Intestinal metaplasia of the esophagus or esophagogastric junction: evidence of distinct clinical, pathologic, and histochemical staining features

Rio de Janeiro Global Consensus on Landmarks, Definitions, and Classifications in Barrett's Esophagus: World Endoscopy Organization Delphi Study

BACKGROUND & AIMS

Despite the significant advances made in the diagnosis and treatment of Barrett's esophagus (BE), there is still a need for standardized definitions, appropriate recognition of endoscopic landmarks, and consistent use of classification systems. Current controversies in basic definitions of BE and the relative lack of anatomic knowledge are significant barriers to uniform documentation. We aimed to provide consensus-driven recommendations for uniform reporting and global application.

METHODS

The World Endoscopy Organization Barrett's Esophagus Committee appointed leaders to develop an evidence-based Delphi study. A working group of 6 members identified and formulated 23 statements, and 30 internationally recognized experts from 18 countries participated in 3 rounds of voting. We defined consensus as agreement by ≥80% of experts for each statement and used the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool to assess the quality of evidence and the strength of recommendations.

RESULTS

After 3 rounds of voting, experts achieved consensus on 6 endoscopic landmarks (palisade vessels, gastroesophageal junction, squamocolumnar junction, lesion location, extraluminal compressions, and quadrant orientation), 13 definitions (BE, hiatus hernia, squamous islands, columnar islands, Barrett's endoscopic therapy, endoscopic resection, endoscopic ablation, systematic inspection, complete eradication of intestinal metaplasia, complete eradication of dysplasia, residual disease, recurrent disease, and failure of endoscopic therapy), and 4 classification systems (Prague, Los Angeles, Paris, and Barrett's International NBI Group). In round 1, 18 statements (78%) reached consensus, with 12 (67%) receiving strong agreement from more than half of the experts. In round 2, 4 of the remaining statements (80%) reached consensus, with 1 statement receiving strong agreement from 50% of the experts. In the third round, a consensus was reached on the remaining statement.

CONCLUSIONS

We developed evidence-based, consensus-driven statements on endoscopic landmarks, definitions, and classifications of BE. These recommendations may facilitate global uniform reporting in BE.

[Barrett's esophagus. An update]

Barrett's esophagus (BE), a well-known complication of gastroesophageal reflux disease (GERD), constitutes a precancerous condition for adenocarcinoma of the distal esophagus. The so-called Barrett's carcinoma shows increasing incidences in countries of the western hemisphere; new data, however, indicate that the rise in incidence is not quite as dramatic as previously assumed. The definition of BE is currently changing: despite good reasons for a purely endoscopic definition of BE, goblet cells are still mandatory for this diagnosis in Germany and the USA. Dysplastic changes in the epithelium are the most important risk factor for the development of Barrett's adenocarcinoma and recently dysplasia was subclassified into a more frequent adenomatous (intestinal) and a non-adenomatous (gastric-foveolar) types. The gold standard for diagnosing dysplasia is still H&E staining. The histological diagnosis of dysplasia is still encumbered by a significant interobserver variability, especially regarding the differentiation between low grade dysplasia and inflammatory/reactive changes and the discrimination between high grade dysplasia and adenocarcinoma. Current data, however, show much higher interobserver agreement in endoscopic resection specimens than in biopsies. Nevertheless, the histological diagnosis of dysplasia should be corroborated by an external second opinion because of its clinical consequences. In endoscopic resections of early Barrett's adenocarcinoma, the pathological report has to include a risk stratification for the likelihood of lymphogenic metastases.

Low-grade dysplasia in Barrett's esophagus: overdiagnosed and underestimated

OBJECTIVES

Published data on the natural history of low-grade dysplasia (LGD) in Barrett's esophagus (BE) are inconsistent and difficult to interpret. We investigated the natural history of LGD in a large community-based cohort of BE patients after reviewing the original histological diagnosis by an expert panel of pathologists.

METHODS

Histopathology reports of all patients diagnosed with LGD between 2000 and 2006 in six non-university hospitals were reviewed by two expert pathologists. This panel diagnosis was subsequently compared with the histological outcome during prospective endoscopic follow-up.

