frequent surveillance or unnecessary interventions in those at lower risk. It is known that progression of BE to dysplasia and EAC is accompanied by a host of genetic alterations, and that exploration of these markers could be potentially useful to diagnose/grade dysplasia and/or to risk stratify BE patients. Several biomarkers have shown promise in identifying early neoplastic transformation and thus may be useful adjuncts to histologic evaluation. This review provides an overview of some of the currently available biomarkers and assays, including p53 immunostaining, Wide Area Transepithelial Sampling with Three-Dimensional Computer-Assisted Analysis (WATS^3D), TissueCypher, mutational load analysis (BarreGen), fluorescence in situ hybridization, and DNA content abnormalities as detected by DNA flow cytometry.

Diagnosis and risk stratification of Barrett's dysplasia by flow cytometric DNA analysis of paraffin-embedded tissue

OBJECTIVE

The diagnosis of dysplasia in Barrett's oesophagus (BO) can be challenging, and reliable ancillary techniques are not available. This study examines if DNA content abnormality detected by flow cytometry can serve as a diagnostic marker of dysplasia and facilitate risk stratification of low-grade dysplasia (LGD) and indefinite for dysplasia (IND) patients using formalin-fixed paraffin-embedded (FFPE) BO samples with varying degrees of dysplasia.

DESIGN

DNA flow cytometry was performed on 80 FFPE BO samples with high-grade dysplasia (HGD), 38 LGD, 21 IND and 14 negative for dysplasia (ND). Three to four 60-micron thick sections were cut from each tissue block, and the area of interest was manually dissected.

RESULTS

DNA content abnormality was identified in 76 HGD (95%), 8 LGD (21.1%), 2 IND (9.5%) and 0 ND samples. As a diagnostic marker of HGD, the estimated sensitivity and specificity of DNA content abnormality were 95% and 85%, respectively. For patients with DNA content abnormality detected at baseline LGD or IND, the univariate HRs for subsequent detection of HGD or oesophageal adenocarcinoma (OAC) were 7.0 and 20.0, respectively (p =<0.001).

CONCLUSIONS

This study demonstrates the promise of DNA flow cytometry using FFPE tissue in the diagnosis and risk stratification of dysplasia in BO. The presence of DNA content abnormality correlates with increasing levels of dysplasia, as 95% of HGD samples showed DNA content abnormality. DNA flow cytometry also identifies a subset of patients with LGD and IND who are at higher risk for subsequent detection of HGD or OAC.

Early Barrett esophagus-related neoplasia in segments 1 cm or longer is always associated with intestinal metaplasia

The assumption that intestinal metaplasia is a prerequisite for intraepithelial neoplasia/dysplasia and adenocarcinoma in the distal esophagus has been challenged by observations of adenocarcinoma without associated intestinal metaplasia. This study describes our experience of intestinal metaplasia in association with early Barrett neoplasia in distal esophagus and gastroesophageal junction. We reviewed the first endoscopic mucosal resection of 139 patients with biopsy-proven neoplasia. In index endoscopic mucosal resection, 110/139 (79%) cases showed intestinal metaplasia. Seven had intestinal metaplasia on prior biopsy specimens and three had intestinal metaplasia in subsequent specimens, totaling 120/139 (86%) patients showing intestinal metaplasia at some point supporting the theory of sampling error for absence of intestinal metaplasia in some cases. Those without intestinal metaplasia (13%) were enriched for higher stage disease (T1a Stolte m2 or above) supporting the assertion of obliteration of intestinal metaplasia by the advancing carcinoma. All cases of intraepithelial neoplasia and T1a Stolte m1 carcinomas had intestinal metaplasia (42/42). The average density of columnar-lined mucosa showing goblet cells was significantly less in shorter segments compared to those ≥3 cm (0.31 vs 0.51, P=0.0304). Cases where segments measured less than 1 cm were seen in a higher proportion of females and also tended to lack intestinal metaplasia. We conclude that early Barrett neoplasia is always associated with intestinal metaplasia; absence of intestinal metaplasia is attributable to sampling error or obliteration of residual intestinal metaplasia by neoplasia and those with segments less than 1 cm show atypical features for Barrett-related disease (absent intestinal metaplasia and female gender), supporting that gastroesophageal junction adenocarcinomas are heterogeneous.

Intestinal metaplasia in Barrett's oesophagus may be an epiphenomenon rather than a preneoplastic condition, and CDX2-positive cardiac-type epithelium is associated with minute Barrett's tumour

AIMS

Although intestinal-type epithelium in Barrett's oesophagus has been traditionally recognized as having a distinct malignant potential, whether this also holds true for cardiac-type epithelium remains controversial. The aim of this study was to identify a type of epithelium that is highly associated with Barrett's tumour.

METHODS AND RESULTS

We analysed tumours and the corresponding background mucosa with special regard to tumour size in 40 cases of superficial Barrett's tumour by using immunohistochemical staining for CDX2, CD10, MUC2, MUC5AC, and MUC6. Intestinal metaplasia in tumour-adjacent mucosa was not associated with tumour size, but was significantly correlated with the extent of Barrett's oesophagus (P < 0.001). The majority (69.2%, 9/13) of small tumours (≤10 mm) had no intestinal metaplasia in adjacent non-neoplastic mucosae. Minute (≤5 mm) tumours were significantly associated with a gastric immunophenotype (P < 0.001). Purely gastric-immunophenotype tumour cells expressed CDX2, and cardiac-type epithelium adjacent to small tumours also showed low-level CDX2 expression.

CONCLUSIONS

Our data suggest that intestinal metaplasia in Barrett's oesophagus is an epiphenomenon rather than a preneoplastic condition, and that CDX2-positive cardiac-type epithelium is highly associated with minute Barrett's tumour. Further prospective studies are needed to evaluate the risk of malignancy of cardiac-type epithelium with regard to sub-morphological intestinalization.

Low grade dysplasia in Barrett’s esophagus: Should we worry?

The optimal management for low-grade dysplasia (LGD) in Barrett’s esophagus is unclear. In this article the importance of LGD is discussed, including the significant risk of progression to esophageal adenocarcinoma. Endoscopic surveillance is a management option but is plagued by sampling error and issues of suboptimal endoscopy. Furthermore endoscopic surveillance has not been demonstrated to be cost-effective or to reduce cancer mortality. The emergence of endoluminal therapy over the past decade has resulted in a paradigm shift in the management of LGD. Ablative therapy, including radiofrequency ablation, has demonstrated promising results in the management of LGD with regards to safety, cost-effectiveness, durability and reduction in cancer risk. It is, however, vital that a shared-decision making process occurs between the physician and the patient as to the preferred management of LGD. As such the management of LGD should be “individualised.”

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

Background

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

Methods

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

Results

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

Conclusions

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

The effect of reactive atypia/inflammation on the laser-induced fluorescence diagnosis of non-dysplastic Barrett's esophagus

BACKGROUND AND OBJECTIVES

Differential Normalized Fluorescence (DNF) technique has been used to distinguish high-grade dysplasia from non-dysplastic Barrett's esophagus. This technology may assist gastroenterologists in targeting biopsies, reducing the number of biopsies using the standard protocol. In the presence of reactive atypia/inflammation, it becomes difficult for the pathologist to differentiate non-dysplastic Barrett's esophagus from Barrett's esophagus with low-grade dysplasia. Before DNF technique may be used to guide target biopsies, it is critical to know whether reactive atypia/inflammation in non-dysplastic Barrett's may result in false positives. This study was conducted to determine whether DNF technique is adversely affected by the presence of reactive atypia/inflammation in non-dysplastic Barrett's esophagus resulting in false positives.

