Cost utility of screening for Barrett's esophagus with esophageal capsule endoscopy versus conventional upper endoscopy

Expanding beyond endoscopy: A review of non-invasive modalities in Barrett’s esophagus screening and surveillance

Barrett’s esophagus (BE) is a condition that results from replacement of the damaged normal squamous esophageal mucosa to intestinal columnar mucosa and is the most significant predisposing factor for development of esophageal adenocarcinoma. Current guidelines recommend endoscopic evaluation for screening and surveillance based on various risk factors which has limitations such as invasiveness, availability of a trained specialist, patient logistics and cost. Trans-nasal endoscopy is a less invasive modality but still has similar limitations such as limited availability of trained specialist and costs. Non-endoscopic modalities, in comparison, require minimal intervention, can be done in an office visit and has the potential to be a more ideal choice for mass public screening and surveillance, particularly in patents at low risk for BE. These include newer generations of esophageal capsule endoscopy which provides direct visualization of BE, and tethered capsule endomicroscopy which can obtain high-resolution images of the esophagus. Various cell collection devices coupled with biomarkers have been used for BE screening. Cytosponge, in combination with TFF3, as well as EsophaCap and EsoCheck have shown promising results in various studies when used with various biomarkers. Other modalities including circulatory microRNAs and volatile organic compounds that have demonstrated favorable outcomes. Use of these cell collection methods for BE surveillance is a potential area of future research.

Innovations in Screening Tools for Barrett's Esophagus and Esophageal Adenocarcinoma

PURPOSE OF REVIEW

Esophageal adenocarcinoma (EAC) is a lethal disease with rapidly rising incidence. Screening for EAC and its metaplastic precursor, Barrett's esophagus (BE), followed by endoscopic surveillance and endoscopic treatment of dysplasia or early EAC are promising approaches to decreasing EAC incidence and EAC mortality. Historically, screening for EAC has been completed with a traditional per-oral esophagogastroduodenoscopy (EGD); however, this method has limitations including cost, tolerability, and accessibility. For this reason, much effort has been put forward to develop more effective, minimally invasive, and accessible BE and EAC screening tools. The purpose of this review is to describe recent developments of these novel tools.

RECENT FINDINGS

While endoscopic alternatives such as transnasal endoscopy are cheaper and well tolerated, they have not gained acceptance. Non-endoscopic modalities namely, swallowable cell collection devices coupled with biomarker analysis have been found to have excellent performance characteristics, tolerability, and cost effectiveness. In this article, we provide an update on innovative developments in EAC/BE screening modalities including transnasal endoscopy, capsule endomicroscopy, swallowable cell collection devices, and exhaled volatile organic compound analyses.

Comparative Cost Effectiveness of Reflux-Based and Reflux-Independent Strategies for Barrett's Esophagus Screening

INTRODUCTION

Minimally invasive tests for Barrett's esophagus (BE) detection have raised the prospect of broader nonreflux-based testing. Cost-effectiveness studies have largely studied men aged 50 years with chronic gastroesophageal reflux disease (GERD) symptoms. We evaluated the comparative cost effectiveness of BE screening tests in GERD-based and GERD-independent testing scenarios.

METHODS

Markov modeling was performed in 3 scenarios in 50 years old individuals: (i) White men with chronic GERD (GERD-based); (ii) GERD-independent (all races, men and women), BE prevalence 1.6%; and (iii) GERD-independent, BE prevalence 5%. The simulation compared multiple screening strategies with no screening: sedated endoscopy (sEGD), transnasal endoscopy, swallowable esophageal cell collection devices with biomarkers, and exhaled volatile organic compounds. A hypothetical cohort of 500,000 individuals followed for 40 years using a willingness to pay threshold of $100,000 per quality-adjusted life year (QALY) was simulated. Incremental cost-effectiveness ratios (ICERs) comparing each strategy with no screening and comparing screening strategies with each other were calculated.

RESULTS

In both GERD-independent scenarios, most non-sEGD BE screening tests were cost effective. Swallowable esophageal cell collection devices with biomarkers were cost effective (<$35,000/QALY) and were the optimal screening tests in all scenarios. Exhaled volatile organic compounds had the highest ICERs in all scenarios. ICERs were low (<$25,000/QALY) for all tests in the GERD-based scenario, and all non-sEGD tests dominated no screening. ICERs were sensitive to BE prevalence and test costs.

DISCUSSION

Minimally invasive nonendoscopic tests may make GERD-independent BE screening cost effective. Participation rates for these strategies need to be studied.

Progress in Screening for Barrett's Esophagus: Beyond Standard Upper Endoscopy

The rapid increase in the incidence of esophageal adenocarcinoma in Western populations over the past 4 decades and its associated poor prognosis, unless detected early has generated great interest in screening for the precursor lesion Barrett's esophagus (BE). Recently, there have been significant developments in imaging-based modalities and esophageal cell-sampling devices coupled with biomarker assays. In this review, the authors discuss the rationale for screening for BE and the factors to consider for targeting the at-risk population. They also explore future avenues for research in this area.

Endoscopic Screening for Barrett's Esophagus and Esophageal Adenocarcinoma: Rationale, Candidates, and Challenges

Barrett's esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC), a cancer with increasing incidence and poor survival. Risk of EAC in patients with BE is higher compared with the general population. Endoscopic screening for BE is performed to identify patients earlier in the metaplasia-dysplasia-carcinoma sequence from BE to EAC to enable eradication therapy. BE screening should be considered in individuals with multiple risk factors for BE and EAC. Challenges to BE screening include the absence of a cost-effective, widely applicable minimally invasive screening tool, gastroesophageal reflux disease centric screening recommendations, and limitations of current endoscopic surveillance practice.