RESULTS

A diagnosis of LGD was made in 147 patients. After pathology review, 85% of the patients were downstaged to non-dysplastic BE (NDBE) or to indefinite for dysplasia. In only 15% of the patients was the initial diagnosis LGD. Endoscopic follow-up was carried out in 83.6% of patients, with a mean follow-up of 51.1 months. For patients with a consensus diagnosis of LGD, the cumulative risk of progressing to high-grade dysplasia or carcinoma (HGD or Ca) was 85.0% in 109.1 months compared with 4.6% in 107.4 months for patients downstaged to NDBE (P<0.0001). The incidence rate of HGD or Ca was 13.4% per patient per year for patients in whom the diagnosis of LGD was confirmed. For patients downstaged to NDBE, the corresponding incidence rate was 0.49%.

CONCLUSIONS

LGD in BE is an overdiagnosed and yet underestimated entity in general practice. Patients diagnosed with LGD should undergo an expert pathology review to purify this group. In case the diagnosis of LGD is confirmed, patients should undergo strict endoscopic follow-up or should be considered for endoscopic ablation therapy.

Histopathologic evaluation of an animal model for Barrett's esophagus and adenocarcinoma of the distal esophagus

INTRODUCTION

Barrett's esophagus and adenocarcinoma of the esophagus are related to long-standing duodeno-gastroesophageal reflux. The development of an animal model in which Barrett's esophagus and/or carcinoma is induced by duodeno-(gastro-)esophageal reflux could provide better understanding of the pathogenesis of the metaplasia-dysplasia-carcinoma sequence and would create the possibility of investigating new treatment strategies for this aggressive disease.

MATERIALS AND METHODS

Two rat models were analyzed. In the first experiment, 44 male Sprague Dawley rats underwent end-to-side esophagojejunostomy with gastric resection, to ensure duodenoesophageal reflux without gastric acid. In the second experiment a side-to-side esophago-gastrojejunostomy was performed in 30 rats, ensuring duodeno-gastroesophageal reflux. In both experiments animals were not exposed to any exogenous carcinogens during the experiment. Sequential morphological changes (i.e., esophagitis, intestinal metaplasia, dysplasia, and carcinoma) were studied after 4, 6, and 12 months. To analyze histopathologic characteristics, evaluation of the hematoxylin and eosin specimens was combined with immunohistochemical stainings for high-iron diamine-alcian blue, alcian blue/periodic acid-Schiff, the proliferation marker PCNA, and mutations in the tumor suppressor gene p53.

RESULTS

In the first experiment, only 11 animals survived the postoperative period. These animals had to be sacrificed at a median of 11 weeks due to persistent weight loss and failure to thrive. Severe ulcerative esophagitis was seen in all animals, with a 2-mm segment of metaplastic epithelium found at the anastomosis. In four animals a large, well-differentiated, mucinous tumor without malignant characteristics was observed. In the second experiment, eight animals died postoperatively. Twelve animals were sacrificed according to protocol at 4 or 6 months. In these animals, extensive esophagitis with squamous cell hyperplasia was found. In addition, a short (2 mm) segment of metaplastic epithelium was observed, without dysplasia. The remaining animals survived 1 year. After 1 year, 9 of the 10 animals had developed a glandular metaplastic segment (median length, 10 mm), which was histologically and immunohistologically characteristic for the specialized columnar epithelium of Barrett's esophagus without signs of dysplasia. Finally, in seven animals a mucinous tumor with cytologic characteristics of a well-differentiated mucinous adenocarcinoma was found without infiltrative growth. These tumors were always found at the site of the anastomosis, originated in the submucosa, and did not reach either the luminal surface or the muscular layer. The mucinous lesions were not positive for p53, and PCNA was only slightly increased. Although they showed cytological characteristics of malignancy, histopathologic evaluation was more suggestive of a reactive mucous producing lesion fitting the diagnosis "esophagitis cystica profunda."

CONCLUSION

This study demonstrates the development of a long Barrett's segment in an animal duodeno-gastroesophageal reflux model. Although mucinous tumors resembling adenocarcinomas develop around the anastomosis, these are probably not reflux induced and are more likely to be reactive lesions. However, the true nature of these tumors remains to be elucidated.

