Hypoxia-inducible factor-1α mediates reflux-induced epithelial-mesenchymal plasticity in Barrett's oesophagus patients.

INTRODUCTION: Epithelial-mesenchymal plasticity (EMP), the process through which epithelial cells acquire mesenchymal features, is needed for wound repair but also might contribute to cancer initiation. Earlier, in vitro studies showed that Barrett's cells exposed to acidic bile salt solutions (ABS) develop EMP. Now, we have (1) induced reflux oesophagitis in Barrett's oesophagus (BO) patients by stopping proton pump inhibitors (PPIs), (2) assessed their biopsies for EMP and (3) explored molecular pathways underlying reflux-induced EMP in BO cells and spheroids. METHODS: 15 BO patients had endoscopy with biopsies of Barrett's metaplasia while on PPIs, and 1 and 2 weeks after stopping PPIs; RNA-seq data were assessed for enrichments in hypoxia-inducible factors (HIFs), angiogenesis and EMP pathways. In BO biopsies, cell lines and spheroids, EMP features (motility) and markers (vascular endothelial growth factor (VEGF), ZEB1, miR-200a&b) were evaluated by morphology, migration assays, immunostaining and qPCR; HIF-1α was knocked down with siRNA or shRNA. RESULTS: At 1 and/or 2 weeks off PPIs, BO biopsies exhibited EMP features and markers, with significant enrichment for HIF-1α, angiogenesis and EMP pathways. In BO cells, ABS induced HIF-1α activation, which decreased miR-200a&b while increasing VEGF, ZEB1 and motility; HIF-1α knockdown blocked these effects. After ABS treatment, BO spheroids exhibited migratory protrusions showing nuclear HIF-1α, increased VEGF and decreased miR-200a&b. CONCLUSIONS: In BO patients, reflux oesophagitis induces EMP changes associated with increased HIF-1α signalling in Barrett's metaplasia. In Barrett's cells, ABS trigger EMP via HIF-1α signalling. Thus, HIF-1α appears to play a key role in mediating reflux-induced EMP that might contribute to cancer in BO. TRIAL REGISTRATION NUMBER: NCT02579460.

Adjunctive Use of WATS-3D in Symptomatic GERD Patients Increases Detection of Barrett's Esophagus and Dysplasia.

BACKGROUND: Patients with gastroesophageal reflux (GERD) symptoms undergoing screening upper endoscopy for Barrett's esophagus (BE) frequently demonstrate columnar-lined epithelium (CLE), with forceps biopsies (FB) failing to yield intestinal metaplasia (IM). Repeat endoscopy is often necessary. AIM: Assess the yield of IM leading to a diagnosis of BE by the addition of Wide-Area Trans-epithelial Sampling (WATS-3D) to FB in the screening of GERD patients. METHODS: We performed a prospective registry study of GERD patients undergoing screening upper endoscopy. Patients had both WATS-3D and FB. Patients were classified by their Z line appearance: regular, irregular (<1 cm CLE), possible short-segment BE (1-<3cm), and possible long-segment BE (≥3cm). Demographics, IM yield, and dysplasia yield were calculated. Adjunctive yield was defined as cases identified by WATS-3D not detected by FB, divided by cases detected by FB. Clinicians were asked if WATS-3D results impacted patient management. RESULTS: Of 23,933 patients, 6,829(28.5%) met endoscopic criteria for BE. Of these, 2,878(42.1%) had IM identified by either FB or WATS-3D. Among patients fulfilling endoscopic criteria for BE, the adjunctive yield of WATS-3D was 76.5%, and absolute yield was 18.1%. 1,317 patients (19.3%) who fulfilled endoscopic BE criteria had IM detected solely by WATS-3D. Of 240 patients with dysplasia, 107(44.6%) were found solely by WATS-3D. Among patients with positive WATS-3D but negative FB, the care plan changed in 90.7%. CONCLUSION: The addition of WATS-3D to FB in GERD patients being screened for BE resulted in confirmation of BE in an additional 1/5 th of patients. Furthermore, dysplasia diagnoses approximately doubled.