STUDY DESIGN/MATERIALS AND METHODS

Four hundred ten-nanometer laser light was used to induce autofluorescence of Barrett's mucosa in 49 patients. The clinical study included 37 males and 12 females. This was a blinded retrospective data analysis study. A total of 303 spectra were collected and matched to non-dysplastic Barrett's biopsy results. One hundred seventy-five spectra were collected from areas with a pathology of non-dysplastic Barrett's esophagus with reactive atypia/inflammation. One hundred twenty-eight spectra were collected from areas with non-dysplastic Barrett's esophagus without reactive changes/inflammation. The spectra were analyzed using the DNF Index at 480 nm and classified as positive or negative using the threshold of -0.75 × 10(-3).

RESULTS

Using DNF technique, 92.6% of non-dysplastic samples with reactive atypia/inflammation were classified correctly (162/175). 92.2% of non-dysplastic samples without reactive atypia/inflammation were classified correctly (118/128). Comparing the ratios of false positives among the two sample groups, there was not a statistically significant difference between the two groups.

CONCLUSION

Using DNF technique for classification of non-dysplastic Barrett's mucosa does not result in false-positive readings due to reactive atypia/inflammation. Target biopsies guided by DNF technique may drastically reduce the number of pinch biopsies using the standard biopsy protocol.

Divergent expression of MUC5AC, MUC6, MUC2, CD10, and CDX-2 in dysplasia and intramucosal adenocarcinomas with intestinal and foveolar morphology: is this evidence of distinct gastric and intestinal pathways to carcinogenesis in Barrett Esophagus?

Dysplasia in Barrett esophagus has been recognized to be morphologically heterogenous, featuring adenomatous, foveolar, and hybrid phenotypes. Recent studies have suggested a tumor suppressor role for CDX-2 in the metaplasia-dysplasia-carcinoma sequence. The phenotypic stability and role of CDX-2 in the neoplastic progression of different types of dysplasias have not been evaluated. Thirty-eight endoscopic mucosal resections with dysplasia and/or intramucosal carcinoma (IMC) arising in Barrett esophagus were evaluated for the expression of MUC5AC, MUC6, MUC2, CD10, and CDX-2. The background mucosa was also evaluated. The results were correlated with morphologic classification and clinicopathologic parameters. Of 38 endoscopic mucosal resections, 23 had IMC and dysplasia, 8 had IMC only, and 7 had dysplasia only. Among dysplastic lesions, 73% were foveolar, 17% were adenomatous, and 10% were hybrid. Twenty of 23 cases with dysplasia and adjacent IMC showed an identical immunophenotype of dysplasia and IMC comprising 16 gastric, 3 intestinal, and 1 mixed immunophenotype. Three cases showed discordance of dysplasia and IMC immunophenotype. These findings suggest that most Barrett-related IMC cases are either gastric or intestinal, with phenotypic stability during progression supporting separate gastric and intestinal pathways of carcinogenesis. CDX-2 showed gradual downregulation of expression during progression in adenomatous dysplasia but not in foveolar or hybrid dysplasia, supporting a tumor suppressor role, at least in the intestinal pathway. CDX-2 was also found to be expressed to a greater degree in intestinal metaplasia compared with nonintestinalized columnar metaplasia. Consistent with CDX-2 as a tumor suppressor, this suggests that nonintestinalized columnar metaplasia may be an unstable intermediate state at risk for neoplastic progression.

The effects of laparoscopic Nissen fundoplication on Barrett's esophagus: long-term results

OBJECTIVE

The aim of our study was to conduct a retrospective investigation of the efficacy of laparoscopic Nissen fundoplication in patients with Barrett's esophagus.

MATERIAL AND METHODS

A total of 78 patients with Barrett's esophagus underwent surgery. Patients were divided into three groups on the basis of the preoperative endoscopic biopsies: a non-intestinal group (n = 63) with fundic or cardiac metaplasia, an intestinal group (n = 18) with intestinal metaplasia, and a dysplastic group (n = 7) with low-grade dysplasia. Clinical follow-up was available in the case of 64 patients at a mean of 42 ± 16.9 months after surgery.

RESULTS

Check-up examination revealed total regression of Barrett's metaplasia in 10 patients. Partial regression was seen in 9 cases, no further progression in 34 patients, and progression into cardiac or intestinal metaplasia in 11 patients. No cases of dysplastic or malignant transformation were registered. Where we observed the regression of BE, among the postoperative functional examinations results of manometry (pressure of lower esophageal sphincter) and pH-metry were significantly better compared with those groups where no changes occurred in BE, or progression of BE was found. Discussion. Our results highlight the importance of the cases of fundic and cardiac metaplasia, which can also transform into intestinal metaplasia.

CONCLUSIONS

Antireflux surgery can appropriately control the reflux disease in a majority of the patients who had unsuccessful medical treatment, and it may inhibit the progression and induce the regression of Barrett's metaplasia in a significant proportion of these patients.

Foveolar type dysplasia in Barrett esophagus

Adenocarcinoma of the lower esophagus and esophagogastric junction is increasing in incidence in Western countries. A metaplasia (Barrett esophagus)-dysplasia-carcinoma sequence induced by gastroesophageal reflux disease is established. Two patterns of Barrett dysplasias have been described-adenomatous (type 1) and non-adenomatous (type 2 or foveolar/hyperplastic type). Interestingly, little is known about non-adenomatous dysplasia. Esophagogastrectomy cases from 41 patients with glandular dysplasia with and without associated invasive adenocarcinoma of the lower esophagus were evaluated for expression of MUC2, MUC5AC, CDX2, villin, Ki67 and p53. Results were correlated with sub-classification of the dysplasia into morphologic patterns of adenomatous vs foveolar vs hybrid type. In addition, clinicopathological parameters including the presence and extent of background intestinal metaplasia were also evaluated. Foveolar type dysplasia was present in 46% of the cases and thus, was more common than adenomatous type or hybrid type (both approximately 27%) dysplasia. Immunohistochemistry confirmed the histological stratification in all cases. Foveolar type dysplasia commonly expressed MUC5AC (P<0.12) but was consistently negative for markers of intestinal differentiation, MUC2, CDX2 and villin (all P<0.01). By contrast, adenomatous type dysplasia frequently displayed intestinal differentiation markers (all P<0.0001) Hybrid-type dysplasia was similar to adenomatous type dysplasia in showing expression of intestinal differentiation markers (P<0.01) and therefore could not be sustained as a separate category. In conclusion, our study provides evidence for a non intestinal pathway to neoplastic development in Barrett esophagus, that is, gastric metaplasia-foveolar dysplasia-adenocarcinoma.

Conversion of metaplastic Barrett's epithelium into post-mitotic goblet cells by gamma-secretase inhibition

Barrett's esophagus (BE) affects approximately 2% of the Western population and progresses to esophageal adenocarcinoma (EAC) in 0.5% of these patients each year. In BE, the stratified epithelium is replaced by an intestinal-type epithelium owing to chronic gastroduodenal reflux. Since self-renewal of intestinal crypts is driven by Notch signaling, we investigated whether this pathway was active in the proliferative crypts of BE. Immunohistochemistry confirmed the presence of an intact and activated Notch signaling pathway in metaplastic BE epithelium, but not in the normal human esophagus. Similar observations were made in two well-known human Barrett's-derived EAC cell lines, OE33 and SKGT-5. We then sought to investigate the effects of Notch inhibition by systemic treatment with a gamma-secretase inhibitor in a well-validated rodent model for BE. As we have shown previously in normal intestinal epithelium, Notch inhibition converted the proliferative Barrett's epithelial cells into terminally differentiated goblet cells, whereas the squamous epithelium remained intact. These data imply that local application of gamma-secretase inhibitors may present a simple therapeutic strategy for this increasingly common pre-malignant condition.

