Controversies in the diagnosis of Barrett esophagus and Barrett-related dysplasia: one pathologist's perspective

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.

Tissue Systems Pathology Test Objectively Risk Stratifies Barrett's Esophagus Patients With Low-Grade Dysplasia

INTRODUCTION

Low-grade dysplasia (LGD) is the best predictor of neoplastic progression in Barrett's esophagus (BE). Most LGD cases are downstaged to nondysplastic (ND) BE on expert pathologist review, which is prone to interobserver variation and not widely available. Recent studies indicate that a risk prediction assay (TissueCypher) risk stratifies patients with NDBE for neoplastic progression. We aimed to investigate whether this risk prediction assay predicts neoplastic progression in BE patients with LGD.

METHODS

A blinded, retrospective cohort study was derived from the screening cohort of a randomized controlled trial of SURveillance vs RadioFrequency ablation for BE patients with LGD. Hematoxylin and eosin and p53 immunohistochemistry slides from the first endoscopy with LGD were independently reviewed by 3 expert pathologists and tested by the risk prediction assay. Revision diagnoses of NDBE were considered low risk, although indefinite for dysplasia, and LGD were considered high risk for progression.

RESULTS

A total of 155 BE patients (123 men), mean age 61 ± 10 years, were analyzed. Thirty-four patients (22%) progressed to high-grade dysplasia/esophageal adenocarcinoma (median time 2.4 years) and 121 did not progress (median high-grade dysplasia/esophageal adenocarcinoma-free surveillance 7.9 years). The risk prediction assay sensitivity was 68% vs 76% for the 3 pathologists, and specificity was 79% vs 64%-77.0% for the pathologists. The assay detected 50%-56% of progressors that were downstaged to NDBE by the pathologists.

DISCUSSION

The risk prediction assay provided significant risk stratification in BE patients with LGD and identified progressors that the experts downstaged to NDBE. This objective assay provides an effective solution to the lack of standardization of expert pathology review of LGD.

Deep learning systems detect dysplasia with human-like accuracy using histopathology and probe-based confocal laser endomicroscopy

Probe-based confocal laser endomicroscopy (pCLE) allows for real-time diagnosis of dysplasia and cancer in Barrett's esophagus (BE) but is limited by low sensitivity. Even the gold standard of histopathology is hindered by poor agreement between pathologists. We deployed deep-learning-based image and video analysis in order to improve diagnostic accuracy of pCLE videos and biopsy images. Blinded experts categorized biopsies and pCLE videos as squamous, non-dysplastic BE, or dysplasia/cancer, and deep learning models were trained to classify the data into these three categories. Biopsy classification was conducted using two distinct approaches-a patch-level model and a whole-slide-image-level model. Gradient-weighted class activation maps (Grad-CAMs) were extracted from pCLE and biopsy models in order to determine tissue structures deemed relevant by the models. 1970 pCLE videos, 897,931 biopsy patches, and 387 whole-slide images were used to train, test, and validate the models. In pCLE analysis, models achieved a high sensitivity for dysplasia (71%) and an overall accuracy of 90% for all classes. For biopsies at the patch level, the model achieved a sensitivity of 72% for dysplasia and an overall accuracy of 90%. The whole-slide-image-level model achieved a sensitivity of 90% for dysplasia and 94% overall accuracy. Grad-CAMs for all models showed activation in medically relevant tissue regions. Our deep learning models achieved high diagnostic accuracy for both pCLE-based and histopathologic diagnosis of esophageal dysplasia and its precursors, similar to human accuracy in prior studies. These machine learning approaches may improve accuracy and efficiency of current screening protocols.

Deep learning systems detect dysplasia with human-like accuracy using histopathology and probe-based confocal laser endomicroscopy

