British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma

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.

Endoscopic grading of gastric intestinal metaplasia on risk assessment for early gastric neoplasia: can we replace histology assessment also in the West?

OBJECTIVES

To assess the value of endoscopic grading of gastric intestinal metaplasia (EGGIM), operative link on gastritis assessment (OLGA) and operative link on gastric intestinal metaplasia (OLGIM) on risk stratification for early gastric neoplasia (EGN) and to investigate other factors possibly associated with its development.

DESIGN

Single centre, case-control study including 187 patients with EGN treated endoscopically and 187 age-matched and sex-matched control subjects. Individuals were classified according to EGGIM, OLGA and OLGIM systems. EGN risk according to gastritis stages and other clinical parameters was further evaluated.

RESULTS

More patients with EGN had EGGIM of ≥5 than control subjects (68.6% vs 13.3%, p<0.001). OLGA and OLGIM stages III/IV were more prevalent in patients with EGN than in control subjects (68% vs 11%, p<0.001, and 61% vs 3%, p<0.001, respectively). The three systems were the only parameters significantly related to the risk of EGN in multivariate analysis: for EGGIM 1-4 (adjusted OR (AOR) 12.9, 95% CI 1.4 to 118.6) and EGGIM 5-10 (AOR 21.2, 95% CI 5.0 to 90.2); for OLGA I/II (AOR 5.0, 95% CI 0.56 to 44.5) and OLGA III/IV (AOR 11.1, 95% CI 3.7 to 33.1); for OLGIM I/II (AOR 11.5, 95% CI 4.1 to 32.3) and OLGIM III/IV (AOR 16.0, 95% CI 7.6 to 33.4).

CONCLUSION

This study confirms the role of histological assessment as an independent risk factor for gastric cancer (GC), but it is the first study to show that an endoscopic classification of gastric intestinal metaplasia is highly associated with that outcome. After further prospective validation, this classification may be appropriate for GC risk stratification and may simplify every day practice by reducing the need for biopsies.

A panel of stomach-specific biomarkers (GastroPanel®) for the diagnosis of atrophic gastritis: A prospective, multicenter study in a low gastric cancer incidence area

BACKGROUND

Analysis of serum biomarkers for the assessment of atrophic gastritis (AG), considered as gastric precancerous lesion, is of growing interest and recommended by current guidelines. Our aim was to evaluate the diagnostic performance of a panel of biomarkers (GastroPanel®) for the detection of AG in France, a country of a low gastric cancer (GC) incidence.

MATERIAL AND METHODS

In this prospective, multicenter, cross-sectional study, consecutive patients considered at increased risk of GC and undergoing upper endoscopy with gastric biopsies were included. Blood samples were collected for the analysis of GastroPanel® (association of Pepsinogens I and II, Gastrin-17, and Helicobacter pylori serology) using ELISA. The results of GastroPanel® were compared to the results of histology considered as the reference.

RESULTS

Between 2016 and 2019, 344 patients (148 cases with AG, 196 controls without AG) were included. Sensitivity, specificity, positive, and negative predictive values for the detection of AG by GastroPanel® were of 39.9% (95% CI 31.9; 48.2), 93.4% (95% CI 88.9; 96.4), 81.9 (95% CI 71.1; 90.0), and 67.3 (95% CI 61.4; 72.8), respectively. The sensitivity was significantly higher for the detection of severe AG [60.8% (95% CI 46.1; 74.6) P = .015] and corpus AG [61.0% (95% CI 49.2; 72.0), P = .004]. Diagnostic performances of GastroPanel® tended to be better than those of Pepsinogen I alone, but the difference did not reach statistical significance (P = .068).

CONCLUSION

Serum pepsinogen and GastroPanel® tests show promising results for the detection of AG, especially of corpus AG and severe AG, in patients at high risk of GC in France.

Helicobacter pylori eradication improved the Kyoto classification score on endoscopy

BACKGROUND AND AIM

Endoscopy-based Kyoto classification predicts the risk of Helicobacter pylori infection and gastric cancer; however, the change in score following H. pylori eradication remains unknown. We retrospectively compared the Kyoto score before and after H. pylori eradication.

