Spatial predisposition of dysplasia in Barrett's esophagus segments: a pooled analysis of the SURF and AIM dysplasia trials

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.

Longitudinal and Circumferential Distributions of Dysplasia and Early Neoplasia in Barrett's Esophagus: A Pooled Analysis of Three Prospective Studies

INTRODUCTION

Studies have shown that dysplasia in Barrett's esophagus (BE) has a predilection for the right hemisphere. There is limited information on the longitudinal distribution. The aim was to determine both the longitudinal and circumferential distributions of dysplasia and early neoplasia from 3 prospective studies.

METHODS

This is a pooled analysis from 3 prospective studies of patients with treatment-naive BE. Both circumferential and longitudinal locations (for BE segments greater than 1 cm) of dysplastic and early neoplastic lesions were recorded.

RESULTS

A total of 177 dysplastic and early neoplastic lesions from 91 patients were included in the pooled analysis; of which 59.3% (n = 105) were seen on high-definition white light endoscopy, 29.4% (n = 52) on advanced imaging, and 11.2% (n = 20) with random biopsies. The average Prague score was C3M5. Of 157 lesions within BE segments greater than 1 cm, 49 (34.8%) lesions were in the proximal half, whereas 92 lesions (65.2%) were in the distal half (P < 0.001). The right hemisphere of the esophagus contained 55% (86/157) of the total lesions compared with 45% (71/157) for the left hemisphere (P = 0.02). This was because of the presence of high-grade dysplasia being concentrated in the right hemisphere compared with the left hemisphere (60% vs 40%, P = 0.002).

DISCUSSION

In this pooled analysis of prospective studies, both low-grade dysplasia and high-grade dysplasia are more frequently found in the distal half of the Barrett's segment. This study confirms that the right hemisphere is a hot spot for high-grade dysplasia. Careful attention to these locations is important during surveillance endoscopy.

Spatial distribution of dysplasia in Barrett's esophagus segments before and after endoscopic ablation therapy: a meta-analysis

BACKGROUND

Dysplasia in Barrett's esophagus (BE) is focal and difficult to locate. The aim of this meta-analysis was to understand the spatial distribution of dysplasia in BE before and after endoscopic ablation therapy.

METHODS

A systematic search was performed of multiple databases to July 2019. The location of dysplasia prior to ablation was determined using a clock-face orientation (right or left half of the esophagus). The location of the dysplasia post-ablation was classified as within the tubular esophagus or at the top of the gastric folds (TGF).

RESULTS

13 studies with 2234 patients were analyzed. Pooled analysis from six studies (819 lesions in 802 patients) showed that before ablation, dysplasia was more commonly located in the right half versus the left half (odds ratio [OR] 4.3; 95 % confidence interval [CI] 2.33 - 7.93; P < 0.001). Pooled analysis from seven studies showed that dysplasia after ablation recurred in 101 /1432 patients (7.05 %; 95 %CI 5.7 % - 8.4 %). Recurrence of dysplasia was located more commonly at the TGF (n = 68) than in the tubular esophagus (n = 34; OR 5.33; 95 %CI 1.75 - 16.21; P = 0.003). Of the esophageal lesions, 90 % (27 /30) were visible, whereas only 46 % (23 /50) of the recurrent dysplastic lesions at the TGF were visible (P < 0.001).

CONCLUSION

Before ablation, dysplasia in BE is found more frequently in the right half of the esophagus versus the left. Post-ablation recurrence is more commonly found in the TGF and is non-visible, compared with the tubular esophagus, which is mainly visible.

The SpaTemp cohort: 168 nondysplastic Barrett's esophagus surveillance patients with and without progression to early neoplasia to evaluate the distribution of biomarkers over space and time

The ReBus cohort is a matched nested case-control cohort of patients with nondysplastic (ND) Barrett's esophagus (BE) at baseline who progressed (progressors) or did not progress (nonprogressors) to high-grade dysplasia (HGD) or cancer. This cohort is constructed using the most stringent inclusion criteria to optimize explorative studies on biomarkers predicting malignant progression in NDBE. These explorative studies may benefit from expanding the number of cases and by incorporating samples that allow assessment of the biomarker over space (spatial variability) and over time (temporal variability). To (i) update the ReBus cohort by identifying new progressors and (ii) identify progressors and nonprogressors within the updated ReBus cohort containing spatial and temporal information. The ReBus cohort was updated by identifying Barrett's patients referred for endoscopic work-up of neoplasia at 4 tertiary referral centers. Progressors and nonprogressors with a multilevel (spatial) endoscopy and additional prior (temporal) endoscopies were identified to evaluate biomarkers over space and over time. The original ReBus cohort consisted of 165 progressors and 723 nonprogressors. We identified 65 new progressors meeting the same strict selection criteria, resulting in a total number of 230 progressors and 723 matched nonprogressors in the updated ReBus cohort. Within the updated cohort, 61 progressors and 107 nonprogressors (mean age 61 ± 10 years) with a spatial endoscopy (median level 3 [2-4]) were identified. 33/61 progressors and 50/107 nonprogressors had a median of 3 (2-4) additional temporal endoscopies. Our updated ReBus cohort consists of 230 progressors and 723 matched nonprogressors using the most strict selection criteria. In a subgroup of 168 Barrett's patients (the SpaTemp cohort), multiple levels have been sampled at baseline and during follow-up providing a unique platform to study spatial and temporal distribution of biomarkers in BE.