Barrett's Esophagus and Associated Dysplasia.

Early detection of dysplasia and effective management are critical steps in halting neoplastic progression in patients with Barrett's esophagus (BE). This review provides a contemporary overview of the BE-related dysplasia, its role in guiding surveillance and management, and discusses emerging diagnostic and therapeutic approaches that might further enhance patient management. Novel, noninvasive techniques for sampling and surveillance, adjunct biomarkers for risk assessment, and their limitations are also discussed.

WATS 3D : An Interobserver Study of Barrett's Esophagus-Associated Dysplasia Among Gastrointestinal Pathologists.

INTRODUCTION: Wide-area transepithelial sampling with 3-dimensional computer-assisted analysis (WATS 3D ) has been shown to increase the detection rate of dysplasia (and intestinal metaplasia) in patients with Barrett's esophagus (BE). The purpose of this study was to evaluate the interobserver variability and accuracy of diagnosing BE-associated dysplasia in WATS 3D specimens among gastrointestinal (GI) pathologists without prior experience with this technology. METHODS: Five GI pathologists underwent a 4-hour in-person (at microscope) and virtual training session and then evaluated digital images of discrete cellular foci from 60 WATS 3D cases with BE (20 nondysplastic BE [NDBE], 20 low-grade dysplasia [LGD], and 20 high-grade dysplasia/esophageal adenocarcinoma [HGD/EAC]). Each case consisted of 1 hematoxylin and eosin-stained image (cell block), and 1 liquid cytology or papanicolaou-stained smear image (120 images in total). RESULTS: The overall kappa value among the 5 study pathologists was excellent (overall kappa = 0.93; kappa = 0.93 and 0.97 for cell block and smear specimens, respectively). There were no significant differences noted in kappa values in interpretation of the cell block vs smear specimens or in any of the individual diagnostic categories when the latter were evaluated separately. Furthermore, agreement was perfect (100%) regarding detection of neoplasia (either LGD, HGD, or EAC). Diagnoses were made with complete confidence in 91% of instances. DISCUSSION: We conclude that GI pathologists, without any prior experience in interpretation of WATS 3D specimens, can undergo a short training session and then diagnose these specimens with a very high level of accuracy and reproducibility.

Significance of Crypt Atypia in Barrett's Esophagus: A Clinical, Molecular, and Outcome Study.

BACKGROUND & AIMS: The aim of this study was to characterize baseline morphologic features of crypts in nondysplastic Barrett's esophagus and correlate them with DNA content abnormalities and risk of progression to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC). METHODS: The morphologic features of nondysplastic crypts in baseline biopsy specimens from 212 BE patients (2956 biopsy specimens) were graded histologically using a 4-point scale (crypt atypia levels, 0-3). DNA content abnormalities were detected using flow cytometry. RESULTS: In patients who had dysplasia in their baseline biopsy specimens, dysplasia was associated significantly with increasing grades of crypt atypia in the background nondysplastic Barrett's esophagus (P < .001). In a subset of patients without dysplasia at baseline (N = 149), a higher grade of crypt atypia was associated with longer Barrett's esophagus segment length (5.5 vs 3.3 cm; P = .0095), and a higher percentage of cells with 4N DNA content (3.67 ± 1.27 vs 2.93 ± 1.22; P = .018). Crypt atypia was associated with the development of any neoplasia (low-grade dysplasia and HGD/EAC). Although no significant association was noted between the grade of crypt atypia and increased 4N, aneuploidy, or progression to HGD/EAC, only patients with grade 2 or 3 crypt atypia showed increased 4N, aneuploidy, or progression to HGD/EAC. CONCLUSIONS: Patients with Barrett's esophagus likely develop dysplasia via a progressive increase in the level of crypt atypia before the onset of dysplasia, and these changes may reflect some alteration of DNA content.