Preemptive surgery for premalignant foregut lesions

INTRODUCTION

Preemptive surgery is the prophylactic removal of an organ at high risk for malignant transformation or the resection of a precancerous or "early" malignant neoplasm in an individual with a hereditary predisposition to cancer. Recent advances in molecular diagnostic techniques have improved our understanding of the biologic behavior of these conditions. Predictive testing is an emerging field that attempts to assess the potential risk of cancer development in predisposed individuals. Despite substantial improvement in these forms of testing, all results are imperfect. This information often becomes an important tool that is used by healthcare providers to evaluate the risk-benefit ratio of various risk modifying strategies (i.e., intensive surveillance or preemptive surgery).

METHODS

A systematic literature review was performed using Medline and the bibliographies of all referenced publications to identify articles relating to preemptive surgery for premalignant foregut lesions.

RESULTS AND DISCUSSION

In this review, we outline the controversies surrounding predictive risk assessment, surveillance strategies, and preemptive surgery in the management of high-grade dysplasia (HGD) in Barrett's esophagus (BE), hereditary diffuse gastric cancer (HDGC), bile duct cysts, primary sclerosing cholangitis (PSC), and pancreatic cystic neoplasms. Resection of BE is supported by the progressive nature of the disease, the risk of occult carcinoma, and the lethality of esophageal cancer. Prophylactic total gastrectomy for HDGC appears reasonable in the absence of accurate screening tests but must be balanced by the impact of surgical complications and altered quality of life. Surgical resection of biliary cysts theoretically eliminates the exposed epithelium to decrease the lifetime risk of cholangiocarcinoma. Liver transplantation for PSC remains controversial given the scarcity of donor organs and inability to accurately identify high-risk individuals. Given the uncertain natural history of pancreatic cystic neoplasms, the merits of selective versus obligatory resection will continue to be debated.

CONCLUSIONS

Preemptive operations require optimal judgment and surgical precision to maximize function and enhance survival. Ultimately, balancing the risk of surgical intervention with less invasive interventions or observation must be individualized on a case-by-case basis.

Histology of metaplasia and dysplasia in Barrett's esophagus

The histologic diagnosis of Barrett's dysplasia requires the identification of intestinal metaplasia, which often presents a challenge due to sampling error, observer variation, and difficulty in histologic interpretation. Particularly problematic is the separation of negative, indefinite, and low-grade dysplasia, the varied histological appearances of high-grade dysplasia, and the diagnosis of suboptimal biopsy material. This article seeks to aid in the histological evaluation of metaplasia and dysplasia in Barrett's esophagus.

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.

Esophagectomy for high grade dysplasia is safe, curative, and results in good alimentary outcome

BACKGROUND

The increasing adoption of endoscopic therapies and expectant surveillance for patients with high grade dysplasia (HGD) in Barrett's esophagus has created considerable controversy regarding the ideal treatment choice. Confusion may be due, in part, to a limited understanding of the outcomes associated with surgical resection for HGD and extrapolation of data derived from patients undergoing an esophagectomy for invasive cancer. The purpose of our study was to document the perioperative and symptomatic outcomes and long-term survival after esophagectomy for HGD of the esophagus.

MATERIAL AND METHODS

The study population consisted of 38 patients who underwent esophagectomy for biopsy-proven HGD between 10/1999 and 6/2005. Three patients were excluded from analysis due to obvious tumor on upper endoscopy. Patients were evaluated regarding ten different foregut symptoms and administered a ten-question appraisal of eating and bowel habits. Outcome measures included postoperative morbidity and mortality, the prevalence of invasive cancer in the esophagectomy specimens, symptomatic and functional alimentary results, patient satisfaction, and long-term survival. Median follow-up was 32 months (range, 7-83).

RESULTS

Thirty-day postoperative and in-hospital mortality was zero. Complications occurred in 37% (13/35), and median length of stay was 10 days. Occult adenocarcinoma was found in 29% (10/35) of surgical specimens (intramucosal in four; submucosal in five; and intramuscular in one with a single positive lymph node.) Patients consumed a median of three meals per day, most (76%, 26/34) had no dietary restrictions, and two-thirds (23/34) considered their eating pattern to be normal or only mildly impacted. Meal size, however, was reported to be smaller in the majority (79%, 27/34) of patients. Median body mass index (BMI) decreased slightly after surgery (28.6 vs 26.6, p>0.05), but no patient's BMI went below normal. The number of bowel movements/day was unchanged or less in a majority (82%) of patients after surgery. Fifteen of 34 (44%) patients reported loose bowel movements, which occurred less often than once per week in 10 of the 15. One patient had symptoms of dumping. Mean symptom severity scores improved for all symptoms except dysphagia and choking. Four patients developed foregut symptoms that occurred daily. Most patients (82%) required at least one postoperative dilation for dysphagia. Almost all (97%) patients were satisfied. Disease-free survival was 100%, and overall survival was 97% (34/35) at a median of 32 months.

CONCLUSION

Esophagectomy is an effective and curative treatment for HGD and can be performed with no mortality, acceptable morbidity, and good alimentary outcome. These data provide a gold standard for comparison to alternative therapies.

Large intra- and inter-individual variability of genes expression levels limits potential predictive value of molecular diagnosis of dysplasia in Barrett's esophagus

Barrett's esophagus represents a well-defined precursor lesion of esophageal adenocarcinoma, although only a subset of patients with these lesions advances to invasive cancer. Currently, reliable markers predicting neoplastic progression in Barrett's esophagus are lacking. The only clinically useful risk factor is the presence of dysplasia in Barrett's epithelium, but its use as a prognostic marker of disease progression has several significant limitations. Thus, identification of biomarkers of potential prognostic value in dysplasia development in Barrett's esophagus is highly important. The aim of the study was to determine if expression levels of selected genes support histologic diagnosis of dysplastic changes in Barrett's esophagus. Upon rigorous sampling and independent histopathologic examination of endoscopic specimens by two experienced gastrointestinal pathologists, 56 patients with Barrett's esophagus (16 negative for dysplasia, 15 with indefinite, 21 with low-grade, and 4 with high-grade dysplasia) were selected for molecular analysis. The relative mRNA levels of ten selected genes were estimated by quantitative real-time polymerase chain reaction (PCR) analysis. Although expression of nine genes showed trends toward down- or upregulation during progression from Barrett's esophagus without dysplasia to Barrett's esophagus with high-grade dysplasia, only a decrease in S100A2 mRNA levels was statistically significant (P<0.05). However, there was considerable variation among individuals and significant overlapping of ranges. Furthermore, detailed, comparative analysis of serial samples from Barrett's mucosa and normal squamous epithelium shows large intra-individual variability of gene expression levels. In conclusion, expression of this set of ten genes cannot be used as a molecular marker aiding histological examination of dysplasia in Barrett's esophagus. Significant inter- and intra-patient variations of gene expression levels makes use of the selected genes impractical.

Molecular defense mechanisms of Barrett's metaplasia estimated by an integrative genomics

Barrett's esophagus is characterized by the replacement of squamous epithelium with specialized intestinal metaplastic mucosa. The exact mechanisms of initiation and development of Barrett's metaplasia remain unknown, but a hypothesis of "successful adaptation" against noxious reflux components has been proposed. To search for the repertoire of adaptation mechanisms of Barrett's metaplasia, we employed high-throughput functional genomic and proteomic methods that defined the molecular background of metaplastic mucosa resistance to reflux. Transcriptional profiling was established for 23 pairs of esophageal squamous epithelium and Barrett's metaplasia tissue samples using Affymetrix U133A 2.0 GeneChips and validated by quantitative real-time polymerase chain reaction. Differences in protein composition were assessed by electrophoretic and mass-spectrometry-based methods. Among 2,822 genes differentially expressed between Barrett's metaplasia and squamous epithelium, we observed significantly overexpressed metaplastic mucosa genes that encode cytokines and growth factors, constituents of extracellular matrix, basement membrane and tight junctions, and proteins involved in prostaglandin and phosphoinositol metabolism, nitric oxide production, and bioenergetics. Their expression likely reflects defense and repair responses of metaplastic mucosa, whereas overexpression of genes encoding heat shock proteins and several protein kinases in squamous epithelium may reflect lower resistance of normal esophageal epithelium than Barrett's metaplasia to reflux components. Despite the methodological and interpretative difficulties in data analyses discussed in this paper, our studies confirm that Barrett's metaplasia may be regarded as a specific microevolution allowing for accumulation of mucosal morphological and physiological changes that better protect against reflux injury.