METHODS

H. pylori-positive patients who underwent baseline esophagogastroduodenoscopy (EGD), successful H. pylori eradication, and surveillance EGD were enrolled. The Kyoto score is a sum of scores for atrophy (Kimura-Takemoto atrophic-border classification none or C1: 0, C-II or C-III: 1, O-I to O-III: 2), intestinal metaplasia (none: 0, antrum: 1, corpus and antrum: 2), enlarged folds (absence: 0, presence: 1), nodularity (absence: 0, presence: 1), and diffuse redness (none: 0, mild: 1, severe: 2) and ranges from 0 to 8.

RESULTS

Eighty-three patients (mean age: 54.9 years; 65.1% women) were enrolled. The mean duration from successful eradication to surveillance EGD was 256 days. The Kyoto score significantly decreased from 3.90 to 2.78 following H. pylori eradication (P < 0.001). Scores for endoscopic atrophy (from 1.43 to 1.46, P = 0.638) and endoscopic intestinal metaplasia (from 0.53 to 0.47, P = 0.543) did not change; however, there was significant improvement in the scores for enlarged folds (from 0.14 to 0.00, P = 0.002), nodularity (from 0.18 to 0.04, P = 0.002), and diffuse redness (from 1.61 to 0.82, P < 0.001).

CONCLUSION

The Kyoto classification score decreased following H. pylori eradication. A decrease in the scores for enlarged folds, nodularity, and diffuse redness contributed to the decrease in Kyoto score.

Frontiers of Robotic Gastroscopy: A Comprehensive Review of Robotic Gastroscopes and Technologies

Simple Summary

With the rapid advancements of medical technologies and patients’ higher expectations for precision diagnostic and surgical outcomes, gastroscopy has been increasingly adopted for the detection and treatment of pathologies in the upper digestive tract. Correspondingly, robotic gastroscopes with advanced functionalities, e.g., disposable, dextrous and not invasive solutions, have been developed in the last years. This article extensively reviews these novel devices and describes their functionalities and performance. In addition, the implementation of artificial intelligence technology into robotic gastroscopes, combined with remote telehealth endoscopy services, are discussed. The aim of this paper is to provide a clear and comprehensive view of contemporary robotic gastroscopes and ancillary technologies to support medical practitioners in their future clinical practice but also to inspire and drive new engineering developments.

Abstract

Upper gastrointestinal (UGI) tract pathology is common worldwide. With recent advancements in robotics, innovative diagnostic and treatment devices have been developed and several translational attempts made. This review paper aims to provide a highly pictorial critical review of robotic gastroscopes, so that clinicians and researchers can obtain a swift and comprehensive overview of key technologies and challenges. Therefore, the paper presents robotic gastroscopes, either commercial or at a progressed technology readiness level. Among them, we show tethered and wireless gastroscopes, as well as devices aimed for UGI surgery. The technological features of these instruments, as well as their clinical adoption and performance, are described and compared. Although the existing endoscopic devices have thus far provided substantial improvements in the effectiveness of diagnosis and treatment, there are certain aspects that represent unwavering predicaments of the current gastroenterology practice. A detailed list includes difficulties and risks, such as transmission of communicable diseases (e.g., COVID-19) due to the doctor–patient proximity, unchanged learning curves, variable detection rates, procedure-related adverse events, endoscopists’ and nurses’ burnouts, limited human and/or material resources, and patients’ preferences to choose non-invasive options that further interfere with the successful implementation and adoption of routine screening. The combination of robotics and artificial intelligence, as well as remote telehealth endoscopy services, are also discussed, as viable solutions to improve existing platforms for diagnosis and treatment are emerging.

Endoscopy-based Kyoto classification score of gastritis related to pathological topography of neutrophil activity

BACKGROUND

Endoscopy-based Kyoto classification for gastritis and pathological topographic distribution of neutrophil infiltration are correlated with gastric cancer risk.

AIM

To investigate the association between Kyoto classification and the topographic distribution of neutrophil activity.

METHODS

Kyoto classification score, ranging from 0 to 8, consisted of atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness. Neutrophil activity was scored according to the updated Sydney System using biopsy samples obtained from the greater curvature of the corpus and the antrum. The participants were divided into four categories, inactive stomach, antrum-predominant gastritis, pangastritis, and corpus-predominant gastritis, based on the topographic distribution of neutrophil activity. Effects of sex, age, body mass index, drinking habit, smoking habit, family history of gastric cancer, serum Helicobacter pylori (H. pylori) antibody, and Kyoto score on topography of neutrophil infiltration were analyzed.

