Definition of Barrett's esophagus: time for a rethink--is intestinal metaplasia dead?

Low-grade dysplasia in Barrett's esophagus: A problematic diagnosis

Although low-grade dysplasia (LGD) in Barrett's esophagus (BE) is a histopathological diagnosis based on different histological abnormalities, it is still problematic for different reasons. Patients without confirmed diagnosis of LGD undergo unnecessary and intensified follow-up where the risk of progression is low in the majority of cases. In contrast, the presence of confirmed LGD indicates a high risk of progression. In this article we try to address these reasons focusing on re-confirmation of LGD diagnosis, interobserver agreement, and persistent confirmed LGD. The progression risk of LGD to high-grade dysplasia and esophageal adenocarcinoma will also be reviewed.

RISK OF PRENEOPLASTIC LESIONS IN MUCOSAL PROJECTIONS OF DIFFERENT SIZES OF THE COLUMNAR EPITHELIUM IN THE LOWER ESOPHAGUS

BACKGROUND

Barrett's esophagus is an acquired condition that predisposes to the development of esophageal adenocarcinoma.

AIMS

The aim of this study was to establish an association between the endoscopic and the histopathological findings regarding differently sized endoscopic columnar epithelial mucosa projections in the low esophagus, under 3.0 cm in the longitudinal extent.

METHODS

This is a prospective study, including 1262 patients who were submitted to upper gastrointestinal endoscopy in the period from July 2015 to June 2017. The suspicious projections were measured and subdivided into three groups according to the sizes encountered (Group I: <0.99 cm; Group II: 1.0-1.99 cm; and Group III: 2.0-2.99 cm), and biopsies were then performed.

RESULTS

There was a general prevalence of suspicious lesions of 6.42% and of confirmed Barrett's lesions of 1.17%, without a general significant statistical difference among groups. However, from Groups I and II to Group III, the differences were significant, showing that the greater the lesion, the higher the probability of Barrett's esophagus diagnosis. The absolute number of Barrett's lesions was 7, 9, and 6 for Groups I, II, and III, respectively.

CONCLUSIONS

The findings led to the conclusion that even projections under 3.0 cm present a similar possibility of evolution to Barrett's esophagus. If, on the one hand, short segments are more prevalent, on the other hand, the long segments have the higher probability of Barrett's esophagus diagnosis, which is why biopsies are required in all suspicious segments.

The path(ology) from reflux oesophagitis to Barrett oesophagus to oesophageal adenocarcinoma

This review seeks to summarise the steps in the path from reflux oesophagitis to Barrett oesophagus to oesophageal adenocarcinoma. The epidemiology, clinical presentation, definitions, pathological features, diagnostic pitfalls, and emerging concepts are reviewed for each entity. The histological features of reflux oesophagitis can be variable and are not specific. Cases of reflux oesophagitis with numerous eosinophils are difficult to distinguish from eosinophilic oesophagitis and other oesophagitides with eosinophils (Crohn's disease, medication effect, and connective tissue disorders). In reflux oesophagitis, the findings are often most pronounced in the distal oesophagus, the eosinophils are randomly distributed throughout the epithelium, and eosinophilic abscesses and degranulated eosinophils are rare. For reflux oesophagitis with prominent lymphocytes, clinical history and ancillary clinical studies are paramount to distinguish reflux oesophagitis from other causes of lymphocytic oesophagitis pattern. For Barrett oesophagus, the definition remains a hotly debated topic for which the requirement for intestinal metaplasia to make the diagnosis is not applied unanimously across the globe. Assessing for dysplasia is a challenging aspect of the histological interpretation that guides clinical management. We describe the histological features that we find useful in making this evaluation. Oesophageal adenocarcinoma has been steadily increasing in incidence and has a poor prognosis. The extent of invasion can be overdiagnosed due to a duplicated muscularis mucosae. We also describe the technical factors that can lead to challenges in distinguishing the mucosal and deep margins of endoscopic resections. Lastly, we give an overview of targeted therapies with emerging importance and the ancillary tests that can identify the cases best suited for each therapy.

Barrett's Esophagus and Intestinal Metaplasia

Intestinal metaplasia refers to the replacement of the differentiated and mature normal mucosal epithelium outside the intestinal tract by the intestinal epithelium. This paper briefly describes the etiology and clinical significance of intestinal metaplasia in Barrett’s esophagus. This article summarizes the impact of intestinal metaplasia on the diagnosis, monitoring, and treatment of Barrett’s esophagus according to different guidelines. We also briefly explore the basis for the endoscopic diagnosis of intestinal metaplasia in Barrett’s esophagus. The identification techniques of goblet cells in Barrett’s esophagus are also elucidated by some scholars. Additionally, we further elaborate on the current treatment methods related to Barrett’s esophagus.

Global prevalence of Barrett's oesophagus and oesophageal cancer in individuals with gastro-oesophageal reflux: a systematic review and meta-analysis

OBJECTIVES

Chronic gastro-oesophageal reflux might lead to the development of Barrett's oesophagus (BO) or even oesophageal adenocarcinoma. There has been no definitive systematic review and meta-analysis of data to estimate global prevalence of BO or oesophageal adenocarcinoma in individuals with gastro-oesophageal reflux.

DESIGN

We searched MEDLINE, Embase and Embase Classic to identify cross-sectional surveys that reported prevalence of BO or oesophageal adenocarcinoma in adults with gastro-oesophageal reflux. We extracted prevalence for all studies, both for endoscopically suspected and histologically confirmed cases. We calculated pooled prevalence according to study location, symptom frequency and sex, as well as ORs with 95% CIs.

RESULTS

Of the 4963 citations evaluated, 44 reported prevalence of endoscopically suspected and/or histologically confirmed BO. Prevalence of BO among individuals with gastro-oesophageal reflux varied according to different geographical regions ranging from 3% to 14% for histologically confirmed BO with a pooled prevalence of 7.2% (95% CI 5.4% to 9.3%), whereas pooled prevalence for endoscopically suspected BO was 12.0% (95% CI 5.5% to 20.3%). There was heterogeneity in many of our analyses. Prevalence of BO was significantly higher in men, both for endoscopically suspected (OR=2.1; 95% CI 1.6 to 2.8) and histologically confirmed BO (OR=2.3; 95% CI 1.7 to 3.2). Dysplasia was present in 13.9% (95% CI 8.9% to 19.8%) of cases of histologically confirmed BO, 80.7% of which was low-grade.

CONCLUSION

The prevalence of Barrett's oesophagus among individuals with gastro-oesophageal reflux varied strikingly among countries, broadly resembling the geographical distribution of gastro-oesophageal reflux itself. Prevalence of BO was significantly higher in men.