Advanced endoscopic imaging for detecting and guiding therapy of early neoplasias of the esophagus

Esophageal cancers, largely adenocarcinoma in Western countries and squamous cell cancer in Asia, present a significant burden of disease and remain one of the most lethal of cancers. Key to improving survival is the development and adoption of new imaging modalities to identify early neoplastic lesions, which may be small, multifocal, subsurface, and difficult to detect by standard endoscopy. Such advanced imaging is particularly relevant with the emergence of ablative techniques that often require multiple endoscopic sessions and may be complicated by bleeding, pain, strictures, and recurrences. Assessing the specific location, depth of involvement, and features correlated with neoplastic progression or incomplete treatment may optimize treatments. While not comprehensive of all endoscopic imaging modalities, we review here some of the recent advances in endoscopic luminal imaging, particularly with surface contrast enhancement using virtual chromoendoscopy, highly magnified subsurface imaging with confocal endomicroscopy, optical coherence tomography, elastic scattering spectroscopy, angle-resolved low-coherence interferometry, and light scattering spectroscopy. While there is no single ideal imaging modality, various multimodal instruments are also being investigated. The future of combining computer-aided assessments, molecular markers, and improved imaging technologies to help localize and ablate early neoplastic lesions shed hope for improved disease outcome.

Recent advances in understanding and preventing oesophageal cancer

Oesophageal cancer is a common cancer that continues to have a poor survival. This is largely in part due to its late diagnosis and early metastatic spread. Currently, screening is limited to patients with multiple risk factors via a relatively invasive technique. However, there is a large proportion of patients diagnosed with oesophageal cancer who have not been screened. This has warranted the development of new screening techniques that could be implemented more widely and lead to earlier identification and subsequently improvements in survival rates. This article also explores progress in the surveillance of Barrett’s oesophagus, a pre-malignant condition for the development of oesophageal adenocarcinoma. In recent years, advances in early endoscopic intervention have meant that more patients are considered at an earlier stage for potentially curative treatment.

Diagnosis of Barrett's esophagus and esophageal varices using a magnetically assisted capsule endoscopy system

BACKGROUND AND AIMS

Magnetically assisted capsule endoscopy (MACE) potentially offers a comfortable, patient friendly, and community-based alternative to gastroscopy (EGD). This pilot study aims to explore whether this approach can be used to accurately diagnose Barrett's esophagus (BE) and esophageal varices.

METHOD

The MiroCam Navi capsule system was used to examine the upper GI tract in patients due to undergo a clinically indicated EGD. A total of 50 participants were enrolled: 34 had known pathology (17 BE, 17 esophageal varices [EV]) and 16 controls. Patients underwent the MACE procedure with the operator blinded to the indication and any previous endoscopic diagnoses. The subsequent EGD was performed by an endoscopist blinded to the MACE findings. Diagnostic yield, comfort, and patient preference between the 2 modalities were compared.

RESULTS

The mean age of the participants was 61 years, the male/female ratio was 2.1:1, the mean body mass index was 29.5 kg/m², and the average chest measurement was 105.3 cm. Forty-seven patients underwent both procedures; 3 patients were unable to swallow the capsule. With the use of the magnet, it was possible to hold the capsule within the esophagus for a mean duration of 190 seconds and up to a maximum of 634 seconds. A correct real-time MACE diagnosis was made in 11 of 15 patients with EV (sensitivity 73.3% [95% confidence interval (CI), 44.9%-92.2%] and specificity 100% [95% CI, 89.1%-100%]) and 15 of 16 patients with BE (sensitivity 93.8% [95% CI, 69.8%-99.8%] and specificity of 100% [95% CI, 88.8%-100%]). MACE was considered more comfortable than conventional endoscopy (P < .0001); the mean score was 9.2 for MACE compared with 6.7 for EGD when assessed on a 10-point scale. No MACE- or EGD-related adverse events occurred.

CONCLUSION

This pilot study demonstrates that MACE is both safe and well tolerated by patients. Accuracy for the diagnosis of BE was high, and therefore MACE may have a role in screening for this condition. (Clinical trial registration number: NCT02852161.).

Novel Screening Tests for Barrett's Esophagus

PURPOSE OF REVIEW

There has been an exponential increase in the incidence of esophageal adenocarcinoma (EAC) over the last half century. Barrett's esophagus (BE) is the only known precursor lesion of EAC. Screening for BE in high-risk populations has been advocated with the aim of identifying BE, followed by endoscopic surveillance to detect dysplasia and early stage cancer, with the intent that treatment can improve outcomes. We aimed to review BE screening methodologies currently recommended and in development.

RECENT FINDINGS

Unsedated transnasal endoscopy allows for visualization of the distal esophagus, with potential for biopsy acquisition, and can be done in the office setting. Non-endoscopic screening methods being developed couple the use of swallowable esophageal cell sampling devices with BE specific biomarkers, as well as trefoil factor 3, methylated DNA markers, and microRNAs. This approach has promising accuracy. Circulating and exhaled volatile organic compounds and the foregut microbiome are also being explored as means of detecting EAC and BE in a non-invasive manner. Non-invasive diagnostic techniques have shown promise in the detection of BE and may be effective methods of screening high-risk patients.