RESULTS

A total of 327 patients (comprising 50.7% women, with an average age of 50.2 years) were enrolled in this study. H. pylori infection rate was 82.9% with a mean Kyoto score of 4.63. The Kyoto score was associated with the topographic distribution of neutrophil activity. Kyoto scores were significantly higher in the order of inactive stomach, antrum-predominant gastritis, pangastritis, and corpus-predominant gastritis (3.05, 4.57, 5.21, and 5.96, respectively). Each individual score of endoscopic findings (i.e., atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness) was correlated with the topographic distribution of neutrophil activity. On multivariate analysis, the Kyoto score, age, and serum H. pylori antibody were independently associated with the topographic distribution of neutrophil activity.

CONCLUSION

The Kyoto classification score was associated with the topographic distribution of neutrophil activity.

Pathways of Gastric Carcinogenesis, Helicobacter pylori Virulence and Interactions with Antioxidant Systems, Vitamin C and Phytochemicals

Helicobacter pylori is a class one carcinogen which causes chronic atrophic gastritis, gastric intestinal metaplasia, dysplasia and adenocarcinoma. The mechanisms by which H. pylori interacts with other risk and protective factors, particularly vitamin C in gastric carcinogenesis are complex. Gastric carcinogenesis includes metabolic, environmental, epigenetic, genomic, infective, inflammatory and oncogenic pathways. The molecular classification of gastric cancer subtypes has revolutionized the understanding of gastric carcinogenesis. This includes the tumour microenvironment, germline mutations, and the role of Helicobacter pylori bacteria, Epstein Barr virus and epigenetics in somatic mutations. There is evidence that ascorbic acid, phytochemicals and endogenous antioxidant systems can modify the risk of gastric cancer. Gastric juice ascorbate levels depend on dietary intake of ascorbic acid but can also be decreased by H. pylori infection, H. pylori CagA secretion, tobacco smoking, achlorhydria and chronic atrophic gastritis. Ascorbic acid may be protective against gastric cancer by its antioxidant effect in gastric cytoprotection, regenerating active vitamin E and glutathione, inhibiting endogenous N-nitrosation, reducing toxic effects of ingested nitrosodimethylamines and heterocyclic amines, and preventing H. pylori infection. The effectiveness of such cytoprotection is related to H. pylori strain virulence, particularly CagA expression. The role of vitamin C in epigenetic reprogramming in gastric cancer is still evolving. Other factors in conjunction with vitamin C also play a role in gastric carcinogenesis. Eradication of H. pylori may lead to recovery of vitamin C secretion by gastric epithelium and enable regression of premalignant gastric lesions, thereby interrupting the Correa cascade of gastric carcinogenesis.

High frequency of gastric cancer precursor lesions in patients with gastric xanthelasma: a prospective case-control study

OBJECTIVE

An association of gastric cancer and precursor lesions with gastric xanthelasma has frequently been reported. However, the incidence of both gastric xanthelasma and gastric cancer precursor lesions increases with age. The aim of this study was to evaluate the frequency and characteristics of atrophic gastritis, intestinal metaplasia and dysplasia in patients with gastric xanthelasma compared to controls.

MATERIAL AND METHODS

Cases with gastric xanthelasma endoscopically and histopathologically were included in this prospective study. The patients included in the study were compared with age- and sex-matched controls in terms of the frequency and characteristics of atrophic gastritis, intestinal metaplasia, dysplasia and cancer.

RESULTS

In a series of 1892 upper endoscopies, 108 patients (5.7%) were found to have gastric xanthelasma. The average age of the patients was 61.41 ± 11.43 years. Among the patients, 58 (53.7%) were male. The frequencies of atrophic gastritis, intestinal metaplasia, dysplasia and gastric cancer in the xanthelasma group (n = 108) were 31.5, 68.5, 3.7 and 2.8%, respectively. The frequencies of atrophic gastritis, intestinal metaplasia, dysplasia and gastric cancer in the control group (n = 183) were 11.5, 31.7, 0.5 and 0.5%, respectively. Compared to the control group, the frequency of these cancer precursor lesions and the prevalence of advanced stage based on operative link on gastritis intestinal metaplasia assessment were found to be higher in the xanthelasma group (P < 0.05).

CONCLUSION

Gastric xanthelasma is associated with an increased frequency of gastric precancerous lesions and should be considered an important marker.