Colorectal dysplasia in chronic inflammatory bowel disease: a contemporary consensus classification and interobserver study.

The clinical management of patients with dysplasia in chronic inflammatory bowel disease (IBD) is currently guided by Riddell et al.'s grading system (negative, indefinite, low grade, high grade) from 1983 which was based primarily on nuclear cytoarchitectural characteristics. Although most dysplasia in IBD resembles sporadic adenomas morphologically, other distinctive potential cancer precursors in IBD have been described over time. Recognizing the need for a updated comprehensive classification for IBD-associated dysplasia, an international working group of pathologists with extensive clinical and research experience in IBD devised a new classification system and assessed its reproducibility by having each participant assess test cases selected randomly from a repository of electronic images of potential cancer precursor lesions. The new classification system now encompasses three broad categories and nine sub-categories: 1) intestinal dysplasia (tubular/villous adenoma-like, goblet cell deficient, crypt cell, traditional serrated adenoma-like, sessile serrated lesion-like and serrated NOS), 2) gastric dysplasia (tubular/villous and serrated), and 3) mixed intestinal-gastric dysplasia. In the interobserver analysis, 67% of the diagnoses were considered definitive and achieved substantial inter-rater agreement. The key distinctions between intestinal and gastric lesions and between serrated and non-serrated lesions achieved substantial and moderate inter-rater agreement overall, respectively, however, the distinctions among certain serrated sub-categories achieved only fair agreement. Based on the Riddell grading system, definite dysplasia accounted for 86% of the collective responses (75% low grade, 11% high grade). Based on these results, this new classification of dysplasia in IBD can provide a sound foundation for future clinical and basic IBD research.

Benefit of adjunctive wide-area transepithelial sampling with 3-dimensional computer-assisted analysis plus forceps biopsy based on Barrett's esophagus segment length.

BACKGROUND AND AIMS: Wide-area transepithelial sampling with 3-dimensional computer-assisted analysis (WATS-3D) has been shown to increase the diagnostic yield of intestinal metaplasia (IM) and dysplasia within a segment of suspected or known Barrett's esophagus (BE) when used as an adjunct to forceps biopsies. Few data are available regarding how segment length affects WATS-3D yield. The purpose of this study was to evaluate adjunctive WATS-3D use in patients with varying lengths of BE. METHODS: A total of 8471 patients (52.5% male; mean age, 63 years) enrolled in 2 registry studies were included in this study. All patients were being screened or surveyed for BE with both forceps biopsies and WATS-3D. The adjunctive and absolute yield of WATS-3D was calculated according to the length of the patient's BE segment. RESULTS: The overall adjunctive and absolute increased diagnostic yields with WATS-3D were 47.6% and 17.5%, respectively, for detection of IM, and 139% and 2.4% for detection of dysplasia. IM and dysplasia detection both increased with the use of WATS-3D regardless of segment length. Increase in IM diagnostic yield was significantly higher in short- versus long-segment cases but higher in long-segment cases for dysplasia detection. CONCLUSIONS: This study shows that when WATS-3D is added as an adjunct to forceps biopsies, it is effective at increasing the diagnostic yield of both BE and associated dysplasia in patients with both short and long segments of esophageal columnar-lined epithelium.

Quantitative p53 immunostaining aids in the detection of prevalent dysplasia.