Probe-based confocal laser endomicroscopy (pCLE) allows for real-time diagnosis of dysplasia and cancer in Barrett's esophagus (BE) but is limited by low sensitivity. Even the gold standard of histopathology is hindered by poor agreement between pathologists. We deployed deep-learning-based image and video analysis in order to improve diagnostic accuracy of pCLE videos and biopsy images. Blinded experts categorized biopsies and pCLE videos as squamous, non-dysplastic BE, or dysplasia/cancer, and deep learning models were trained to classify the data into these three categories. Biopsy classification was conducted using two distinct approaches-a patch-level model and a whole-slide-image-level model. Gradient-weighted class activation maps (Grad-CAMs) were extracted from pCLE and biopsy models in order to determine tissue structures deemed relevant by the models. 1970 pCLE videos, 897,931 biopsy patches, and 387 whole-slide images were used to train, test, and validate the models. In pCLE analysis, models achieved a high sensitivity for dysplasia (71%) and an overall accuracy of 90% for all classes. For biopsies at the patch level, the model achieved a sensitivity of 72% for dysplasia and an overall accuracy of 90%. The whole-slide-image-level model achieved a sensitivity of 90% for dysplasia and 94% overall accuracy. Grad-CAMs for all models showed activation in medically relevant tissue regions. Our deep learning models achieved high diagnostic accuracy for both pCLE-based and histopathologic diagnosis of esophageal dysplasia and its precursors, similar to human accuracy in prior studies. These machine learning approaches may improve accuracy and efficiency of current screening protocols.

TissueCypher Barrett's esophagus assay impacts clinical decisions in the management of patients with Barrett's esophagus

Background and study aims  The TissueCypher Barrett's Esophagus Assay is a novel tissue biomarker test, and has been validated to predict progression to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) in patients with Barrett's esophagus (BE). The aim of this study was to evaluate the impact of TissueCypher on clinical decision-making in the management of BE. Patients and methods  TissueCypher was ordered for 60 patients with non-dysplastic (ND, n = 18) BE, indefinite for dysplasia (IND, n = 25), and low-grade dysplasia (LGD, n = 17). TissueCypher reports a risk class (low, intermediate or high) for progression to HGD or EAC within 5 years. The impact of the test results on BE management decisions was assessed. Results  Fifty-two of 60 patients were male, mean age 65.2 ± 11.8, and 43 of 60 had long segment BE. TissueCypher results impacted 55.0 % of management decisions. In 21.7 % of patients, the test upstaged the management approach, resulting in endoscopic eradication therapy (EET) or shorter surveillance interval. The test downstaged the management approach in 33.4 % of patients, leading to surveillance rather than EET. In the subset of patients whose management plan was changed, upstaging was associated with a high-risk TissueCypher result, and downstaging was associated with a low-risk result ( P  < 0.0001). Conclusions  TissueCypher was used as an adjunct to support a surveillance-only approach in 33.4 % of patients. Upstaging occurred in 21.7 % of patients, leading to therapeutic intervention or increased surveillance. These results indicate that the TissueCypher test may enable physicians to target EET for TissueCypher high-risk BE patients, while reducing unnecessary procedures in TissueCypher low-risk patients.

Artificial Intelligence and Its Role in Identifying Esophageal Neoplasia

Randomized trials have demonstrated that ablation of dysplastic Barrett's esophagus can reduce the risk of progression to cancer. Endoscopic resection for early stage esophageal adenocarcinoma and squamous cell carcinoma can significantly reduce postoperative morbidity compared to esophagectomy. Unfortunately, current endoscopic surveillance technologies (e.g., high-definition white light, electronic, and dye-based chromoendoscopy) lack sensitivity at identifying subtle areas of dysplasia and cancer. Random biopsies sample only approximately 5% of the esophageal mucosa at risk, and there is poor agreement among pathologists in identifying low-grade dysplasia. Machine-based deep learning medical image and video assessment technologies have progressed significantly in recent years, enabled in large part by advances in computer processing capabilities. In deep learning, sequential layers allow models to transform input data (e.g., pixels for imaging data) into a composite representation that allows for classification and feature identification. Several publications have attempted to use this technology to help identify dysplasia and early esophageal cancer. The aims of this reviews are as follows: (a) discussing limitations in our current strategies to identify esophageal dysplasia and cancer, (b) explaining the concepts behind deep learning and convolutional neural networks using language appropriate for clinicians without an engineering background, (c) systematically reviewing the literature for studies that have used deep learning to identify esophageal neoplasia, and (d) based on the systemic review, outlining strategies on further work necessary before these technologies are ready for "prime-time," i.e., use in routine clinical care.