The complexity of cancer origins at the gastro-oesophageal junction

Chronic acid-biliary reflux and Helicobacter pylori infection are instrumental environmental drivers of cancer initiation and progression in the upper gastrointestinal tract. Remarkably, although these environmental carcinogens are quite dissimilar, the tumour progression cascade these carcinogens engender is highly comparable. For this reason, studies of malignant progression occurring at the anatomic borderland between the oesophagus and the stomach have traditionally lumped junctional adenocarcinomas with either oesophageal adenocarcinoma or gastric adenocarcinoma. Whilst studies have revealed remarkable epidemiological and genetic similarities of these cancers and their associated premalignant conditions, these works have also revealed some key differences. This highlights that further scientific effort demands a dedicated focus on the understanding of the cell-cell interaction between the epithelium and the local microenvironment in this anatomic region. We here review available evidence with regards to tumour progression occurring at the gastro-oesophageal junction and contrast it with available data on cancer evolution in the metaplastic oesophagus and distal stomach.

The indications for biopsy in routine upper gastrointestinal endoscopy

This review describes the indications and contraindications for endoscopic biopsy, in routine practice, of the upper gastrointestinal (GI) tract. We accept that this review provides grounds for controversy, as our stance in certain situations is counter to some national guidelines. Nevertheless, we provide evidence to support our viewpoints, especially on efficiency and economic grounds. We describe the particular controversies concerning the biopsy assessment of Barrett's oesophagus, chronic gastritis and the duodenum in the investigation of coeliac disease. We accept that there are indications for more extensive upper GI biopsy protocols in children than in adults; the latter constitute our main focus in this article. We would encourage detailed discussion between pathologists and their endoscopy colleagues about the indications, or lack of them, for routine upper GI endoscopic biopsy, as studies have shown that adherence to agreed guidelines has resulted in a very considerable diminution in the biopsy workload without compromising patient management. Furthermore, where biopsy is indicated, we emphasise the importance of accompanying clinical information provided to the pathologist, in particular regarding biopsy site(s), and regular feedback to endoscopists to improve and maintain the quality of such information. Finally, local dialogue is also advised, when necessary, to indicate to endoscopists the need to appropriately segregate biopsies into separate, individually labelled specimens, to maximise the information that can be derived by pathological evaluation and thereby improve the quality of the final pathology report.

Endoscopic features of esophageal adenocarcinoma derived from short-segment versus long-segment Barrett's esophagus

BACKGROUND AND AIM

The study aims to clarify the endoscopic features and clinicopathological differences in superficial Barret's esophageal adenocarcinoma (s-BEA) derived from short-segment Barrett's esophagus (SSBE) and long-segment Barrett's esophagus (LSBE).

METHODS

We reviewed data of 130 patients (141 lesions) with pathologically confirmed s-BEA (SSBE: 95 patients and 95 lesions; LSBE: 35 patients and 46 lesions). We analyzed endoscopic and clinicopathological features of s-BEA in patients with SSBE and LSBE.

RESULTS

The distribution of lesions according to macroscopic findings were as follows (s-BEA in SSBE vs LSBE): flat type (0-IIb), 3.2% (3/95) vs 32.6% (15/46) (P < 0.001); accompanied type 0-IIb, 2.1% (2/95) vs 21.7% (10/46) (P < 0.001); and complex type (0-I + IIb, 0-IIa + IIc, etc.), 30.5% (29/95) vs 50.0% (23/46) (P = 0.025). Complex-type s-BEAs had high incidences of T1b invasions and poorly differentiated components (simple type: 22.5% [20/89] and 18.0% [16/89]; complex type: 59.6% [31/52] and 44.2% [23/52], P < 0.001 and P = 0.002, respectively). In SSBE, 72.6% (69/95) of lesions were located at the right anterior wall (P = 0.01). All flat-type or depressed-type lesions derived from SSBE were identified as reddish areas, whereas only 65.2% (15/23) from LSBE were identified as reddish areas (P < 0.001).

CONCLUSIONS

In LSBE, flat-type, accompanied-type 0-IIb, and complex-type lesions were significantly more prevalent. Furthermore, complex-type s-BEAs tended to have T1b invasions and poorly differentiated components. S-BEAs in LSBE should be more carefully evaluated on endoscopic appearance including flat-type and complex-type lesions than in SSBE.

Evaluation and Management of Premalignant Conditions of the Esophagus: A Systematic Survey of International Guidelines

Esophageal cancer represents one of the most lethal forms of malignancy. The growing incidence of esophageal adenocarcinoma represents an emerging public health concern. This review article summarizes current diagnostic, management, and therapeutic practices of premalignant conditions of the esophagus including Barrett's esophagus, tylosis, granular cell tumors, achalasia, and the ingestion of caustic substances. Our report provides clinicians and academics with a global clinical perspective regarding presentation, surveillance guidelines, and therapeutic management of these esophageal conditions.

Histopathology of Barrett’s Esophagus and Early-Stage Esophageal Adenocarcinoma: An Updated Review

Esophageal adenocarcinoma carries a very poor prognosis. For this reason, it is critical to have cost-effective surveillance and prevention strategies and early and accurate diagnosis, as well as evidence-based treatment guidelines. Barrett’s esophagus is the most important precursor lesion for esophageal adenocarcinoma, which follows a defined metaplasia–dysplasia–carcinoma sequence. Accurate recognition of dysplasia in Barrett’s esophagus is crucial due to its pivotal prognostic value. For early-stage esophageal adenocarcinoma, depth of submucosal invasion is a key prognostic factor. Our systematic review of all published data demonstrates a “rule of doubling” for the frequency of lymph node metastases: tumor invasion into each progressively deeper third of submucosal layer corresponds with a twofold increase in the risk of nodal metastases (9.9% in the superficial third of submucosa (sm1) group, 22.0% in the middle third of submucosa (sm2) group, and 40.7% in deep third of submucosa (sm3) group). Other important risk factors include lymphovascular invasion, tumor differentiation, and the recently reported tumor budding. In this review, we provide a concise update on the histopathological features, ancillary studies, molecular signatures, and surveillance/management guidelines along the natural history from Barrett’s esophagus to early stage invasive adenocarcinoma for practicing pathologists.

