Optimizing endoscopic biopsy detection of early cancers in Barrett's high-grade dysplasia

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.

Incidence of Barrett's Esophagus Following Sleeve Gastrectomy in Southeast Asian Population

Background: Variable incidences (up to 18.8%) of Barrett's esophagus (BE) have been reported following sleeve gastrectomy (SG), however, there is no published data from the Southeast Asian population. Objective: To determine the incidence of BE following SG in Southeast Asians. Materials and Methods: In this cross-sectional observational study from a tertiary-care center, all patients who had undergone SG from 2008 to 2021 and completed a minimum of 1-year follow-up were contacted to participate. Preoperative data were retrieved from a prospectively maintained database. On recruitment, all patients underwent barium swallow and upper gastrointestinal endoscopy, and weight parameters and reflux symptoms were recorded. Results: One hundred fourteen patients with no preoperative evidence of BE were included. The mean follow-up duration was 5.4 ± 3.1 years. On follow-up endoscopy, Barrett's was suspected in 4 patients. However, 3 patients had columnar-lined epithelium and only 1 patient (0.87%) had evidence of intestinal metaplasia without dysplasia on histology. Reflux esophagitis (grade LA-A) resolved in 9 out of 11 patients, while the rate of de novo esophagitis was reported in 22.3%. The mean reflux Symptom Severity score increased from 0.6 ± 1.8 to 2.6 ± 5.4 (P = .002). The mean body mass index reduced from 44.1 ± 7.1 to 33.6 ± 6.9 kg/m2 (P < .0001), however, 23.7% of the patients experienced significant weight recidivism. Conclusions: Southeast Asians might have a low incidence of BE following SG. Hence, endoscopic surveillance for the sole purpose of diagnosing BE may not be advisable for these patients.

Esophageal OCT Imaging Using a Paddle Probe Externally Attached to Endoscope

BACKGROUND AND AIMS

Endoscopic surveillance of Barrett's esophagus (BE) by white light examination is insufficient to diagnose dysplastic change. In this work, we describe an optical imaging method to obtain high-resolution cross-sectional imaging using a paddle-shaped probe affixed to the endoscope tip.

METHODS

We integrated Optical Coherence Tomography (OCT), an optical imaging method that produces cross-sectional images, into a paddle probe attached to video endoscope. We acquired images of esophageal epithelium from patients undergoing routine upper GI endoscopy. Images were classified by a reviewer blinded to patient identity and condition, and these results were compared with clinical diagnosis.

RESULTS

We successfully captured epithelial OCT images from 30 patients and identified features consistent with both squamous epithelium and Barrett's esophagus. Our blinded image reviewer classified BE versus non-BE with 91.5% accuracy (65/71 image regions), including sensitivity of 84.6% for BE (11/13) and a specificity of 93.1% (54/58). However, in 16 patients, intubation of the probe into the esophagus could not be achieved.

CONCLUSIONS

A paddle probe is a feasible imaging format for acquiring cross-sectional OCT images from the esophagus and can provide a structural assessment of BE and non-BE tissue. Probe form factor is the current limiting obstacle, but could be addressed by further miniaturization.

Tubularized and Effaced Gastric Cardia Mimicking Barrett Esophagus following Sleeve Gastrectomy: Protocolized Endoscopic and Histological Assessment with High-Resolution Manometry Analysis

OBJECTIVE

To describe expected endoscopic and histological changes at gastro-esophageal junction (GEJ) and define diagnostic paradigms for Barrett esophagus (BE) post-sleeve gastrectomy (SG).

SUMMARY BACKGROUND DATA

De novo incidence of BE post-SG was reported as high as 18.8%. A confounding factor is the lack of standardized definition of BE post-SG, which may differ from the general population due to procedure-induced alterations of GEJ.

METHODS

Part 1 involved evaluating endoscopic changes of GEJ post-SG (N = 567) compared to pre-SG (N = 320), utilizing protocolized pre-operative screening, post-operative surveillance and synoptic reporting. Part 2 involved dedicated studies examining causes of altered anatomical and mucosal GEJ appearance using histopathology (N = 55) and high-resolution manometry (HRM) (N = 15).

RESULTS

Part 1 - A characteristic tubularized cardia segment projecting supra-diaphragmatically was identified and almost exclusive to post-SG (0.6%vs.26.6%, p < 0.001). True BE prevalence was low (4.1%pre-SG vs. 3.8%post-SG, p = 0.756), esophagitis was comparable (32.1%vs.25.9%, p = 0.056).Part 2 - Histologically-confirmed BE was found in 12/55 patients, but 70.8% had glandular-type gastric mucosa implying tubularized cardia herniation. HRM of tubularized cardia demonstrated concordance of supra-diaphragmatic cardia herniation between endoscopy and HRM (3cmvs.3.2 cm, p = 0.168), with frequent elevated isobaric intraluminal pressurizations in supra- and infra-diaphragmatic cardia compartments.

CONCLUSION

A novel appearance of tubularized cardia telescoping supra-diaphragmatically with flattening of gastric folds is common post-SG, likely associated with isobaric hyper-pressurization of proximal stomach. Incidence of true BE post-SG is low in short-intermediate term. These provided a clear framework for approaching endoscopic screening and surveillance, with correct anatomical and mucosal identifications, and clarified key issues of SG and BE.

Management of nondysplastic Barrett’s esophagus: When to survey? When to ablate?

Barrett’s esophagus (BE), a precursor for esophageal adenocarcinoma (EAC), is defined as salmon-colored mucosa extending more than 1 cm proximal to the gastroesophageal junction with histological evidence of intestinal metaplasia. The actual risk of EAC in nondysplastic Barrett’s esophagus (NDBE) is low with an annual incidence of 0.3%. The mainstay in the management of NDBE is control of gastroesophageal reflux disease (GERD) along with enrollment in surveillance programs. The current recommendation for surveillance is four-quadrant biopsies every 2 cm (or 1 cm in known or suspected dysplasia) followed by biopsy of mucosal irregularity (nodules, ulcers, or other visible lesions) performed at 3- to 5-year intervals. Challenges to surveillance include missed cancers, suboptimal adherence to surveillance guidelines, and lack of strong evidence for efficacy. There is minimal role for endoscopic eradication therapy in NDBE. The role for enhanced imaging techniques, artificial intelligence, and risk prediction models using clinical data and molecular markers is evolving.