Differences and similarities of adenocarcinomas of the esophagus and esophagogastric junction

During the last few decades there has been an alarming rise in the incidence of tumors originating at the esophagogastric junction (EGJ) [1]. The reason for this is unknown. Tumors of the EGJ can be categorized in two types of cancer divided according to their anatomical origin: distal esophageal adenocarcinoma and adenocarcinoma of the gastric cardia. However, due to their location, in the transitional zone of the esophagus and stomach, there is constant debate about the proper classification, staging, and management of these tumors. The etiology of distal esophageal adenocarcinoma is clearly related to gastroesophageal reflux disease (GERD) and the development of a Barrett's esophagus [2]. The etiology of adenocarcinoma of the gastric cardia is less well understood. In the present paper, we will discuss the clinical characteristics and clinical management of esophagogastric tumors. Special attention will be given to differences and similarities of adenocarcinomas of the gastric cardia and distal esophagus.

Prospective analysis of patients with adenocarcinoma of the gastric cardia and lymph node metastasis in the proximal field of the chest

BACKGROUND

The extent to which adenocarcinoma of the cardia with lymph node metastasis in the upper mediastinum is amenable to cure by radical surgery is open to debate. It remains unclear whether these relatively distant metastases have an effect on long-term survival. The aim of this study was to identify the incidence of such positive nodes and evaluate their prognostic significance.

METHODS

Some 50 patients with adenocarcinoma of the gastric cardia and substantial invasion of the oesophagus (junctional type II), who underwent an extended transthoracic oesophagectomy as part of a prospective randomized trial between 1994 and 2000, were studied.

RESULTS

Eleven patients (22 per cent) had lymph node metastasis in the proximal field of the chest. These patients had more positive nodes overall (P = 0.020) and a shorter median survival (P = 0.009) than those without such metastasis. Multivariate analysis identified positive nodes in the proximal field as an independent predictor of poor survival.

CONCLUSION

Lymph node metastasis in the proximal field of the chest is common and is an indicator of poor prognosis in patients with adenocarcinoma of the cardia.

Human defensin 5 expression in intestinal metaplasia of the upper gastrointestinal tract

BACKGROUND

Upper gastrointestinal tract intestinal metaplasia (IM) is termed Barrett's oesophagus (BO) or gastric intestinal metaplasia (GIM), depending on its location. BO and GIM are associated with chemical exposure resulting from gastro-oesophageal reflux and chronic Helicobacter pylori infection, respectively. Paneth cells (PCs), characterised by cytoplasmic eosinophilic granules, are found in a subset of IM at these sites, but histology may not accurately detect them.

AIM

To determine human defensin 5 (HD5; an antimicrobial peptide produced by PCs) expression in BO and GIM, and to investigate its association with H pylori infection.

METHODS

Endoscopic biopsies from 33 patients with BO and 51 with GIM, and control tissues, were examined by routine histology and for H pylori infection and HD5 mRNA and protein expression.

RESULTS

In normal tissues, HD5 expression was specific for PCs in the small intestine. Five patients with BE and 42 with GIM expressed HD5, but few HD5 expressing cells in IM had the characteristic histological features of PCs. Most HD5 positive specimens were H pylori infected and most HD5 negative specimens were not infected.

CONCLUSIONS

HD5 immunohistochemistry was often positive in IM when PCs were absent by conventional histology. Thus, HD5 immunohistochemistry may be superior to histology for identifying metaplastic PCs and distinguishing GIM from BO. The higher frequency of HD5 expression in GIM than in BO is associated with a higher frequency of H pylori infection, suggesting that in IM PCs may form part of the mucosal antibacterial response.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Loss of Heterozygosity and Immunohistochemistry of Adenocarcinomas of the Esophagus and Gastric Cardia

PURPOSE

Adenocarcinomas of the distal esophagus and gastric cardia are two tumors that have many features in common. They have similar prognoses, treatment modalities, and patterns of dissemination. The etiology is different, with gastroesophageal reflux disease playing a major role for esophageal adenocarcinoma, in contrast to adenocarcinoma of the gastric cardia. In the present study, we investigated several genetic and immunohistochemical features of adenocarcinomas of the distal esophagus and gastric cardia.