What is the optimal surveillance strategy for non-dysplastic Barrett's esophagus?

PURPOSE OF REVIEW

There is conflicting data on the effectiveness of the currently recommended endoscopic surveillance strategy in non-dysplastic BE patients. We reviewed the literature to evaluate the (cost) effectiveness of the current surveillance strategy. We also reviewed critical strategies and new technologies which could improve dysplasia detection.

RECENT FINDINGS

Adherence to the current EGD surveillance guidelines is suboptimal with high rates of missed dysplasia/EAC. The influence of surveillance on EAC mortality appears modest. Careful cleansing, inspection and sampling of the BE mucosa using high resolution while light and (electronic) chromoendoscopy is critical. Newer sampling techniques coupled with computer aided diagnosis and emerging imaging technologies have shown promise in improving dysplasia detection. Personalized surveillance with risk stratification based on risk factors for progression may be on the horizon.

SUMMARY

Current BE surveillance strategy will likely be further refined and optimized by emerging new technologies in tissue sampling, advanced imaging and risk stratification.

Assessment of Barrett's esophagus and dysplasia with ultrahigh-speed volumetric en face and cross-sectional optical coherence tomography

BACKGROUND

This study aimed to evaluate the use of ultrahigh-speed volumetric en face and cross-sectional optical coherence tomography (OCT) with micromotor catheters for the in vivo assessment of Barrett's esophagus and dysplasia.

METHODS

74 OCT datasets with correlated biopsy/endoscopic mucosal resection histology (49 nondysplastic Barrett's esophagus [NDBE], 25 neoplasia) were obtained from 14 patients with Barrett's esophagus and a history of dysplasia and 30 with NDBE. The associations between irregular mucosal patterns on en face OCT, absence of mucosal layering, surface signal > subsurface, and > 5 atypical glands on cross-sectional OCT vs. histology and treatment history were assessed by three blinded readers.

RESULTS

Atypical glands under irregular mucosal patterns occurred in 75 % of neoplasia (96 % of treatment-naïve neoplasia) vs. 30 % of NDBE datasets (43 % of short- and 18 % of long-segment NDBE). Mucosal layering was absent in 35 % of neoplasia and 50 % of NDBE datasets, and surface signal > subsurface occurred in 29 % of neoplasia and 30 % of NDBE datasets.

CONCLUSIONS

Atypical glands under irregular mucosal patterns are strongly associated with neoplasia, suggesting potential markers for dysplasia and a role in pathogenesis.

Length of Barrett's segment predicts failure of eradication in radiofrequency ablation for Barrett's esophagus: a retrospective cohort study

Background

We aim to investigate factors that may contribute to failure of eradication of dysplastic Barrett’s Esophagus among patients undergoing radiofrequency ablation treatment.

Methods

A retrospective review of patients undergoing radiofrequency ablation for treatment of Barrett’s Esophagus was performed. Data analyzed included patient demographics, medical history, length of Barrett’s Esophagus, number of radiofrequency ablation sessions, and histopathology. Subsets of patients achieving complete eradication were compared with those not achieving complete eradication.

Results

A total of 107 patients underwent radiofrequency ablation for Barrett’s Esophagus, the majority white, overweight, and male. Before treatment, 63 patients had low-grade dysplasia, and 44 patients had high-grade dysplasia or carcinoma. Complete eradication was achieved in a majority of patients (57% for metaplasia, and 76.6% for dysplasia). Failure of eradication occurred in 15.7% of patients. The median number of radiofrequency ablation treatments in patients achieving complete eradication was 3 sessions, compared to 4 sessions for failure of eradication (p = 0.06). Barrett’s esophagus length of more than 5 cm was predictive of failure of eradication (p < 0.001).

Conclusions

Radiofrequency ablation for dysplastic Barrett’s Esophagus is a proven and effective treatment modality, associated with a high rate of complete eradication. Our rates of eradication from a center starting an ablation program are comparable to previously published studies. Length of Barrett’s segment > 5 cm was found to be predictive of failure of eradication in patients undergoing radiofrequency ablation.