Utility of ancillary studies in the diagnosis and risk assessment of Barrett's esophagus and dysplasia

Barrett's esophagus (BE) is a major risk factor for the development of esophageal adenocarcinoma (EAC). BE patients undergo periodic endoscopic surveillance with biopsies to detect dysplasia and EAC, but this strategy is imperfect owing to sampling error and inconsistencies in the diagnosis and grading of dysplasia, which may result in an inaccurate diagnosis or risk assessment for progression to EAC. The desire for more accurate diagnosis and better risk stratification has prompted the investigation and development of potential biomarkers that might assist pathologists and clinicians in the management of BE patients, allowing more aggressive endoscopic surveillance and treatment options to be targeted to high-risk individuals, while avoiding frequent surveillance or unnecessary interventions in those at lower risk. It is known that progression of BE to dysplasia and EAC is accompanied by a host of genetic alterations, and that exploration of these markers could be potentially useful to diagnose/grade dysplasia and/or to risk stratify BE patients. Several biomarkers have shown promise in identifying early neoplastic transformation and thus may be useful adjuncts to histologic evaluation. This review provides an overview of some of the currently available biomarkers and assays, including p53 immunostaining, Wide Area Transepithelial Sampling with Three-Dimensional Computer-Assisted Analysis (WATS^3D), TissueCypher, mutational load analysis (BarreGen), fluorescence in situ hybridization, and DNA content abnormalities as detected by DNA flow cytometry.

Barrett's Esophagus: Diagnosis, Management, and Key Updates

Barrett's esophagus (BE) is the precursor lesion for esophageal adenocarcinoma (EAC) development. Unfortunately, BE screening/surveillance has not provided the anticipated EAC reduction benefit. Noninvasive techniques are increasingly available or undergoing testing to screen for BE among those with/without known risk factors, and the use of artificial intelligence platforms to aid endoscopic screening and surveillance will likely become routine, minimizing missed cases or lesions. Management of high-grade dysplasia and intramucosal EAC is clear with endoscopic eradication therapy preferred to surgery. BE with low-grade dysplasia can be managed with removal of visible lesions combined with endoscopic eradication therapy or endoscopic surveillance at present.

Gastro-esophageal reflux disease and Barrett's esophagus: an overview with an histologic diagnostic approach

The first part of this overview on non-neoplastic esophagus is focused on gastro-esophageal reflux disease (GERD) and Barrett’s esophagus. In the last 20 years much has changed in histological approach to biopsies of patients with gastro-esophageal reflux disease. In particular, elementary histologic lesions have been well defined and modality of evaluation and grade are detailed, their sensitivity and specificity has been evaluated and their use has been validated by several authors. Also if there is not a clinical indication to perform biopsies in patient with GERD, the diagnosis of microscopic esophagitis, when biopsies are provided, can be performed by following simple rules for evaluation which allow pathologists to make the diagnosis with confidence. On the other hand, biopsies are required for the diagnosis of Barrett’s esophagus. This diagnosis is the synthesis of endoscopic picture (which has to be provided with the proper description on extent and with adequate biopsies number) and histologic pattern. The current guidelines and expert opinions for the correct management of these diagnosis are detailed.

Wide-area transepithelial sampling in adjunct to forceps biopsy increases the absolute detection rates of Barrett's oesophagus and oesophageal dysplasia: a meta-analysis and systematic review

Background

Wide-area transepithelial sampling (WATS) is a new technique that uses an abrasive brush to obtain samples from a larger surface area of the oesophagus. Studies have shown promising results that WATS in adjunct to forceps biopsy (FB) increases the detection rate of Barrett’s oesophagus (BE) as well as oesophageal dysplasia (ED). We conducted a systematic review and meta-analysis to compare the detection rates of BE and ED between FB and WATS in adjunct to FB.

Methods

A Literature search was done using electronic databases, including PubMed, Embase, Scopus, Cochrane and CINAHL from inception to 26 April 2020. A meta-analysis comparing detection rates of WATS in adjunct to FB versus FB using the random-effects model was done using RevMan V.5.3.

Results

Pooled data from 20 392 endoscopies across 11 studies showed an absolute increase in detection of 16% (95% CI 0.10% to 0.22%, p<0.00001). A relative increase of 1.62 was seen in detection rates of BE (95% CI 1.28 to 2.05, p<0.0001) when WATS was used with FB with the number needed to test (NNT) of 6.1 patients. For ED, a 2% absolute increase (95% CI 0.01 to 0.03, p=0.001) in additional diagnostic yield from WATS. A relative increase of 2.05 was seen in the detection rate of ED (95% CI 1.42 to 2.98, p=0.0001) yielding an NNT of 50 patients.

Conclusion

Our study shows that WATS, as an adjunct to FB, improves both the absolute detection rate and relative detection rate of both BE and ED as compared to FB alone.

Use of Artificial Intelligence to Improve the Quality Control of Gastrointestinal Endoscopy

With the rapid development of science and technology, artificial intelligence (AI) systems are becoming ubiquitous, and their utility in gastroenteroscopy is beginning to be recognized. Digestive endoscopy is a conventional and reliable method of examining and diagnosing digestive tract diseases. However, with the increase in the number and types of endoscopy, problems such as a lack of skilled endoscopists and difference in the professional skill of doctors with different degrees of experience have become increasingly apparent. Most studies thus far have focused on using computers to detect and diagnose lesions, but improving the quality of endoscopic examination process itself is the basis for improving the detection rate and correctly diagnosing diseases. In the present study, we mainly reviewed the role of AI in monitoring systems, mainly through the endoscopic examination time, reducing the blind spot rate, improving the success rate for detecting high-risk lesions, evaluating intestinal preparation, increasing the detection rate of polyps, automatically collecting maps and writing reports. AI can even perform quality control evaluations for endoscopists, improve the detection rate of endoscopic lesions and reduce the burden on endoscopists.

Endoscopic radiofrequency ablation or surveillance in patients with Barrett's oesophagus with confirmed low-grade dysplasia: a multicentre randomised trial

OBJECTIVE

Due to an annual progression rate of Barrett's oesophagus (BO) with low-grade dysplasia (LGD) between 9% and 13% per year endoscopic ablation therapy is preferred to surveillance. Since this recommendation is based on only one randomised trial, we aimed at checking these results by another multicentre randomised trial with a similar design.

DESIGN

A prospective randomised study was performed in 14 centres comparing radiofrequency ablation (RFA) (maximum of 4 sessions) to annual endoscopic surveillance, including patients with a confirmed diagnosis of BO with LGD. Primary outcome was the prevalence of LGD at 3 years. Secondary outcomes were the prevalence of LGD at 1 year, the complete eradication of intestinal metaplasia (CE-IM) at 3 years, the rate of neoplastic progression at 3 years and the treatment-related morbidity.