Location of TEF at the carina as an indicator of long-gap C-type esophageal atresia

We analyzed retrospectively the outcomes in long gap Gross type C esophageal atresia. We hypothesized that outcomes in type C (long gap) atresia differ from type C (normal gap) and be similar with outcomes in Gross type A and B esophageal atresia. Location of the distal tracheoesophageal fistula (TEF) at the carina was chosen as the hallmark of type C atresia (long gap). We compared the type of esophageal repair, major reoperations for anastomotic complications and gastroesophageal reflux, and long-term mucosal changes between type C (normal gap), type C (long gap), and type A/B. We analyzed the hospital charts of 247 successive patients from 1984 to 2014 who either underwent repair of esophageal atresia in our institution (n = 232) or were referred from elsewhere because of anastomotic complications (n = 15). Among the 232 patients of our institution, 181 had type C and 21 type A or B esophageal atresia. Twenty-two (12%) of type C patients had TEF at the carina and were considered as type C (long gap). The referred patients included a disproportionately high number (42%) of patients with type C (long gap). We attempted primary anastomosis in 98% of patients with type C (normal gap), in 95% with type C (long gap), and 53% with type A/B underwent delayed primary anastomosis. Leakage after primary anastomosis occurred in 40% of patients with type A/B and in 23% with type C (long gap) compared with 6% in patients with type C (normal gap) (P < 0.05). Recalcitrant anastomotic stricture that eventually required esophageal resection occurred in 30% of patients with type A/B and in 18% with type C (long gap) compared with 3% in patients with type C (normal gap) (P < 0.05). The overall rate of major reoperations for anastomotic complications after primary anastomosis, type A/B (36%), type C (long gap) (27%), and antireflux surgery, type A/B (100%) and type C (long gap) (61%) were higher than in type C (normal gap), (9% and 24%), (P < 0.05 in both). Ten (47%) patients with type A/B esophageal atresia (primary anastomosis not possible n = 10), three (14%) with type C (long gap) (primary anastomosis not possible n = 1, significant loss of esophageal length after complications n = 2) and two (1%) with type C (normal gap) (significant loss of esophageal length after complications n = 2) underwent esophageal reconstruction. Endoscopic follow-up, median length 7.0 (IQR: 3.0-14) years, disclosed gastric metaplasia in 31% and 33% of patients with type A/B and type C (long gap) compared with 11% in type C (normal gap) (P < 0.05). Intestinal metaplasia was found in one patient type C (normal gap) (0.7%) and one with type C (long gap) (5.6%), (P = 0.21), only. The outcomes of type C (long gap) esophageal atresia are associated with more frequent complications, gastroesophageal reflux and esophageal mucosal changes than outcomes in type C (normal gap). Outcomes in type C (long gap) esophageal atresia resemble those in type A/B. The percentage of patients who remain with their native esophagus is, however, higher in type C (long gap) atresia (86%) than in type A/B (53%).

Histology of Barrett's Metaplasia: Do Goblet Cells Matter?

This review has provided a summary of the biology of goblet cell metaplasia in CLE as it pertains to BE. Goblet cells are terminally differentiated nonproliferative cells that have many overlapping histochemical characteristics with mucinous columnar cells and pseudogoblet cells. There is an abundance of evidence that suggests that use of goblet cells as a biomarker of BE, and its progression to malignancy, is problematic. Some of these limitations include the fact that the background non-goblet epithelium in most patients with CLE is biologically intestinalized and contains molecular abnormalities similar to goblet cell CLE, goblet cells fluctuate with time and decrease in number with progression of neoplasia, and pathologists have problems with interpretation, and distinction, of goblet cells from other types of cells in the esophagus. Sampling error results in sensitivity and specificity issues that limit its positive predictive value. Goblet cells are fewest in number in the same population of patients with CLE that are hardest to detect endoscopically (i.e., those with short or ultrashort CLE). Nevertheless, the risk of cancer in patients with short-segment BE, a condition difficult to distinguish from the stomach, is very low regardless of the presence or absence of goblet cells so it is unclear what the role of goblet cells is in these patients as a biomarker. Nevertheless, if the answer to the following question, "Would you as a gastroenterologist recommend surveillance for a patient with clear endoscopic evidence of CLE, particularly if it is ≥ 3 cm in length, but in which goblet cells were not reported to be present by the pathologist," is yes, then the US requirement for goblet cells as part of the criteria for "BE" is superfluous.

The metaplastic mosaic of Barrett's oesophagus

Barrett's oesophagus surveillance biopsies represent a significant share of the daily workload for a busy histopathology department. Given the emphasis on endoscopic detection and dysplasia grading, it is easy to forget that the benefits of these screening programs remain unproven. The majority of patients are at low risk of progression to oesophageal adenocarcinoma, and periodic surveillance of these patients is burdensome and costly. Here, we investigate the parallels in the development of Barrett's oesophagus and other scenarios of wound healing in the intestine. There is now increased recognition of the full range of glandular phenotypes that can be found in patients' surveillance biopsies, and emerging evidence suggests parallel pathways to oesophageal adenocarcinoma. Greater understanding of the conditions that favour progression to cancer in the distal oesophagus will allow us to focus resources on patients at increased risk.

Endoscopic and histopathologic reflux-associated mucosal damage in the remnant esophagus following transthoracic esophagectomy for cancer-5-year long-term follow-up

Gastroesophageal reflux is a common problem following esophagectomy and reconstruction with gastric interposition. Despite a routine prescription of proton pump inhibitors, reflux-associated mucosal damage in the remnant esophagus is frequently observed. Purpose of this study is to evaluate mucosal damage in the esophageal remnant during long-term follow-up and to compare the prevalence of this damage between the subgroups of esophageal squamous cell and adenocarcinoma. All patients undergoing transthoracic Ivor-Lewis esophagectomy were prospectively entered in our IRB approved database. All patients underwent a routine check-up program with yearly surveillance endoscopies following esophagectomy. Only patients with a complete follow-up were included into this study. Endoscopic and histopathologic mucosal changes of the remnant esophagus were analyzed in close intervals. A total of 50 patients met the inclusion criteria, consisting of 31 adenocarcinomas (AC) and 19 squamous cell carcinomas (SCC). Mucosal damage was already seen 1 year after surgery in 20 patients macroscopically (43%) and in 21 patients microscopically (45%). At 5-year follow-up the prevalence for macroscopic and microscopic damage was 55% and 60%, respectively. The prevalence of mucosal damage was higher in AC patients than in SCC patients (1y-FU: 51% [AC] vs. 28% [SCC]; 5y-FU: 68% [AC] vs. 35% [SCC], P < 0.05). Newly acquired Barrett's esophagus was seen in 10 patients (20%) with two of those patients (20%) showing histopathologic proof of neoplasia. This study shows a high prevalence of reflux-associated mucosal damage in the remnant esophagus one year out of surgery and only a moderate increase in prevalence in the following years. Mucosal damage was more frequently seen in AC patients and the occurrence of de-novo Barrett's esophagus and de-novo neoplasia was high. Endoscopic surveillance with targeted biopsies seems to be an indispensable tool to follow patients after esophagectomy appropriately.