Differential MicroRNA Signatures in the Pathogenesis of Barrett's Esophagus

OBJECTIVES:

Barrett's esophagus (BE) is the precursor lesion and a major risk factor for esophageal adenocarcinoma (EAC). Although patients with BE undergo routine endoscopic surveillance, current screening methodologies have proven ineffective at identifying individuals at risk of EAC. Since microRNAs (miRNAs) have potential diagnostic and prognostic value as disease biomarkers, we sought to identify an miRNA signature of BE and EAC.

METHODS:

High-throughput sequencing of miRNAs was performed on serum and tissue biopsies from 31 patients identified either as normal, gastroesophageal reflux disease (GERD), BE, BE with low-grade dysplasia (LGD), or EAC. Logistic regression modeling of miRNA profiles with Lasso regularization was used to identify discriminating miRNA. Quantitative reverse transcription polymerase chain reaction was used to validate changes in miRNA expression using 46 formalin-fixed, paraffin-embedded specimens obtained from normal, GERD, BE, BE with LGD or HGD, and EAC subjects.

RESULTS:

A 3-class predictive model was able to classify tissue samples into normal, GERD/BE, or LGD/EAC classes with an accuracy of 80%. Sixteen miRNAs were identified that predicted 1 of the 3 classes. Our analysis confirmed previous reports indicating that miR-29c-3p and miR-193b-5p expressions are altered in BE and EAC and identified miR-4485-5p as a novel biomarker of esophageal dysplasia. Quantitative reverse transcription polymerase chain reaction validated 11 of 16 discriminating miRNAs.

DISCUSSION:

Our data provide an miRNA signature of normal, precancerous, and cancerous tissue that may stratify patients at risk of progressing to EAC. We found that serum miRNAs have a limited ability to distinguish between disease states, thus limiting their potential utility in early disease detection.

Independent Blinded Validation of a Tissue Systems Pathology Test to Predict Progression in Patients With Barrett's Esophagus

INTRODUCTION

A risk prediction test was previously validated to predict progression to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) in patients with Barrett's esophagus (BE). The aim of our study was to independently validate this test to predict the risk of progression to HGD/EAC in BE patients with nondysplastic (ND), indefinite for dysplasia and low-grade dysplasia (LGD).

METHODS

A single-blinded, case-control study was conducted to stratify patients with BE as low, intermediate, or high risk for progression to HGD/EAC within 5 years using a previously described risk prediction test. Patients with BE who progressed to HGD/EAC after at least 1 year (n = 58) were matched to patients undergoing surveillance without progression (n = 210, median surveillance 7 years). Baseline biopsies with subspecialist diagnoses of ND, indefinite for dysplasia, or LGD were tested in a blinded manner, and the predictive performance of the test was assessed.

RESULTS

This risk prediction test stratified patients with BE based on progression risk with the high-risk group at 4.7-fold increased risk for HGD/EAC compared with the low-risk group (95% confidence interval 2.5-8.8, P < 0.0001). Prevalence-adjusted positive predictive value at 5 years was 23%. The high-risk class and male sex provided predictive power that was independent of pathologic diagnosis, age, segment length, and hiatal hernia. Patients with ND BE who scored high risk progressed at a higher rate (26%) than patients with subspecialist-confirmed LGD (21.8%) at 5 years.

DISCUSSION

A risk prediction test identifies patients with ND BE who are at high risk for progression to HGD/EAC and may benefit from early endoscopic therapy or increased surveillance.

A Cost-Effectiveness Analysis Of An Adenocarcinoma Risk Prediction Multi-Biomarker Assay For Patients With Barrett's Esophagus

PURPOSE

This study evaluates the cost-effectiveness of a quantitative multi-biomarker assay (the Assay) that stratifies patients with Barrett's Esophagus (BE) by risk of progression to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC) and can be used to guide clinical decisions, versus the current guidelines (standard of care [SOC]) for surveillance and treatment of BE.

PATIENTS AND METHODS

Markov decision modeling and simulation were used to compare cost and quality-adjusted life-years (QALYs) from the perspective of a US health insurer with care delivered by an integrated health system. Model assumptions and disease progression probabilities were derived from the literature. Performance metrics for the Assay were from an independent clinical validation study. Cost of the Assay was based on reimbursement rates from multiple payers. Other costs were derived from Geisinger payment data.