RESULTS

125 patients were initially included, of whom 82 with confirmed LGD (76 men, mean age 62.3 years) were finally randomised, 40 patients in the RFA and 42 in the surveillance group. At 3 years, CE-IM rates were 35% vs 0% in the RFA and surveillance groups, respectively (p<0.001). At the same time, the prevalence LGD was 34.3% (95% CI 18.6 to 50.0) in the RFA group vs 58.1% (95% CI 40.7 to 75.4) in the surveillance group (OR=0.38 (95% CI 0.14 to 1.02), p=0.05). Neoplastic progression was found in 12.5% (RFA) vs 26.2% (surveillance; p=0.15). The complication rate was maximal after the first RFA treatment (16.9%).

CONCLUSION

RFA modestly reduced the prevalence of LGD as well as progression risk at 3 years. The risk-benefit balance of endoscopic ablation therapy should therefore be carefully weighted against surveillance in patients with BO with confirmed LGD.

TRIAL REGISTRATION NUMBER

NCT01360541.

Barrett esophagus: What to expect from Artificial Intelligence?

The evaluation and assessment of Barrett's esophagus is challenging for both expert and nonexpert endoscopists. However, the early diagnosis of cancer in Barrett's esophagus is crucial for its prognosis, and could save costs. Pre-clinical and clinical studies on the application of Artificial Intelligence (AI) in Barrett's esophagus have shown promising results. In this review, we focus on the current challenges and future perspectives of implementing AI systems in the management of patients with Barrett's esophagus.

Barrett's esophagus: current standards in advanced imaging

Esophageal adenocarcinoma (EAC) continues to be one of the fastest rising incident cancers in the Western population with the majority of patients presenting with late stage disease and associated with a dismal 5-year survival rate. Barrett's esophagus (BE) is the only identifiable precursor lesion to EAC. Strategies to screen for and survey BE are critical to detect earlier cancers and reduce morbidity and mortality related to EAC. A high-quality endoscopic examination with careful inspection of the Barrett's segment and adherence to the Seattle protocol for tissue sampling are critical. Advanced imaging modalities offer the potential to improve dysplasia detection, predict histopathology in real time and guide endoscopic eradication therapy (EET). Several technologies have been studied and although most are not yet recommended for routine clinical practice, high definition white light endoscopy (HD-WLE) as well as chromoendoscopy (including virtual chromoendoscopy) improved dysplasia detection in numerous studies supporting their use. Future studies should evaluate the role of artificial intelligence in optimizing detection of dysplasia in BE patients.

Best Practices in Surveillance for Barrett's Esophagus

Barrett's esophagus is the precursor lesion for esophageal adenocarcinoma. The goals of endoscopic surveillance are to detect dysplasia and early esophageal adenocarcinoma in order to improve patient outcomes. Despite the ongoing debate regarding the efficacy of surveillance, all current gastrointestinal societies recommend surveillance at this time. Optimal surveillance technique includes adequate inspection time, evaluation using high-definition white light and chromoendoscopy, appropriate documentation of the metaplastic segment using the Prague C & M criteria as well as the Paris classification should lesions be found, utilization of the Seattle biopsy protocol, and endoscopic resection of visible lesions.

Artificial intelligence and its impact on quality improvement in upper and lower gastrointestinal endoscopy

Artificial intelligence (AI) and its application in medicine has grown large interest. Within gastrointestinal (GI) endoscopy, the field of colonoscopy and polyp detection is the most investigated, however, upper GI follows the lead. Since endoscopy is performed by humans, it is inherently an imperfect procedure. Computer-aided diagnosis may improve its quality by helping prevent missing lesions and supporting optical diagnosis for those detected. An entire evolution in AI systems has been established in the last decades, resulting in optimization of the diagnostic performance with lower variability and matching or even outperformance of expert endoscopists. This shows a great potential for future quality improvement of endoscopy, given the outstanding diagnostic features of AI. With this narrative review, we highlight the potential benefit of AI to improve overall quality in daily endoscopy and describe the most recent developments for characterization and diagnosis as well as the recent conditions for regulatory approval.

Distal Esophageal Impedance Measured by High-resolution Esophageal Manometry With Impedance Suggests the Presence of Barrett's Esophagus

Background/Aims

Barrett's esophagus (BE) is characterized by intestinal metaplasia in the distal esophagus. The aims of this study are to: (1) Compare baseline distal esophageal impedance (DEI) using high-resolution esophageal manometry with impedance (HREMI) in patients with BE, esophagitis, and healthy volunteers and (2) Correlate length of low impedance on HREMI in patients with BE to the length of endoscopic BE.

Methods

Patients with BE or esophagitis who underwent HREMI were included. Ten volunteers had HREMI. Baseline DEI was calculated from HREMI using the landmark segment. In patients with BE, the impedance was plotted to measure the extent of plotted low impedance (PLI) and visual low impedance (VLI). Lengths of VLI and PLI were correlated to endoscopic length of BE by Prague score.

Results

Forty-five patients were included (16 BE; 19 esophagitis; 10 volunteers). BE patients had lower baseline DEI at the first, second, and third sensors above the lower esophageal sphincter (mean ± SEM: 1.37 ± 0.45, 0.97 ± 0.27, and 0.81 ± 0.20) compared to volunteers (8.73 ± 0.60, 8.20 ± 0.73, and 6.94 ± 0.99; P < 0.001). Baseline DEI was lower in BE than esophagitis patients (2.98 ± 0.65, 2.49 ± 0.56, and 2.01 ± 0.51) at the first, second, and third sensors (P < 0.052 for second and third sensors); ie, BE < esophagitis < controls. PLI and VLI had a stronger correlation to circumferential score (r² = 0.84 and 0.83) than maximal score (r² = 0.76 and 0.68).

Conclusions

Baseline DEI is lower in BE compared with esophagitis and healthy volunteers. The length of low impedance correlates to the endoscopic extent of BE. Thus, impedance values during HREMI may help suggest the presence and extent of BE or esophagitis.

Aneuploidy in targeted endoscopic biopsies outperforms other tissue biomarkers in the prediction of histologic progression of Barrett's oesophagus: A multi-centre prospective cohort study

Background

The cancer risk in Barrett's oesophagus (BO) is difficult to estimate. Histologic dysplasia has strong predictive power, but can be missed by random biopsies. Other clinical parameters have limited utility for risk stratification. We aimed to assess whether a molecular biomarker panel on targeted biopsies can predict neoplastic progression of BO.