EXPERIMENTAL DESIGN

Sixty-two resection specimens of either adenocarcinoma of the esophagus or adenocarcinoma of the gastric cardia were carefully selected. The genetic analysis included loss of heterozygosity of several tumor suppressor genes known to be involved in esophagogastric carcinogenesis. Immunohistochemical studies included the analysis of p53, c-Met, c-erbB-2, beta-catenin, and cyclooxygenase-2. In addition, a mutation analysis of the Tcf1 gene was done by direct sequencing.

RESULTS

Patients with cardiac carcinoma had a significantly worse tumor stage and poorer differentiation on histology. Loss of heterozygosity analysis did not reveal significant differences between esophageal adenocarcinoma and cardiac adenocarcinoma. Immunohistochemical analysis revealed significantly more nuclear accumulation of beta-catenin and overexpression of cyclooxygenase-2 in patients with esophageal adenocarcinoma, compared with patients with cardiac carcinoma. No mutation was found in the Tcf1 gene in either tumor type.

CONCLUSIONS

Although adenocarcinomas of the distal esophagus and gastric cardia have many features in common, we have found some evidence that they might form two different entities.

Distinction between intestinal metaplasia in the cardia and in Barrett's esophagus: the role of histology and immunohistochemistry

Intestinal metaplasia in Barrett's esophagus (BIM) is a precancerous condition, whereas the carcinogenic potential of intestinal metaplasia of the cardia (CIM) is uncertain. Although clinically important, histological distinction between both conditions by endoscopic biopsies is considered problematic. In the present study, 4-mm samples of BIM (n=31) and CIM (n=9) were selected from esophagectomy specimens that had been resected for esophageal cancer. Slides were coded and stained with hematoxylin and eosin (H&E), Alcian blue-periodic acid-Schiff (PAS), cytokeratins (CK) 7 and 20, and CD10, which labels the intestinal brush border. The predictive value of these stains for the recognition of BIM and CIM was evaluated independently by two senior pathologists. With the use of H&E-stained slides exclusively, BIM samples were categorized correctly in 93.5% and 83.9% of cases (pathologists 1 and 2, respectively), and CIM samples, in 100% and 88.9% of cases. Alcian blue-PAS-positive goblet cells were identified by both investigators in all BIM and CIM samples. BIM-typical CK 7 and 20 immunostaining pattern was identified in 90.3%/83.9% of BIM but only in 11.1%/11.1% of CIM. CD10-positive brush border was present in 32.3%/25.8% of BIM and in 88.9%/88.9% of CIM. When HE-stained slides and immunohistologically stained slides were used together for tissue recognition, BIM were categorized correctly in 90.3%/80.6% of cases, and CIM, in 88.9%/88.9% of cases. In conclusion, BIM and CIM can be usually distinguished on the basis of HE sections. CK 7 and CK 20 expression pattern analysis discriminates correctly between BIM and CIM in the majority of cases. CD10-positive intestinal brush border is present in the majority of CIM but only in a minority of BIM. However, immunohistochemical investigations could not improve the diagnostic accuracy of HE histology alone.

The presence and mucin histochemistry of cardiac type mucosa at the esophagogastric junction

OBJECTIVES

Traditionally, the gastric cardia has been described as a native part of the stomach connecting to the esophagus. In recent literature, however, it is suggested that the cardia is an acquired lesion that develops due to gastroesophageal reflux disease. As a contribution to this debate, we evaluated the presence of cardiac mucosa at the esophagogastric junction (EGJ) in a random group of patients who presented at our endoscopy unit.

METHODS

In 253 unselected patients, biopsies were taken from the EGJ. In order to prevent sampling error, we selected only those EGJ biopsies in which the squamocolumnar junction (SCJ) was present in the histological biopsy material. Fifty-five patients were excluded since the SCJ was located proximal to the EGJ in the esophagus. The type of columnar mucosa immediately distal to the SCJ, and its mucin histochemistry, were assessed. The columnar mucosa was categorized as purely cardiac, oxyntocardiac, or fundic mucosa.

RESULTS

In 63 of the 198 patients, the SCJ was actually present in the EGJ biopsies. Purely cardiac mucosa was present in 39 (62%) biopsies and oxyntocardiac mucosa was present in 24 (38%) biopsies. Fundic mucosa was not seen directly adjacent to squamous epithelium. Acid mucins were present in 23 (37%) patients and they correlated with histological esophagitis and presence of H. pylori in the cardia.