RESULTS

Base-case model results for a 5-year period comparing the Assay-directed care to the SOC estimated an incremental cost-effectiveness ratio (ICER) of $52,483/QALY in 2012 US dollars. Assay-directed care increased the use of endoscopic treatments by 58.4%, which reduced the progression to HGD, EAC and reduced EAC-related deaths by 51.7%, 47.1%, and 37.6%, respectively, over the 5-year period. Sensitivity analysis indicated that the probability of the Assay being cost-effective compared to the SOC was 57.3% at the $100,000/QALY acceptability threshold.

CONCLUSION

Given the model assumptions, the new Assay would be cost-effective after 5 years and improves patient outcomes due to improvement in the effectiveness of surveillance and treatment protocols resulting in fewer patients progressing to HGD and EAC and fewer EAC-related deaths.

Discordance Among Pathologists in the United States and Europe in Diagnosis of Low-Grade Dysplasia for Patients With Barrett's Esophagus

BACKGROUND & AIMS

There is suboptimal inter-observer agreement, even among expert gastrointestinal pathologists, in the diagnosis of low-grade dysplasia (LGD) in patients with Barrett's esophagus (BE). We analyzed histopathologic criteria required for a diagnosis of LGD using the new subcategories of LGD with inflammatory and dysplastic features. We categorized each diagnosis based on the level of confidence and assessed inter-observer agreement among gastrointestinal pathologists from 5 tertiary centers in the United States and Europe.

METHODS

In the first phase of the study, 3 pathologists held a consensus conference at which they discussed the diagnostic criteria for LGD. In the second phase, 79 slides from patients with BE (23 samples of non-dysplastic BE, 22 samples of LGD, and 34 samples of high-grade dysplasia) were identified, randomly assigned to 7 pathologists (4 from the United States and 3 from Europe), and interpreted in a blinded fashion. κ Values were calculated for inter-observer agreement. We performed multinomial logistic regression analysis to assess the weighting of histologic features with the diagnosis.

RESULTS

The overall κ value for diagnosis was 0.43 (95% confidence interval [CI], 0.42-0.48). When categorized based on degree of dysplasia, the κ value was 0.22 (95% CI, 0.11-0.29) for non-dysplastic BE, 0.11 (95% CI, 0.004-0.15) for LGD, and 0.43 (95% CI, 0.36-0.46) for high-grade dysplasia. When all pathologists made a diagnosis with high confidence, the inter-observer agreement was substantial among the US pathologists (κ, 0.63; 95% CI, 0.61-0.66) and European pathologists (κ, 0.80; 95% CI, 0.74-0.97). The κ values for all diagnoses made by European pathologists were higher than those made by US pathologists.

CONCLUSIONS

In an analysis of criteria used in histopathologic diagnosis of LGD, we did not observe improvement in level of agreement among experienced pathologists, even after accounting for inflammation. The level of inter-observer agreement increased with level of pathologist confidence. There was also a difference in reading of histopathology samples of BE tissues between US and European pathologists.

A Tissue Systems Pathology Assay for High-Risk Barrett's Esophagus

BACKGROUND

Better methods are needed to predict risk of progression for Barrett's esophagus. We aimed to determine whether a tissue systems pathology approach could predict progression in patients with nondysplastic Barrett's esophagus, indefinite for dysplasia, or low-grade dysplasia.

METHODS

We performed a nested case-control study to develop and validate a test that predicts progression of Barrett's esophagus to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC), based upon quantification of epithelial and stromal variables in baseline biopsies. Data were collected from Barrett's esophagus patients at four institutions. Patients who progressed to HGD or EAC in ≥1 year (n = 79) were matched with patients who did not progress (n = 287). Biopsies were assigned randomly to training or validation sets. Immunofluorescence analyses were performed for 14 biomarkers and quantitative biomarker and morphometric features were analyzed. Prognostic features were selected in the training set and combined into classifiers. The top-performing classifier was assessed in the validation set.

RESULTS

A 3-tier, 15-feature classifier was selected in the training set and tested in the validation set. The classifier stratified patients into low-, intermediate-, and high-risk classes [HR, 9.42; 95% confidence interval, 4.6-19.24 (high-risk vs. low-risk); P < 0.0001]. It also provided independent prognostic information that outperformed predictions based on pathology analysis, segment length, age, sex, or p53 overexpression.

CONCLUSION

We developed a tissue systems pathology test that better predicts risk of progression in Barrett's esophagus than clinicopathologic variables.