Considering the esophagogastric junction as a 'zone'

Siewert's classification of adenocarcinoma of the esophagogastric junction (EGJ) classifies tumors anatomically for determining the appropriate surgical technique. According to this classification, a type II tumor, true carcinoma of the cardia, is defined as a cancer within 1 cm proximal to 2 cm distal of the EGJ. Histological analysis indicates that the cardiac gland is present with a high degree of frequency between 1-2 cm to the gastric side and 1-2 cm to the esophageal side of the EGJ, which means that this zone can be considered as neither the stomach nor the esophagus but rather as a third zone known as the 'EGJ zone'. It has been suggested that there are multiple causes for development of adenocarcinoma in the EGJ zone. The TNM Classification of Malignant Tumours 7th Edition considers EGJ adenocarcinoma (EGJAC) occurring in the EGJ zone to be a part of esophageal adenocarcinoma (EAC). However, recent studies have indicated that EGJAC behaves differently from EAC and gastric carcinoma. Barrett's esophagus is now considered an important factor in the etiology of EGJAC, but, as yet, no studies have elucidated the differences between cancer arising from short-segment Barrett's esophagus and cancer of the gastric cardia. Thus, there is currently no clinical relevance to subdivision of adenocarcinoma in the EGJ zone into above or below the EGJ line.

The importance of a second opinion in the diagnosis of Barrett's esophagus: a "real life" study

BACKGROUND

Barrett's esophagus is a precancerous lesion, and its identification with the early detection of dysplasia is of paramount importance to prevent adenocarcinoma onset. However, there is still debate on the correct pathological identification of Barrett's esophagus (and of associated dysplasia), and most studies have been conducted in an experimental setting.

AIMS

To assess previous uncertain diagnoses of Barrett's (with and without dysplasia) via a second opinion of an expert pathologist in a real life setting.

PATIENTS AND METHODS

Histological sections of 32 suspected Barrett's patients from ten general Pathology units were centralized into one single unit in which an expert pathologist reviewed the slides blindly.

RESULTS

Overall, in 78% of cases there was diagnostic discordance; in particular, in 64% of cases the presence of low grade dysplasia was not confirmed. Of interest, 28% of cases with the original diagnosis were reclassified as non-Barrett's.

CONCLUSIONS

The pathological diagnosis of Barrett's esophagus, especially with regard to the presence of dysplasia, is still misinterpreted, particularly in the setting of general Pathology units. Thus, a second opinion from an experienced pathologist may help in the interpretation of the results and in starting appropriate follow-up programs.

Evolving management of metaplasia and dysplasia in Barrett's epithelium

Oesophageal cancer affects more than 450000 people worldwide and despite continued medical advancements the incidence of oesophageal cancer is increasing. Oesophageal cancer has a 5 year survival of 15%-25% and now globally attempts are made to more aggressively diagnose and treat Barrett's oesophagus the known precursor to invasive disease. Currently diagnosis the of Barrett's oesophagus is predominantly made after endoscopic visualisation and histopathological confirmation. Minimally invasive techniques are being developed to improve the viability of screening programs. The management of Barrett's oesophagus can vary greatly dependent on the presence and severity of dysplasia. There is no consensus between the major international medical societies to determine and agreed surveillance and intervention pathway. In this review we analysed the current literature to demonstrate the evolving management of metaplasia and dysplasia in Barrett's epithelium.

Goblet Cell Ratio in Combination with Differentiation and Stem Cell Markers in Barrett Esophagus Allow Distinction of Patients with and without Esophageal Adenocarcinoma

The increasing incidence of esophageal adenocarcinoma (EAC) is mirrored by the increasing prevalence of Barrett esophagus, a precursor lesion resulting in a large number of individuals "at risk" for this lethal malignancy. Among patients with Barrett esophagus, only about 0.3% annually will develop EAC. Because large numbers of patients are followed in endoscopic surveillance, there is a need for risk prediction among a growing population of patients with Barrett esophagus. We identified four potential biomarkers from an inflammation (IL1β)-dependent mouse model of Barrett esophagus and tested them in 189 patients with Barrett esophagus with and without high-grade dysplasia (HGD)/early cancer (T1). The primary goal was to distinguish patients with Barrett esophagus with no evidence of dysplasia from those with dysplasia. Increasing stem cell marker LGR5 and niche cell marker DCLK1 and decreasing differentiation marker (secretory mucus cells, TFF2⁺ cells) correlated with elevated tumor score in the mouse. Having outlined the origin of those markers in the Barrett esophagus mouse model, we showed the applicability for human Barrett esophagus. We compared 94 patients with nondysplastic Barrett esophagus tissue with 95 patients with Barrett esophagus and HGD or early cancer. Low levels of TFF2 (AUC 87.2%) provided the best discrimination between nondysplastic Barrett esophagus and Barrett esophagus with cancer, followed by high levels of DCLK1 (AUC 83.4%), low goblet cell ratio (AUC 79.4%), and high LGR5 (AUC 71.4%). The goblet cell ratio, rather than the presence of goblet cells per se, was found to be an important discriminator. These findings may be useful in developing future risk prediction models for patients with Barrett esophagus and ultimately to improve EAC surveillance. Cancer Prev Res; 10(1); 55-66. ©2016 AACR.

Diagnosis and Surveillance of Barrett's Esophagus: Addressing the Transatlantic Divide

BACKGROUND

Barrett's esophagus is a premalignant condition of the esophagus leading to esophageal adenocarcinoma. No consensus exists between the UK and USA concerning the diagnosis of Barrett's esophagus. Although the diagnostic procedure is common, the required findings and diagnostic criteria vary. Both guidelines require endoscopy showing columnar epithelia lining the esophagus, but the US guidelines require the additional finding of intestinal metaplasia on biopsy to confirm diagnosis. Achievement of a consensus is of particular importance due to the established progression from Barrett's esophagus to esophageal adenocarcinoma. Of further importance is the increasing incidence of esophageal adenocarcinoma, a condition with poor overall survival, leading to various opinions on the utility of surveillance in patients.

DISCUSSION

A review of the vast array of literature revealed that substantial evidence exists in favor of both diagnostic criteria; hence, there is no easy way to identify the "correct" method of diagnosing Barrett's esophagus. USA recommends surveillance of Barrett's esophagus, whereas UK does not advocate it unless dysplasia is present. Surveillance was found to be effective, but this varied as did cost-effectiveness. Further research into diagnostic methods for Barrett's esophagus is needed to address areas of limited understanding, such that agreement can be reached and practice standardized. Surveillance was generally advocated, but with different criteria and time intervals, and new methods are being evaluated.

Update on management of Barrett's esophagus

Barrett's esophagus (BE) is a common condition that develops as a consequence of gastroesophageal reflux disease. The significance of Barrett's metaplasia is that predisposes to cancer development. This article provides a current evidence-based review for the management of BE and related early neoplasia. Controversial issues that impact the management of patients with BE, including definition, screening, clinical aspects, diagnosis, surveillance, and management of dysplasia and early cancer have been assessed.

Endoscopic Surveillance After Repair of Oesophageal Atresia: Longitudinal Study in 209 Patients

AIM

After repair of oesophageal atresia (OA), the need for endoscopic follow-up (EFU) remains unclear. To end this, we assessed the trends of oesophageal mucosal changes in successive follow-up biopsies.