AIMS: The lack of accepted scoring criteria has precluded the use of p53 in routine practice. We evaluate the utility of automated quantitative p53 analysis in risk stratifying Barrett's oesophagus (BE) patients using non-dysplastic BE (NDBE) biopsies in a multicentric cohort of BE progressor (P) and non-progressor (NP) patients. METHODS: NDBE biopsies prior to the diagnosis of advanced neoplasia from 75 BE-P, and index and last surveillance biopsies from 148 BE-NP were stained for p53, and scored digitally as 1+, 2+ and 3+. A secondary cohort of 30 BE-P was evaluated. RESULTS: Compared with BE-NP, BE-P was predominantly men (p=0.001), ≥55 years of age (p=0.008), with longer BE segments (71% vs 33%; p<0.001). The mean number of 3+p53 positive cells and 3+ positive glands were significantly more in BE-P versus BE-NP NDBE biopsies (175 vs 9.7, p<0.001; 9.8 vs 0.1; p<0.001, respectively). At a cut-off of ≥10 p53 (3+) positive cells, the sensitivity and specificity of the assay to identify BE-P were 39% and 93%. On multivariate analysis, scoring p53 in NDBE biopsies, age, gender and length of BE were significantly associated with neoplastic progression. 54% of patients classified as prevalent dysplasia showed an abnormal p53 immunohistochemical stain. These findings were validated in the secondary cohort. CONCLUSIONS: Automated p53 analysis in NDBE biopsies serves as a promising tool for assessing BE neoplastic progression and risk stratification. Our study highlights the practical applicability of p53 assay to routine surveillance practice and its ability to detect prevalent dysplasia.

High rate of missed Barrett's esophagus when screening with forceps biopsies.

BACKGROUND: Screening for Barrett's esophagus (BE) with endoscopy plus forceps biopsy (FB) has poor compliance with the recommended Seattle protocol and fails to sample large areas of mucosa. This statistical modeling study estimates, for the first time, the actual frequency of missed BE cases by FB. METHODS: Published, calibrated models in the literature were combined to calculate the age-specific prevalence of BE in white males with gastroesophageal reflux disease (GERD). We started with estimates of the prevalence of BE and GERD, and applied the relative risk for BE in patients with GERD based on the literature. This created estimates of the true prevalence of BE in white males with GERD by decade of life. The proportion of BE missed was calculated as the difference between the prevalence and the proportion with a positive screen. RESULTS: The prevalence of BE in white males with GERD was 8.9%, 12.1%, 15.3%, 18.7% and 22.0% for the third through eighth decades of life. Even after assuming no false positives, missed cases of BE were about 50% when estimated for patients of ages 50 or 60 years, and over 60% for ages of 30, 40 or 70 years. Sensitivity analysis was done for all variables in the model calculations. For ages 50 and 60 years, this resulted in values from 30.3 to 57.3% and 36.4 to 60.9%. CONCLUSION: Screening for BE with endoscopy and FB misses approximately 50% of BE cases. More sensitive methods of BE detection or better adherence to the Seattle protocol are needed.

An Endoscopic and Histologic Study on Healing of Radiofrequency Ablation Wounds in Patients With Barrett's Esophagus.

INTRODUCTION: Radiofrequency ablation (RFA) of Barrett's esophagus (BE) inflicts a wound spanning 3 epithelial types (stratified squamous, Barrett's metaplasia, gastric epithelium), yet the esophageal injury heals almost completely with squamous epithelium. Knowledge of how this unique wound heals might elucidate mechanisms underlying esophageal metaplasia. We aimed to prospectively and systematically characterize the early endoscopic and histologic features of RFA wound healing. METHODS: Patients with nondysplastic BE had endoscopy with systematic esophageal photographic mapping, biopsy, and volumetric laser endomicroscopy performed before and at 1, 2, and 4 weeks after RFA. RESULTS: Seven patients (6 men; mean age 56.1 ± 10.9 years) completed this study. Squamous re-epithelialization of RFA wounds did not only progress exclusively through squamous cells extending from the proximal wound edge but also progressed through islands of squamous epithelium sprouting throughout the ablated segment. Volumetric laser endomicroscopy revealed significant post-RFA increases in subepithelial glandular structures associated with the squamous islands. In 2 patients, biopsies of such islands revealed newly forming squamous epithelium contiguous with immature-appearing squamous cells arising from esophageal submucosal gland ducts. Subsquamous intestinal metaplasia (SSIM) was found in biopsies at 2 and/or 4 weeks after RFA in 6 of 7 patients. DISCUSSION: RFA wounds in BE are re-epithelialized, not just by squamous cells from the proximal wound margin but by scattered squamous islands in which esophageal submucosal gland duct cells seem to redifferentiate into the squamous progenitors that fuel squamous re-epithelialization. SSIM can be found in most patients during the healing process. We speculate that this SSIM might underlie Barrett's recurrences after apparently successful eradication.