CONCLUSIONS

Cardiac mucosa was uniformly present adjacent to the squamous epithelium at the EGJ. This argues against the hypothesis that the gastric cardia is an acquired metaplastic lesion. The presence of acid mucins was frequently observed and could be a pathological condition as it was associated with histological esophagitis and the presence of H. pylori in the cardia.

Metaplasia intestinal especializada de esôfago distal na doença do refluxo gastroesofágico: prevalência e aspectos clínico-epidemiológicos

RACIONAL: A metaplasia intestinal especializada pode ser classificada, de acordo com os achados endoscópicos e histológicos, em Barrett longo, Barrett curto e metaplasia intestinal da cárdia. O esôfago de Barrett é doença adquirida que ocorre em aproximadamente 10% a 13% dos indivíduos com doença do refluxo gastroesofágico e representa uma condição pré-neoplásica. É caracterizado por substituição do epitélio escamoso estratificado pelo metaplásico colunar especializado, contendo células caliciformes. OBJETIVOS: Determinar, prospectivamente, a prevalência e as características clínico-epidemiológicas da metaplasia intestinal especializada de esôfago distal na doença do refluxo gastroesofágico. MÉTODOS: Entre abril e outubro de 2002, 402 pacientes com sintomas da doença do refluxo gastroesofágico foram avaliados através de questionário padronizado que abordava as variáveis demográficas e foram submetidos a exame endoscópico com biopsias 1 cm abaixo da junção escamocolunar, nos quatro quadrantes. RESULTADOS: Metaplasia intestinal especializada foi encontrada em 18,4% dos pacientes: 0,5% Barrett longo, 3,2% Barrett curto e 14,7% metaplasia intestinal da cárdia. Houve tendência de maior número de homens apresentando esôfago de Barrett e mulheres com metaplasia intestinal da cárdia. Todos com esôfago de Barrett eram da raça branca. Não houve relação entre a intensidade dos sintomas da doença do refluxo gastroesofágico e a presença de metaplasia intestinal especializada. O tempo de duração de sintomas superior a 5 anos foi uma tendência nos portadores de esôfago de Barrett. Este grupo também apresentou mais hérnia de hiato e esofagite mais intensa do que aqueles com metaplasia intestinal da cárdia. Não houve relação entre uso de tabaco ou álcool e metaplasia intestinal especializada. CONCLUSÕES: Esôfago de Barrett foi mais relacionado ao sexo masculino, com sintomas de longa cronicidade, esofagite mais intensa e sem associação com tabaco ou álcool.

Role of cytology in the diagnosis of Barrett's esophagus and associated neoplasia

We studied 327 consecutive paired esophageal biopsies and brushing specimens obtained during the same endoscopic session to evaluate the role of cytology for the diagnosis of Barrett's esophagus (BE) and/or surveillance for associated dysplasia. A diagnosis of BE was based on the cytologic presence of goblet cells. Cases were reviewed and categorized into: 1) benign esophageal lesions (125 cases), with 48 cases of Candida (32 cases diagnosed by both techniques and 16 diagnosed only by cytology), 3 cases of herpes simplex with only 1 case diagnosed by cytology, and 74 cases of inflammation and/or repair; 2) benign BE (141 cases), with 74 cases (52%) diagnosed by both techniques, 11 cases by cytology only (8%), and 56 cases (40%) by histology only; 3) low-grade dysplasia (LGD, 30 cases), with 5 cases (17%) diagnosed with both specimens, one case (3%) by cytology only, and 24 cases (80%) by histology only; 4) high-grade dysplasia (HGD, 10 cases), with 8 cases (80%) diagnosed with both specimens, 1 case (10%) by cytology, and 1 case (10%) by histology; and 5) carcinomas (23 cases), with 20 cases (87%) diagnosed with both specimens, 2 cases (9%) by cytology only, and 1 case (4%) by histology only. Our results support the high degree of diagnostic accuracy of cytology for the diagnosis of Barrett's-associated HGD and/or carcinoma, and moderate sensitivity for BE.