METHODS

EFU records of 264 patients including histological grades of oesophagitis (from 0 to III), gastric (GM) or intestinal (IM) metaplasia and dysplasia (mild to severe) at 1, 3, 5 10, 15, and >15 years after repair of OA were reviewed.

RESULTS

Included were 209 patients with 616 biopsies. A total of 60 patients had undergone antireflux surgery and 24 had long-gap OA (LG). Median follow-up was 12 (range 1-17) years with 3 (1-6) endoscopies per patient. Highest grade of oesophagitis was Gr 0 (no oesophagitis) in 47%, Gr I in 37%, and Gr II or III in 16%. Metaplasia, GM (n = 31), IM (n = 4), occurred in 17% of patients and reached 15% prevalence by 15 years. Dysplasia and cancer were not found. From 1 to 15 years after repair grade of histological oesophagitis often fluctuated between Gr 0 and Gr I, but further progression was unlikely, hazard ratio = 0.2-3.4 (95% confidence interval 0.0-29), P = 0.06-0.87. LG and antireflux surgery predicted early detection of metaplasia (P < 0.001). Only 9% of patients with metaplasia and 32% with Gr II oesophagitis were symptomatic. A total of 6 (3%) patients had a symptomatic anastomotic stenosis at 1 year.

CONCLUSIONS

EFU revealed frequent oesophagitis and metaplasia, but no dysplasia or cancer. Routine endoscopic surveillance had limited benefit and seems unnecessary during childhood after repair of OA.

Definition of Barrett's esophagus dysplasia: are we speaking the same language?

The definition of Barrett's esophagus (BE) is still a matter of debate. The diagnostic criteria adopted around the world for both BE and BE-related pre-cancerous lesions are inconsistent, particularly between Eastern and Western pathologists. From a clinical perspective, these different clinico-biological approaches may affect how the literature is interpreted, with detrimental effects on the clinical management of patients. The present review focuses on the major discrepancies in the field, covering both the non-neoplastic and the pre-cancerous lesions associated with Barrett's disease.

Biopsies in Gastrointestinal Endoscopy: When and How

Gastrointestinal endoscopy and the acquisition of tissue samples are essential for the diagnosis and treatment of various diseases of the digestive system. However, given the differences between the recommendations and the clinical practice, the inexorable increase of requests for endoscopic examinations and the financial burden associated with it, it is crucial that we concentrate on the challenge that endoscopic biopsies represent. In this review we describe the available evidence in the literature, including the more recent published guidelines, on when or not to perform endoscopic biopsies in upper and lower endoscopy, focusing on the precise diagnosis of the most common gastrointestinal diseases that motivate endoscopic examinations and on the rational use of available resources without compromising proper management of patients.

High Goblet Cell Count Is Inversely Associated with Ploidy Abnormalities and Risk of Adenocarcinoma in Barrett's Esophagus

Purpose

Goblet cells may represent a potentially successful adaptive response to acid and bile by producing a thick mucous barrier that protects against cancer development in Barrett's esophagus (BE). The aim of this study was to determine the relationship between goblet cells (GC) and risk of progression to adenocarcinoma, and DNA content flow cytometric abnormalities, in BE patients.

Experimental Design

Baseline mucosal biopsies (N=2988) from 213 patients, 32 of whom developed cancer during the follow up period, enrolled in a prospective dynamic cohort of BE patients were scored in a blinded fashion, for the total number (#) of GC, mean # of GC/crypt (GC density), # of crypts with ≥ 1 GC, and the proportion of crypts with ≥1 GC, in both dysplastic and non-dysplastic epithelium separately. The relationship between these four GC parameters and DNA content flow cytometric abnormalities and adenocarcinoma outcome was compared, after adjustment for age, gender, and BE segment length.

Results

High GC parameters were inversely associated with DNA content flow cytometric abnormalities, such as aneuploidy, ploidy >2.7N, and an elevated 4N fraction > 6%, and with risk of adenocarcinoma. However, a Kaplan-Meier analysis showed that the total # of GC and the total # crypts with ≥1 GC were the only significant GC parameters (p<0.001 and 0.003, respectively).

Conclusions

The results of this study show, for the first time, an inverse relationship between high GC counts and flow cytometric abnormalities and risk of adenocarcinoma in BE. Further studies are needed to determine if GC depleted foci within esophageal columnar mucosa are more prone to neoplastic progression or whether loss of GC occurs secondary to underlying genetic abnormalities.

The changing role of the pathologist in the management of Barrett's oesophagus

Pathological specimens from columnar-lined oesophagus (CLO) comprise a considerable proportion of the workload of gastrointestinal pathologists in Western countries. There remain controversies concerning the diagnostic role of pathology. More recently, in the UK at least, the diagnosis has been regarded as primarily an endoscopic endeavour, with pathology being corroborative and only diagnostic when endoscopic features are equivocal or when there are additional features that make the endoscopic diagnosis unclear. There is also recognition that demonstration of intestinalisation or 'goblet cells' is not paramount, and should not be required for the diagnosis. There have been notable changes in the management of CLO neoplasia: pathologists are centrally involved in its management. Pathological assessment of endoscopic mucosal resection (EMR) specimens provides the most useful means of determining the management of early neoplasia and of determining indications for surgery. This represents an extraordinarily rapid change in management, in that, <10 years ago, laborious Seattle-type biopsy protocols were recommended, and high grade dysplasia was an indication for resectional surgery. Now, individual patient management is paramount: multi-professional meetings determine management after biopsy and EMR assessment. One significant change is that major resections are undertaken less often, in Western countries, for CLO neoplasia.

Barrett's esophagus: recent insights into pathogenesis and cellular ontogeny

Esophageal adenocarcinoma (EAC) has increased 6-fold in its incidence in the last 2 decades. Evidence supports the hypothesis of stepwise progression from normal squamous epithelium → reflux esophagitis → metaplasia (Barrett's esophagus, BE) → dysplasia → adenocarcinoma. The precursor, BE, stands as the bridge connecting the widespread but naive reflux disease and the rare but fatal EAC. The step of metaplasia from squamous to intestine-like columnar phenotype is perhaps pivotal in promoting dysplastic vulnerability. It is widely accepted that chronic inflammation because of gastroesophageal reflux disease leads to the development of metaplasia, however the precise molecular mechanism is yet to be discovered. Additionally, how this seemingly adaptive change in the cellular phenotype promotes dysplasia remains a mystery. This conceptual void is deterring further translational research and clouding clinical decision making. This article critically reviews theories on the pathogenesis of Barrett's esophagus and the various controversies surrounding its diagnosis. We further discuss unanswered questions and future directions, which are vital in formulating effective preventive and therapeutic guidelines for Barrett's esophagus.