Cytosponge-trefoil factor 3 versus usual care to identify Barrett's oesophagus in a primary care setting: a multicentre, pragmatic, randomised controlled trial

BACKGROUND

Treatment of dysplastic Barrett's oesophagus prevents progression to adenocarcinoma; however, the optimal diagnostic strategy for Barrett's oesophagus is unclear. The Cytosponge-trefoil factor 3 (TFF3) is a non-endoscopic test for Barrett's oesophagus. The aim of this study was to investigate whether offering this test to patients on medication for gastro-oesophageal reflux would increase the detection of Barrett's oesophagus compared with standard management.

METHODS

This multicentre, pragmatic, randomised controlled trial was done in 109 socio-demographically diverse general practice clinics in England. Randomisation was done both at the general practice clinic level (cluster randomisation) and at the individual patient level, and the results for each type of randomisation were analysed separately before being combined. Patients were eligible if they were aged 50 years or older, had been taking acid-suppressants for symptoms of gastro-oesophageal reflux for more than 6 months, and had not undergone an endoscopy procedure within the past 5 years. General practice clinics were selected by the local clinical research network and invited to participate in the trial. For cluster randomisation, clinics were randomly assigned (1:1) by the trial statistician using a computer-generated randomisation sequence; for individual patient-level randomisation, patients were randomly assigned (1:1) by the general practice clinics using a centrally prepared computer-generated randomisation sequence. After randomisation, participants received either standard management of gastro-oesophageal reflux (usual care group), in which participants only received an endoscopy if required by their general practitioner, or usual care plus an offer of the Cytosponge-TFF3 procedure, with a subsequent endoscopy if the procedure identified TFF3-positive cells (intervention group). The primary outcome was the diagnosis of Barrett's oesophagus at 12 months after enrolment, expressed as a rate per 1000 person-years, in all participants in the intervention group (regardless of whether they had accepted the offer of the Cytosponge-TFF3 procedure) compared with all participants in the usual care group. Analyses were intention-to-treat. The trial is registered with the ISRCTN registry, ISRCTN68382401, and is completed.

FINDINGS

Between March 20, 2017, and March 21, 2019, 113 general practice clinics were enrolled, but four clinics dropped out shortly after randomisation. Using an automated search of the electronic prescribing records of the remaining 109 clinics, we identified 13 657 eligible patients who were sent an introductory letter with 14 days to opt out. 13 514 of these patients were randomly assigned (per practice or at the individual patient level) to the usual care group (n=6531) or the intervention group (n=6983). Following randomisation, 149 (2%) of 6983 participants in the intervention group and 143 (2%) of 6531 participants in the usual care group, on further scrutiny, did not meet all eligibility criteria or withdrew from the study. Of the remaining 6834 participants in the intervention group, 2679 (39%) expressed an interest in undergoing the Cytosponge-TFF3 procedure. Of these, 1750 (65%) met all of the eligibility criteria on telephone screening and underwent the procedure. Most of these participants (1654 [95%]; median age 69 years) swallowed the Cytosponge successfully and produced a sample. 231 (3%) of 6834 participants had a positive Cytosponge-TFF3 result and were referred for an endoscopy. Patients who declined the offer of the Cytosponge-TFF3 procedure and all participants in the usual care group only had an endoscopy if deemed necessary by their general practitioner. During an average of 12 months of follow-up, 140 (2%) of 6834 participants in the intervention group and 13 (<1%) of 6388 participants in the usual care group were diagnosed with Barrett's oesophagus (absolute difference 18·3 per 1000 person-years [95% CI 14·8-21·8]; rate ratio adjusted for cluster randomisation 10·6 [95% CI 6·0-18·8], p<0·0001). Nine (<1%) of 6834 participants were diagnosed with dysplastic Barrett's oesophagus (n=4) or stage I oesophago-gastric cancer (n=5) in the intervention group, whereas no participants were diagnosed with dysplastic Barrett's oesophagus or stage I gastro-oesophageal junction cancer in the usual care group. Among 1654 participants in the intervention group who swallowed the Cytosponge device successfully, 221 (13%) underwent endoscopy after testing positive for TFF3 and 131 (8%, corresponding to 59% of those having an endoscopy) were diagnosed with Barrett's oesophagus or cancer. One patient had a detachment of the Cytosponge from the thread requiring endoscopic removal, and the most common side-effect was a sore throat in 63 (4%) of 1654 participants.

