Ultrathin esophagoscopy in screening for Barrett's esophagus at a Veterans Administration Hospital: easy access does not lead to referrals

Accurate Nonendoscopic Detection of Barrett's Esophagus by Methylated DNA Markers: A Multisite Case Control Study

INTRODUCTION

Nonendoscopic Barrett's esophagus (BE) screening may help improve esophageal adenocarcinoma outcomes. We previously demonstrated promising accuracy of methylated DNA markers (MDMs) for the nonendoscopic diagnosis of BE using samples obtained from a capsule sponge-on-string (SOS) device. We aimed to assess the accuracy of these MDMs in an independent cohort using a commercial grade assay.

METHODS

BE cases had ≥ 1 cm of circumferential BE with intestinal metaplasia; controls had no endoscopic evidence of BE. The SOS device was withdrawn 8 minutes after swallowing, followed by endoscopy (the criterion standard). Highest performing MDMs from a previous study were blindly assessed on extracted bisulfite-converted DNA by target enrichment long-probe quantitative amplified signal (TELQAS) assays. Optimal MDM combinations were selected and analyzed using random forest modeling with in silico cross-validation.

RESULTS

Of 295 patients consented, 268 (91%) swallowed the SOS device; 112 cases and 89 controls met the pre-established inclusion criteria. The median BE length was 6 cm (interquartile range 4-9), and 50% had no dysplasia. The cross-validated sensitivity and specificity of a 5 MDM random forest model were 92% (95% confidence interval 85%-96%) and 94% (95% confidence interval 87%-98%), respectively. Model performance was not affected by age, gender, or smoking history but was influenced by the BE segment length. SOS administration was well tolerated (median [interquartile range] tolerability 2 [0, 4] on 10 scale grading), and 95% preferred SOS over endoscopy.

DISCUSSION

Using a minimally invasive molecular approach, MDMs assayed from SOS samples show promise as a safe and accurate nonendoscopic test for BE prediction.

Systematic review and meta-analysis of prevalence and risk factors for Barrett's esophagus

BACKGROUND AND AIMS

Although screening for Barrett's esophagus (BE) is recommended in individuals with multiple risk factors, the type and number of risk factors necessary to trigger screening is unclear. In this systematic review and meta-analysis, we aimed to assess the relationship between number of risk factors and prevalence of BE.

METHODS

Through October 17, 2018 we searched studies that described the prevalence of BE in the general population and based on presence of risk factors that included GERD, male gender, age >50 years, family history of BE and esophageal adenocarcinoma, and obesity (defined as body mass index >35). Risk of BE based on number of risk factors was assessed using meta-regression while controlling for potential confounders.

RESULTS

Of 2741 studies, 49 were included in the analysis (307,273 individuals, 1948 with biopsy specimen-proven BE). Indications varied by study. The prevalence of BE for various populations was as follows: low-risk general population, .8% (95% confidence interval [CI], .6%-1.1%); GERD, 3% (95% CI, 2.3%-4%); GERD plus presence of any other risk factor, 12.2% (95% CI, 10.2%-14.6%); family history, 23.4% (95% CI, 13.7% -37.2%); age >50, 6.1% (95% CI, 4.6%-8.1%); obesity, 1.9% (95% CI, 1.2%-3%); and male sex, 6.8% (95% CI, 5.3%-8.6%). Prevalence of BE varied significantly between Western and non-Western populations. In a meta-regression, controlling for the region of the study, age, and gender, there was a positive linear relationship between the number of risk factors and the prevalence of BE.

CONCLUSIONS

Results of this study provide estimates of BE prevalence based on the presence and the number of risk factors. These results add credence to current guidelines that suggest screening in the presence of multiple risk factors.