Barrett's oesophagus?a pathologist's view

Barrett's oesophagus, a precancerous condition for oesophageal adenocarcinoma, detected on endoscopy and confirmed on histology, shows intestinal metaplasia of the lower oesophagus. The significance of microscopic foci of intestinal metaplasia at the gastro-oesophageal junction, corresponding either to so-called 'ultrashort' segment Barrett's oesophagus, or to carditis with intestinal metaplasia, is still a matter of debate. The surveillance of patients with Barrett's oesophagus is still based on systematic biopsy sampling of Barrett's mucosa on endoscopy, looking for dysplasia. Although well-established classifications of dysplasia are now used by most pathologists, there remain numerous problems with this subjective marker (sampling, diagnostic reproducibility, natural history, etc). Therefore, many alternative biomarkers have been proposed, but only DNA aneuploidy, proliferation markers and p53 loss of heterozygosity/overexpression have been shown to be of some use at the present time. Some endoscopic improvements already allow a better selection of biopsies, and it may be that in future new technologies will allow 'virtual biopsies'. On the other hand, the role of pathologists now extends to the evaluation of new therapeutic modalities of early neoplastic lesions in Barrett's oesophagus, especially endoscopic mucosal resection.

Barrett's esophagus and adenocarcinoma of the gastroesophageal junction: a pathologic perspective

Barrett's esophagus is defined clinically by the presence of endoscopically evident columnar mucosa in the distal esophagus with histopathologic confirmation of the presence of intestinal-type epithelium. The etiology of Barrett's esophagus is understood poorly, but chronic gastroesophageal reflux disease is considered a major contributing factor. Barrett's esophagus is associated with the development of adenocarcinoma of the gastroesophageal junction. It is believed that the development of a Barrett-type mucosa with intestinal goblet-type cells is due to an altered process of differentiation of pluripotent epithelial stem cells in response to the local injury and repair process. The potential identification and isolation of markers for screening purposes and possibly prognostic information are areas of considerable clinical and scientific interest.

Barrett esophagus: risk factors for progression to dysplasia and adenocarcinoma

OBJECTIVE

To evaluate risk factors for dysplasia and adenocarcinoma development in nondysplastic Barrett mucosa.

SUMMARY BACKGROUND DATA

The risk for patients with Barrett esophagus to develop esophageal adenocarcinoma is low, and most patients undergoing surveillance will not develop malignancy. Identification of risk factors may allow for more rational surveillance programs in which patients are stratified according to their individual risk of progressing to dysplasia and invasive adenocarcinoma.

METHODS

The development of dysplasia and esophageal adenocarcinoma was studied during long-term endoscopic and histologic surveillance in 140 patients with Barrett esophagus free from dysplasia. Risk factors for progression to dysplasia and adenocarcinoma were evaluated.

RESULTS

Median follow-up was 5.8 years. Forty-four patients (31.4%) developed low-grade dysplasia and 7 patients (5%) developed high-grade dysplasia or esophageal adenocarcinoma. Dysplasia development was significantly less common after antireflux surgery compared with conventional medical therapy. Low-grade dysplasia (relative risk = 5.5; 95% confidence interval, 1.1-28.6) and long duration of reflux symptoms (relative risk = 1.3; 95% confidence interval, 1.2-1.7) were independently associated with an increased risk of developing high-grade dysplasia or esophageal adenocarcinoma.

CONCLUSIONS

Successful antireflux surgery protects the Barrett mucosa from developing high-grade dysplasia and esophageal adenocarcinoma, possibly by better control of reflux of gastric contents. Low-grade dysplasia is the only clinically useful risk factor that permits stratification of the surveillance intervals according to the risk of the individual patient.

Visible endoscopic and histologic changes in the cardia, before and after complete Barrett's esophagus ablation

BACKGROUND

Adverse events associated with the thermal ablation of Barrett's esophagus (BE) include the generation of gastric mucosa buried beneath the neosquamous regrowth, and unrecognized development and growth of adenocarcinomas. No reports exist regarding the endoscopic appearance and histology of the cardia before and after BE ablation. The aim of our study was to assess the relative frequency of the occurrence of visible endoscopic and histologic changes in the cardia, before and after complete BE ablation.

METHODS

A subset analysis of patients with uncomplicated BE, BE with dysplasia, or early carcinoma, who had been enrolled into one of 4 ongoing prospective studies of mucosal ablation, was examined. Eighty-two patients were identified who entered a BE ablation study, with 75 of these completing BE mucosal ablation. Cardia biopsy specimens were taken in all patients before ablation and serially after BE ablation. Cardia histology was graded by using the modified Sydney System for gastritis.

RESULTS

Before ablation, cardia nodules were noted in 3, cardia intestinal metaplasia (IM) in 7 (8.5%), and none harbored cardia dysplasia. Postablation surveillance ranged from 3 to 75 months (mean 31.1 months [19.5]). Six subjects (8%) developed cardia nodules during surveillance; cardia IM was found in 21(28%), with 17 of these being a new finding (incidence of 25%). Cardia low-grade dysplasia incidence was 1.3% and high-grade dysplasia was 4% after BE ablation.

CONCLUSIONS

The pathophysiology of the abnormal cardia histology and the endoscopic lesions (nodules) is unclear, but endoscopic surveillance of not only the neosquamous epithelium but also the cardia should be considered after ablation, especially in those high-grade dysplasia and early adenocarcinoma BE patients.

Risk stratification of Barrett's esophagus: updated prospective multivariate analysis

OBJECTIVES

Prospective evaluation of Barrett's esophagus (BE) in order to determine what demographic, endoscopic, and histologic features are predictive of the prevalence and incidence of Barrett's high-grade dysplasia (HGD) and adenocarcinoma (Ca).

METHODS

Newly diagnosed BE patients were entered into and followed in a standardized surveillance protocol. The following features were examined using either forward, stepwise multiple regression analysis, or Cox proportional hazards to determine their ability to predict the presence of HGD or Ca at index BE diagnosis as well as their ability to predict progression of BE during follow-up: age, race, gender, length of BE in cm, size of a hiatal hernia, severity of dysplasia at index diagnosis as well as during surveillance, gastric Helicobacter pylori infection status, and type of medical acid-reflux treatment.

RESULTS

A total of 550 patients were diagnosed with BE over the study period. Stepwise multiple regression analysis showed three factors significantly associated with index diagnosis of HGD or Ca: hiatal hernia (larger size), Barrett's length (longer length), and absence of H. pylori infection. Three hundred and twenty-four BE entered the surveillance protocol. Cox proportional hazards models revealed a significant and independent association for five factors predictive of the time to progression of BE: presence of dysplasia at index diagnosis (p < 0.001), severity of dysplasia during surveillance (p < 0.001), length of Barrett's epithelium (p= 0.012), size of hiatal hernia (p= 0.006), and gastric H. pylori infection status (p= 0.023).

CONCLUSIONS

Endoscopic and histologic features of BE at initial diagnosis are predictive of index HGD and cancer as well as with risk of BE progression.

High-resolution chromoendoscopy in the esophagus

The major role for chromoendoscopy in the esophagus is the identification of premalignant or early cancerous lesions. In combination with high-resolution or magnification endoscopes, chromoendoscopy can potentially increase the diagnostic yield of clinically relevant lesions. Preliminary data have indicated a good correlation of findings using this technique to histopathologic readings. The ultimate goal of chromoendoscopy in combination with high resolution/magnification endoscopy is the determination of histology without obtaining tissue samples. In this article we review the different stains, the technical aspects, and current data in esophageal chromoendoscopy. We summarize possible clinical applications of these techniques and future directions of their use in esophageal diseases.

