Biopsy Sampling in Upper Gastrointestinal Endoscopy: A Survey from 10 Tertiary Referral Centres Across Europe.

BACKGROUND: Guidelines give robust recommendations on which biopsies should be taken when there is endoscopic suggestion of gastric inflammation. Adherence to these guidelines often seems arbitrary. This study aimed to give an overview on current practice in tertiary referral centres across Europe. METHODS: Data were collected at 10 tertiary referral centres. Demographic data, the indication for each procedure, endoscopic findings, and the number and sampling site of biopsies were recorded. Findings were compared between centres, and factors influencing the decision to take biopsies were explored. RESULTS: Biopsies were taken in 56.6% of 9,425 procedures, with significant variation between centres (p < 0.001). Gastric biopsies were taken in 43.8% of all procedures. Sampling location varied with the procedure indication (p < 0.001) without consistent pattern across the centres. Fewer biopsies were taken in centres which routinely applied the updated Sydney classification for gastritis assessment (46.0%), compared to centres where this was done only upon request (75.3%, p < 0.001). This was the same for centres stratifying patients according to the OLGA system (51.8 vs. 73.0%, p < 0.001). More biopsies were taken in centres following the MAPS guidelines on stomach surveillance (68.1 vs. 37.1%, p < 0.001). Biopsy sampling was more likely in younger patients in 8 centres (p < 0.05), but this was not true for the whole cohort (p = 0.537). The percentage of procedures with biopsies correlated directly with additional costs charged in case of biopsies (r = 0.709, p = 0.022). CONCLUSION: Adherence to guideline recommendations for biopsy sampling at gastroscopy was inconsistent across the participating centres. Our data suggest that centre-specific policies are applied instead.

The Rationale and Efficacy of Primary and Secondary Prevention in Adenocarcinomas of the Upper Gastrointestinal Tract.

While the primary risk factor for oesophageal adenocarcinoma (OAC) and its precursor lesion Barrett's oesophagus (BO) is gastro-oesophageal reflux, the infection with Helicobacter pylori (H. pylori) is the dominant risk factor for gastric cancer. Reduction of reflux by dietary measures and proton pump inhibitors has some merits in OAC prevention, and the chemopreventive effect of Aspirin and statins is being widely investigated; however, improved outcome in OAC occurs primarily as the result of secondary prevention. Early detection of neoplastic lesions in Barrett's metaplasia can be achieved by surveillance endoscopies. Novel endoscopic imaging modalities carry similar importance as the endoscopic treatment techniques as without detection of early lesions, therapy cannot be applied. Minimally invasive approaches are currently being investigated to identify patients with BO who are at particular risk of neoplastic progression. While dietary factors also play an important role in the prevention of gastric cancer and chemoprevention seems to be promising, the most beneficial effect has been shown for the eradication of H. pylori infection, which results in at least a one third reduction of gastric cancer risk. This effect can be further improved if the eradication takes place prior to the development of pre-neoplastic gastric conditions such as mucosal atrophy or intestinal metaplasia (IM). The definition of the "point of no return", after which eradication is less effective, is of high importance, although H. pylori eradication can still be beneficial even at more advance stages of mucosal changes. For this reason, patients with advanced atrophy and IM should undergo endoscopic surveillance in the same way as patients with BO. There is also need for development of non-invasive tests to identify patients at high risk of progression to gastric cancer to improve outcome of these surveillance approaches.

Autofluorescence-Directed Confocal Endomicroscopy in Combination With a Three-Biomarker Panel Can Inform Management Decisions in Barrett's Esophagus.

OBJECTIVES: Barrett's esophagus (BE) surveillance with white-light endoscopy and quadrantic biopsies (Seattle protocol) is resource intensive and limited by sampling error. Previous work suggests that autofluorescence imaging (AFI) in combination with a molecular panel might reduce the number of biopsies, but this was not sufficiently sensitive for low-grade dysplasia, now a point for endoscopic intervention. Here we used AFI to direct narrow-field imaging tools for real-time optical assessment of dysplasia and biopsies for a biomarker panel. We compared the new diagnostic algorithm with the current standard. METHODS: A total of 55 patients with BE were recruited at a single tertiary referral center. Patients underwent high-resolution endoscopy followed by AFI. AFI-targeted areas (n=194) were examined in turn by narrow-band imaging with magnification (NBIz) and probe-based confocal laser endomicroscopy (pCLE). Biopsies were taken from AFI-targeted areas and tested using an established molecular panel comprising aneuploidy plus cyclin A and p53 immunohistochemistry. RESULTS: In the per-patient analysis the overall sensitivity and specificity of AFI-targeted pCLE were 100% and 53.6% for high-grade dysplasia/intramucosal cancer and 96.4% and 74.1% for any grade of dysplasia, respectively. NBIz had equal specificity for dysplasia detection (74.1%), but significantly lower sensitivity (57.1%) than pCLE. The time required to perform AFI-targeted pCLE was shorter that that taken by the Seattle protocol (P=0.0004). We found enrichment of molecular abnormalities in areas with optical dysplasia by pCLE (P<0.001), regardless of histologic dysplasia. The addition of the 3-biomarker panel reduced the false positive rate of pCLE by 50%, leading to sensitivity and specificity for any grade of dysplasia of 89.2% and 88.9%, respectively. CONCLUSIONS: The combination of pCLE on AFI-targeted areas and a 3-biomarker panel identifies patients with dysplasia.

Population-based study reveals new risk-stratification biomarker panel for Barrett's esophagus.