INTERPRETATION

In patients with gastro-oesophageal reflux, the offer of Cytosponge-TFF3 testing results in improved detection of Barrett's oesophagus. Cytosponge-TFF3 testing could also lead to the diagnosis of treatable dysplasia and early cancer. This strategy will lead to additional endoscopies with some false positive results.

FUNDING

Cancer Research UK, National Institute for Health Research, the UK National Health Service, Medtronic, and the Medical Research Council.

Recent advances in the detection and management of early gastric cancer and its precursors

Despite declines in incidence, gastric cancer remains a disease with a poor prognosis and limited treatment options due to its often late stage of diagnosis. In contrast, early gastric cancer has a good to excellent prognosis, with 5-year survival rates as high as 92.6% after endoscopic resection. There remains an East-West divide for this disease, with high incidence countries such as Japan seeing earlier diagnoses and reduced mortality, in part thanks to the success of a national screening programme. With missed cancers still prevalent at upper endoscopy in the West, and variable approaches to assessment of the high-risk stomach, the quality of endoscopy we provide must be a focus for improvement, with particular attention paid to the minority of patients at increased cancer risk. High-definition endoscopy with virtual chromoendoscopy is superior to white light endoscopy alone. These enhanced imaging modalities allow the experienced endoscopist to accurately and robustly detect high-risk lesions in the stomach. An endoscopy-led staging strategy would mean biopsies could be targeted to histologically confirm the endoscopic impression of premalignant lesions including atrophic gastritis, gastric intestinal metaplasia, dysplasia and early cancer. This approach to quality improvement will reduce missed diagnoses and, combined with the latest endoscopic resection techniques performed at expert centres, will improve early detection and ultimately patient outcomes. In this review, we outline the latest evidence relating to diagnosis, staging and treatment of early gastric cancer and its precursor lesions.

Decision model analyses of upper endoscopy for gastric cancer screening and preneoplasia surveillance: a systematic review

AIMS

Gastric cancer (GC) is the third leading cause of cancer death worldwide, but the burden of disease is not distributed evenly. GC screening routinely occurs in some high-incidence regions/countries and is generally cost-effective, which is attributed largely to the associated GC mortality reduction. In regions of low-intermediate incidence, less is known about the outcomes of GC screening and gastric precancer surveillance, including cost-effectiveness, since there are no comparative clinical studies. Decision analytic studies are informative in such instances where logistical limitations preclude "gold standard" study designs. We therefore aimed to conduct a systematic review of decision model analyses focused on endoscopic GC screening or precancer surveillance.

METHODS

We identified decision model analyses, including cost effectiveness and cost utility studies, of GC screening or preneoplasia surveillance. At minimum, articles were evaluated for: study country; analytic design; population and health states; time horizon; model assumptions; outcomes; threshold value(s) for "cost-effective" determination; and sensitivity analyses. Quality appraisal was performed using a modified Drummond's analytic scoring system. Data sources were PubMed, Web of Science, Embase, and the Cochrane Library.

RESULTS

We identified 17 studies (8 screening, 4 surveillance, and 5 screening and surveillance) that met full inclusion criteria. Endoscopic screening in countries of high GC incidence was cost-effective across all studies; targeted screening of high-risk populations within otherwise low-intermediate incidence countries was also generally cost-effective. Surveillance of gastric precancer, including atrophic gastritis or gastric intestinal metaplasia, was generally cost-effective. Most studies had high appraisal scores, with 4 (24%) studies achieving perfect scores on the Drummond scale.

CONCLUSION

Decision model analyses offer a unique mechanism with which to efficiently explore the cost benefit of various prevention and early detection strategies. Based on this comprehensive systematic review, upper endoscopy for GC screening and gastric precancer surveillance might be cost-effective depending on the population and protocol. Focused efforts are especially needed not only to define the optimal approach, but also to define the populations within otherwise low-intermediate regions/countries who might benefit most.