A critical review of the diagnosis and management of Barrett's esophagus: the AGA Chicago Workshop

BACKGROUND & AIMS

The diagnosis and management of Barrett's esophagus (BE) are controversial. We conducted a critical review of the literature in BE to provide guidance on clinically relevant issues.

METHODS

A multidisciplinary group of 18 participants evaluated the strength and the grade of evidence for 42 statements pertaining to the diagnosis, screening, surveillance, and treatment of BE. Each member anonymously voted to accept or reject statements based on the strength of evidence and his own expert opinion.

RESULTS

There was strong consensus on most statements for acceptance or rejection. Members rejected statements that screening for BE has been shown to improve mortality from adenocarcinoma or to be cost-effective. Contrary to published clinical guidelines, they did not feel that screening should be recommended for adults over age 50, regardless of age or duration of heartburn. Members were divided on whether surveillance prolongs survival, although the majority agreed that it detects curable neoplasia and can be cost-effective in selected patients. The majority did not feel that acid-reduction therapy reduces the risk of esophageal adenocarcinoma but did agree that nonsteroidal antiinflammatory drugs are associated with a cancer risk reduction and are of promising (but unproven) value. Participants rejected the notion that mucosal ablation with acid suppression prevents adenocarcinoma in BE but agreed that this may be an appropriate strategy in a subgroup of patients with high-grade dysplasia.

CONCLUSIONS

Based on this review of BE, the opinions of workshop members on issues pertaining to screening and surveillance are at variance with published clinical guidelines.

Chronology of the Barrett's metaplasia-dysplasia-carcinoma sequence

The objective of this study was to assess the course over time of the Barrett's metaplasia-dysplasia-carcinoma sequence. The method used was a retrospective analysis of the medical records of a patient series with a median follow-up of 25 months. The study was undertaken in a university hospital foregut laboratory. The progress of seven patients was followed through the sequence of Barrett's esophagus, low-grade dysplasia and high-grade dysplasia to cancer. They all underwent subsequent esophagectomy and were found to have intramucosal adenocarcinoma. The main outcome measure was the time from the first diagnosis of intestinal metaplasia to the development of low-grade dysplasia, high-grade dysplasia and adenocarcinoma. Low-grade dysplasia developed in a median of 24 months, high-grade dysplasia after a median of 33 months and cancer after 36 months. All patients underwent esophagectomy with reconstruction and no patient has had a recurrence at a median follow-up of 25 months (range 10-204 months). Patients on Barrett's surveillance who develop early esophageal adenocarcinoma did so within approximately 3 years after the diagnosis of non-dysplastic Barrett's esophagus.

Chromosomal gains and genomic loss of p53 and p16 genes in Barrett's esophagus detected by fluorescence in situ hybridization of cytology specimens

Endoscopic brush cytology is a promising surveillance technique for Barrett's esophagus. Ancillary markers are sought to increase the sensitivity of cytology and allow identification of patients at increased risk for disease progression. To determine if there are specific genetic changes in Barrett's esophagus with associated high-grade dysplasia/intramucosal adenocarcinoma compared to those without dysplasia, we performed fluorescence in situ hybridization (FISH) on cytologic specimens using probes to chromosomes and genomic regions previously described as altered in this disease. We studied archival brush cytology slides from 40 Barrett's esophagus patients: 21 with biopsy-proven high-grade dysplasia/carcinoma and 19 with no dysplasia and a minimum 5 years of negative follow-up. Centromeric enumeration probes (CEP) for chromosomes 6, 7, 11, and 12, and locus-specific probes (LSI) for 9p21 (p16 gene), and 17p13.1 (p53 gene) loci along with their corresponding CEP (9 and 17, respectively) were used in this study. A positive FISH result was defined as the presence of cells with >2 CEP signals or with a loss of the LSI signals relative to their corresponding CEP. p53 locus loss and/or aneusomy of chromosomes 6, 7, 11, and 12 abnormalities could be detected by FISH in routinely processed endoscopic brush cytology specimens from 95% of biopsy-positive cases with a specificity of 100%. Interestingly, all five cases with cytologic changes classified as indefinite for dysplasia from patients with a positive biopsy showed changes by FISH. Loss of the p16 locus was seen commonly in patients both with and without dysplasia/carcinoma. Selected biomarkers from this study merit further investigation to determine their potential to detect genetic changes in patients with Barrett's esophagus prior to the development of high-grade dysplasia.

TP53 mutations in malignant and premalignant Barrett's esophagus

In order to improve the efficacy of endoscopic surveillance of Barrett's esophagus, markers of neoplastic progression in addition to dysplasia are required. The aim of the present study was to assess TP53 mutational analysis as a method of identifying patients with Barrett's esophagus who are at greatest risk of adenocarcinoma, for whom endoscopic surveillance is most appropriate. TP53 mutational analysis was initially performed on premalignant and malignant tissue from 30 patients undergoing esophagectomy for adenocarcinoma, and on premalignant biopsies from 48 patients participating in a Barrett's surveillance program. Surveillance patients were followed up endoscopically and histologically for a median of 5 years following TP53 assessment. Mutational analysis was performed by single-strand conformation polymorphism analysis and direct DNA sequencing. TP53 mutations were detected in 10 of 30 esophageal adenocarcinomas, and were more common in well-differentiated carcinomas. An identical TP53 mutation was detected in carcinoma and adjacent dysplasia. Two patients with premalignant Barrett's esophagus had TP53 mutations and one of these patients developed adenocarcinoma on follow up whilst the other has not yet progressed beyond metaplasia. No patient without TP53 mutation developed high-grade dysplasia or adenocarcinoma. TP53 mutations are detected in 33% of esophageal adenocarcinomas and in 4% of premalignant Barrett's esophagus in patients undergoing endoscopic surveillance. TP53 mutation can be detected before the development of high-grade dysplasia or carcinoma, and may be useful in stratifying the risk of adenocarcinoma in patients with Barrett's esophagus.

Cdx2 as a marker of epithelial intestinal differentiation in the esophagus

The histologic diagnosis of Barrett's esophagus requires the presence of goblet cells, but this finding may not be the earliest indicator of intestinal metaplasia. We used immunohistochemistry to detect Cdx2, a transcriptional regulator important in the early differentiation and maintenance of intestinal epithelium, in 134 esophageal biopsy or resection specimens, including 62 with junctional-type epithelium (13 of which had equivocal histologic features of Barrett's epithelium), 34 with Barrett's epithelium without dysplasia, and 38 with Barrett's epithelium and dysplasia or carcinoma (13 low-grade dysplasias, 19 high-grade dysplasias, and 6 adenocarcinomas). We also performed PAS-alcian blue staining (pH 2.5) on adjacent sections. Cdx2 was observed in all cases of Barrett's epithelium. In some dysplasias (chiefly high-grade) and adenocarcinomas, there was diminution or focal loss of detectable protein. Cdx2 was detected in 20 of 62 cases (30%) of junctional-type epithelium, including 10 of 13 (77%) with equivocal histologic features of Barrett's epithelium. Acid mucin was present in goblet cells and non-goblet columnar cells in all cases of Barrett's esophagus and in non-goblet columnar cells in 48 of 62 cases (77%) with junctional-type epithelium only, including 17 of 20 (85%) that were Cdx2 positive and 31 of 42 (74%) that were Cdx2 negative. These results provide evidence that Cdx2 protein is a sensitive marker of intestinal metaplasia in the upper gastrointestinal tract and may be useful in detecting histologically equivocal cases of Barrett's esophagus. Cdx2 is present in dysplasia and adenocarcinoma, with some loss of protein primarily in high-grade dysplasia and adenocarcinoma. Acid mucin in non-goblet columnar cells is a common feature of Barrett's and junctional-type epithelium and may not always be indicative of intestinal metaplasia.