Barrett's esophagus: novel strategies for screening and surveillance

Barrett’s esophagus is the precursor lesion for esophageal adenocarcinoma. Screening and surveillance of Barrett’s esophagus are undertaken with the goal of earlier detection and lowering the mortality from esophageal adenocarcinoma. The widely used technique is standard esophagogastroduodenoscopy with biopsies per the Seattle protocol for screening and surveillance of Barrett’s esophagus. Surveillance intervals vary depending on the degree of dysplasia with endoscopic eradication therapy confined to patients with Barrett’s esophagus and confirmed dysplasia. In this review, we present various novel techniques for screening of Barrett’s esophagus such as unsedated transnasal endoscopy, cytosponge with trefoil factor-3, balloon cytology, esophageal capsule endoscopy, liquid biopsy, electronic nose, and oral microbiome. In addition, advanced imaging techniques such as narrow band imaging, dye-based chromoendoscopy, confocal laser endomicroscopy, volumetric laser endomicroscopy, and wide-area transepithelial sampling with computer-assisted three-dimensional analysis developed for better detection of dysplasia are also reviewed.

Point-Counterpoint: Screening and Surveillance for Barrett's Esophagus, Is It Worthwhile?

The exponential rise in incidence of esophageal adenocarcinoma (EAC), paired with persistently poor survival, continues to drive efforts to improve and optimize screening and surveillance practices. While advancements in endoscopic therapy have generated a shift in management and significantly improved the outcomes of patients with early-stage EAC, the majority of prevalent EAC continues to be diagnosed at advanced stages, remaining ineligible for curative therapy. Barrett's esophagus (BE) screening, when applied to high-yield target populations, using minimally or noninvasive accurate tests, followed by endoscopic surveillance to detect prevalent or incident dysplasia/EAC (which can then be treated successfully) is the cornerstone of the current BE management paradigm. While supported by some empiric evidence and attractive, this approach faces a number of challenges, which are also balanced by numerous recent advances in these areas. In this manuscript, we review the rationale, supportive evidence, current challenges, and recent progress in BE screening and surveillance.

Screening and Surveillance for Barrett's Esophagus: Is It Cost-Effective?

The cost-effectiveness of screening and surveillance for Barrett's esophagus continues to evolve as the incidence of esophageal adenocarcinoma increases, biomarkers enhance the identification of individuals at highest risk for developing cancer, and endoscopic eradication of Barrett's esophagus improves. Screening to detect Barrett's esophagus may be cost-effective in selected high-risk groups based on age, race, sex and other factors such as symptoms of heartburn. Currently, endoscopic eradication therapy for Barrett's esophagus and high-grade dysplasia is a cost-effective intervention, while endoscopic therapy for non-dysplastic Barrett's esophagus is not a cost-effective strategy. As diagnosis of low-grade dysplasia improves, endoscopic eradication therapy may also prove to be a cost-effective intervention.

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.

Endoscopic Management of Early Adenocarcinoma and Squamous Cell Carcinoma of the Esophagus: Screening, Diagnosis, and Therapy

Because the esophagus is easily accessible with endoscopy, early diagnosis and curative treatment of esophageal cancer is possible. However, diagnosis is often delayed because symptoms are not specific during early stages of tumor development. The onset of dysphagia is associated with advanced disease, which has a survival at 5 years lower than 15%. Population screening by endoscopy is not cost-effective, but a number of alternative imaging and cell analysis technologies are under investigation. The ideal screening test should be inexpensive, well tolerated, and applicable to primary care. Over the past 10 years, significant progress has been made in endoscopic diagnosis and treatment of dysplasia (squamous and Barrett's), and early esophageal cancer using resection and ablation technologies supported by evidence from randomized controlled trials. We review the state-of-the-art technologies for early diagnosis and minimally invasive treatment, which together could reduce the burden of disease.

Costs associated with Barrett's esophagus screening in the community: an economic analysis of a prospective randomized controlled trial of sedated versus hospital unsedated versus mobile community unsedated endoscopy

BACKGROUND AND AIMS

Data on the economic impact associated with screening for Barrett's esophagus (BE) are limited. As part of a comparative effectiveness randomized trial of unsedated transnasal endoscopy (uTNE) and sedated EGD (sEGD), we assessed costs associated with BE screening.

METHODS

Patients were randomly allocated to 3 techniques: sEGD or uTNE in a hospital setting (huTNE) versus uTNE in a mobile research van (muTNE). Patients were called 1 and 30 days after screening to assess loss of work (because of the screening procedure) and medical care sought after procedure. Direct medical costs were extracted from billing claims databases. Indirect costs (loss of work for subject and caregiver) were estimated using patient reported data. Statistical analyses including multivariable analysis accounting for comorbidities were conducted to compare costs.

RESULTS

Two hundred nine patients were screened (61 sEGD, 72 huTNE, and 76 muTNE). Thirty-day direct medical costs and indirect costs were significantly higher in the sEGD than the huTNE and muTNE groups. Total costs (direct medical + indirect costs) were also significantly higher in the sEGD than in the uTNE group. The muTNE group had significantly lower costs than the huTNE group. Adjustment for age, sex, and comorbidities on multivariable analysis did not change this conclusion.

CONCLUSIONS

Short-term direct, indirect, and total costs of screening are significantly lower with uTNE compared with sEGD. Mobile uTNE costs were lower than huTNE costs, raising the possibility of mobile screening as a novel method of screening for BE and esophageal adenocarcinoma.