Agrin Loss in Barrett's Esophagus-Related Neoplasia and Its Utility as a Diagnostic and Predictive Biomarker.

PURPOSE: There is an unmet need for identifying novel biomarkers in Barrett's esophagus that could stratify patients with regards to neoplastic progression. We investigate the expression patterns of extracellular matrix (ECM) molecules in Barrett's esophagus and Barrett's esophagus-related neoplasia, and assess their value as biomarkers for the diagnosis of Barrett's esophagus-related neoplasia and to predict neoplastic progression. EXPERIMENTAL DESIGN: Gene-expression analyses of ECM matrisome gene sets were performed using publicly available data on human Barrett's esophagus, Barrett's esophagus-related dysplasia, esophageal adenocarcinoma (ADCA) and normal esophagus. Immunohistochemical expression of basement membrane (BM) marker agrin (AGRN) and p53 was analyzed in biopsies of Barrett's esophagus-related neoplasia from 321 patients in three independent cohorts. RESULTS: Differential gene-expression analysis revealed significant enrichment of ECM matrisome gene sets in dysplastic Barrett's esophagus and ADCA compared with controls. Loss of BM AGRN expression was observed in both Barrett's esophagus-related dysplasia and ADCA. The mean AGRN loss in Barrett's esophagus glands was significantly higher in Barrett's esophagus-related dysplasia and ADCA compared with non-dysplastic Barrett's esophagus (NDBE; P < 0.001; specificity = 82.2% and sensitivity = 96.4%). Loss of AGRN was significantly higher in NDBE samples from progressors compared with non-progressors (P < 0.001) and identified patients who progressed to advanced neoplasia with a specificity of 80.2% and sensitivity of 54.8%. Moreover, the combination of AGRN loss and abnormal p53 staining identified progression to Barrett's esophagus-related advanced neoplasia with a specificity and sensitivity of 86.5% and 58.7%. CONCLUSIONS: We highlight ECM changes during Barrett's esophagus progression to neoplasia. BM AGRN loss is a novel diagnostic biomarker that can identify patients with NDBE at increased risk of developing advanced neoplasia.

Progression of Barrett's esophagus, crypt dysplasia, and low-grade dysplasia diagnosed by wide-area transepithelial sampling with 3-dimensional computer-assisted analysis: a retrospective analysis.

BACKGROUND AND AIMS: Wide-area transepithelial sampling with 3-dimensional computer-assisted analysis (WATS3D) is used as an adjunct to forceps biopsy sampling in Barrett's esophagus (BE). BE-associated crypt dysplasia (CD), which can be detected by WATS3D, involves crypts but not surface epithelium. The risk of neoplastic progression of CD has never been evaluated. The prognosis of WATS3D-diagnosed nondysplastic BE (NDBE) and low-grade dysplasia (LGD) is also unknown. We assessed the risk of progression of WATS3D-reported NDBE, CD, and LGD with high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC). METHODS: We analyzed patients who underwent WATS3D in routine care. Eligible patients had 2 WATS3D ≥12 months apart. Patients were categorized by the initial WATS3D finding as NDBE, CD, or LGD. Patient-years of observation were calculated by multiplying the mean follow-up by the number of patients. Progression, defined as a subsequent finding of HGD/EAC on forceps biopsy sampling, was assessed. The crude progression rate was calculated, and Kaplan-Meier analysis compared progression rates stratified by baseline histology. Bivariate analysis identified progression risk factors. RESULTS: Of 151,224 WATS3D cases, 43,145 (29%) had BE. Of these, 4545 patients had 2 WATS3D separated by ≥12 months. The mean follow-up was 1.97 years (range, 1.0-6.42). In patients with baseline NDBE, progression was .08% per patient-year (95% confidence interval [CI], .02%-.14%). Progression of baseline CD was significantly higher, at 1.42% per patient-year (95% CI, 0%-3.01%). For baseline LGD, progression was 5.79% per patient-year (95% CI, 1.02%-10.55%). Other risk factors for progression were increasing age and BE segment length. CONCLUSIONS: NDBE found on WATS3D has a very low risk of progression. CD reported on WATS3D appears to be a neoplastic precursor lesion, with a risk of progression in this study significantly higher than NDBE but lower than LGD. The clinical utility of CD requires further investigation.