IMPACT

The test has the potential to improve upon histologic analysis as an objective method to risk stratify Barrett's esophagus patients. Cancer Epidemiol Biomarkers Prev; 25(6); 958-68. ©2016 AACR.

Inter-Observer Agreement among Pathologists Using Wide-Area Transepithelial Sampling With Computer-Assisted Analysis in Patients With Barrett's Esophagus

OBJECTIVES

The histopathological diagnosis of Barrett's esophagus (BE)-associated dysplasia has poor inter-observer agreement. The wide-area transepithelial sampling (WATS) procedure uses a minimally invasive brush biopsy technique for acquiring wide-area sampling of BE tissue followed by computer-assisted analysis. In this study, our aim was to assess inter-observer agreement among pathologists in the diagnosis of Barrett's-associated dysplasia using the WATS computer-assisted analysis technique.

METHODS

WATS slides with varying degrees of BE dysplasia were randomly selected and distributed to four pathologists. Each pathologist graded the slides as nondysplastic, low-grade dysplasia (LGD), or high-grade dysplasia/esophageal adenocarcinoma (HGD/EAC) and completed a standardized case report form (CRF) for each slide.

RESULTS

In all, 149 BE slides were evaluated in a blinded manner by 4 pathologists. The slides included the following: no dysplasia (n=109), LGD, and HGD/EAC (n=40). The overall mean kappa value for all 3 diagnoses for the 4 observers was calculated at 0.86 (95% confidence interval (CI) 0.75-0.97). The kappa values (95% CI) for HGD/EAC, IND/LGD, and no dysplasia were 0.95 (0.88-0.99), 0.74 (0.61-0.85), and 0.88 (0.81-0.94), respectively.

CONCLUSIONS

The diagnosis of BE and associated dysplasia using the WATS technique has very high inter-observer agreement. This appears to be significantly higher as compared with previously published data using standard histopathology.

Barrett esophagus

Although there are many unanswered questions with Barrett esophagus, we can safely say that the incidence is increasing, chemoprevention strategies for the prevention of Barrett metaplasia and its progression to adenocarcinoma may be in the offing, surveillance should be considered for all patients who are discovered to have Barrett esophagus, RFA is the treatment of choice for those with HGD and strongly considered in those with LGD, EMR should be the treatment of choice for patients with nodular high-grade Barrett esophagus, and, finally, vagal-sparing esophagectomy reserved for patients with persistent HGD or a strong suspicion of carcinoma, with consideration of a concomitant fundoplication.

Australian clinical practice guidelines for the diagnosis and management of Barrett's esophagus and early esophageal adenocarcinoma

Barrett's esophagus (BE), a common condition, is the only known precursor to esophageal adenocarcinoma (EAC). There is uncertainty about the best way to manage BE as most people with BE never develop EAC and most patients diagnosed with EAC have no preceding diagnosis of BE. Moreover, there have been recent advances in knowledge and practice about the management of BE and early EAC. To aid clinical decision making in this rapidly moving field, Cancer Council Australia convened an expert working party to identify pertinent clinical questions. The questions covered a wide range of topics including endoscopic and histological definitions of BE and early EAC; prevalence, incidence, natural history, and risk factors for BE; and methods for managing BE and early EAC. The latter considered modification of lifestyle factors; screening and surveillance strategies; and medical, endoscopic, and surgical interventions. To answer each question, the working party systematically reviewed the literature and developed a set of recommendations through consensus. Evidence underpinning each recommendation was rated according to quality and applicability.

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.

Evaluation of Barrett esophagus by multiphoton microscopy

CONTEXT

Multiphoton microscopy (MPM) based on 2-photon excitation fluorescence and second-harmonic generation allows simultaneous visualization of cellular details and extracellular matrix components of fresh, unfixed, and unstained tissue. Portable multiphoton microscopes, which could be placed in endoscopy suites, and multiphoton endomicroscopes are in development, but their clinical utility is unknown.

OBJECTIVE

To examine fresh, unfixed endoscopic biopsies obtained from the distal esophagus and gastroesophageal junction to (1) define the MPM characteristics of normal esophageal squamous mucosa and gastric columnar mucosa, and (2) evaluate whether diagnosis of intestinal metaplasia/Barrett esophagus (BE) could be made reliably with MPM.