Alternatives to Traditional Per-Oral Endoscopy for Screening

Barrett's esophagus (BE) predisposes patients to esophageal adenocarcinoma. 3 to 6% of individuals with gastro-esophageal reflux disease are estimated to have BE but only 20 to 25% of BE patients are currently diagnosed. The current gold standard for diagnosis of BE is per-oral upper GI endoscopy. As this is not suitable for large-scale screening, a number of alternative methods are currently being investigated: transnasal and video capsule endoscopy, endomicroscopy, cell collection devices like the cytosponge and biomarkers. Some of these are promising, however, well powered studies carried out in relevant screening populations are needed.

Effectiveness and Cost-Effectiveness of Endoscopic Screening and Surveillance

Guidelines for the screening and surveillance of Barrett's esophagus continue to evolve as the incidence of esophageal adenocarcinoma increases, identification of individuals at highest risk for cancer improves, and management of dysplasia evolves. This article reviews related studies and economic analyses. Advances in diagnosis offer promising strategies to help focus screening efforts on those individuals who are most likely to develop esophageal adenocarcinoma.

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.

ACG Clinical Guideline: Diagnosis and Management of Barrett's Esophagus

Barrett's esophagus (BE) is among the most common conditions encountered by the gastroenterologist. In this document, the American College of Gastroenterology updates its guidance for the best practices in caring for these patients. These guidelines continue to endorse screening of high-risk patients for BE; however, routine screening is limited to men with reflux symptoms and multiple other risk factors. Acknowledging recent data on the low risk of malignant progression in patients with nondysplastic BE, endoscopic surveillance intervals are attenuated in this population; patients with nondysplastic BE should undergo endoscopic surveillance no more frequently than every 3-5 years. Neither routine use of biomarker panels nor advanced endoscopic imaging techniques (beyond high-definition endoscopy) is recommended at this time. Endoscopic ablative therapy is recommended for patients with BE and high-grade dysplasia, as well as T1a esophageal adenocarcinoma. Based on recent level 1 evidence, endoscopic ablative therapy is also recommended for patients with BE and low-grade dysplasia, although endoscopic surveillance continues to be an acceptable alternative. Given the relatively common recurrence of BE after ablation, we suggest postablation endoscopic surveillance intervals. Although many of the recommendations provided are based on weak evidence or expert opinion, this document provides a pragmatic framework for the care of the patient with BE.

Cost-Analyses Studies in Barrett's Esophagus: What Is Their Utility?

Approximately 10% to 15% of the chronic gastroesophageal reflux disease population is at risk for the development of Barrett's esophagus, particularly in the setting of other risk factors, including male gender, Caucasian race, age more than 50, and central obesity. The risk of cancer progression for patients with nondysplastic BE has been estimated to be approximately 0.2% to 0.5% per year. Given these low progression rates and the high cost of endoscopic surveillance, cost-effectiveness analyses in this area are useful to determine appropriate resource allocation.

BOB CAT: A Large-Scale Review and Delphi Consensus for Management of Barrett's Esophagus With No Dysplasia, Indefinite for, or Low-Grade Dysplasia

OBJECTIVES

Barrett's esophagus (BE) is a common premalignant lesion for which surveillance is recommended. This strategy is limited by considerable variations in clinical practice. We conducted an international, multidisciplinary, systematic search and evidence-based review of BE and provided consensus recommendations for clinical use in patients with nondysplastic, indefinite, and low-grade dysplasia (LGD).

METHODS

We defined the scope, proposed statements, and searched electronic databases, yielding 20,558 publications that were screened, selected online, and formed the evidence base. We used a Delphi consensus process, with an 80% agreement threshold, using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to categorize the quality of evidence and strength of recommendations.

RESULTS

In total, 80% of respondents agreed with 55 of 127 statements in the final voting rounds. Population endoscopic screening is not recommended and screening should target only very high-risk cases of males aged over 60 years with chronic uncontrolled reflux. A new international definition of BE was agreed upon. For any degree of dysplasia, at least two specialist gastrointestinal (GI) pathologists are required. Risk factors for cancer include male gender, length of BE, and central obesity. Endoscopic resection should be used for visible, nodular areas. Surveillance is not recommended for <5 years of life expectancy. Management strategies for indefinite dysplasia (IND) and LGD were identified, including a de-escalation strategy for lower-risk patients and escalation to intervention with follow-up for higher-risk patients.

CONCLUSIONS

In this uniquely large consensus process in gastroenterology, we made key clinical recommendations for the escalation/de-escalation of BE in clinical practice. We made strong recommendations for the prioritization of future research.

Screening for Barrett's Esophagus

The large increase in the incidence of esophageal adenocarcinoma in the West during the past 30 years has stimulated interest in screening for Barrett's esophagus (BE), a precursor to esophageal cancer. Effective endoscopic treatments for dysplasia and intramucosal cancer, coupled with screening programs to detect BE, could help reverse the increase in the incidence of esophageal cancer. However, there are no accurate, cost-effective, minimally invasive techniques available to screen for BE, reducing the enthusiasm of gastroenterologists. Over the past 5 years, there has been significant progress in the development of screening technologies. We review existing and developing technologies, new minimally invasive imaging techniques, nonendoscopic devices for cell collection, and biomarkers that can be measured in blood or stool samples. We discuss the status of these approaches, data from clinical studies of their effects, and their anticipated strengths and weaknesses in screening. The area is rapidly evolving, and new tools will soon be ready for prime time.

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.