Role of Wide-Area Transepithelial Sampling With 3D Computer-Assisted Analysis in the Diagnosis and Management of Barrett's Esophagus.

Barrett's esophagus (BE) is a premalignant condition in which cancer prevention is performed by endoscopic surveillance combined with Seattle protocol mucosal biopsies. The Seattle protocol has significant limitations, including a high rate of sampling error due to the focality of dysplasia/carcinoma, low endoscopist adherence to the protocol, and a high degree of variability in pathologic interpretation. These factors all contribute to a high incidence of cancers missed within 1 year of surveillance endoscopy. Wide-area transepithelial sampling with computer-assisted three-dimensional analysis (WATS3D) is a relatively new technique that minimizes sampling error by using a brush biopsy device that extensively samples "at risk" mucosa and helps pathologists diagnose dysplasia/neoplasia by generating three-dimensional images of whole crypts using a neural network-based software program. Several large prospective trials (involving both academic and community practices) have shown significantly increased rates of detection of dysplasia and intestinal metaplasia in both screening and surveillance in patients with BE when used as an adjunct to Seattle protocol-based forceps biopsies. The WATS3D diagnostic platform was included in the most recent American Society for Gastrointestinal Endoscopy Barrett's guideline as an adjunct to forceps biopsies (conditional recommendation and low quality of evidence). This review summarizes the scientific and pathologic basis of WATS3D technology, its potential impact on BE surveillance and management, and its limitations and future directions.

Diagnosis of digestive system tumours.

The WHO Classification of Tumours provides the international standards for the classification and diagnosis of tumours. It enables direct comparisons to be made between different countries. In the new fifth edition, the series has gone digital with the launch of a website as well as a series of books, known widely as the WHO Blue Books. The first volume to be produced is on the classification of Digestive System tumours, replacing the successful 2010 version. It has been rewritten and updated accordingly. This article summarises the major diagnostic innovations that have occurred over the last decade and that have now been incorporated in the classification. As an example, it incorporates the recently proposed classification of neuroendocrine tumours, based on the recognition that neuroendocrine tumours and carcinomas differ substantially in the genetic abnormalities that drive their growth, findings relevant to treatment selection and outcome prediction. Several themes have emerged during the production process. One is the importance of the progression from hyperplasia to dysplasia to carcinoma in the evolution of the malignant process. Advances in imaging techniques and endoscopy have resulted in enhanced access to precancerous lesions in the gastrointestinal and biliary tract, necessitating both changes in classification schema and clinical practice. Diagnosis of tumours is no longer the sole purview of pathologists, and some patients now receive treatment before tissue is obtained, based on clinical, radiological and liquid biopsy results. This makes the classification relevant to many disciplines involved in the care of patients with tumours of the digestive system.

Gastrointestinal tissue-based molecular biomarkers: a practical categorisation based on the 2019 World Health Organization classification of epithelial digestive tumours.