BOB CAT: A Large-Scale Review and Delphi Consensus for Management of Barrett's Esophagus With No Dysplasia, Indefinite for, or Low-Grade Dysplasia

OBJECTIVES

Barrett's esophagus (BE) is a common premalignant lesion for which surveillance is recommended. This strategy is limited by considerable variations in clinical practice. We conducted an international, multidisciplinary, systematic search and evidence-based review of BE and provided consensus recommendations for clinical use in patients with nondysplastic, indefinite, and low-grade dysplasia (LGD).

METHODS

We defined the scope, proposed statements, and searched electronic databases, yielding 20,558 publications that were screened, selected online, and formed the evidence base. We used a Delphi consensus process, with an 80% agreement threshold, using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to categorize the quality of evidence and strength of recommendations.

RESULTS

In total, 80% of respondents agreed with 55 of 127 statements in the final voting rounds. Population endoscopic screening is not recommended and screening should target only very high-risk cases of males aged over 60 years with chronic uncontrolled reflux. A new international definition of BE was agreed upon. For any degree of dysplasia, at least two specialist gastrointestinal (GI) pathologists are required. Risk factors for cancer include male gender, length of BE, and central obesity. Endoscopic resection should be used for visible, nodular areas. Surveillance is not recommended for <5 years of life expectancy. Management strategies for indefinite dysplasia (IND) and LGD were identified, including a de-escalation strategy for lower-risk patients and escalation to intervention with follow-up for higher-risk patients.

CONCLUSIONS

In this uniquely large consensus process in gastroenterology, we made key clinical recommendations for the escalation/de-escalation of BE in clinical practice. We made strong recommendations for the prioritization of future research.

Barrett's oesophagus diagnostic criteria: endoscopy and histology

This review summarizes the endoscopic and histologic features of Barrett's oesophagus(BO) as well as some of the recent advancements and controversies. BO represents metaplastic conversion of normal squamous epithelium of tubular oesophagus to columnar epithelium. The diagnosis of BO requires a combination of endoscopic and histopathologic findings. There is worldwide controversy regarding the exact definition of BO, particularly with regard to the requirement to histologically identify goblet cells in biopsies. The presence and detectability of goblet cells might vary depending on a variety of factors and is subject to sampling error. Therefore, a systematic biopsy sampling with sufficient number of biopsies is currently recommended to limit the likelihood of a false negative result for detection of goblet cells. There are both endoscopic and pathologic challenges in evaluating gastro-oesophageal junction biopsies in patients with irregular Z lines to determine the exact location of the sample (i.e., oesophagus versus stomach). Recently, several novel endoscopic techniques have been developed to improve BO detection. However, none have been validated yet in clinical practice. The surveillance of patients with BO relies on histologic evaluation of dysplasia. However, there are significant pathologic limitations and diagnostic variability in evaluating the presence and grading of BO dysplasia, particularly with regard to the more recently recognized non-intestinal types of dysplasia. All BO dysplasia samples should be reviewed by an expert gastrointestinal pathologist to confirm the diagnosis. Finally, it is important to emphasize that close interaction between gastroenterologists and pathologists is essential to ensure proper evaluation of endoscopic biopsies in order to optimize the surveillance and clinical management of patients with BO.

Current issues in Barrett's esophagus and Barrett's-related dysplasia

Surgical pathologists frequently encounter biopsies in patients with Barrett's esophagus (BE), defined as replacement of the normal stratified squamous epithelium of the distal esophagus by metaplastic columnar epithelium containing goblet cells. Thus, one of the primary roles of the pathologist is to definitively identify goblet cells, best done on routine stained sections. It has recently been questioned as to whether goblet cells should be absolutely necessary to render a diagnosis of BE, given immunohistochemical and flow cytometric similarities between columnar-lined esophagus with and without goblet cells. Once a diagnosis of BE is rendered, the pathologist must state, using a simple classification, whether the biopsy is negative for dysplasia or shows dysplasia (low-grade dysplasia or high-grade dysplasia). However, there are a number of known pitfalls in distinguishing dysplasia from reactive epithelium, and it can be similarly difficult to distinguish low-grade dysplasia from high-grade dysplasia. In addition, there are some cases in which the distinction of high-grade dysplasia from intramucosal adenocarcinoma can be challenging. All of these issues are summarized in this paper.

The Barrett's Gland in Phenotype Space

Barrett's esophagus is characterized by the erosive replacement of esophageal squamous epithelium by a range of metaplastic glandular phenotypes. These glandular phenotypes likely change over time, and their distribution varies along the Barrett's segment. Although much recent work has addressed Barrett's esophagus from the genomic viewpoint-its genotype space-the fact that the phenotype of Barrett's esophagus is nonstatic points to conversion between phenotypes and suggests that Barrett's esophagus also exists in phenotype space. Here we explore this latter concept, investigating the scope of glandular phenotypes in Barrett's esophagus and how they exist in physical and temporal space as well as their evolution and their life history. We conclude that individual Barrett's glands are clonal units; because of this important fact, we propose that it is the Barrett's gland that is the unit of selection in phenotypic and indeed neoplastic progression. Transition between metaplastic phenotypes may be governed by neutral drift akin to niche turnover in normal and dysplastic niches. In consequence, the phenotype of Barrett's glands assumes considerable importance, and we make a strong plea for the integration of the Barrett's gland in both genotype and phenotype space in future work.

Barrett oesophagus: lessons on its origins from the lesion itself

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

Evaluation of human tissue kallikrein-related peptidases 6 and 10 expression in early gastroesophageal adenocarcinoma

Kallikreins are a family of serine proteases that are linked to malignancy of different body organs with potential clinical utility as tumor markers. In this study, we investigated kallikrein-related peptidase 6 (KLK6) and KLK10 expression in early gastroesophageal junction adenocarcinoma and Barrett esophagus (BE) with and without dysplasia. Immunohistochemistry revealed significantly increased KLK6 expression in early invasive cancer compared with dysplastic (P = .009) and nondysplastic BE (P = .0002). There was a stepwise expression increase from metaplasia to dysplasia and invasive tumors. Significantly higher KLK10 was seen in dysplastic lesions compared with metaplasia but not between dysplastic lesions and invasive cancers. KLK6 staining intensity was increased at the invasive front (P = .006), suggesting its role in tumor invasiveness. Neither KLK6 nor KLK10 was significantly associated with other prognostic markers, including depth of invasion, indicating their potential as independent biomarkers. Our results should be interpreted with caution due to limited sample size. There was a significant correlation between KLK6 and KLK10 expression both at the invasive front and within the main tumor, indicating a collaborative effect. We then compared KLK6 and KLK10 messenger RNA expression between metaplastic and cancerous tissues in an independent data set of esophageal carcinoma from The Cancer Genome Atlas. KLK6 and KLK10 may be useful markers and potential therapeutic targets in gastroesophageal junction tumors.

Is It Barrett's Esophagus or Gastric Heterotopia?