Methods

203 patients with BO were tested at index endoscopy for 9 biomarkers (p53 and cyclin A expression; aneuploidy and tetraploidy; CDKN2A (p16), RUNX3 and HPP1 hypermethylation; 9p and 17p loss of heterozygosity) on autofluorescence-targeted biopsies and followed-up prospectively. Data comparing progressors to non-progressors were evaluated by univariate and multivariate analyses using survival curves, Cox-proportional hazards and logistic regression models.

Findings

127 patients without high-grade dysplasia (HGD) or oesophageal adenocarcinoma (OAC) at index endoscopy were included, of which 42 had evidence of any histologic progression over time. Aneuploidy was the only predictor of progression from non-dysplastic BO (NDBO) to any grade of neoplasia (p = 0.013) and HGD/OAC (p = 0.002). Aberrant p53 expression correlated with risk of short-term progression within 12 months, with an odds ratio of 6.0 (95% CI: 3.1–11.2). A panel comprising aneuploidy and p53 had an area under the receiving operator characteristics curve of 0.68 (95% CI: 0.59–0.77) for prediction of any progression.

Interpretation

Aneuploidy is the only biomarker that predicts neoplastic progression of NDBO. Aberrant p53 expression suggests prevalent dysplasia, which might have been missed by random biopsies, and warrants early follow up.

Volumetric laser endomicroscopy in Barrett's esophagus: ready for primetime

Barrett's esophagus (BE) is the condition where intestinal metaplastic changes are found in the normal stratified squamous epithelium of the esophagus predisposing an individual to dysplasia and esophageal adenocarcinoma (EAC). It tends to affect males and is often the result of chronic gastroesophageal reflux disease (GERD). The current standard of therapy for diagnosing Barrett's is white light endoscopy (WLE) with biopsies obtained using the Seattle protocol. Multiple newer advanced modalities have been developed to improve diagnostic abilities, including volumetric laser endomicroscopy (VLE). This technique utilizes second generation optical coherence tomography (OCT) to provide an enhanced circumferential image to a depth of 3 mm with the potential for improved diagnostic yield for dysplasia, particularly submucosal lesions or lesions not seen by WLE. It has also been evaluated in guiding mapping of endotherapy as well as post therapy surveillance for recurrence. Although the results have been promising when used with current diagnostic standards, overall data are limited to support the routine use of VLE.

Clinical impact of FDG PET/CT in alimentary tract malignancies: an updated review

The use of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography combined with computed tomography (PET/CT) is well established in the evaluation of alimentary tract malignancies. This review of the literature and demonstration of correlative images focuses on the current role of PET/CT in the diagnosis (including pathologic/clinical staging) and post-therapy follow-up of esophageal, gastric, and colorectal cancers. PET/CT provides utility in the management of esophageal cancer, including detection of distant disease prior to resection. In gastric cancer, PET/CT is useful in detecting solid organ metastases and in characterizing responders vs. non-responders after neoadjuvant chemotherapy, the latter of which have poorer overall survival. In patients with GIST tumors, PET/CT also determines response to imatinib therapy with greater expedience as compared to CECT. For colorectal cancer, PET/CT has proven helpful in detecting hepatic and other distant metastases, treatment response, and differentiating post-radiation changes from tumor recurrence. Our review also highlights several pitfalls in PET/CT interpretation of alimentary tract lesions.

Predictors of dysplastic and neoplastic progression of Barrett’s esophagus

Background

It is unknown why some cases of Barrett’s esophagus progress to invasive malignant disease rapidly while others do so more slowly or not at all. The aim of this study was to identify demographic and endoscopic factors that predict dysplastic and neoplastic progression in patients with Barrett’s esophagus.

Methods

Patients with Barrett’s esophagus who were assessed in 2000–2010 were assessed for inclusion in this retrospective study. Demographic and endoscopic variables were collected from an endoscopy database and the medical chart. Dysplastic and neoplastic progression was examined by time-to-event analysis. We used Cox proportional hazard regression modelling and generalized estimating equation methods to identify variables that were most predictive of neoplastic progression.

Results

A total of 518 patients had Barrett’s esophagus confirmed by endoscopy and pathology and at least 2 surveillance visits. Longer Barrett’s esophagus segment (≥ 3 cm) (odds ratio [OR] 1.2, 95% confidence interval [CI] 1.1–1.3) and increased age (≥ 60 yr) (OR 3.5, 95% CI 1.7–7.4) were independent predictors of progression from nondysplasia to dysplastic or neoplastic grades. Presence of mucosal irregularities (OR 8.6, 95% CI 2.4–30.4) and increased age (OR 5.1, 95% CI 1.6–16.6) were independent predictors of progression from nondysplasia to high-grade dysplasia or adenocarcinoma.

Conclusion

Increased age, longer Barrett’s segment and presence of mucosal irregularities were associated with increased risk of dysplastic and neoplastic progression. In addition to dysplasia, these factors may help stratify patients according to risk of neoplastic progression and be used to individualize surveillance. More prospective studies with larger samples are required to validate these results.

Modeling clinical assessor intervariability using deep hypersphere encoder–decoder networks

In medical imaging, a proper gold-standard ground truth as, e.g., annotated segmentations by assessors or experts is lacking or only scarcely available and suffers from large intervariability in those segmentations. Most state-of-the-art segmentation models do not take inter-observer variability into account and are fully deterministic in nature. In this work, we propose hypersphere encoder–decoder networks in combination with dynamic leaky ReLUs, as a new method to explicitly incorporate inter-observer variability into a segmentation model. With this model, we can then generate multiple proposals based on the inter-observer agreement. As a result, the output segmentations of the proposed model can be tuned to typical margins inherent to the ambiguity in the data. For experimental validation, we provide a proof of concept on a toy data set as well as show improved segmentation results on two medical data sets. The proposed method has several advantages over current state-of-the-art segmentation models such as interpretability in the uncertainty of segmentation borders. Experiments with a medical localization problem show that it offers improved biopsy localizations, which are on average 12% closer to the optimal biopsy location.

Endoscopists systematically undersample patients with long-segment Barrett's esophagus: an analysis of biopsy sampling practices from a quality improvement registry

BACKGROUND AND AIMS

Guidelines recommend systematic biopsy sampling in Barrett's esophagus (BE) to reduce sampling error. Adherence to this biopsy sampling protocol has been suggested as a quality indicator; however, estimates of adherence are not available. Using a national registry, we assessed adherence and identified predictors of adherence to biopsy sampling protocols.