Capsule endoscopy--not just for the small bowel: a review

Video capsule endoscopy is being increasingly used to investigate the esophagus and colon as well as the small bowel. With the advancement of technology used in capsule endoscopy there have been marked improvements in diagnostic rates for colon capsule endoscopy in the detection of colonic polyps and colorectal cancer. It is also being increasingly used in the field if inflammatory bowel disease to investigate for mucosal inflammation and could potentially be used to assess mucosal healing. It also has role in completing the evaluation of colonic pathology in those in whom colonoscopy is incomplete. Esophageal capsule is preferred by patients over esophagogastroduodenoscopy (EGD) but as yet does not rival EGD in terms of diagnostic accuracy however the advent of magnetically steerable capsules may improve this. This review covers advances in the field of colon and esophageal capsule endoscopy; it covers diagnostic capabilities of these 2 tools as well as technical aspects of both procedures and preparation.

Wireless capsule endoscopy: Perspectives beyond gastrointestinal bleeding

Wireless capsule endoscopy (CE) is a technology developed for the endoscopic exploration of the small bowel. The first capsule model was approved by the Food and Drug Administration in 2001, and its first and essential indication was occult gastrointestinal (GI) bleeding. Over subsequent years, this technology has been refined to provide superior resolution, increased battery life, and capabilities to view different parts of the GI tract. Indeed, cases for which CE proved useful have increased significantly over the last few years, with new indications for the small bowel and technical improvements that have expanded its use to other parts of the GI tract, including the esophagus and colon. The main challenges in the development of CE are new devices with the ability to provide therapy, air inflation for a better vision of the small bowel, biopsy sampling systems attached to the capsule and the possibility to guide and move the capsule with an external motion control. In this article we review the current and new indications of CE, and the evolving technological changes shaping this technology, which has a promising potential in the coming future of gastroenterology.

Controversies in Barrett esophagus

Barrett esophagus develops when metaplastic columnar epithelium predisposed to develop adenocarcinoma replaces esophageal squamous epithelium damaged by gastroesophageal reflux disease. Although several types of columnar metaplasia have been described in Barrett esophagus, intestinal metaplasia with goblet cells currently is required for a definitive diagnosis in the United States. Studies indicate that the risk of adenocarcinoma for patients with nondysplastic Barrett esophagus is only 0.12% to 0.38% per year, which is substantially lower than previous studies had suggested. Nevertheless, the incidence of esophageal adenocarcinoma continues to rise at an alarming rate. Regular endoscopic surveillance for dysplasia is the currently recommended cancer prevention strategy for Barrett esophagus, but a high-quality study has found no benefit of surveillance in preventing deaths from esophageal cancer. Medical societies currently recommend endoscopic screening for Barrett esophagus in patients with multiple risk factors for esophageal adenocarcinoma, including chronic gastroesophageal reflux disease, age of 50 years or older, male sex, white race, hiatal hernia, and intra-abdominal body fat distribution. However, because the goal of screening is to identify patients with Barrett esophagus who will benefit from endoscopic surveillance and because such surveillance may not be beneficial, the rationale for screening might be made on the basis of faulty assumptions. Endoscopic ablation of dysplastic Barrett metaplasia has been reported to prevent its progression to cancer, but the efficacy of endoscopic eradication of nondysplastic Barrett metaplasia as a cancer preventive procedure is highly questionable. This review discusses some of these controversies that affect the physicians and surgeons who treat patients with Barrett esophagus. Studies relevant to controversial issues in Barrett esophagus were identified using PubMed and relevant search terms, including Barrett esophagus, ablation, dysplasia, radiofrequency ablation, and endoscopic mucosal resection.

Cost-effectiveness of Barrett's oesophagus screening and surveillance

Endoscopic screening and surveillance of patients with Barrett's oesophagus to detect oesophageal cancer at earlier stages is contentious. As a consequence, their cost-effectiveness is also debatable. Current health economic evidence shows mixed results for demonstrating their value, mainly due to varied assumptions around progression rates to cancer, quality of life and treatment pathways. No randomized controlled trial exists to definitively support the efficacy of surveillance programs and one is unlikely to be undertaken. Contemporary treatment, cost and epidemiological data to contribute to cost-effectiveness analyses are needed. Risk assessment to stratify patients at low- or high-risk of developing cancer should improve cost-effectiveness outcomes as higher gains will be seen for those at higher risk, and medical resource use will be avoided in those at lower risk. Rapidly changing technologies for imaging, biomarker testing and less-invasive endoscopic treatments also promise to lower health system costs and avoid adverse events in patients.

Accounting for increased non-target-disease-specific mortality in decision-analytic screening models for economic evaluation

BACKGROUND

Positive screening results are often associated not only with target-disease-specific but also with non-target-disease-specific mortality. In general, this association is due to joint risk factors. Cost-effectiveness estimates based on decision-analytic models may be biased if this association is not reflected appropriately.

OBJECTIVE

To develop a procedure for quantifying the degree of bias when an increase in non-target-disease-specific mortality is not considered.

METHODS

We developed a family of parametric functions that generate hazard ratios (HRs) of non-target-disease-specific mortality between subjects screened positive and negative, with the HR of target-disease-specific mortality serving as the input variable. To demonstrate the efficacy of this procedure, we fitted a function within the context of coronary artery disease (CAD) risk screening, based on HRs related to different risk factors extracted from published studies. Estimates were embedded into a decision-analytic model, and the impact of 'modelling increased non-target-disease-specific mortality' was assessed.

RESULTS

In 55-year-old German men, based on a risk screening with 5% positively screened subjects, and a CAD risk ratio of 6 within the first year after screening, incremental quality-adjusted life-years were 19% higher and incremental costs were 8% lower if no adjustment was made. The effect varied depending on age, gender, the explanatory power of the screening test and other factors.