Adenocarcinoma in situ arising from the submucosal oesophageal mucous glands

The incidence of adenocarcinoma of the oesophagus is increasing; this type of carcinoma commonly arises on Barrett's oesophagus. We report a case of in-situ adenocarcinoma of the lower oesophagus arising in submucosal oesophageal mucous glands without intestinal metaplasia. We describe the histological findings, discuss the difficulties of differentiating this from invasive disease and review the current literature regarding this rare condition.

Long-term endoscopic surveillance of patients with Barrett's esophagus. Incidence of dysplasia and adenocarcinoma: a prospective study

OBJECTIVE

Barrett's esophagus (BE) is a premalignant condition for which regular endoscopic follow-up is usually advised. We evaluated the incidence of esophageal adenocarcinoma (AC) in patients with BE and the impact of endoscopic surveillance on mortality from AC.

METHODS

A cohort of newly diagnosed BE patients was studied prospectively. Endoscopic and histological surveillance was recommended every 2 yr. Follow-up status was determined from hospital and registry office records and telephone calls to the patients.

RESULTS

From 1987 to 1997, BE was diagnosed in 177 patients. We excluded three with high-grade dysplasia (HGD) at the time of enrollment. Follow-up was complete in 166 patients (135 male, 31 female). The mean length of endoscopic follow-up was 5.5 yr (range 0.5-13.3). Low-grade dysplasia (LGD) was present initially in 16 patients (9.6%) and found during follow-up in another 24 patients. However, in 75% of cases, LGD was not confirmed on later biopsies. HGD was found during surveillance in three patients (1.8%), one with simultaneous AC; two with HGD developed AC later. AC was detected in five male patients during surveillance. The incidence of AC was 1/220 (5/1100) patient-years of total follow-up, or 1/183.6 (5/918) patient-years in subjects undergoing endoscopy. Four AC patients died, and one was alive with advanced-stage tumor. The mean number of endoscopies performed for surveillance, rather than for symptoms, was 2.4 (range 1-10) per patient. During the follow-up years the cohort had a total of 528 examinations and more than 4000 biopsies.

CONCLUSIONS

The incidence of AC in BE is low, confirming recent data from the literature reporting an overestimation of cancer risk in these patients. In our patient cohort, surveillance involved a large expenditure of effort but did not prevent any cancer deaths. The benefit of surveillance remains uncertain.

Follow-up for high-grade dysplasia in Barrett's esophagus

This article will focus on the value of endoscopic follow-up for patients with high-grade dysplasia (HGD). Because the diagnosis of HGD in Barrett's esophagus is not a simple straightforward task, the article first will discuss the controversies regarding the histological diagnosis, followed by a discussion of the importance of endoscopic imaging for making the clinical diagnosis of HGD, and a systematic review of the literature relating to the presence of synchronous cancers in patients with HGD and the occurrence of cancer during endoscopic follow-up in these patients (metachronous cancers). Furthermore, the article will also discuss endoscopic techniques currently available for surveillance of these patients and make recommendations regarding surveillance intervals and the optimal biopsy protocol.

Surgical therapies in Barrett's esophagus

The two main aspects relevant to the role of surgery in the management of patients with Barrett's esophagus are to define the role of surgery in controlling reflux and associated symptoms and to define the surgical options in case of dysplasia or early neoplasia. This article also will address the issue of whether complete reflux control in patients with Barrett's esophagus can prevent the metaplastic mucosa from further progression to dysplasia and adenocarcinoma.

Barrett's esophagus: an update

Barrett's esophagus (BE) is a complication observed in a small subset of patients with chronic gastroesophageal reflux. It is characterized by the presence of intestinal-type goblet cells in biopsies from the lower esophagus. The prevalence of BE increases with age, affecting 1% of the population older than 60 years. A genetic predisposition to reflux disease has been proposed. In a twin study of reflux disease, concordance was greater in monozygotic than dizygotic twins. An association between BE and esophageal adenocarcinoma, the incidence of which has increased remarkably in the last few decades, has been established. Esophagogastric junction cancers can arise from small areas of cardia intestinal metaplasia (CIM). Regular endoscopic and histologic follow-up of BE patients is recommended. Surveillance of patients with CIM is not advised. Chromoendoscopy may help to detect areas of high-grade dysplasia (HGD). The ablation of BE, e.g. by PDT or argon plasma coagulation, is not yet proven to reduce the cancer risk. Esophagectomy is still the standard management of HGD. Endoscopic mucosal resection may be used for visible, localized lesions with HGD, and this technique may be combined with thermal ablation for areas of HGD without visible abnormality.

Biomarkers in Barrett's esophagus

This article provides a framework for clinicians who are attempting the difficult task of interpreting the Barrett's biomarker literature with the goal of improving care for their patients. Although many articles. including more that 60 proposed biomarkers, have been published on this subject, only a few describe phase 3 and 4 studies that are of interest to the clinical gastroenterologist (Table 1). For year, dysplasia grade has been the sole means of risk stratification for patients with BE, and it likely will continue to be used in the foreseeable future. The current authors believe that dysplasia classification can be valuable using the team management approach and quality controls described previously. Significant problems, however, have emerged in phase 2 through 4 studies of dysplasia that make it imperative for the Barrett's field to incorporate additional biomarkers as they are validated. These problems include poor reproducibility of dysplasia interpretations, poor predictive value for negative, indefinite, and low-grade dysplasia, and inconsistent results for HGD in different centers, all of which makes it virtually impossible to develop national guidelines for surveillance. Some studies have even suggested that endoscopic biopsy surveillance using dysplasia may not be worthwhile. Currently, flow cytometric tetraploidy and aneuploidy have progressed furthest in biomarker validation (see Table 1). With proper handling, endoscopic biopsy specimens can be shipped to reference laboratories that have the instruments, computer analytic methods, and expertise to reproducibly detect tetraploidy and aneuploidy. The results of phase 4 studies indicate that flow cytometry appears to be useful in detecting a subset of patients who do not have HGD and yet have an increased risk of progression to cancer that cannot be identified by dysplasia grade. For many reasons, the authors anticipate that the number of validated biomarkers will increase substantially in the future. Biopsy repositories are now readily available for phase 3 studies that can evaluate and compare biomarkers. There are initiatives for multi-institutional Barrett's Centers of Excellence that could provide rapid progress in biomarker evaluation. In addition to new candidate biomarkers, the human genome project has provided high-throughput methodologies and methods for computer analysis of data, which can provide the volume and quality control required for clinically useful biomarkers. Currently, 17p (p53) LOH has progressed the furthest among molecular biomarkers. The authors do not recommend its routine clinical use at the present time, however. Finally, it is likely that clinicians will want to follow the results of clinical treatment-response studies and epidemiologic studies that evaluate relationship between clinical interventions or environmental risk and protective factors and surrogate endpoints, especially if the endpoints are progessing well along the phases of biomarker validation. These studies are likely to be of clinical interest because they may becoming the basis for randomized clinical trials to prevent cancer in BE.

Barrett's esophagus and Barrett's-related dysplasia

Barrett's esophagus is a complication of chronic gastroesophageal reflux disease and can be diagnosed when there is an endoscopic abnormality in which a biopsy shows evidence of specialized columnar epithelium, characterized by the presence of acid mucin-containing goblet cells. Much of the controversy in this body of literature relates to the complex anatomy of the esophagogastric junction and the difficulty in precisely identifying this landmark at endoscopy. By definition, in Barrett's esophagus, the squamocolumnar junction is proximal to the esophagogastric junction. Although fundic-type or cardiac-type (junctional) columnar epithelium may be present in Barrett's esophagus, it is only the presence of specialized columnar epithelium that is diagnostic of this condition. Patients with Barrett's esophagus are at risk of progressing to esophageal dysplasia and adenocarcinoma. There are several problems with using dysplasia as a marker for increased cancer risk in these patients, including problems with sampling error and intra- and interobserver variation in the recognition of dysplasia. It may be difficult to distinguish regenerative epithelial changes from dysplasia, low-grade from high-grade dysplasia, and high-grade dysplasia from intramucosal adenocarcinoma. Finally, there are relatively few prospective data evaluating the natural history of high-grade dysplasia. The management of patients with Barrett's-related dysplasia is controversial and varies from institution to institution. Future emphasis should be on cost-effective techniques for sampling as much of the esophageal mucosa as possible in patients who are at the highest risk of progressing to dysplasia and adenocarcinoma. Identification of biomarkers that identify such patients before the histologic recognition of dysplasia will be an area of intensive research.