Hepatocyte antigen as a marker of intestinal metaplasia

Intestinal metaplasia is a histologic hallmark of Barrett's esophagus and chronic gastritis. Intestinal metaplasia may progress to dysplasia or carcinomas without proper treatment. Most cases of intestinal metaplasia are easily recognized on hematoxylin and eosin-stained sections. However, some cases of intestinal metaplasia may be hard to recognize if they lack the characteristic mucin-producing cells and Paneth cells, or if they are small in size. Recently, keratin 7, keratin 20, and MUC2 expression patterns were reported to be useful in confirming the diagnosis of intestinal metaplasia. We studied hepatocyte (Hep) antigen (a hepatocellular antigen mainly expressing in normal and neoplastic hepatic tissues) in 33 cases of Barrett's esophagus (9 cases associated with esophageal adenocarcinoma) and 13 cases of chronic gastritis associated with intestinal metaplasia and gastric adenocarcinoma. Hep monoclonal antibody recognizes intestinal metaplasia in all cases. We also compared expression of Hep with that of keratin 7, keratin 20, and MUC2 in intestinal metaplasia. The specificity and sensitivity of Hep for intestinal metaplasia were higher than that of keratin 7 and keratin 20, or MUC2. We conclude that Hep may be used as a single diagnostic marker for intestinal metaplasia.

Primary adenocarcinomas of lower esophagus, esophagogastric junction and gastric cardia: in special reference to China

Gastric cardia adenocarcinoma (GCA) is an under-studied subject. The pathogenesis, molecular changes in the early stage of carcinogenesis and related risk factors have not been well characterized. There is evidence, however, that GCA differs from cancer of the rest of the stomach in terms of natural history and histopathogenesis. Adenocarcinomas of the lower esophagus, esophagogastric junction (EGJ) and gastric cardia have been given much attention because of their increasing incidences in the past decades, which is in striking contrast with the steady decrease in distal stomach adenocarcinoma. In China, epidemiologically, GCA shares very similar geographic distribution with esophageal squamous cell carcinoma (SCC), especially in Linzhou (formerly Linxian County), Henan Province, North China, the highest incidence area of esophageal SCC in the world. Historically, both GCA and SCC in these areas were referred to as esophageal cancer (EC) by the public because of the common syndrome of dysphagia. In Western countries, Barrett's esophagus is very common and has been considered as an important precancerous lesion of adenocarcinoma at EGJ. Because of the low incidence of Barrett's esophagus in China, it is unlikely to be an important factor in early stage of EGJ adenocarcinoma development. However, Z line up-growth into lower esophagus may be one of the characteristic changes in these areas in early stage of GCA development. Whether intestinal metaplasia (IM) is a premalignant lesion for GCA is still not clear. Higher frequency of IM observed at adjacent GCA tissues in Henan suggests the possibility of IM as a precancerous lesion for GCA in these areas. Molecular information on GCA, especially in early stage, is very limited. The accumulated data about the changes of tumor suppressor gene, such as p53 mutation, and ontogeny, such as C-erbB2, especially the similar alterations in GCA and SCC in the same patient, indicated that there might be some similar risk factors, such as nitrosamine, involved in both GCA and SCC in Henan population. The present observations also suggest that GCA should be considered as a distinct entity.

Barrett's esophagus and Barrett's carcinoma

The alarming rise in the incidence of esophageal adenocarcinomas in the Western world has focused interest on so-called Barrett's esophagus. Barrett's esophagus is characterized by specialized intestinal epithelium replacing the normal squamous epithelium in the distal esophagus and is considered a consequence of long-lasting and severe gastroesophageal reflux disease. A metaplasia-dysplasia-carcinoma sequence links Barrett's esophagus with adenocarcinoma of the distal esophagus (Barrett's cancer). Despite intensive research, many questions concerning the pathogenesis, diagnosis, and treatment of Barrett's esophagus and associated adenocarcinoma are still unanswered. Based on current data, the malignant progression of Barrett's esophagus cannot be substantially prevented by medical or surgical therapy for reflux. Although no firm data are available to show that surveillance strategies can reduce overall mortality from Barrett's cancer, early detection and cure are possible. Management of Barrett's esophagus and carcinoma is reviewed with reference to the sequence of disease from metaplasia to carcinoma.