Molecular biomarkers have come to constitute one of the cornerstones of oncological pathology. The method of classification not only directly affects the manner in which patients are diagnosed and treated, but also guides the development of drugs and of artificial intelligence tools. The aim of this article is to organise and update gastrointestinal molecular biomarkers in order to produce an easy-to-use guide for routine diagnostics. For this purpose, we have extracted and reorganised the molecular information on epithelial neoplasms included in the 2019 World Health Organization classification of tumours. Digestive system tumours, 5th edn.

Role of submucosal glands in the development and progression of carcinoma in Barrett's oesophagus.

Oesophageal submucosal glands secrete mucins and other chemicals that are believed to serve as protectants of the mucosal surface from luminal noxious agents, either ingested or refluxed. Changes in the type, distribution or number of submucosal glands may contribute to, or be associated with, the development of Barrett's oesophagus and progression to cancer. The aim of this study was to investigate the anatomical, morphological and immunohistochemical characteristics of submucosal glands in Barrett's oesophagus-associated neoplasia in 64 oesophageal resections for Barrett's oesophagus-associated adenocarcinoma and 32 squamous cell carcinomas (as a control group). Gland density was not significantly different between the oesophageal adenocarcinoma (0.91/cm) and squamous cell carcinoma (0.81/cm) groups (p=0.7). In the oesophageal adenocarcinoma group, glands underlying Barrett's oesophagus-associated neoplastic epithelium showed a significant decrease in the percentage of mucinous acini and a significant increase in the percentage of atrophic acini compared to glands underlying epithelium without dysplasia or carcinoma (74% vs 83%, p=0.03; and 24% vs 14%, p=0.01). There was also an increase in the percentage of glands with moderate to severe inflammation underlying neoplastic epithelium compared to glands underlying epithelium without dysplasia or carcinoma (53% vs 33%, p=0.001). None of these differences was seen in the squamous cell carcinoma group. The immunohistochemical characteristics of the different histological subtypes were also distinct. Atrophic and oncocytic acini were diffusely and strongly positive for CK7, SOX2, SOX9 and CK5/6 (a progenitor cell phenotype) while mucinous acini showed weak or moderate staining for those markers. Our results suggest that submucosal glands play a role in the progression of neoplasia, possibly by offering less protection to the mucosal surface of the oesophageal epithelium from chemical injury.

LGR5 in Barrett's Esophagus and its Utility in Predicting Patients at Increased Risk of Advanced Neoplasia.

INTRODUCTION: The expression of LGR5, a known stem cell marker, is poorly understood in Barrett's esophagus (BE) and related neoplasia. The aim of this study was to evaluate LGR5 in BE and related neoplasia and to evaluate its utility as a potential biomarker of progression to advanced neoplasia. METHODS: We evaluated total 137 patients, including 119 with BE and 18 with normal gastroesophageal mucosa for expression of LGR5 using RNA in situ hybridization; this also included 28 progressors and 30 nonprogressors. The LGR5 stain was evaluated using 1 qualitative and 2 quantitative parameters, using manual and automated platforms. RESULTS: Surface LGR5 expression was mainly seen in high-grade dysplasia (12/18) compared with low-grade dysplasia (1/8) and nondysplastic BE (0/17) (P < 0.0001). In contrast to nondysplastic BE, low- and high-grade dysplasia showed a higher percentage of mean number of LGR5-positive crypts per patient (P < 0.0001) and an increase in the mean number of LGR5 transcripts per cell (P < 0.0001). The mean percentage of LGR5-positive crypts per patient and the mean number of LGR5 transcripts per cell were also significantly higher in nondysplastic BE from progressor compared with nonprogressor (P < 0.0001, P = 0.014). The sensitivity and specificity of LGR5 for distinguishing progressor from nonprogressor were 50% and 87%, respectively. DISCUSSION: BE-related advanced neoplasia shows an expansion of the LGR5-positive cellular compartment, supporting its role as a stem cell marker in this disease. Quantitative LGR5 expression and surface epithelial reactivity are novel biomarkers of increased risk of progression to advanced neoplasia in BE.