METHODS

We analyzed data from the GI Quality Improvement Consortium Registry that included procedure indication, demographics, endoscopy, and pathology results. Patients with an indication of BE screening/surveillance or an endoscopic finding of BE were included. Adherence to the Seattle protocol was assessed by dividing BE length by number of pathology jars, with a ratio ≤2.0 with rounding down (lenient definition) or rounding up (stringent definition) for odd BE lengths considered adherent. Variables associated with adherence were assessed using generalized estimating equations to control for clustering within individual physicians.

RESULTS

Of 786,712 EGDs assessed, 58,709 (7.5%) EGDs in 53,541 patients met inclusion criteria (mean age, 61.3 years; 60.4% men; 90.2% white; mean BE length, 2.3 cm). When the lenient and stringent definitions for adherence were used, 87.8% and 82.7% of EGDs were adherent, respectively. Increasing BE length was the most significant predictor of nonadherence (odds ratio, .69; 95% confidence interval, .67-.71). Other predictors were increasing age, male gender, increasing American Society of Anesthesiologists class, and practice location. Performance of EGD by nongastroenterologist physicians was associated with nonadherence (odds ratio, .07; 95% confidence interval, .06-.10).

CONCLUSIONS

Nearly 20% of endoscopies performed in BE patients were not adherent to the Seattle protocol. As BE length increases, endoscopists become less compliant with odds of nonadherence increasing by 31% with every 1-cm increase in length.

Anatomic location of Barrett's esophagus recurrence after endoscopic eradication therapy: development of a simplified surveillance biopsy strategy

BACKGROUND AND AIMS

Surveillance endoscopy is recommended after endoscopic eradication therapy (EET) for Barrett's esophagus (BE) because of the risk of recurrence. Currently recommended biopsy protocols are based on expert opinion and consist of sampling visible lesions followed by random 4-quadrant biopsy sampling throughout the length of the original BE segment. Despite this protocol, some recurrences are not visibly identified. We aimed to identify the anatomic location and histology of recurrences after successful EET with the goal of developing a more efficient and evidence-based surveillance biopsy protocol.

METHODS

We performed an analysis of a large multicenter database of 443 patients who underwent EET and achieved complete eradication of intestinal metaplasia (CE-IM) from 2005 to 2015. The endoscopic location of recurrence relative to the squamocolumnar junction (SCJ), visible recurrence identified during surveillance endoscopy, and time to recurrence after CE-IM were assessed.

RESULTS

Fifty patients with BE recurrence were studied in the final analysis. Seventeen patients (34%) had nonvisible recurrences. In this group, biopsy specimens demonstrating recurrence were taken from within 2 cm of the SCJ in 16 of these 17 patients (94%). Overall, 49 of 50 recurrences (98%) occurred either within 2 cm of the SCJ or at the site of a visible lesion. Late recurrences (>1 year) were more likely to be visible than early (<1 year) recurrences (P = .006).

CONCLUSIONS

Recurrence after EET detected by random biopsy sampling is identified predominately in the distal esophagus and occurs earlier than visible recurrences. As such, we suggest a modified biopsy protocol with targeted sampling of visible lesions followed by random biopsy sampling within 2 cm of the SCJ to optimize detection of recurrence after EET. (Clinical trial registration number: NCT02634645.).

Therapeutic options for early cancer of the esophagogastric junction

Early-stage (T1) esophagogastric junction cancer continues to represent 2-3% of all cases. Adenocarcinoma is the most frequent and important type, the main risk factors for which are gastroesophageal reflux and Barrett's esophagus with dysplasia. Patients with mucosal (T1a) or submucosal (T1b) involvement initially require a thorough digestive endoscopy, and narrow-band imaging can improve visualization. Endoscopic treatment of these lesions includes endoscopic mucosal resection, radiofrequency ablation and endoscopic submucosal dissection. Accurate staging is necessary in order to provide optimal treatment. The most precise staging technique in these cases is endoscopic ultrasound. The suspicion of deep invasion of the submucosa, presence of unfavorable anatomopathological characteristics or impossibility to perform endoscopic resection make it necessary to consider surgical resection.

Squamous Cellular Carcinoma Antigen Serum Determination as a Biomarker of Barrett Esophagus and Esophageal Cancer: A Phase III Study

GOAL

To evaluate the potential role of the determination of the immunocomplexed form of squamous cell carcinoma antigen [SCCA-immunoglobulin (Ig)M] for the screening of Barrett esophagus (BE) and esophageal adenocarcinoma (EAC).

BACKGROUND

The cost-effectiveness of surveillance in BE is still debated and the use of biomarkers in screening and surveillance still not recommended. No information is available regarding SCCA-IgM determination in BE.

STUDY

SCCA-IgM levels were determined (enzyme-linked immunosorbent assay) in 231 patients prospectively recruited, 71 with BE, 53 with EAC, and 107 controls, including 42 blood donors and 65 patients with gastroesophageal reflux. SCCA-IgM cutoffs between BE/EAC and controls and for BE "at risk" versus short nondysplastic BE were calculated by receiver operating characteristic curves. Immunostaining for SCCA-IgM was obtained in a subgroup of patients.

RESULTS

Median SCCA-IgM values were significantly higher in BE and EAC than in controls (P=0.0001). Patients with SCCA-IgM levels above the cutoff had a 33 times higher relative risk of harboring BE or EAC (P=0.0001). Patients "at risk," with long or dysplastic BE had SCCA-IgM levels significantly higher than those with short nondysplastic BE (P=0.035) and patients with SCCA-IgM above the cutoff had a 8 times higher relative risk of having BE "at risk." SCCA was expressed in Barrett mucosa but not in cardiac metaplasia.

CONCLUSIONS

Serum SCCA-IgM determination allows the identification of patients at risk for BE/EAC and the stratification of BE patients in subgroups with different cancer risk. Because of the still limited number of controls, large, prospective studies are required to confirm this evidence.