Neodymium:yttrium-aluminum garnet contact laser ablation of Barrett's high grade dysplasia and early adenocarcinoma

OBJECTIVES

We describe the efficacy and safety of neodymium:yttrium-aluminum garnet (Nd:YAG) contact laser ablation of Barrett's high grade dysplasia (HGD) and/or early adenocarcinoma.

METHODS

Consecutive Barrett's patients in whom HGD or adenocarcinoma was detected were eligible. Radial array echoendosonography and high frequency catheter probe ultrasonography were performed. Patients were excluded if ultrasound revealed the presence of Barrett's cancer with regional lymph nodes or celiac trunk metastases or extension of the tumor into superficial submucosa (T1sm1) or greater. Nd:YAG laser used quartz contact probes, with all Barrett's epithelium targeted at each session. Complete ablation was confirmed with Lugol's iodine chromoendoscopy followed by surveillance biopsies of the neosquamous epithelium. Adverse events were ascertained by scheduled telephone contact interviews.

RESULTS

A total of 36 patients with HGD/adenocarcinoma were evaluated at our center, 17 of whom met all inclusion criteria. Of the patients, 14 have remained in the study, and all have had successful elimination of HGD and cancer. In addition, 11 patients (78.6%) achieved complete endoscopic and histological ablation of all Barrett's tissue. Two patients (14.3%) achieved 95% destruction of Barrett's with residual metaplastic columnar epithelium containing goblet cells without dysplasia. The remaining patient has obtained 75% ablation of Barrett's, with residual metaplastic columnar epithelium harboring Barrett's with low grade dysplasia. Major complications included two esophageal strictures (11.8%) and one mild upper GI bleed (5.9%).

CONCLUSIONS

This preliminary experience with Nd:YAG contact laser for the treatment of Barrett's HGD and early superficial cancers seems promising. The need for additional controlled trials with larger numbers of patients with longer follow-up, as well as consideration of a head-to-head trial with Photofrin photodynamic therapy, is warranted.

Utilization of cytokeratins 7 and 20 does not differentiate between Barrett's esophagus and gastric cardiac intestinal metaplasia

Long segment Barrett's esophagus (LSBE) is a recognized risk factor for the development of esophageal dysplasia and carcinoma. However, the risk of dysplasia arising within intestinal metaplasia below a normal-appearing Z-line (i.e., in native cardiac mucosa) is unknown. Regular endoscopic surveillance is required in patients with LSBE and is frequently performed in short segment BE (SSBE), but the need for surveillance in cardiac intestinal metaplasia (CIM) is unknown. Unfortunately IM arising in SSBE and immediately below a normal Z-line can be indistinguishable histologically on H&E stains. Previous reports suggest that the appearance of superficial CK20 immunohistochemical staining accompanied by intermediate and deep CK7 positivity is characteristic of BE, whereas CIM specimens show superficial and deep CK20 positivity and weak to absent CK7 staining. We hypothesized that CK7/20 immunostaining of metaplastic biopsies from the esophagus and stomach would allow complete differentiation of these two entities when correlated with the endoscopic appearance. We undertook an evaluation of gastric and esophageal specimens to determine whether these characteristics were valid. Cases of both BE (long and short segment) and CIM, as well as cases of gastric cardiac biopsies lacking IM, were evaluated for CK7 and CK20 and correlated with the endoscopic appearance. We observed that, although the "Barrett's" pattern of CK7/20 was maintained for many cases of BE, the sensitivity and specificity were only moderate (65% and 56%, respectively). The pattern of staining for the CIM was variable, i.e., some cases showed a CK7/20 Barrett's pattern despite a normal appearance at endoscopy. The differences between this and previous studies may be due to inaccurate visualization of SSBE on endoscopy, the development of very early SSBE cases, inter-observer variability, fixation differences, or antibody differences. Whatever the cause of the differences, if results between laboratories are not comparable, CK7/20 immunostaining cannot be used to differentiate reliably between IM present in biopsy specimens taken from above versus below the Z-line. However, further studies should be performed to determine whether the presence or absence of a Barrett's pattern of CK7/20 immunostaining could predict progression to dysplasia or carcinoma.

High-grade dysplasia in Barrett's esophagus. The case for esophagectomy

The main principles for optimal management of HGD arising in Barrett's esophagus are that unequivocal diagnosis of HGD is a prerequisite for making the decision of any kind of treatment. HGD must be resected because of the presence of neoplastic cells in the lamina propria in 40% of patients. No reliable endoscopic or endosonographic feature exists that allows accurate prediction of the existence of neoplastic cells within the lamina propria of a patient having HGD in endoscopic biopsy material. Prompt decision to remove an HGD lesion as soon as unequivocal histologic diagnosis has been settled prevents the development of extraesophageal neoplastic spread. Esophagectomy is preferable to endoscopic mucosal excision because approximately 20% of patients who have HGD in preoperative biopsy material carry neoplastic cells beyond the muscularis mucosae. Esophagectomy can be limited to the removal of the esophageal tube without extended lymphadenectomy because 96% of patients who have HGD in endoscopic biopsy samples have a neoplastic process confined to the esophageal wall. Esophageal resection must encompass all the Barrett's area because of the risk for the further development of a second cancer in the metaplastic remnant. Vagus-sparing esophagectomy with colon interposition or elevation of the antrally innervated stomach up to the neck is preferable to conventional esophagectomy with gastric pull up because the former procedure maintains gastric function intact, whereas the latter exposes patients to the risk for the long-term development of reflux esophagitis and even of metaplastic transformation of the proximal esophageal remnant. Subtle details in the understanding of a given patient's clinical course may be critical for making the decision of the most relevant mode of therapy; therefore, patients who have HGD should be treated in dedicated centers, the experience of which offers the best chances of uneventful recovery if the surgical option is retained.

Dysplasia in barrett's esophagus. New techniques and markers

In this article, the authors describe the histologic features and classification of dysplasia in Barrett's esophagus. The histologic problems in the diagnosis and grading of dysplasia are discussed. Techniques that can serve as aids to the histologic diagnosis of dysplasia, such as flow cytometry and molecular markers, are reviewed.

Dysplasia and adenocarcinoma after classic antireflux surgery in patients with Barrett's esophagus: the need for long-term subjective and objective follow-up

OBJECTIVE

To assess the clinical, endoscopic, and functional results in a group of patients with Barrett's esophagus undergoing classic antireflux surgery in whom dysplasia and adenocarcinoma were found at a late objective follow-up.

SUMMARY BACKGROUND DATA

There have been isolated reports of patients with Barrett's esophagus undergoing antireflux surgery who show dysplasia or even adenocarcinoma on follow-up.

METHODS

Of 161 patients undergoing surgery, dysplasia developed in 17 (10.5%) at late follow-up and adenocarcinoma developed in 4 (2.5%). These 21 patients represent the group assessed and were compared with 126 surgical patients with long-segment Barrett's in whom dysplasia did not develop. They were evaluated by clinical questionnaire, multiple endoscopic procedures and biopsy specimens, 24-hour pH studies, and 24-hour bilirubin monitoring.