Autoimmune gastritis

Autoimmune gastritis (AIG) is an increasingly prevalent, organ-specific, immune-mediated disorder characterized by the destruction of gastric parietal cells, leading to the loss of intrinsic factor and reduced acid output. These alterations result in malabsorption of iron, vitamin B₁₂ (pernicious anaemia) and potentially other micronutrients. For several years, most studies have focused on pernicious anaemia only, generating confusion between the two entities. In AIG, the gastric proton pump, H⁺/K⁺ ATPase, is the major autoantigen recognized by autoreactive T cells. The T cell-dependent activation of B cells stimulates the production of anti-parietal cell antibodies, the serological hallmark of AIG. The role of Helicobacter pylori infection in activating or favouring the autoimmune process is still uncertain. Early histopathological alterations allowing a more precise and prompt recognition have recently been described. AIG is burdened by a substantial diagnostic delay as it can present with varied clinical signs including, among others, gastrointestinal symptoms and neuropsychiatric manifestations. In advanced stages, AIG might progress to neuroendocrine tumours and gastric adenocarcinoma. Management includes early detection through a proactive case-finding strategy, micronutrient supplementation and endoscopic surveillance. This Primer comprehensively describes the most important insights regarding the epidemiology, pathophysiology, diagnosis and management of AIG, focusing on the most controversial, outstanding issues and future directions.

Recent Guidelines on the Management of Patients with Gastric Atrophy: Common Points and Controversies

Patients with gastric precancerous lesions (atrophic gastritis and intestinal metaplasia) have increased risk of developing gastric cancer, and adequate management and surveillance of these patients should allow to reduce gastric cancer-related mortality. The guidelines on the management of these patients have been recently published by the European Societies (MAPS II guidelines) and by the American Gastroenterological Association (AGA). The aim of this commentary is to compare these two guidelines by highlighting the common points and differences between them. Both guidelines recommend a systematic detection and eradication of Helicobacter pylori in all patients with gastric atrophy. However, there is a major difference in the recommendations for surveillance: while the MAPS II guidelines recommend systematic endoscopic surveillance in all patients with severe gastric atrophy (with or without intestinal metaplasia), the AGA guidelines focus only on intestinal metaplasia and plead against systematic surveillance, leaving the possibility of surveillance in individual patients based on shared decision between clinicians and patients. The difference between two guidelines comes essentially from the different arguments used by two authorities (randomized control studies by AGA and observational cohort studies by the European Societies), and may be, at least in part, related to the difference between the European and American health care systems and potential economic burden.

Role of serum matrix metalloproteinase in the diagnosis of gastric cancer

Objective

To determine the clinical value of a matrix metalloproteinase (MMP) antibody array in diagnosing gastric cancer (GC).

Methods

In this prospective study, serum samples of patients with GC (n=66) and non-neoplastic gastric disease (NGD; n=34) were collected between November 2017 and July 2018. The quantitative measurement of 10 MMP-related proteins was done using MMP arrays and compared between the two groups.

Results

The serum levels of MMPs 3, 8, 9 and tissue inhibitor of metalloproteinases (TIMPs) 1 and 2 were significantly higher in the GC group than in the NGD group (p<0.05). The area under curve (AUC) of the 10 MMP proteins for the diagnosis of GC varied between 0.500 and 0.658. The total AUC of all MMPs was 0.897 (95% CI: 0.837-0.957). The total AUC of the five MMPs (MMPs 3, 8, 9, and TIMPs 1 and 2) was 0.821 (95% CI: 0.733-0.909) for diagnosing GC. Also, the 10-factor and 5-factor predictive models had good diagnostic ability for early GC with an AUC of 0.865 (95% CI: 0.753-0.977) and 0.749 (95% CI: 0.600-0.898), respectively.

Conclusions

The detection of multiple serum MMPs with protein biochip technology is promising to be used as a novel non-invasive tool for facilitating early diagnosis or screening of GC.