CONCLUSION

Some bias can occur when an increase in non-target-disease-specific mortality is not considered when modelling the outcomes of screening tests.

Prediction of Barrett's esophagus among men

OBJECTIVES

Risk factors for Barrett's esophagus include gastroesophageal reflux disease (GERD) symptoms, age, abdominal obesity, and tobacco use. We aimed to develop a tool using these factors to predict the presence of Barrett's esophagus.

METHODS

Male colorectal cancer (CRC) screenees were recruited to undergo upper endoscopy, identifying newly diagnosed cases of Barrett's esophagus. Logistic regression models predicting Barrett's esophagus using GERD symptoms alone and together with abdominal obesity, tobacco use, and age were compared.

RESULTS

Barrett's esophagus was found in 70 (8.5%) of 822 CRC screenees. Mutually adjusting for other covariates, Barrett's esophagus was associated with weekly GERD (odds ratio (OR)=2.33, 95% confidence interval (CI)=1.34, 4.05), age (OR per 10 years=1.53, 95% CI=1.05, 2.25), waist-to-hip ratio (OR per 0.10=1.44, 95% CI=0.898, 2.32) and pack-years of cigarette use (OR per 10 pack-years=1.09, 95% CI=1.04, 1.14). A model including those four factors had a greater area under the receiver operating characteristics curve than did a model based on GERD frequency and duration alone (0.72 vs. 0.61, P<0.001), and it had a net reclassification improvement index of 19-25%.

CONCLUSIONS

The prevalence of Barrett's esophagus was substantial in our population of older overweight men. A model based on GERD, age, abdominal obesity, and cigarette use more accurately classified the presence of Barrett's esophagus than did a model based on GERD alone. Following validation of the tool in another population, its use in clinical practice might improve the efficiency of screening for Barrett's esophagus.

Screening and risk stratification for Barrett's esophagus: how to limit the clinical impact of the increasing incidence of esophageal adenocarcinoma

Barrett's esophagus (BE) and gastroesophageal reflux disease are the strongest risk factors for esophageal adenocarcinoma. To reduce the clinical impact of this disease, endoscopic screening to detect BE has been proposed and nonendoscopic diagnostic techniques are under investigation. Because screening would result in new diagnoses of BE and additional costs related to endoscopic surveillance, novel tools for risk stratification are also warranted. Dysplasia is the gold standard for risk stratification. Molecular biomarkers may provide a more objective and reproducible estimation of the individual risk, and further prospective studies are required as a prelude to introducing biomarkers into routine clinical practice.

Management of Barrett's esophageal carcinoma

Barrett's esophagus (BE) is the premalignant lesion from which esophageal adenocarcinoma near the esophagogastric junction arises. The management of BE and the treatment of Barrett's esophageal adenocarcinoma (BEA) are important clinical issues in Europe and the United States. As the Helicobacter pylori infection rate in Japan is decreasing in the younger population, the incidence of BE and adenocarcinoma arising from BE may start increasing. Thus, we review the current status of BEA and its management. Magnifying endoscopy with narrow-band imaging is important for diagnosing dysplasia arising from BE. In Japan, adenocarcinoma arising from BE is managed the same way as squamous cell carcinoma in the same location. Strategies to prevent BEA may include medication such as non-steroidal anti-inflammatory drugs and proton pump inhibitors, and anti-reflux surgery. Understanding the pathophysiology of BE will help to reduce the incidence of BEA.

Health benefits and cost effectiveness of endoscopic and nonendoscopic cytosponge screening for Barrett's esophagus

BACKGROUND & AIMS

We developed a model to compare the health benefits and cost effectiveness of screening for Barrett's esophagus by either Cytosponge™ or by conventional endoscopy vs no screening, and to estimate their abilities to reduce mortality from esophageal adenocarcinoma.

METHODS

We used microsimulation modeling of a hypothetical cohort of 50-year-old men in the United Kingdom with histories of gastroesophageal reflux disease symptoms, assuming the prevalence of Barrett's esophagus to be 8%. Participants were invited to undergo screening by endoscopy or Cytosponge (invitation acceptance rates of 23% and 45%, respectively), and outcomes were compared with those from men who underwent no screening. We estimated the number of incident esophageal adenocarcinoma cases prevented and the incremental cost-effectiveness ratio of quality-adjusted life years (QALYs) of the different strategies. Patients found to have high-grade dysplasia or intramucosal cancer received endotherapy. Model inputs included data on disease progression, test accuracy, post-treatment status, and surveillance protocols. Costs and benefits were discounted at 3.5% per year. Supplementary and sensitivity analyses comprised esophagectomy management of high-grade dysplasia or intramucosal cancer, screening by ultrathin nasal endoscopy, and different assumptions of uptake of screening invitations for either strategy.

RESULTS

We estimated that compared with no screening, Cytosponge screening followed by treatment of patients with dysplasia or intramucosal cancer costs an additional $240 (95% credible interval, $196-$320) per screening participant and results in a mean gain of 0.015 (95% credible interval, -0.001 to 0.029) QALYs and an incremental cost-effectiveness ratio of $15.7 thousand (K) per QALY. The respective values for endoscopy were $299 ($261-$367), 0.013 (0.003-0.023) QALYs, and $22.2K. Screening by the Cytosponge followed by treatment of patients with dysplasia or intramucosal cancer would reduce the number of cases of incident symptomatic esophageal adenocarcinoma by 19%, compared with 17% for screening by endoscopy, although this greater benefit for Cytosponge depends on more patients accepting screening by Cytosponge compared with screening by endoscopy.