Barrett Esophagus

Barrett esophagus is a metaplastic change in the lining of the distal esophageal epithelium, characterized by replacement of the normal squamous epithelium by specialized intestinal metaplasia. The presence of Barrett esophagus increases the risk of esophageal adenocarcinoma several-fold. Esophageal adenocarcinoma is a malignancy with rapidly rising incidence and persistently poor outcomes when diagnosed after the onset of symptoms. Risk factors for Barrett esophagus include chronic gastroesophageal reflux, central obesity, white race, male gender, older age, smoking, and a family history of Barrett esophagus or esophageal adenocarcinoma. Screening for Barrett esophagus in those with several risk factors followed by endoscopic surveillance to detect dysplasia or adenocarcinoma is currently recommended by society guidelines. Minimally invasive nonendoscopic tools for the early detection of Barrett esophagus are currently being developed. Multimodality endoscopic therapy-using a combination of endoscopic resection and ablation techniques-for the treatment of dysplasia and early adenocarcinoma is successful in eliminating intestinal metaplasia and preventing progression to adenocarcinoma, with outcomes comparable to those after esophagectomy. Risk stratification of those diagnosed with Barrett esophagus is a challenge at present, with active research focused on identifying clinical and biomarker panels to identify those with low and high risk of progression. This narrative review highlights some of the challenges and recent progress in this field.

Highly Discriminant Methylated DNA Markers for the Non-endoscopic Detection of Barrett's Esophagus

BACKGROUND

Minimally invasive methods have been described to detect Barrett's esophagus (BE), but are limited by subjectivity and suboptimal accuracy. We identified methylated DNA markers (MDMs) for BE in tissue and assessed their accuracy on whole esophagus brushings and capsule sponge samples.

METHODS

Step 1: Unbiased whole methylome sequencing was performed on DNA from BE and normal squamous esophagus (SE) tissue. Discriminant MDM candidates were validated on an independent patient cohort (62 BE cases, 30 controls) by quantitative methylation specific PCR (qMSP). Step 2: Selected MDMs were further evaluated on whole esophageal brushings (49 BE cases, 36 controls). 35 previously sequenced esophageal adenocarcinoma (EAC) MDMs were also evaluated. Step 3: 20 BE cases and 20 controls were randomized to swallow capsules sponges (25 mm, 10 pores or 20 pores per inch (ppi)) followed endoscopy. DNA yield, tolerability, and mucosal injury were compared. Best MDM assays were performed on this cohort.

RESULTS

Step 1: 19 MDMs with areas under the ROC curve (AUCs) >0.85 were carried forward. Step 2: On whole esophageal brushings, 80% of individual MDM candidates showed high accuracy for BE (AUCs 0.84-0.94). Step 3: The capsule sponge was swallowed and withdrawn in 98% of subjects. Tolerability was superior with the 10 ppi sponge with minimal mucosal injury and abundant DNA yield. A 2-marker panel (VAV3 + ZNF682) yielded excellent BE discrimination (AUC = 1).

CONCLUSIONS

Identified MDMs discriminate BE with high accuracy. BE detection appears safe and feasible with a capsule sponge. Corroboration in larger studies is warranted. ClinicalTrials.gov number NCT02560623.

Recent Advances in Screening for Barrett's Esophagus

OPINION STATEMENT

PURPOSE OF REVIEW: There is a pressing need for effective strategies to halt the increase in both the incidence and mortality of esophageal adenocarcinoma (EAC). Screening for Barrett's esophagus, which is the only known precursor of EAC, remains a ripe area for research, particularly with regard to identifying the target population, screening tools, and management of screen-detected populations. This review aims to explore in depth the rationale for screening for Barrett's esophagus, recent biotechnological advances which may have the potential of making screening feasible, and also highlight the challenges which will have to be overcome in order make screening for BE a realistic prospect.

RECENT FINDINGS

Imaging techniques such as portable transnasal endoscopy have the advantage of providing an immediate diagnosis of Barrett's esophagus as well as other significant pathologies such as reflux esophagitis and cancer; however, larger studies in non-enriched community screening populations are required to evaluate their feasibility. The capsule sponge is a cell-sampling device coupled with a biomarker, which has been most extensively evaluated with very promising results as regards feasibility, acceptability, accuracy, and cost-effectiveness. Its effectiveness in increasing the detection of Barrett's esophagus in primary care is currently being evaluated. Several Barrett's esophagus risk prediction scores have been developed with variable degrees of accuracy. Several minimally and non-invasive screening techniques have been studied including imaging and cell-sampling devices. Barrett's risk assessment models need to be further validated in independent, relevant screening populations with clear cut-offs for recommending screening to be defined.

Comparative Assessment of Patient Preferences and Tolerability in Barrett Esophagus Screening: Results From a Randomized Trial

GOALS

To determine patient preference for the Barrett esophagus (BE) screening techniques.