DESIGN

The study examined 35 untreated, fresh biopsy specimens from 25 patients who underwent routine upper endoscopy. A Zeiss LSM 710 Duo microscope (Carl Zeiss, Thornwood, New York) coupled to a Spectra-Physics (Mountain View, California) Tsunami Ti:sapphire laser was used to obtain a MPM image within 4 hours of fresh specimen collection. After obtaining MPM images, the biopsy specimens were placed in 10% buffered formalin and submitted for routine histopathologic examination. Then, the MPM images were compared with the findings in the hematoxylin-eosin-stained, formalin-fixed, paraffin-embedded sections. The MPM characteristics of the squamous, gastric-type columnar and intestinal-type columnar epithelium were analyzed. In biopsies with discrepancy between MPM imaging and hematoxylin-eosin-stained sections, the entire tissue block was serially sectioned and reevaluated. A diagnosis of BE was made when endoscopic and histologic criteria were satisfied.

RESULTS

Based on effective 2-photon excitation fluorescence of cellular reduced pyridine nucleotides and flavin adenine dinucleotide and lack of 2-photon excitation fluorescence of mucin and cellular nuclei, MPM could readily identify and distinguish among squamous epithelial cells, goblet cells, gastric foveolar-type mucous cells, and parietal cells in the area of gastroesophageal junction. Based on the cell types identified, the mucosa was defined as squamous, columnar gastric type (cardia/fundic-type), and metaplastic columnar intestinal-type/BE. Various types of mucosa seen in the study of 35 biopsies included normal squamous mucosa only (n = 14; 40%), gastric cardia-type mucosa only (n = 2; 6%), gastric fundic mucosa (n = 6; 17%), and both squamous and gastric mucosa (n = 13; 37%). Intestinal metaplasia was identified by the presence of goblet cells in 10 of 25 cases (40%) leading to a diagnosis of BE on MPM imaging and only in 7 cases (28%) by histopathology. In 3 of 35 biopsies (9%), clear-cut goblet cells were seen by MPM imaging but not by histopathology, even after the entire tissue block was sectioned. Based on effective 2-photon excitation fluorescence of elastin and second-harmonic generation of collagen, connective tissue in the lamina propria and the basement membrane was also visualized with MPM.

CONCLUSIONS

Multiphoton microscopy has the ability to accurately distinguish squamous epithelium and different cellular elements of the columnar mucosa obtained from biopsies around the gastroesophageal junction, including goblet cells that are important for the diagnosis of BE. Thus, use of MPM in the endoscopy suite might provide immediate microscopic images during endoscopy, improving screening and surveillance of patients with BE.

Review on novel concepts of columnar lined esophagus

BACKGROUND

Columnar lined esophagus (CLE) is a marker for gastroesophageal reflux and associates with an increased cancer risk among those with Barrett's esophagus. Recent studies fostered the development of integrated CLE concepts.

METHODS

Using PubMed, we conducted a review of studies on novel histopathological concepts of nondysplastic CLE.

RESULTS

Two histopathological concepts-the squamo-oxyntic gap (SOG) and the dilated distal esophagus (DDE), currently model our novel understanding of CLE. As a consequence of reflux, SOG interposes between the squamous lined esophagus and the oxyntic mucosa of the proximal stomach. Thus the SOG describes the histopathology of CLE within the tubular esophagus and the DDE, which is known to develop at the cost of a shortened lower esophageal sphincter and foster increased acid gastric reflux. Histopathological studies of the lower end of the esophagus indicate, that the DDE is reflux damaged, dilated, gastric type folds forming esophagus and cannot be differentiated from proximal stomach by endoscopy. While the endoscopically visible squamocolumnar junction (SCJ) defines the proximal limit of the SOG, the assessment of the distal limit requires the histopathology of measured multilevel biopsies. Within the SOG, CLE types distribute along a distinct zonation with intestinal metaplasia (IM; Barrett's esophagus) and/or cardiac mucosa (CM) at the SCJ and oxyntocardiac mucosa (OCM) within the distal portion of the SOG. The zonation follows the pH-gradient across the distal esophagus. Diagnosis of SOG and DDE includes endoscopy, histopathology of measured multi-level biopsies from the distal esophagus, function, and radiologic tests. CM and OCM do not require treatment and are surveilled in 5 year intervals, unless they associate with life quality impairing symptoms, which demand medical or surgical therapy. In the presence of an increased cancer risk profile, it is justified to consider radiofrequency ablation (RFA) of IM within clinical studies in order to prevent the progression to dysplasia and cancer. Dysplasia justifies RFA ± endoscopic resection.