CONCLUSIONS

In a microsimulation model, screening 50-year-old men with symptoms of gastroesophageal reflux disease by Cytosponge is cost effective and would reduce mortality from esophageal adenocarcinoma compared with no screening.

String capsule endoscopy for screening and surveillance of esophageal varices in patients with cirrhosis

BACKGROUND

EGD is the gold standard for the screening and surveillance of esophageal varices. A less invasive, safer and sedationless alternative procedure is needed.

OBJECTIVE

To assess the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) as well as the beyond the chance agreement (kappa index), of string capsule endoscopy (SCE) in the diagnosis of esophageal varices.

METHODS

Cirrhotic patients underwent string capsule endoscopy (SCE) and EGD for screening and surveillance purposes. Varices were graded at EGD and SCE as small, medium and large. Descriptors at SCE were added as follows: PLUS, for the presence of red wale signs or, MINUS for their absence, irrespective of the estimated variceal size. Clinically significant varices were defined by their size (medium/large at either EGD or SCE) and/or, the PLUS descriptor irrespective of the estimated size at SCE. Sensitivity, specificity, PPV, NPV, accuracy and kappa index were calculated. Procedure time, procedure-related discomfort and patient's preference were documented.

RESULTS

100 patients (33 for screening and 67 for surveillance) were enrolled. The sensitivity and specificity of SCE for clinically significant varices when using the PLUS/MINUS descriptors were 82% and 90%, respectively with a PPV of 84% and NPV of 89% and a kappa of 0.73.

CONCLUSION

String capsule endoscopy had an acceptable sensitivity and specificity for the diagnosis of clinically significant esophageal varices but the lack of air insufflation still hampers its correlation with the grading used with EGD.

Endoscopy for upper GI cancer screening in the general population: a cost-utility analysis

BACKGROUND

Colon cancer screening with colonoscopy is an accepted strategy; however, there are limited data regarding the cost-effectiveness of screening for upper GI cancers (esophageal adenocarcinoma with its premalignant precursor Barrett's esophagus, esophageal squamous cell cancer, gastric adenocarcinoma) in the United States.

OBJECTIVE

To evaluate the cost-effectiveness of screening the general population for upper GI cancers by performing an upper endoscopy at the time of screening colonoscopy.

DESIGN

Decision analysis.

SETTING

Third-party-payer perspective with a time horizon of 30 years or until death.

PATIENTS

This study involved 50-year-old patients already undergoing screening colonoscopy.

INTERVENTION

Comparison of two strategies: performing and not performing a screening upper endoscopy at the time of screening colonoscopy.

MAIN OUTCOME MEASUREMENTS

Incremental cost-effectiveness ratio (ICER).

RESULTS

One-time screening for the general population at the age of 50 for upper GI cancers required $115,664 per quality-adjusted life year (QALY) compared with no screening or surveillance. A strategy of screening and surveillance for Barrett's esophagus required only $95,559 per QALY saved. In 1-way sensitivity analyses, the prevalence rates of esophageal adenocarcinoma, esophageal squamous cell cancer, or gastric adenocarcinoma would have to increase by 654%, 1948%, and 337%, respectively, to generate an ICER of less than $50,000 per QALY.

LIMITATIONS

Omission of premalignant conditions for squamous cell cancer and gastric adenocarcinoma.

CONCLUSION

The ICER for screening the general population for upper GI cancers with endoscopy remains high, despite accounting for reduced endoscopy costs and the combined benefits of detecting early esophageal adenocarcinoma, esophageal squamous cell cancer, and gastric adenocarcinoma. However, the ICER compares favorably with commonly performed screening strategies for other cancers.

Cost estimation of small bowel capsule endoscopy based on "real world" data: inpatient or outpatient procedure?

BACKGROUND

Although capsule endoscopy is the cornerstone for the evaluation of the small bowel in patients with obscure GI bleeding data about costs are lacking.

AIM

To evaluate, from a third party payer point of view, whether performing capsule endoscopy as an outpatient instead of an inpatient procedure can reduce costs.

MATERIALS AND METHODS

The data source is a multicentre survey collecting data for 2921 patients; 1486 of them underwent capsule endoscopy for obscure GI bleeding or chronic unexplained iron-deficiency anaemia as inpatients (814 with positive, 211 with inconclusive and 461 with negative result). We estimated costs of inpatient procedures based on the diagnosis related groups (DRG) system, while those of outpatient procedures on reimbursement provided in five Italian regions.

RESULTS

We estimated that the cost for each inpatient undergoing capsule endoscopy is about € 1775.90. Assuming that all these patients had undergone the same procedure as outpatients, € 175.00-741.00 per patient (depending on the reimbursement and/or on diagnosis related group codes applied) would have been saved.

CONCLUSIONS

Our estimate suggests that, from the third party payer's perspective and using the diagnosis related group reimbursement system, shifting capsule endoscopy from inpatient to outpatient procedure, would be potentially cost saving at least for patients referred for obscure GI bleeding or chronic unexplained anaemia.

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.

Age- and sex-specific yield of Barrett's esophagus by endoscopy indication

BACKGROUND

Barrett's esophagus is a precursor of esophageal adenocarcinoma, both of which are associated with GERD. Screening GERD patients for Barrett's esophagus has been suggested, but it is not known which patients should be screened and at what age.

OBJECTIVE

To determine the age-specific yield of endoscopy for Barrett's esophagus stratified by sex and indication for endoscopy.

