Cost considerations in implementing a screening and surveillance strategy for Barrett's oesophagus

Design and Evaluation of ScanCap: A Low-Cost, Reusable Tethered Capsule Endoscope with Blue-Green Illumination Imaging for Unsedated Screening and Early Detection of Barrett's Esophagus

Esophageal carcinoma is the sixth-leading cause of cancer death worldwide. A precursor to esophageal adenocarcinoma (EAC) is Barrett's Esophagus (BE). Early-stage diagnosis and treatment of esophageal neoplasia (Barrett's with high-grade dysplasia/intramucosal cancer) increase the five-year survival rate from 10% to 98%. BE is a global challenge; however, current endoscopes for early BE detection are costly and require extensive infrastructure for patient examination and sedation. We describe the design and evaluation of the first prototype of ScanCap, a high-resolution optical endoscopy system with a reusable, low-cost tethered capsule, designed to provide high-definition, blue-green illumination imaging for the early detection of BE in unsedated patients. The tethered capsule (12.8 mm diameter, 35.5 mm length) contains a color camera and rotating mirror and is designed to be swallowed; images are collected as the capsule is retracted manually via the tether. The tether provides electrical power and illumination at wavelengths of 415 nm and 565 nm and transmits data from the camera to a tablet. The ScanCap prototype capsule was used to image the oral mucosa in normal volunteers and ex vivo esophageal resections; images were compared to those obtained using an Olympus CV-180 endoscope. Images of superficial capillaries in intact oral mucosa were clearly visible in ScanCap images. Diagnostically relevant features of BE, including irregular Z-lines, distorted mucosa, and dilated vasculature, were clearly visible in ScanCap images of ex vivo esophageal specimens.

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.

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.

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.

Cancer incidence and mortality risks in a large US Barrett's oesophagus cohort

OBJECTIVE

Barrett's oesophagus (BE) increases the risk of oesophageal adenocarcinoma by 10-55 times that of the general population, but no community-based cancer-specific incidence and cause-specific mortality risk estimates exist for large cohorts in the USA.

DESIGN

Within Kaiser Permanente Northern California (KPNC), we identified patients with BE diagnosed during 1995-2012. KPNC cancer registry and mortality files were used to estimate standardised incidence ratios (SIR), standardised mortality ratios (SMR) and excess absolute risks.

RESULTS

There were 8929 patients with BE providing 50 147 person-years of follow-up. Compared with the greater KPNC population, patients with BE had increased risks of any cancer (SIR=1.40, 95% CI 1.31 to 1.49), which slightly decreased after excluding oesophageal cancer. Oesophageal adenocarcinoma risk was increased 24 times, which translated into an excess absolute risk of 24 cases per 10 000 person-years. Although oesophageal adenocarcinoma risk decreased with time since BE diagnosis, oesophageal cancer mortality did not, indicating that the true risk is stable and persistent with time. Relative risks of cardia and stomach cancers were increased, but excess absolute risks were modest. Risks of colorectal, lung and prostate cancers were unaltered. All-cause mortality was slightly increased after excluding oesophageal cancer (SMR=1.24, 95% CI 1.18 to 1.31), but time-stratified analyses indicated that this was likely attributable to diagnostic bias. Cause-specific SMRs were elevated for ischaemic heart disease (SMR=1.39, 95% CI 1.18 to 1.63), respiratory system diseases (SMR=1.51, 95% CI 1.29 to 1.75) and digestive system diseases (SMR=2.20 95% CI 1.75 to 2.75).

CONCLUSIONS

Patients with BE had a persistent excess risk of oesophageal adenocarcinoma over time, although their absolute excess risks for this cancer, any cancer and overall mortality were modest.

Natural History of Barrett's Esophagus

Barrett's esophagus (BE) is a very common condition. We have obtained fairly profound knowledge of the natural history of this condition. This results from many cross-sectional and cohort studies, many describing patients undergoing long-term surveillance. Their consent to use their clinical data has improved our knowledge to the benefit of these same and other patients. The prevalence of BE increases with age both in men and in women. This increase starts at a younger age in men than in women. The incidence of high-grade dysplasia and cancer in BE depends on segment length, gender, and age. The latter two likely indicate the duration of the presence of BE in an individual patient. Other factors that influence the incidence of dysplasia and cancer are smoking behavior and use of certain medications such as PPIs, statins, and NSAIDs. Surveillance of BE and treatment of dysplasia can impact the incidence of and mortality due to esophageal adenocarcinoma. This is of major benefit to a subgroup of BE patients. The epidemiology and burden of disease ask for further efforts to develop targeted screening, surveillance, and intervention techniques in coming years.

Economic evaluation of endoscopic radiofrequency ablation for the treatment of dysplastic Barrett's esophagus in Spain

BACKGROUND AND STUDY AIMS

To assess the cost-effectiveness of introducing endoscopic treatment based on radiofrequency ablation plus endoscopic mucosal resection in selected patients into the standard of care of Barrett's esophagus patients with high-grade dysplasia or low-grade dysplasia in Spain.