BACKGROUND

Sedated esophagogastroduodenoscopy (sEGD) and unsedated transnasal endoscopy (uTNE) are both potential techniques for BE screening. However, systematic assessment of patient preference for these 2 techniques is lacking. As part of a comparative effectiveness randomized trial of BE screening modalities, we measured short-term patient preferences for the following approaches: in-clinic uTNE (huTNE), mobile-based uTNE (muTNE), and sEGD using a novel assessment instrument.

STUDY

Consenting community patients without known BE were randomly assigned to receive huTNE, muTNE, or sEGD, followed by a telephone administered preference and tolerability assessment instrument 24 hours after study procedures. Patient preference was measured by the waiting trade-off method.

RESULTS

In total, 201 patients completed screening with huTNE (n=71), muTNE (n=71), or sEGD (n=59), and a telephone interview. Patients' preferences for sEGD and uTNE using the waiting trade-off method were comparable (P=0.51). Although tolerability scores were superior for sEGD (P<0.001) compared with uTNE, scores for uTNE examinations were acceptable.

CONCLUSIONS

Patient preference is comparable between sEGD and uTNE for diagnostic examinations conducted in an endoscopy suite or in a mobile setting. Given acceptable tolerability, uTNE may be a viable alternative to sEGD for BE screening.

Screening and Preventive Strategies in Esophagogastric Cancer

Gastric adenocarcinoma, esophageal adenocarcinoma, and esophageal squamous cell carcinoma are among the most prevalent and deadly of malignancies worldwide. Screening and prevention programs will be critical to finally improving outcomes in these diseases. For gastric adenocarcinoma, screening in high-risk populations has significantly reduced mortality. More research is needed on screening high-risk individuals in low-risk populations. For esophageal adenocarcinoma, work is needed to develop efficient and effective techniques in mass screening programs. For most Western populations, current screening is not cost effective. Avoiding environmental risk factors is critical to reducing the incidence of this deadly illness.

The Role of Esophagogastroduodenoscopy Surveillance for Patients with Barrett Esophagus

Approximately 10% to 15% of patients who experience chronic gastroesophageal reflux disease have Barrett esophagus, which is associated with an increased risk of esophageal adenocarcinoma. If symptoms persist after 8 weeks of adhering to treatment and lifestyle modifications, or if alarm symptoms develop, patients should be referred for screening upper endoscopy. Those with evidence of Barrett esophagus with dysplasia should be monitored in an endoscopic surveillance program, and those with high-grade dysplasia should consider surgical treatment.

Screening for Barrett's esophagus and esophageal adenocarcinoma: rationale, recent progress, challenges, and future directions

As the incidence and mortality of esophageal adenocarcinoma continue to increase, strategies to counter this need to be explored. Screening for Barrett's esophagus, which is the known precursor of a large majority of adenocarcinomas, has been debated without a firm consensus. Given evidence for and against perceived benefits of screening, the multitude of challenges in the implementation of such a strategy and in the downstream management of subjects with Barrett's esophagus who could be diagnosed by screening, support for screening has been modest. Recent advances in the form of development and initial accuracy of noninvasive tools for screening, risk assessment tools, and biomarker panels to risk stratify subjects with BE, have spurred renewed interest in the early detection of Barrett's esophagus and related neoplasia, particularly with the advent of effective endoscopic therapy. In this review, we explore in depth the potential rationale for screening for Barrett's esophagus, recent advances that have the potential of making screening feasible, and also highlight some of the challenges that will have to be overcome to develop an effective approach to improve the outcomes of subjects with esophageal adenocarcinoma.

Comparative acceptability of transnasal esophagoscopy and esophageal capsule esophagoscopy: a randomized, controlled trial in veterans

BACKGROUND

EGD screening for Barrett's esophagus (BE) is costly, with insufficient evidence to support its effectiveness.

OBJECTIVE

To compare acceptance and tolerability of 2 novel, office-based, endoscopic screening techniques done on nonsedated patients.

DESIGN

Randomized block study design with allocation concealment.

SETTING

Outpatient clinic setting at a Veterans Affairs medical center.

PATIENTS

A total of 184 veterans with or without GERD symptoms.

INTERVENTIONS

Transnasal esophagoscopy (TNE) or esophageal capsule esophagoscopy (ECE).

MAIN OUTCOME MEASUREMENTS

Acceptance and tolerability of TNE and ECE and effectiveness of BE screening.