DESIGN

Retrospective cross-sectional study.

SETTING

National Endoscopic Database of the Clinical Outcomes Research Initiative (CORI).

PATIENTS

A total of 155,641 patients undergoing their first endoscopy at one of the CORI sites for clinical indications.

MAIN OUTCOME MEASUREMENTS

Age-specific yield of Barrett's esophagus.

RESULTS

Among white men with GERD, the yield of Barrett's esophagus increases steeply from early adulthood (2.1% in the third decade of life) to middle adulthood (9.3% in the sixth decade) and then plateaus (the difference for the eighth decade minus the sixth decade is -1.1%; 95% CI, -3.9% to 1.7%). There is no difference in the yield of Barrett's esophagus between middle-aged white women with GERD and white men without GERD (difference is -0.46%; 95% CI, -1.23% to 0.31%).

LIMITATIONS

Possible bias by selection for endoscopy and the potential for misclassification of GERD status.

CONCLUSIONS

The yield of upper endoscopy for the diagnosis of Barrett's esophagus increases rapidly among white men with GERD until approximately age 50 and then reaches a plateau. White women with GERD are at no increased risk compared with white men without GERD.

Cost-effectiveness of endoscopic screening followed by surveillance for Barrett's esophagus: a review

Screening interventions for Barrett's esophagus (BE) are appealing, but there is little supporting evidence. We reviewed health economics studies about BE endoscopic screening followed by, as required, endoscopic surveillance ("screening and surveillance" hereafter) to help inform the design and conduct of future research. Health economics studies about BE screening and surveillance were identified using electronic database searches and personal contact with authors of identified studies. No studies examined general population screening. Five US studies published between 2003 and 2007 examined the cost effectiveness of screening and surveillance (against no intervention) in patients with chronic gastroesophageal reflux disease (GERD). There was no randomized trial evidence to inform model construction. Assumptions about prevalence and transition probabilities between BE histologic subtypes and about surveillance and treatment protocols varied substantially between studies. Parameters such as potential BE diagnosis-related reduction in quality of life or increase in health care use, diagnostic accuracy, and infrastructural costs (for quality assurance) were considered either "optimistically" or not at all. Only 2 studies considered endoscopic treatments. No study considered the recently introduced radiofrequency ablation technique, or the potential for biomarker-based risk stratification of surveillance interval or duration. Current health economics evidence is likely to have provided optimistic cost-effectiveness estimates and is not sufficient to support introduction of endoscopic BE screening programs among GERD patients. The evidence does not adequately incorporate novel (endoscopic) treatments and the potential for (clinical, endoscopic, or biomarker-based) risk stratification of surveillance. Future research should aim to encompass both these factors.

Cost-effectiveness of prophylactic surgery for duodenal cancer in familial adenomatous polyposis

BACKGROUND

Duodenal cancer is the leading cause of cancer death in familial adenomatous polyposis after colorectal cancer. The lifetime risk for developing duodenal cancer is 4% to 10%. Current treatment guidelines recommend endoscopic surveillance with a prophylactic pancreaticoduodenectomy in advanced duodenal polyposis, defined using the Spigelman staging system. Because no clinical trials have assessed this recommendation, a modeling approach was used to evaluate the cost-effectiveness of various treatment strategies.

METHODS

A Markov model was constructed to estimate the life expectancy and cost of three different strategies: pancreaticoduodenectomy at Spigelman stage III, pancreaticoduodenectomy at Spigelman stage IV, and pancreaticoduodenectomy at cancer diagnosis. A cohort of 30-year-old familial adenomatous polyposis patients with total colectomies was simulated until age 80. The analysis was from a societal perspective. Extensive sensitivity analysis was performed to assess the impact of model uncertainty on results.

RESULTS

At all stages of polyposis and all ages <80 years, prophylactic surgery at Spigelman stage IV resulted in the greatest life expectancy. Surgery at stage IV was more effective and more expensive than surgery at cancer diagnosis, with an incremental cost of $3,200 per quality-adjusted life year gained. Surgery at stage III was not a viable option. The results were robust to wide variation in model parameters but were sensitive to the post-pancreaticoduodenectomy quality of life score.

CONCLUSIONS

Prophylactic pancreaticoduodenectomy at stage IV duodenal polyposis in familial adenomatous polyposis is a cost-effective approach that results in greater life expectancy than surgery at either stage III or cancer diagnosis.

[Future prospects in digestive endoscopy: wireless capsule endoscopy]

Since the beginning of the millennium, the development of wireless capsule endoscopy has represented a major technological advance. The capsule is ingested by the patient and images are transmitted via several sensors positioned on the skin of the patient and downloaded in a computer system. The first applications were focused on the exploration of the small bowel which was previously considered as an obscure area for conventional endoscopy. Wireless capsule endoscopy of the small bowel is now an established technique with many acknowledged indications for the diagnosis of obscure bleeding, anemia of presumed digestive origin, Crohn's disease and small bowel tumors. Recently, thanks to technological progresses, novel capsules have been developed for specific segments of the gut namely the oesophagus and the colon. Recent data suggest that these new capsules could have potential applications for the diagnosis of oesophageal varices, Barrett's oesophagus and for the screening and/or surveillance of polyps of the colon. However, further studies are required before such strategies could be approved for clinical use or even replace conventional endoscopic modalities. In the long-term, progresses in signal processing as well as in the miniaturisation of sensors or markers may lead to a new generation of endoscopic robots. This technological breakthrough may ultimately result in new concepts and change current practice of digestive endoscopy.