METHODS

The disease evolution was modeled via a semi-Markov model. The treatment strategies compared included endoscopic treatment based on radiofrequency ablation plus endoscopic mucosal resection and the Standard of Care (esophagectomy or palliative chemoradiotherapy according to disease status for high-grade dysplasia and endoscopic surveillance for low-grade dysplasia). Efficacy rates, transition probabilities and utility values were obtained from the literature. Clinical management patterns and resource use were modeled according to Spanish clinical expert opinion. Costs were expressed in euros (€) from 2016 reflecting the Spanish National Health System perspective. Sensitivity analyses were performed to assess the robustness of the model.

RESULTS

With respect to the Spanish Standard of Care, endoscopic treatment based on radiofrequency ablation plus endoscopic mucosal resection was a dominant strategy for high-grade dysplasia patients. When a willingness-to-pay threshold of €30,000 per quality-adjusted life-years gained was considered, this was cost-effective for low-grade dysplasia patients (€12,865 per quality-adjusted life-years gained). The sensitivity analyses supported the base case analysis results and pointed towards the main drivers of uncertainty in the model.

CONCLUSIONS

From a health care decision-maker, endoscopic treatment based on radiofrequency ablation plus endoscopic mucosal resection is the intervention of choice for dysplasic Barrett's esophagus patients in Spain.

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.

Esophageal Acid Clearance During Random Swallowing Is Faster in Patients with Barrett's Esophagus Than in Healthy Controls

Background/Aims

Impaired esophageal acid clearance may be a contributing factor in the pathogenesis of Barrett’s esophagus. However, few studies have measured acid clearance as such in these patients. In this explorative, cross-sectional study, we aimed to compare esophageal acid clearance and swallowing rate in patients with Barrett’s esophagus to that in healthy controls.

Methods

A total of 26 patients with histology-confirmed Barrett’s esophagus and 12 healthy controls underwent (1) upper endoscopy, (2) an acid clearance test using a pH-impedance probe under controlled conditions including controlled and random swallowing, and (3) an ambulatory pH-impedance measurement.

Results

Compared with controls and when swallowing randomly, patients cleared acid 46% faster (P = 0.008). Furthermore, patients swallowed 60% more frequently (mean swallows/minute: 1.90 ± 0.74 vs 1.19 ± 0.58; P = 0.005), and acid clearance time decreased with greater random swallowing rate (P < 0.001). Swallowing rate increased with lower distal esophageal baseline impedance (P = 0.014). Ambulatory acid exposure was greater in patients (P = 0.033), but clearance times assessed from the ambulatory pH-measurement and acid clearance test were not correlated (all P > 0.3).

Conclusions

More frequent swallowing and thus faster acid clearance in Barrett’s esophagus may constitute a protective reflex due to impaired mucosal integrity and possibly acid hypersensitivity. Despite these reinforced mechanisms, acid clearance ability seems to be overthrown by repeated, retrograde acid reflux, thus resulting in increased esophageal acid exposure and consequently mucosal changes.

Systematic Analysis and Critical Appraisal of the Quality of the Scientific Evidence and Conflicts of Interest in Practice Guidelines (2005-2013) for Barrett's Esophagus

BACKGROUND

Barrett's esophagus (BE) is a condition that has a small but important risk of progressing to esophageal cancer. To date, no study has assessed the strength of evidence supporting the recommendations for BE. We sought to assess the overall quality of the recommendations and strength of the BE using the AGREE II instrument.

METHODS

A PubMed search was performed to identify guidelines published pertaining to BE. Every guideline was reviewed using the AGREE II format to assess the methodological rigor and validity of the guideline. Additionally, guidelines were reviewed for the level of evidence used to support recommendations, conflicts of interest (COI), and differences in recommendations. Statistical analysis was performed using Stata (version 12).

RESULTS

In total, 234 manuscripts were identified of which 8 guidelines published between 2005 and 2013 pertained to BE. Seventy-five percentage (6/8) graded the evidence used to formulate recommendations. Of the 126 recommendations with supporting evidence, 6 % were supported by level A evidence, 49 % level B evidence, and 45 % level C evidence. Using the AGREE II format, the highest overall assessment grade was the BSG BE guideline (6.5 ± 0.6) followed by the AGA (5.5 ± 0.6). The highest rated domains were scope and purpose (mean 77 range 24-96) and clarity of presentation (mean 75), while the lowest rated domains were editorial independence (mean 32 range 0-92) and applicability of the guideline (mean 35 range 7-90). There was significant variability in recommendations regarding who to screen for BE and surveillance intervals. Finally, only 50 % of the guidelines disclosed if COI were present and 75 % (3/4) reported potentially relevant COI.

CONCLUSIONS

Majority of the BE guideline fail to meet the AGREE II domains, and most of the recommendations are level B or C quality evidence. Further interventions are necessary to improve the overall quality of the guidelines.