RESULTS

Of the 17 patients with dysplasia, 3 were asymptomatic at the time that dysplastic changes appeared; all patients with adenocarcinoma had symptoms. Two patients (12%) in the dysplasia group had short-segment Barrett's; all patients with adenocarcinoma had long-segment Barrett's. Manometric studies revealed an incompetent lower esophageal sphincter in 70% of the dysplasia group, similar to nondysplasia patients with recurrence, and in 100% of the adenocarcinoma group. The 24-hour pH study showed pathologic acid reflux in 94% of the patients with dysplasia, similar to patients with recurrence without dysplasia, whereas bilirubin monitoring showed duodenal abnormal reflux in 86% of the patients. Among patients with dysplasia, three different histologic patterns were identified. All patients with adenocarcinoma had initially intestinal metaplasia, with appearance of this tumor 6 to 8 years after surgery.

CONCLUSIONS

Patients with Barrett's esophagus who undergo antireflux surgery need close and long-term endoscopic and histologic surveillance because dysplasia or even adenocarcinoma can appear at late follow-up. Metaplastic changes from fundic to cardiac mucosa and then to intestinal metaplasia and later to dysplasia or adenocarcinoma can clearly be documented. There were no significant differences in terms of clinical, endoscopic, manometric, 24-hour pH, and bilirubin monitoring studies between patients with recurrence of symptoms without dysplastic changes, and patients with dysplasia. Therefore, the high-risk group for the development of dysplasia is mainly the group with failed antireflux surgery.

Screening and surveillance for complications related to gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) and columnar-lined esophagus with intestinal metaplasia (Barrett's esophagus) are the major recognized risk factors for adenocarcinoma of the esophagus. The American College of Gastroenterology recommends that patients with long-standing GERD symptoms (particularly those 50 years of age or older) undergo endoscopic screening to identify Barrett's esophagus and that those patients who have Barrett's esophagus undergo regular endoscopic surveillance. These recommendations are made with the expectation that screening and surveillance will decrease mortality from esophageal cancer, although this association is unclear. Nonetheless, retrospective studies have shown that endoscopic surveillance can detect some early, curable neoplasms in patients with Barrett's esophagus. Dysplasia in Barrett's esophagus is widely regarded as the precursor of invasive malignancy. Although grading dysplastic changes is largely subjective, dysplasia remains the most appropriate biomarker for clinical evaluation of Barrett's esophagus. Flow-cytometric and p53 abnormalities may be earlier and more specific markers for cancer development, but application of these abnormalities is not yet recommended for clinical practice. Endoscopic surveillance also is adversely affected by biopsy sampling error. Techniques that may minimize biopsy sampling error include chromoendoscopy, endosonography, optical coherence tomography, and fluorescence detection techniques. Further studies are needed to clearly define the role of these techniques in surveillance, and none is practical for routine clinical use at this time. Although not specifically recommended, experimental ablative therapies, such as photodynamic therapy, can be considered by physicians for their patients with high-grade dysplasia in Barrett's esophagus, if they are provided as part of an established, approved research protocol.

p53 protein overexpression in low grade dysplasia (LGD) in Barrett's esophagus: immunohistochemical marker predictive of progression

OBJECTIVES

The presence of low grade dysplasia (LGD) within Barrett's esophagus (BE) has a multitude of ramifications. Identification of markers that could risk stratify LGD would be of great clinical benefit. We aimed to prospectively evaluate the prognosis of the immunohistochemical overexpression of p53 protein in BE colocalized to LGD.

METHODS

Consecutive BE patients in whom LGD was found had a repeat esophagogastroduodenoscopy within 8-12 wk per an ongoing prospective study. At each esophagogastroduodenoscopy, a therapeutic scope was used in conjunction with the Seattle Biopsy Protocol. Patients were observed until development of multifocal high grade dysplasia (mHGD), presence of an HGD dysplasia-associated lesion or mass (DALM) lesion, or frank adenocarcinoma. p53 protein overexpression was determined by computerized immunoquantitation using image analysis software on step serial-sectioned specimens of BE segment(s) harboring LGD. Kaplan-Meier survival curves were made on the ability of p53 staining colocalized to areas of LGD to predict progression to mHGD, HGD DALM, or cancer during prospective follow-up.

RESULTS

Forty-eight BE patients with LGD were observed for a mean of 41.2+/-22.5 months. During this period, five of 48 patients progressed to mHGD with a focus in which intramucosal cancer could not be excluded (one), mHGD/DALM with one or more foci in which intramucosal cancer could not be excluded (two), cancer (one), or mHGD (one). Twelve had persistent LGD and 31 had regressed to no dysplasia. p53 staining was positive and colocalized to areas of LGD in 4/31 of patients that regressed, 3/12 that persisted, and 3/5 that progressed. Kaplan-Meier curves differed significantly between p53 positive and negative patients for outcome defined as progression of LGD.

CONCLUSIONS

p53 colocalization with LGD at index LGD diagnosis is a risk factor for progression of LGD. This can potentially be used to risk stratify BE LGD patients in terms of surveillance intervals or enrollment into secondary prevention studies.

The pathology of epithelial pre-malignancy of the gastrointestinal tract

This chapter deals with pre-malignant epithelial lesions of the gastrointestinal tract that have the potential to become cancers. Pre-malignant lesions are divided into two types: those characterized by dysplastic mucosa and those without dysplasia. Examples of the two types are present in the oesophagus, stomach and intestine. In the oesophagus, dysplasia of the squamous epithelium is a precursor to squamous carcinoma. There are differences in interpretation between Western and Japanese pathologists in the diagnosis of oesophageal squamous lesions. Dysplasia in Barrett's oesophagus is regarded as a precursor of adenocarcinoma. The goal of endoscopic surveillance in Barrett's mucosa is the detection of high-grade dysplasia. There are several problems with our current knowledge of high-grade dysplasia and controversies regarding its management. There are differences in the interpretation of biopsies of gastric epithelial dysplasia between Japanese and Western pathologists. In the colon, pre-malignant lesions include dysplasia seen in inflammatory bowel disease and colonic adenomas. The most significant predictor of the risk of malignancy in patients with inflammatory bowel disease is the presence of dysplasia in colonic biopsies. Because of the similarity of neoplasia throughout the gastrointestinal tract, there have been attempts to unify its classification, terminology and diagnostic criteria internationally, the most recently proposed modified classification of gastrointestinal neoplasia being the Vienna classification. Dysplasia of the columnar mucosa has a similar appearance in Barrett's oesophagus, the stomach and the colon. Criteria for its histological diagnosis and grading are reviewed, with an emphasis on areas of diagnostic difficulty such as interobserver variation, and discrepancies between Western and Japanese pathologists. Implication of the presence of dysplasia that are specific to each organ site are discussed, highlighting weaknesses and controversies in current knowledge.

Endoscopic and histologic diagnosis of Barrett esophagus

Endoscopy plays an important role in the identification, diagnosis, and treatment of Barrett esophagus. Short-segment (<2-3 cm) and traditional long-segment (>2-3 cm) Barrett esophagus are distinguished solely on the length of metaplastic tissue above the esophagogastric junction. The histologic hallmark of intestinal metaplasia is required to confirm diagnosis. Biopsy specimens obtained from tissue of presumed Barrett esophagus or an irregular Z line confirm metaplastic glandular mucosa and permit evaluation of dysplastic or neoplastic changes. In the appropriate clinical setting, the use of adjunctive diagnostic techniques may facilitate the diagnosis of Barrett esophagus and sequelae such as dysplasia. Chromoendoscopy with high-resolution or magnified endoscopy is simple, safe, and desirable for surveillance but requires additional procedural time. The use of light-induced fluorescence endoscopy and light-scattering spectroscopy (i.e., optical biopsy) is appealing for the diagnosis and characterization of suspicious lesions. Adjunctive endoscopic techniques and adherence to a protocol for performing biopsies facilitate the early detection and subsequent surveillance of Barrett esophagus.