Predictive features for early cancer detection in Barrett's esophagus using Volumetric Laser Endomicroscopy

The incidence of Barrett cancer is increasing rapidly and current screening protocols often miss the disease at an early, treatable stage. Volumetric Laser Endomicroscopy (VLE) is a promising new tool for finding this type of cancer early, capturing a full circumferential scan of Barrett's Esophagus (BE), up to 3-mm depth. However, the interpretation of these VLE scans can be complicated, due to the large amount of cross-sectional images and the subtle grayscale variations. Therefore, algorithms for automated analysis of VLE data can offer a valuable contribution to its overall interpretation. In this study, we broadly investigate the potential of Computer-Aided Detection (CADe) for the identification of early Barrett's cancer using VLE. We employ a histopathologically validated set of ex-vivo VLE images for evaluating and comparing a considerable set of widely-used image features and machine learning algorithms. In addition, we show that incorporating clinical knowledge in feature design, leads to a superior classification performance and additional benefits, such as low complexity and fast computation time. Furthermore, we identify an optimal tissue depth for classification of 0.5-1.0 mm, and propose an extension to the evaluated features that exploits this phenomenon, improving their predictive properties for cancer detection in VLE data. Finally, we compare the performance of the CADe methods with the classification accuracy of two VLE experts. With a maximum Area Under the Curve (AUC) in the range of 0.90-0.93 for the evaluated features and machine learning methods versus an AUC of 0.81 for the medical experts, our experiments show that computer-aided methods can achieve a considerably better performance than trained human observers in the analysis of VLE data.

1.65 mm diameter forward-viewing confocal endomicroscopic catheter using a flip-chip bonded electrothermal MEMS fiber scanner

We report a 1.65 mm diameter forward-viewing confocal endomicroscopic catheter using a flip-chip bonded electrothermal MEMS fiber scanner. Lissajous scanning was implemented by the electrothermal MEMS fiber scanner. The Lissajous scanned MEMS fiber scanner was precisely fabricated to facilitate flip-chip connection, and bonded with a printed circuit board. The scanner was successfully combined with a fiber-based confocal imaging system. A two-dimensional reflectance image of the metal pattern 'OPTICS' was successfully obtained with the scanner. The flip-chip bonded scanner minimizes electrical packaging dimensions. The inner diameter of the flip-chip bonded MEMS fiber scanner is 1.3 mm. The flip-chip bonded MEMS fiber scanner is fully packaged with a 1.65 mm diameter housing tube, 1 mm diameter GRIN lens, and a single mode optical fiber. The packaged confocal endomicroscopic catheter can provide a new breakthrough for diverse in-vivo endomicroscopic applications.

Diagnosis and Endoscopic Management of Barrett's Esophagus: an Italian Experts' Opinion based document

BACKGROUND

Barrett's esophagus (BE) is recognized as a risk factor for esophageal adenocarcinoma. An expert panel was organized in Italy with the aim of drafting a series of statements on BE to guide diagnosis and management of patients with BE.

METHODS

The working Group Coordinators worked on a literature search to identify key topics regarding critical steps of the endoscopic approach to BE. Based on the search and their expert opinion, a list of most meaningful questions was prepared and emailed to all members who were asked to vote the questions. When the survey was completed a consensus meeting was organized. According to the survey results, Group Coordinators proposed a draft statement that was voted. By definition, the statement was formulated when there was an agreement of ≥50% among participants.

RESULTS

Twenty nine participants deliberated 18 questions. The agreement was reached for 16 questions for which a recommendation was formulated.

CONCLUSION

The generated statements highlight the Italian contribution to the European Position Statement of the European Society of Gastrointestinal Endoscopy. The Italian statements preserve peculiarities when dealing with the endoscopic management of BE and wishes to be considered as a contribution for the care of BE patients even with a low risk of progression to esophageal neoplasia.

Evolution of Premalignant Disease

Where does cancer come from? Although the cell-of-origin is difficult to pinpoint, cancer clones harbor information about their clonal ancestries. In an effort to find cells before they evolve into a life-threatening cancer, physicians currently diagnose premalignant diseases at frequencies that substantially exceed those of clinical cancers. Cancer risk prediction relies on our ability to distinguish between which premalignant features will lead to cancer mortality and which are characteristic of inconsequential disease. Here, we review the evolution of cancer from premalignant disease, and discuss the concept that even phenotypically normal cell progenies inherently gain more malignant potential with age. We describe the hurdles of prognosticating cancer risk in premalignant disease by making reference to the underlying continuous and multivariate natures of genotypes and phenotypes and the particular challenge inherent in defining a cell lineage as "cancerized."

Performance characteristics of optical coherence tomography in assessment of Barrett's esophagus and esophageal cancer: systematic review

Optical coherence tomography (OCT) can generate high-resolution images of the esophagus that allows cross-sectional visualization of esophageal wall layers. We conducted a systematic review to assess the utility of OCT for diagnosing of esophageal intestinal metaplasia (IM; Barrett's esophagus BE)), dysplasia, cancer and staging of early esophageal cancer. English language human observational studies and clinical trials published in PubMed and Embase were included if they assessed any of the following: (i) in-vivo features and accuracy of OCT at diagnosing esophageal IM, sub-squamous intestinal metaplasia (SSIM), dysplasia, or cancer, and (ii) accuracy of OCT in staging esophageal cancer. Twenty-one of the 2,068 retrieved citations met inclusion criteria. In the two prospective studies that assessed accuracy of OCT at identifying IM, sensitivity was 81%-97%, and specificity was 57%-92%. In the two prospective studies that assessed accuracy of OCT at identifying dysplasia and early cancer, sensitivity was 68%-83%, and specificity was 75%-82%. Observational studies described significant variability in the ability of OCT to accurately identify SSIM. Two prospective studies that compared the accuracy of OCT at staging early squamous cell carcinoma to histologic resection specimens reported accuracy of >90%. Risk of bias and applicability concerns was rated as low among the prospective studies using the QUADAS-2 questionnaire. OCT may identify intestinal metaplasia and dysplasia, but its accuracy may not meet recommended thresholds to replace 4-quadrant biopsies in clinical practice. OCT may be more accurate than EUS at staging early esophageal cancer, but randomized trials and cost-effective analyses are lacking.

Endoscopic imaging using surface-enhanced Raman scattering

In this review, we assessed endoscopic imaging using surface-enhanced Raman scattering (SERS). As white-light endoscopy, the current standard for gastrointestinal endoscopy, is limited to morphology, Raman endoscopy using surface-enhanced Raman scattering nanoparticles (SERS endoscopy) was introduced as one of the novel functional modalities. SERS endoscopy has multiplex capability and high sensitivity with low autofluorescence and photobleaching. As a result, multiple molecular characteristics of the lesion can be accurately evaluated in real time while performing endoscopy using SERS probes and appropriate instrumentation. Especially, recently developed dual modality of fluorescence and SERS endoscopy offers easy localization with identification of multiple target molecules. For clinical use of SERS endoscopy in the future, problems of limited field of view and cytotoxicity should be addressed by fusion imaging, topical administration, and non-toxic coating of nanoparticles. We expect SERS endoscopic imaging would be an essential endoscopic technique for diagnosis of cancerous lesions, assessment of resection margins and evaluation of therapeutic responses.