CONCLUSIONS

SOG and DDE represent novel concepts fusing the morphological and functional aspects of CLE. Future studies should examine the impact of SOG and DDE for monitoring and management of gastroesophageal reflux disease (GERD).

Advanced precancerous lesions in the lower oesophageal mucosa: high-grade dysplasia and intramucosal carcinoma in Barrett's oesophagus

Adenocarcinoma developed in Barrett's oesophagus is a tumour with an increasing incidence and still a poor prognosis. The only marker that can be used for surveillance remains dysplasia (intraepithelial neoplasia), especially when it is high-grade, that precedes intramucosal carcinoma. New forms of dysplasia have been described in complement to the classical intestinal type (foveolar dysplasia, basal crypt dysplasia). High-grade dysplasia and intramucosal carcinoma are diagnosed on biopsies taken during endoscopy. Standard endoscopy is now challenged by various techniques that represent recent major technical improvements (chromoendoscopy, virtual chromoendoscopy, optical frequency domain imaging, confocal laser endomicroscopy). In numerous cases, high-grade dysplasia and intramucosal carcinoma can be treated by endoscopic procedures, allowing a precise histopathological diagnosis on the resected specimen (endoscopic mucosal resection, submucosal endoscopic dissection) or destroying the neoplastic tissue. Radiofrequency ablation is currently considered as the best available technique for treatment of flat high grade dysplasia and for eradication of residual Barrett's mucosa after focal endoscopic mucosal resection.

DNA methylation as an adjunct to histopathology to detect prevalent, inconspicuous dysplasia and early-stage neoplasia in Barrett's esophagus

PURPOSE

Endoscopic surveillance of Barrett's esophagus is problematic because dysplasia/early-stage neoplasia is frequently invisible and likely to be missed because of sampling bias. Molecular abnormalities may be more diffuse than dysplasia. The aim was therefore to test whether DNA methylation, especially on imprinted and X-chromosome genes, is able to detect dysplasia/early-stage neoplasia.

EXPERIMENTAL DESIGN

27K methylation arrays were used to find genes best able to differentiate between 22 Barrett's esophagus and 24 esophageal adenocarcinoma (EAC) samples. These were validated using pyrosequencing on a retrospective cohort (60 Barrett's esophagus, 36 dysplastic, and 90 EAC) and then in a prospective multicenter study (98 Barrett's esophagus patients, including 28 dysplastic and 9 early EAC) designed to utilize biomarkers to stratify patients according to their prevalent dysplasia/EAC status.

RESULTS

Genes (23%) on the array, including 7% of X-linked and 69% of imprinted genes, have shown statistically significant changes in methylation in EAC versus Barrett's esophagus (Wilcoxon P < 0.05). 6/7 selected candidate genes were successfully internally (Pearson's P < 0.01) and externally validated (ANOVA P < 0.001). Four genes (SLC22A18, PIGR, GJA12, and RIN2) showed the greatest area under curve (0.988) to distinguish between Barrett's esophagus and dysplasia/EAC in the retrospective cohort. This methylation panel was able to stratify patients from the prospective cohort into three risk groups based on the number of genes methylated (low risk: <2 genes, intermediate: 2, and high: >2).

CONCLUSION

Widespread DNA methylation changes were observed in Barrett's carcinogenesis including ≈70% of known imprinted genes. A four-gene methylation panel stratified patients with Barrett's esophagus into three risk groups with potential clinical utility.