Columnar epithelium in the distal part of the esophagus is generally related to Barrett's esophagus. Barrett's esophagus is a well-known premalignant lesion for adenocarcinoma of the esophagus. Therefore, its diagnosis and surveillance are important. Columnar epithelium in the esophagus other than Barrett's esophagus can be gastric heterotopia, which generally takes place in the upper part of the esophagus and is named inlet patch. The presence of gastric metaplasia in the distal part of the esophagus is rare and can cause misdiagnosis. Therefore, its differentiation from Barrett's esophagus is important. Here we present a case of gastric heterotopia located in the distal part of the esophagus that caused reflux-like symptoms and needed differentiation from Barrett's esophagus.

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.

Comparison of cancer-associated genetic abnormalities in columnar-lined esophagus tissues with and without goblet cells

OBJECTIVE

To determine and compare the frequency of cancer-associated genetic abnormalities in esophageal metaplasia biopsies with and without goblet cells.

BACKGROUND

Barrett's esophagus is associated with increased risk of esophageal adenocarcinoma (EAC), but the appropriate histologic definition of Barrett's esophagus is debated. Intestinal metaplasia (IM) is defined by the presence of goblet cells whereas nongoblet cell metaplasia (NGM) lacks goblet cells. Both have been implicated in EAC risk but this is controversial. Although IM is known to harbor genetic changes associated with EAC, little is known about NGM. We hypothesized that if NGM and IM infer similar EAC risk, then they would harbor similar genetic aberrations in genes associated with EAC.

METHODS

Ninety frozen NGM, IM, and normal tissues from 45 subjects were studied. DNA copy number abnormalities were identified using microarrays and fluorescence in situ hybridization. Targeted sequencing of all exons from 20 EAC-associated genes was performed on metaplasia biopsies using Ion AmpliSeq DNA sequencing.

RESULTS

Frequent copy number abnormalities targeting cancer-associated genes were found in IM whereas no such changes were observed in NGM. In 1 subject, fluorescence in situ hybridization confirmed loss of CDKN2A and amplification of chromosome 8 in IM but not in a nearby NGM biopsy. Targeted sequencing revealed 11 nonsynonymous mutations in 16 IM samples and 2 mutations in 19 NGM samples.

CONCLUSIONS

This study reports the largest and most comprehensive comparison of DNA aberrations in IM and NGM genomes. Our results show that IM has a much higher frequency of cancer-associated mutations than NGM.

Guidance on the effective use of upper gastrointestinal histopathology

Given the ever-increasing demand for upper gastrointestinal endoscopy, for diagnosis and surveillance, there is a need to consider when it is appropriate, and when it is not appropriate, to take an endoscopic biopsy for histological evaluation. In this article, we consider this in relation to each of the anatomical compartments encountered during oesophagogastroduodenoscopy, and in relation to the common clinical scenarios and endoscopic abnormalities encountered. There are clear indications to biopsy suspicious ulceration or mass lesions and for investigation of some inflammatory conditions, such as eosinophilic oesophagitis and coeliac disease. Increasing guidance is available on optimal biopsy sites and biopsy numbers to maximise yield from histology. Outside these areas, the endoscopist should consider whether biopsy of normal or abnormal appearing mucosa is likely to contribute to patient management, to ensure effective use of limited healthcare resources.

Barrett esophagus: diagnostic challenges

The incidence of esophageal adenocarcinoma and associated mortality has risen dramatically over the past several decades, and, thus, it is increasingly important to understand its pathogenesis and risk factors. Barrett esophagus is the established precursor to esophageal adenocarcinoma that progresses through a metaplasia-dysplasia-carcinoma sequence. Its risk of transforming to carcinoma is not as high as previously reported and there appears to be a biological heterogeneity among patients with this disease. The overall prevalence of Barrett esophagus in the United States ranges from 1% to 25% and is closer to 5% in patients with gastroesophageal reflux disease. Because of the frequency of Barrett esophagus and associated implications, it is important for the practicing pathologist to have a thorough understanding of this disease and its diagnostic pitfalls. In this review, we will discuss issues associated with the diagnosis of Barrett esophagus, including the definition of Barrett esophagus and its distinction from carditis with intestinal metaplasia. We will also discuss challenges in the grading of dysplasia and new variants of dysplasia, including crypt dysplasia and foveolar-type dysplasia. Finally, we will touch upon the evaluation of dysplasia in endoscopic mucosal resection specimens.

Histopathology in barrett esophagus and barrett esophagus-related dysplasia

Pathologic specimens, both biopsies and endoscopic mucosal resections, for Barrett esophagus and Barrett-associated dysplasia and malignancy are common for pathologists in North America, and the incidence in South Asian countries seems to be increasing. Dysplasia and malignancy arising in intestinalized gastric-type mucosa raises issues in the interpretation of dysplasia and the evaluation of the depth of invasion of malignancies that are not seen in squamous dysplasia and squamous cell carcinoma. We review the North American approach to these lesions.

British Society of Gastroenterology guidelines on the diagnosis and management of Barrett's oesophagus

These guidelines provide a practical and evidence-based resource for the management of patients with Barrett's oesophagus and related early neoplasia. The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument was followed to provide a methodological strategy for the guideline development. A systematic review of the literature was performed for English language articles published up until December 2012 in order to address controversial issues in Barrett's oesophagus including definition, screening and diagnosis, surveillance, pathological grading for dysplasia, management of dysplasia, and early cancer including training requirements. The rigour and quality of the studies was evaluated using the SIGN checklist system. Recommendations on each topic were scored by each author using a five-tier system (A+, strong agreement, to D+, strongly disagree). Statements that failed to reach substantial agreement among authors, defined as >80% agreement (A or A+), were revisited and modified until substantial agreement (>80%) was reached. In formulating these guidelines, we took into consideration benefits and risks for the population and national health system, as well as patient perspectives. For the first time, we have suggested stratification of patients according to their estimated cancer risk based on clinical and histopathological criteria. In order to improve communication between clinicians, we recommend the use of minimum datasets for reporting endoscopic and pathological findings. We advocate endoscopic therapy for high-grade dysplasia and early cancer, which should be performed in high-volume centres. We hope that these guidelines will standardise and improve management for patients with Barrett's oesophagus and related neoplasia.

Carcinogenesis of Barrett's esophagus: a review of the clinical literature

Barrett's esophagus (BE) is a premalignant condition of esophageal adenocarcinoma (EAC). Although the incidence of BE has risen rapidly in the West, it is rare in Asia despite a recent increase in the prevalence of gastroesophageal reflux disease. Controversies over the definition of BE are presented because most cases show short-segment BE, especially ultra-short BE, in Asia. Here we review possible risk factors for the development of EAC, particularly possible roles of ethnicity, specialized intestinal metaplasia (SIM), BE length, and environmental factors, such as Helicobacter pylori infection and obesity. Additionally, we summarize recent studies on the effect of chemoprevention including proton pump inhibitors, nonsteroidal anti-inflammatory drugs or aspirin in order to reduce the risk of neoplastic progression in BE patients. Although substantial knowledge of risk factors of dysplasia/EAC in BE is shown, the risk for neoplastic development may be influenced by geographic variation, study population, the presence or absence of SIM or dysplasia at baseline, and the small number of BE patients investigated. Recently, the efficiency of surveillance for BE patients has been discussed from the standpoint of cost-effectiveness. It may be too difficult to draw conclusions because no randomized clinical trials of BE surveillance have been performed.