Update on Endoscopy-Based Imaging Techniques in the Diagnosis of Esophageal Cancer

ABSTRACT: The early diagnosis of esophageal cancer is necessary for improving the surviving of patients with this disease. To ensure an accurate staging, there are necessary imaging tests to establish the local and regional extension, as well as excluding the metastases. Computed tomography (CT), endoscopic ultrasonography (EUS), and positron emission computed tomography (PET-CT) constitute standard methods for esophageal cancer staging. These techniques are complementary; using only one of these tests is not suitable for correct staging. The role of EUS has improved the doctors’ ability to evaluate and select the patients to undergo surgery, radiotherapy, or chemotherapy.

Application of a multi-gene next-generation sequencing panel to a non-invasive oesophageal cell-sampling device to diagnose dysplastic Barrett's oesophagus

The early detection and endoscopic treatment of patients with the dysplastic stage of Barrett's oesophagus is a key to preventing progression to oesophageal adenocarcinoma. However, endoscopic surveillance protocols are hampered by the invasiveness of repeat endoscopy, sampling bias, and a subjective histopathological diagnosis of dysplasia. In this case-control study, we investigated the use of a non-invasive, pan-oesophageal cell-sampling device, the Cytosponge™, coupled with a cancer hot-spot panel to identify patients with dysplastic Barrett's oesophagus. Formalin-fixed, paraffin-embedded (FFPE) Cytosponge™ samples from 31 patients with non-dysplastic and 28 with dysplastic Barrett's oesophagus with good available clinical annotation were selected for inclusion. Samples were microdissected and amplicon sequencing performed using a panel covering >2800 COSMIC hot-spot mutations in 50 oncogenes and tumour suppressor genes. Strict mutation criteria were determined and duplicates were run to confirm any mutations with an allele frequency <12%. When compared with endoscopy and biopsy as the gold standard the panel achieved a 71.4% sensitivity (95% CI 51.3-86.8) and 90.3% (95% CI 74.3-98.0) specificity for diagnosing dysplasia. TP53 had the highest rate of mutation in 14/28 dysplastic samples (50%). CDKN2A was mutated in 6/28 (21.4%), ERBB2 in 3/28 (10.7%), and 5 other genes at lower frequency. The only gene from this panel found to be mutated in the non-dysplastic cases was CDKN2A in 3/31 cases (9.7%) in keeping with its known loss early in the natural history of the disease. Hence, it is possible to apply a multi-gene cancer hot-spot panel and next-generation sequencing to microdissected, FFPE samples collected by the Cytosponge™, in order to distinguish non-dysplastic from dysplastic Barrett's oesophagus. Further work is required to maximize the panel sensitivity.

Association between coffee or tea drinking and Barrett's esophagus or esophagitis: an Italian study

BACKGROUND/OBJECTIVES

Only a few papers have treated of the relationship between Barrett's esophagus (BE) or erosive esophagitis (E) and coffee or tea intake. We evaluated the role of these beverages in BE and E occurrence.

SUBJECTS/METHODS

Patients with BE (339), E (462) and controls (619) were recruited. Data on coffee and tea and other individual characteristics were collected using a structured questionnaire.

RESULTS

BE risk was higher in former coffee drinkers, irrespective of levels of exposure (cup per day; ⩽1: OR=3.76, 95% CI 1.33-10.6; >1: OR=3.79, 95% CI 1.31-11.0; test for linear trend (TLT) P=0.006) and was higher with duration (>30 years: OR=4.18, 95% CI 1.43-12.3; TLT P=0.004) and for late quitters, respectively (⩽3 years from cessation: OR=5.95, 95% CI 2.19-16.2; TLT P<0.001). The risk of BE was also higher in subjects who started drinking coffee later (age >18 years: OR=6.10, 95% CI 2.15-17.3). No association was found in current drinkers, but for an increased risk of E in light drinkers (<1 cup per day OR =1.85, 95% CI 1.00-3.43).A discernible risk reduction of E (about 20%, not significant) and BE (about 30%, P<0.05) was observed in tea drinkers.

CONCLUSIONS

Our data were suggestive of a reduced risk of BE and E with tea intake. An adverse effect of coffee was found among BE patients who had stopped drinking coffee. Coffee or tea intakes could be indicative of other lifestyle habits with protective or adverse impact on esophageal mucosa.

Role of EUS in patients with suspected Barrett's esophagus with high-grade dysplasia or early esophageal adenocarcinoma: impact on endoscopic therapy

BACKGROUND AND AIMS

Endoscopic therapy is the standard treatment for high-grade dysplasia and some cases of T1a esophageal adenocarcinoma (EAC), but it is not appropriate for deeply invasive disease. Data on the value of EUS for patient selection for endoscopic or surgical resection are conflicting. We investigated the outcome of esophageal EUS for the staging and treatment selection of patients with treatment-naive, premalignant Barrett's esophagus (BE) and suspected superficial EAC.

METHODS

We retrospectively reviewed consecutive patients who underwent EUS for staging of treatment-naive, suspected premalignant BE and superficial EAC from January 2006 to June 2014. All patients referred for endoscopic therapy routinely underwent EUS. Patients with esophageal masses, squamous cell cancers, previous neoadjuvant therapy, or unrelated pathologies were excluded. Each patient's final diagnosis was verified by EMR, esophagectomy, or forceps biopsy sampling. Test characteristics of EUS were calculated.

RESULTS

Three hundred thirty-five patients (mean age, 68 years; 86% male) with BE, a Prague C mean of 2.8 cm, and a Prague M mean of 4.5 cm were staged (pT0, 78% [6% nondysplastic, 24% low-grade dysplasia, 42% high-grade dysplasia]; pT1a, 14%; pT1b, 7%; and pT2, 1%). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for patient selection to endoscopic (T1aN0 or less) or surgical therapy with EUS TN staging were 50%, 93%, 40%, 95%, and 90%, respectively. Comparable rates were achieved for patients with nodular BE. Overstaging occurred in 7% of patients, and EUS selected 11% for incorrect treatment modalities compared with pathologic staging.