RESULTS

Esophageal screening was accepted by 184 of 1210 (15.2%) veterans. The majority were men (96%) and African American (58%), with a mean (± standard deviation) age of 58.9 (± 8.1) years. Five TNE participants (5%) and 2 ECE participants (2%) refused the assigned procedure after randomization (P = .25). Eleven patients (12.6%) randomized to TNE crossed the minimal clinically important threshold for overall procedure tolerability, as opposed to no patients randomized to ECE (P = .001). Effectiveness of BE screening was not significantly different in both procedures (TNE vs ECE = 3.2% vs 5.4%; P = .47). Overall, BE was present in 8 of 75 white participants (10.6%) and in 0 of 107 African American participants (P < .001).

LIMITATIONS

The general veteran population may not reflect the screening population for BE.

CONCLUSION

Despite a small proportion of veterans expressing interest in esophageal screening, both TNE and ECE were feasible in the outpatient clinic setting and were accepted by >95% of participants who did express an interest. Screening was effective only in white participants. Moderate differences in tolerability between TNE and ECE notwithstanding, cost considerations along with availability of equipment and trained personnel should guide the modality to be used for BE screening.

Barrett's oesophagus: epidemiology, cancer risk and implications for management

Although endoscopic surveillance of patients with Barrett's oesophagus has been widely implemented, its effectiveness is debateable. The recently reported low annual oesophageal adenocarcinoma risk in population studies, the failure to identify most Barrett's patients at risk of disease progression, the poor adherence to surveillance and biopsy protocols, and the significant risk of misclassification of dysplasia all tend to undermine the effectiveness of current management, in particular, endoscopic surveillance programmes, to prevent or improve the outcomes of patients with oesophageal adenocarcinoma. The ongoing increase in incidence of Barrett's oesophagus and consequent growth of the surveillance population, together with the associated discomfort and costs of endoscopic surveillance, demand improved techniques for accurately determining individual risk of oesophageal adenocarcinoma. More accurate techniques are needed to run efficient surveillance programmes in the coming decades. In this review, we will discuss the current knowledge on the epidemiology of Barrett's oesophagus, and the challenging epidemiological dilemmas that need to be addressed when assessing the current screening and surveillance strategies.

Screening for Barrett's Esophagus

Barrett's esophagus (BE) increases the risk for development of esophageal adenocarcinoma. Because of the rapid rise in incidence of esophageal adenocarcinoma, screening for BE with subsequent surveillance when found has been proposed as a method of early detection. Sedated endoscopy, however, is too expensive for wide spread screening. As a result, other techniques including unsedated transnasal esophagoscopy and capsule esophagoscopy have been proposed to expand screening programs.

Barrett's Esophagus and esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has risen dramatically over the past three decades in western countries. The importance of Barrett's esophagus (BE) derives from its potential to transform to adenocarcinoma. BE is characterized by endoscopically recognized displacement of the squamocolumnar junction proximal to the gastroesophageal junction, with replacement of squamous mucosa with columnar lined mucosa. Adenocarcinomas of the esophagus appear to arise from Barrett's mucosa through progressive degrees of dysplasia, but the pathogenesis and natural history of this process are still unclear. Much of our knowledge regarding BE and the risk of EAC is based on observational and cross-sectional analyses, and recommendations regarding management have traditionally represented "expert opinion." The past few years have seen an explosion in new information and the initiation of longitudinal studies to define the risk of adenocarcinoma in BE, the identification of predictive and prognostic markers of cancer risk, sensitive and cost-effective methods of surveillance, and methods of management of dysplasia and early neoplasia including disease prevention.

Barrett's esophagus: where do we stand?

Barrett's esophagus (BE) is a precursor for esophageal adenocarcinoma, which has an increased incidence rate over the last few decades. Its importance stems from the poor five-year survival of esophageal adenocarcinoma and current data that suggest a survival benefit when surveillance programs are implemented. In this review, we will cover the pathophysiology and natural history of BE and the different endoscopic findings. The prevalence of BE in different geographic areas and the incidence of high-grade dysplasia and adenocarcinoma in this patient population is reviewed. Recent recommendation for screening and surveillance of BE has been covered in this review as well as the efficacy of nonconventional imaging modalities and endoscopic ablation therapies.