Reduced expression of αGlcNAc in Barrett's oesophagus adjacent to Barrett's adenocarcinoma--a possible biomarker to predict the malignant potential of Barrett's oesophagus

AIMS

Gastric gland mucin contains O-glycans exhibiting terminal α1,4-linked N-acetylglucosamine residues (αGlcNAc). Recently we demonstrated that mice deficient in αGlcNAc in gastric gland mucin develop gastric adenocarcinoma spontaneously, indicating that αGlcNAc is a tumour suppressor for gastric cancer. However, the role of αGlcNAc in Barrett's oesophagus (BO) remains unknown. In this study, we investigated whether reduced αGlcNAc expression in BO is associated with development of Barrett's adenocarcinoma (BAC).

METHODS AND RESULTS

Thirty-five BO lesions adjacent to BAC were examined by immunohistochemistry for αGlcNAc, MUC6 and CDX2. As controls, 35 BO lesions without BAC obtained from patients with oesophageal squamous cell carcinoma were also analysed. Expression of αGlcNAc relative to its scaffold MUC6 in BO adjacent to BAC was reduced significantly compared to control BO. Decreased αGlcNAc expression in BO adjacent to BAC was particularly significant in patients with smaller tumour size (<20 mm) and minimal invasion of tumour cells to the superficial muscularis mucosae. There was also a significant inverse correlation between αGlcNAc and CDX2 expression in BO adjacent to BAC.

CONCLUSIONS

Decreased expression of αGlcNAc compared with MUC6 in BO is a possible hallmark in predicting BAC development.

MicroRNA Expression Profiling in the Histological Subtypes of Barrett's Metaplasia

OBJECTIVES:

The histological definition of Barrett's esophagus (BE) is debated, particularly regarding the phenotype of its metaplastic columnar epithelium. Histologically proven intestinal metaplasia (IM) was the sine qua non condition for a diagnosis of BE but, more recently, non-intestinalized (i.e., cardiac gastric-type; GM) columnar metaplasia has been re-included in the spectrum of Barrett's histology. MicroRNAs modulate cell commitment, and are also reportedly dysregulated in Barrett's carcinogenesis. This study investigates miRNA expression in the histological spectrum of esophageal columnar metaplastic changes, specifically addressing the biological profile of GM vs. IM.

METHODS:

A study was performed to discover microRNA microarray in 30 matching mucosa samples obtained from 10 consecutive BE patients; for each patient, biopsy tissue samples were obtained from squamous, GM and intestinalized epithelium. Microarray findings were further validated by qRT-PCR analysis in another bioptic series of 75 mucosa samples.

RESULTS:

MicroRNA profiling consistently disclosed metaplasia-specific microRNA signatures. Six microRNAs were significantly dysregulated across the histological phenotypes considered; five of them (two overexpressed (hsa-miR-192; -miR-215) and three under-expressed (hsa-miR-18a* -miR-203, and -miR-205)) were progressively dysregulated in the phenotypic sequence from squamous to gastric-type, to intestinal-type mucosa samples.

CONCLUSIONS:

A consistent microRNA expression signature underlies both gastric- and intestinal-type esophageal metaplasia. The pattern of microRNA dysregulation suggests that GM may further progress to IM. The clinico-pathological implications of these molecular profiles prompt further study on the “personalized” cancer risk associated with each of these metaplastic transformations.

Esophageal atresia: metaplasia, Barrett

Barrett's esophagus is characterized by the replacement of squamous epithelium by columnar epithelium that is intestinal metaplasia-positive or -negative in the distal esophagus. Gastroesophageal reflux disease, which is frequent and prolonged in esophageal atresia, probably plays a major role in the development of Barrett's esophagus through repeated mucosal damage. Long-term acid exposure contributes to carcinogenesis in Barrett's esophagus of intestinal type, but its effect on gastric metaplasia is less well defined. Recent studies have suggest that metaplasia arises in about 15% of patients with esophageal atresia, with a lag time to developing metaplasia from initial surgical correction of about 10 years. Preliminary data from an ongoing multicenter study including 88 patients with esophageal atresia aged 15-19 years showed gastric metaplasia in 42% of patients (29 fundic and 7 cardial metaplasia), while one patient presented intestinal metaplasia. Esophageal mucosal abnormalities can be observed in esophageal atresia patients at endoscopy despite the absence of symptoms. Whether prolonged, aggressive, acid suppression is beneficial in these situations remains to be determined. Barrett's metaplasia can be removed by endoscopic mucosal resection or destroyed with endoscopic ablative techniques, such as photodynamic therapy, radiofrequency ablation, and cryotherapy. The risk of developing esophageal carcinoma is still a controversial issue as only a few clinical cases have been reported in young adults with esophageal atresia. As late complications of esophageal atresia, particularly esophagitis and Barrett's esophagus, are increasingly being recognized, long-time systematic follow up of the esophageal mucosa including multistage biopsies is therefore required even in asymptomatic patients.

Predictable Marker for Regression of Barrett's Esophagus by Proton Pump Inhibitor Treatment in Korea

Background/Aims

There has been no report regarding the regression of Barrett's esophagus (BE) by continuous treatment of proton pump inhibitor (PPI). The aim of this study was to determine the regression rate of BE by PPI and predictable markers related to regression.

Methods

Thirty-five patients diagnosed as BE were consecutively enrolled and most of them took continuous PPI. The 25 patients underwent endoscopic surveillance and received biopsy. If the specialized intestinal metaplasia (SIM) was lost at any point of surveillance and did not recur, the case was regarded as the regression group. The proportion of SIM was graded and the mucin phenotype was decided using immunohistochemistry for MUC2, MUC5AC and MUC6. To assess the cell proliferation indexes and the degree of intestinal maturation, immunohistochemistry for Ki67 and CDX2 were performed.

Results

The regression of BE occurred in the 11 (44%) patients. The clinical and demographic factors showed no difference between the regression (n = 11) and persistence group (n = 14). The lower grade of SIM (P < 0.001) and gastric predominant mucin phenotype (P = 0.018) were more frequent, and the number of Ki67 positive cell per gland (P = 0.008) and the mean extent of CDX2 (P = 0.022) were lower in the regression group than in the persistence group.

Conclusions

The regression of BE by PPI treatment was frequent in Korea. The immunohistochemical detection of mucin phenotype, grade of SIM, Ki67 and CDX2 expression in Barrett's mucosa could be useful as a predictable marker for regression of SIM in BE.