Life-long learning and self-assessment

New Frontiers in Pathology is a unique educational event intended to meet the ongoing educational needs of practicing pathologists. Continuous medical education (CME) is required for maintenance of licensure by virtually all state licensing bodies. Satisfying CME requirements hinges on earning a minimum number of American Medical Association Physician Recognition Award category 1 credits through various activities, including courses like New Frontiers in Pathology that are accredited by the Accreditation Council for Continuing Medical Education. Self-assessment modules (SAMs) are a key component of the American Board of Pathology expectations for maintenance of board certification. Beginning in 2006, the American Board of Pathology granted only time-limited certificates as part of an American Board of Medical Specialties-wide process for maintenance of board certification. Maintenance of board certification has requirements in 4 categories: professional standing, life-long learning and self-assessment, cognitive expertise, and evaluation of performance in practice. Life-long learning and self-assessment includes not only the traditional elements of CME but also the SAMs that are defined as educational products comprising self-administered examinations with a predetermined minimum performance level and a mechanism for receiving feedback. New Frontiers in Pathology will offer SAMs, in addition to the American Medical Association Physician Recognition Award category 1 credits, which it has been accredited to do since its inception, at its 2012 conference scheduled for August 3 through August 5 at The Homestead Resort, Michigan's largest waterfront resort on beautiful Lake Michigan.

[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.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Barrett's Esophagus: Emerging Knowledge and Management Strategies

The incidence of esophageal adenocarcinoma (EAC) has increased exponentially in the last 3 decades. Barrett's esophagus (BE) is the only known precursor of EAC. Patients with BE have a greater than 40 folds higher risk of EAC compared with the general population. Recent years have witnessed a revolution in the clinical and molecular research related to BE. However, several aspects of this condition remain controversial. Data regarding the true prevalence of BE have varied widely. Recent studies have suggested a lower incidence of EAC in nondysplastic BE (NDBE) than previously reported. There is paucity of prospective data showing a survival benefit of screening or surveillance for BE. Furthermore, the ever-increasing emphasis on healthcare cost containment has called for reexamination of the screening and surveillance strategies for BE. There is a need for identification of reliable clinical predictors or molecular biomarkers to risk-stratify patients who might benefit the most from screening or surveillance for BE. Finally, new therapies have emerged for the management of dysplastic BE. In this paper, we highlight the key areas of controversy and uncertainty surrounding BE. The paper discusses, in detail, the current literature about the molecular pathogenesis, biomarkers, histopathological diagnosis, and management strategies for BE.

How to diagnose and manage patients with Barrett's esophagus in China

In order to prevent the development of Barrett's esophagus (BE)-related esophageal cancer in China and facilitate the communication of research results among different centers, we propose using standardized diagnostic criteria and taking a conservative approach to diagnose and manage BE patients. BE patients without dysplasia need to be treated medically. For low-grade dysplasia, an annual endoscopy with biopsies is recommended, along with medical therapy. For high-grade dysplasia and intramucosal carcinoma, an endoscopic or surgical intervention is suggested. All BE patients should be followed up closely.

Bile acid and inflammation activate gastric cardia stem cells in a mouse model of Barrett-like metaplasia

Esophageal adenocarcinoma (EAC) arises from Barrett esophagus (BE), intestinal-like columnar metaplasia linked to reflux esophagitis. In a transgenic mouse model of BE, esophageal overexpression of interleukin-1β phenocopies human pathology with evolution of esophagitis, Barrett-like metaplasia and EAC. Histopathology and gene signatures closely resembled human BE, with upregulation of TFF2, Bmp4, Cdx2, Notch1, and IL-6. The development of BE and EAC was accelerated by exposure to bile acids and/or nitrosamines, and inhibited by IL-6 deficiency. Lgr5(+) gastric cardia stem cells present in BE were able to lineage trace the early BE lesion. Our data suggest that BE and EAC arise from gastric progenitors due to a tumor-promoting IL-1β-IL-6 signaling cascade and Dll1-dependent Notch signaling.

[Intraepithelial neoplasia of Barrett's esophagus: prognosis of potential malignancy]

Adenocarcinomas of the distal esophagus mainly develop from intestinal metaplasia (Barrett's esophagus) through intermediate steps of low-grade and high-grade intraepithelial neoplasia. Histopathological examination of endoscopic biopsies constitutes the gold standard for estimating the cancer risk of a patient with Barrett's esophagus. Several prospective biomarker phase IV studies have demonstrated the predictive value of e.g. allelic loss of TP53, tetraploidy and aneuploidy as well as cyclin D1 expression. Among the relevant biomarkers from retrospective phase III studies are polysomy and specific DNA gains and losses, markers of proliferation (Mib-1) and methylation markers. As there are conflicting results in the literature and these analyses are costly, their use in routine patient care cannot yet be recommended. However, immunostaining for several markers may assist in the classification of intraepithelial neoplasia in individual difficult cases.