BACKGROUND & AIMS: The risk of progression of Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC) is low and difficult to calculate. Accurate tools to determine risk are needed to optimize surveillance and intervention. We assessed the ability of candidate biomarkers to predict which cases of BE will progress to EAC or high-grade dysplasia and identified those that can be measured in formalin-fixed tissues. METHODS: We analyzed data from a nested case-control study performed using the population-based Northern Ireland BE Register (1993-2005). Cases who progressed to EAC (n = 89) or high-grade dysplasia ≥ 6 months after diagnosis with BE were matched to controls (nonprogressors, n = 291), for age, sex, and year of BE diagnosis. Established biomarkers (abnormal DNA content, p53, and cyclin A expression) and new biomarkers (levels of sialyl Lewis(a), Lewis(x), and Aspergillus oryzae lectin [AOL] and binding of wheat germ agglutinin) were assessed in paraffin-embedded tissue samples from patients with a first diagnosis of BE. Conditional logistic regression analysis was applied to assess odds of progression for patients with dysplastic and nondysplastic BE, based on biomarker status. RESULTS: Low-grade dysplasia and all biomarkers tested, other than Lewis(x), were associated with risk of EAC or high-grade dysplasia. In backward selection, a panel comprising low-grade dysplasia, abnormal DNA ploidy, and AOL most accurately identified progressors and nonprogressors. The adjusted odds ratio for progression of patients with BE with low-grade dysplasia was 3.74 (95% confidence interval, 2.43-5.79) for each additional biomarker and the risk increased by 2.99 for each additional factor (95% confidence interval, 1.72-5.20) in patients without dysplasia. CONCLUSIONS: Low-grade dysplasia, abnormal DNA ploidy, and AOL can be used to identify patients with BE most likely to develop EAC or high-grade dysplasia.

Randomized crossover study comparing efficacy of transnasal endoscopy with that of standard endoscopy to detect Barrett's esophagus.

BACKGROUND: Unsedated transnasal endoscopy (TNE) may be safer and less expensive than standard endoscopy (SE) for detecting Barrett's esophagus (BE). Emerging technologies require robust evaluation before routine use. OBJECTIVE: To evaluate the sensitivity, specificity, and acceptability of TNE in diagnosing BE compared with those of SE. DESIGN: Prospective, randomized, crossover study. SETTING: Single, tertiary-care referral center. PATIENTS: This study enrolled consecutive patients with BE or those referred for diagnostic assessment. INTERVENTION: All patients underwent TNE followed by SE or the reverse. Spielberger State-Trait Anxiety Inventory short-form questionnaires, a visual analogue scale, and a single question addressing preference for endoscopy type were administered. MAIN OUTCOME MEASUREMENTS: Diagnostic accuracy and tolerability of TNE were compared with those of SE. RESULTS: Of 95 patients randomized, 82 completed the study. We correctly diagnosed 48 of 49 BE cases by TNE for endoscopic findings of columnar lined esophagus compared with the criterion standard, SE, giving a sensitivity and specificity of 0.98 and 1.00, respectively. The BE median length was 3 cm (interquartile range [IQR] 1-5 cm) with SE and 3 cm (IQR 2-4 cm) with TNE, giving high correlations between the two modalities (R(2) = 0.97; P < .001). The sensitivity and specificity for detecting intestinal metaplasia by TNE compared with those by SE was 0.91 and 1.00, respectively. The mean (± standard deviation) post-endoscopy Spielberger State-Trait Anxiety Inventory short-form score for TNE (30.0 ± 1.10 standard error of the mean [SEM]) was lower than that for SE (30.7 ± 1.29 SEM), (P = .054). The visual analogue scale scores were no different (P = .07). The majority of patients (59%) expressed a preference for TNE. LIMITATIONS: This is a small study, with limited generalizability, a high prevalence of patients with BE, differential drop-out between the two procedures, and use of sedation. CONCLUSION: TNE is an accurate and well-tolerated method for diagnosing BE compared with SE. TNE warrants further evaluation as a screening tool for BE.

Molecular imaging using fluorescent lectins permits rapid endoscopic identification of dysplasia in Barrett's esophagus.

Barrett's esophagus is an example of a pre-invasive state, for which current endoscopic surveillance methods to detect dysplasia are time consuming and inadequate. The prognosis of cancer arising in Barrett's esophagus is improved by early detection at the stage of mucosal carcinoma or high-grade dysplasia. Molecular imaging methods could revolutionize the detection of dysplasia, provided they permit a wide field of view and highlight abnormalities in real time. We show here that cell-surface glycans are altered in the progression from Barrett's esophagus to adenocarcinoma and lead to specific changes in lectin binding patterns. We chose wheat germ agglutinin as a candidate lectin with clinical potential. The binding of wheat germ agglutinin to human tissue was determined to be specific, and we validated this specific binding by successful endoscopic visualization of high-grade dysplastic lesions, which were not detectable by conventional endoscopy, with a high signal-to-background ratio of over 5.

Barrett's esophagus.

Barrett's esophagus is an important step in the pathway to esophageal adenocarcinoma. Since most patients with Barrett's esophagus are undiagnosed and patients present with advanced adenocarcinoma de novo, prognosis for this disease remains poor. To identify those people with Barrett's esophagus who are at particular risk many new technologies are being developed. In association with these advances in risk stratification, progress is being made in the endoscopic treatment of Barrett's. Chemoprevention is also an area of interest and trials are underway.