CONCLUSIONS

This study confirms the limited value of EUS suggested in the latest American College of Gastroenterology guidelines for BE management.

Barrett’s oesophagus: Current controversies

Oesophageal adenocarcinoma is rapidly increasing in Western countries. This tumour frequently presents late in its course with metastatic disease and has a very poor prognosis. Barrett’s oesophagus is an acquired condition whereby the native squamous mucosa of the lower oesophagus is replaced by columnar epithelium following prolonged gastro-oesophageal reflux and is the recognised precursor lesion for oesophageal adenocarcinoma. There are multiple national and society guidelines regarding screening, surveillance and management of Barrett’s oesophagus, however all are limited regarding a clear evidence base for a well-demonstrated benefit and cost-effectiveness of surveillance, and robust risk stratification for patients to best use resources. Currently the accepted risk factors upon which surveillance intervals and interventions are based are Barrett’s segment length and histological interpretation of the systematic biopsies. Further patient risk factors including other demographic features, smoking, gender, obesity, ethnicity, patient age, biomarkers and endoscopic adjuncts remain under consideration and are discussed in full. Recent evidence has been published to support earlier endoscopic intervention by means of ablation of the metaplastic Barrett’s segment when the earliest signs of dysplasia are detected. Further work should concentrate on establishing better risk stratification and primary and secondary preventative strategies to reduce the risk of adenocarcinoma of the oesophagus.

Editorial: Best Practices in Surveillance of Barrett's Esophagus

Endoscopic surveillance in Barrett's esophagus (BE) has numerous limitations and thus provides several opportunities for improving the effectiveness of our current surveillance strategies. Several risk stratification and prediction tools have been investigated to identify patients at highest risk for progression to esophageal adenocarcinoma (EAC). Persistence of non-dysplastic BE (NDBE) has been proposed as an indicator of lower risk of progression to EAC. This editorial highlights the variable results and methodologies in studies evaluating persistence of NDBE as a risk stratification tool in the surveillance of BE patients and provides guidance for optimizing outcomes in BE patients enrolled in surveillance programs.

Alcohol consumption pattern and risk of Barrett's oesophagus and erosive oesophagitis: an Italian case-control study

Knowledge about the association between alcohol and Barrett's oesophagus and reflux oesophagitis is conflicting. In this case-control study we evaluated the role of specific alcoholic beverages (red and white wine, beer and liquors) in 339 Barrett's oesophagus and 462 oesophagitis patients compared with 619 endoscopic controls with other disorders, recruited in twelve Italian endoscopic units. Data on alcohol and other individual characteristics were obtained from structured questionnaires. No clear, monotonic significant dose-response relationship was pointed out for red wine. However, a generalised U-shaped trend of Barrett's oesophagus/oesophagitis risk due to red wine consumption particularly among current drinkers was found. Similar results were also found for white wine. Liquor/spirit consumption seemed to bring about a 1·14-2·30 risk excess, although statistically non-significant, for current Barrett's oesophagus/oesophagitis drinkers. Statistically significant decreasing dose-response relationships were found in Barrett's oesophagus for frequency and duration of beer consumption. Similar, but less clear downward tendencies were also found for oesophagitis patients. In conclusion, although often not statistically significant, our data suggested a reduced risk of Barrett's oesophagus and oesophagitis with a low/moderate intake of wine and beer consumption. A non-significant increased risk of Barrett's oesophagus/oesophagitis was observed with a higher intake of any type of heavy alcohol consumption, but no conclusion can be drawn owing to the high number of non-spirit drinkers and to the small number of drinkers at higher alcohol intake levels.

Barrett Esophagus and Intramucosal Esophageal Adenocarcinoma

Barrett esophagus (BE) is a precursor lesion for esophageal adenocarcinoma (EAC). Developments in imaging and molecular markers, and endoscopic eradication therapy, are available to curb the increase of EAC. Endoscopic surveillance is recommended, despite lack of data. The cancer risk gets progressively downgraded, raising questions about the understanding of risk factors and molecular biology involved. Recent data point to at least 2 carcinogenic pathways operating in EAC. The use of p53 overexpression and high-risk human papillomavirus may represent the best chance to detect progressors. Genome-wide technology may provide molecular signatures to aid diagnosis and risk stratification in BE.

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.

The importance of biopsy sampling practices in the pathologic evaluation of gastrointestinal disorders

PURPOSE OF REVIEW

To summarize the literature regarding appropriate endoscopic sampling and surveillance protocols for common inflammatory diseases of the digestive tract. Gastroenterologists increasingly use endoscopy with mucosal biopsy to detect inflammatory diseases, assess response to therapy, and monitor for progression to dysplasia.

RECENT FINDINGS

Many diseases show a patchy distribution in the digestive tract and there may be poor correlation between the endoscopic appearance and presence of histologic abnormalities. Indeed, a clinician's ability to render a diagnosis is limited by endoscopic mucosal sampling. The appropriate number of tissue samples and required biopsy sites are not established for many gastrointestinal disorders, and adherence to guidelines may not yield a reliable diagnosis in all cases.

SUMMARY

We discuss the evidence supporting current recommendations and emerging endoscopic techniques for the evaluation of eosinophilic esophagitis, Barrett esophagus, chronic gastritis, celiac disease, and inflammatory bowel disease.

Esophageal Cancer

Esophageal cancer carries a poor prognosis among gastrointestinal malignancies. Although esophageal squamous cell carcinoma predominates worldwide, Western nations have seen a marked rise in the incidence of esophageal adenocarcinoma that parallels the obesity epidemic. Efforts directed toward early detection have been difficult, given that dysplasia and early cancer are generally asymptomatic. However, significant advances have been made in the past 10 to 15 years that allow for endoscopic management and often cure in early stage esophageal malignancy. New diagnostic imaging technologies may provide a means by which cost-effective, early diagnosis of dysplasia allows for definitive therapy and ultimately improves the overall survival among patients.

Endoscopic Resection and Ablation for Early-Stage Esophageal Cancer

Endoscopic resection and ablation have become the preferred therapy for most patients with high-grade dysplasia or superficial esophageal cancer. Endoscopic therapy offers esophageal preservation with similar oncologic outcomes and significantly fewer complications compared with the alternative of esopahgectomy. The goal of endotherapy is eradication of all the premalignant intestinal metaplasia to minimize the risk for metachronous cancer development. Once accomplished, careful follow-up is necessary to address recurrent intestinal metaplasia or dysplasia and prevent long-term failure of an endoscopic approach in these patients.