Management of Barrett's esophagus with low-grade dysplasia

Barrett's esophagus progresses to esophageal adenocarcinoma in a stepwise histological fashion of no dysplasia, low grade dysplasia, high grade dysplasia and cancer. Hence the progression to cancer from various histological stages is different. Progression to cancer from low grade dysplasia is highly variable in the literature due to high inter-observer variability between pathologists in diagnosing it. Studies have shown the utility of having confirmation of low grade dysplasia by expert pathologists or documenting its persistence on two subsequent endoscopies in order to unify the diagnosis. The treatment of low grade dysplasia is variable. In this article we summarize the diagnosis, evaluation and management of low grade dysplasia in Barrett's Esophagus.

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

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

Diagnosis and Management of Low-Grade Dysplasia in Barrett's Esophagus: Expert Review From the Clinical Practice Updates Committee of the American Gastroenterological Association

The purpose of this clinical practice update expert review is to define the key principles in the diagnosis and management of low-grade dysplasia (LGD) in Barrett's esophagus patients. The best practices outlined in this review are based on relevant publications, including systematic reviews and expert opinion (when applicable). Practice Advice 1: The extent of Barrett's esophagus should be defined using a standardized grading system documenting the circumferential and maximal extent of the columnar lined esophagus (Prague classification) with a clear description of landmarks and visible lesions (nodularity, ulceration) when present. Practice Advice 2: Given the significant interobserver variability among pathologists, the diagnosis of Barrett's esophagus with LGD should be confirmed by an expert gastrointestinal pathologist (defined as a pathologist with a special interest in Barrett's esophagus-related neoplasia who is recognized as an expert in this field by his/her peers). Practice Advice 3: Expert pathologists should report audits of their diagnosed cases of LGD, such as the frequency of LGD diagnosed among surveillance patients and/or the difference in incidence of neoplastic progression among patients diagnosed with LGD vs nondysplastic Barrett's esophagus. Practice Advice 4: Patients in whom the diagnosis of LGD is downgraded to nondysplastic Barrett's esophagus should be managed as nondysplastic Barrett's esophagus. Practice Advice 5: In Barrett's esophagus patients with confirmed LGD (based on expert gastrointestinal pathology review), repeat upper endoscopy using high-definition/high-resolution white-light endoscopy should be performed under maximal acid suppression (twice daily dosing of proton pump inhibitor therapy) in 8-12 weeks. Practice Advice 6: Under ideal circumstances, surveillance biopsies should not be performed in the presence of active inflammation (erosive esophagitis, Los Angeles grade C and D). Pathologists should be informed if biopsies are obtained in the setting of erosive esophagitis and if pathology findings suggest LGD, or if no biopsies are obtained, surveillance biopsies should be repeated after the anti-reflux regimen has been further intensified. Practice Advice 7: Surveillance biopsies should be performed in a four-quadrant fashion every 1-2 cm with target biopsies obtained from visible lesions taken first. Practice Advice 8: Patients with a confirmed histologic diagnosis of LGD should be referred to an endoscopist with expertise in managing Barrett's esophagus-related neoplasia practicing at centers equipped with high-definition endoscopy and capable of performing endoscopic resection and ablation. Practice Advice 9: Endoscopic resection should be performed in Barrett's esophagus patients with LGD with endoscopically visible abnormalities (no matter how subtle) in order to accurately assess the grade of dysplasia. Practice Advice 10: In patients with confirmed Barrett's esophagus with LGD by expert GI pathology review that persists on a second endoscopy, despite intensification of acid-suppressive therapy, risks and benefits of management options of endoscopic eradication therapy (specifically adverse events associated with endoscopic resection and ablation), and ongoing surveillance should be discussed and documented. Practice Advice 11: Endoscopic eradication therapy should be considered in patients with confirmed and persistent LGD with the goal of achieving complete eradication of intestinal metaplasia. Practice Advice 12: Patients with LGD undergoing surveillance rather than endoscopic eradication therapy should undergo surveillance every 6 months times 2, then annually unless there is reversion to nondysplastic Barrett's esophagus. Biopsies should be obtained in 4-quadrants every 1-2 cm and of any visible lesions. Practice Advice 13: In patients with Barrett's esophagus-related LGD undergoing ablative therapy, radiofrequency ablation should be used. Practice Advice 14: Patients completing endoscopic eradication therapy should be enrolled in an endoscopic surveillance program. Patients who have achieved complete eradication of intestinal metaplasia should undergo surveillance every year for 2 years and then every 3 years thereafter to detect recurrent intestinal metaplasia and dysplasia. Patients who have not achieved complete eradication of intestinal metaplasia should undergo surveillance every 6 months for 1 year after the last endoscopy, then annually for 2 years, then every 3 years thereafter. Practice Advice 15: Following endoscopic eradication therapy, the biopsy protocol of obtaining biopsies in 4 quadrants every 2 cm throughout the length of the original Barrett's esophagus segment and any visible columnar mucosa is suggested. Practice Advice 16: Endoscopists performing endoscopic eradication therapy should report audits of their rates of complete eradication of dysplasia and intestinal metaplasia and adverse events in clinical practice.