Identification of hsa_circ_0005654 as a new early biomarker of gastric cancer

Gastric cancer is one of the most common cancers in the world. However, current medical technologies have not identified a reliable method to cure advanced gastric cancer, and early gastric cancer is difficult to diagnose. Therefore, we focused on circular RNAs (circRNAs) that have been proven to be involved in the carcinogenesis of gastric cancer. We first used quantitative reverse transcription-polymerase chain reaction (qRT-PCR) to evaluate the expression levels of hsa_circ_0005654 in 301 tissues, including 122 healthy gastric mucosa samples, 68 paired tissues from early gastric cancer and adjacent nontumor mucosae obtained by submucosal dissection, and 43 chronic gastritis tissues. Then, we analyzed the relationship between the expression levels of hsa_circ_0005654 and the clinicopathological characteristics of patients with early gastric cancer. We ultimately confirmed the clinical diagnostic value of hsa_circ_0005654 through generating receiver operating characteristic (ROC) curves and comparing the areas under the ROC curves (AUCs).Our data revealed that hsa_circ_0005654 was significantly downregulated in early gastric cancer tissues compared with matched normal mucosae (P< 0.001). Meanwhile, the expression levels of hsa_circ_0005654 in early gastric cancer tissues were also obviously lower than those in chronic gastritis tissues (P< 0.001). The AUCs of early gastric cancer tissues vs. paired normal adjacent mucosae, and that of early gastric cancer vs. healthy controls, were 0.927 and 0.924, respectively. These results clearly demonstrated that hsa_circ_0005654 may serve as a new and promising diagnostic biomarker for screening early gastric cancer. The AUC, sensitivity and specificity of hsa_circ_0005654 are significantly higher than those of present gastric cancer associated-biomarkers.

Current status of endoscopic submucosal tunnel dissection for treatment of superficial gastrointestinal neoplastic lesions

INTRODUCTION

With the widespread application of screening endoscopy and development of endoscopy-related instruments, more and more gastrointestinal cancers are detected in an early stage. Endoscopic resection is a preferred method for selected patients with superficial gastrointestinal neoplastic lesions, and endoscopic submucosal dissection (ESD) has become a standard method for its ability to perform en bloc resection regardless of the lesion size. ESD can be performed in a conventional or tunneling way, and the latter is termed endoscopic submucosal tunnel dissection (ESTD).

AREA COVERED

In the present review, we provided a comprehensive review on ESTD for treatment of superficial gastrointestinal neoplastic lesions. We mainly focus on technical details, safety and efficacy of ESTD for esophageal, gastric and colorectal lesions. The present review is expected to provide tips for operators who are going to perform ESTD.

EXPERT OPINION

The best indication of ESTD is large superficial esophageal neoplastic lesions (circumferential extent > 1/3 and longitudinal extent > 3 cm). Although ESTD has shown promising primary results for superficial gastric and colorectal neoplastic lesions, it is technically difficult and should be attempted only in experienced hands. Post-treatment stricture is a major concern, and preventive measures are recommended for patients with high risk of post-ESTD stricture.

Improving Efficacy of Endoscopic Diagnosis of Early Gastric Cancer: Gaps to Overcome from the Real-World Practice in Vietnam

OBJECTIVE

To identify factors associated with increased proportion of early gastric cancer to total detected gastric cancer among patients undergoing diagnostic esophagogastroduodenoscopy.

METHODS

A nationwide survey was conducted across 6 central-type and 6 municipal-type Vietnamese hospitals. A questionnaire regarding annual esophagogastroduodenoscopy volume, esophagogastroduodenoscopy preparation, the use of image-enhanced endoscopy, and number of gastric cancer diagnosed in 2018 was sent to each hospital.

RESULTS

The total proportion of early gastric cancer was 4.0% (115/2857). Routine preparation with simethicone and the use of image-enhanced endoscopy were associated with higher proportion of early gastric cancer (OR 1.9, 95% CI: 1.1-3.2, p = 0.016; OR 2.7, 95% CI: 1.8-4.0, p < 0.001, respectively). Esophagogastroduodenoscopies performed at central-type hospitals were associated with higher proportion of early gastric cancer (OR 1.9, 95% CI: 1.1-3.2, p = 0.017). Esophagogastroduodenoscopies performed at hospitals with an annual volume of 30.000-60.000 were associated with higher proportion of early gastric cancer than those performed at hospitals with an annual volume of 10.000-<30.000 (OR 2.7, 95% CI: 1.6-4.8, p < 0.001) and with a volume of >60.000-100.000 (OR 2.7, 95% CI: 1.7-4.2, p < 0.001). Only four (33.3%) hospitals reported all endoscopic types of early gastric cancer.

CONCLUSIONS

The detection of early gastric cancer is still challenging even for endoscopists working in regions with relatively high prevalence. The real-world evidence showed that endoscopic detection of early gastric cancer could potentially improve with simple adjustments of esophagogastroduodenoscopy protocols.

Identification of downregulated circRNAs from tissue and plasma of patients with gastric cancer and construction of a circRNA-miRNA-mRNA network

The connection between circular RNAs (circRNAs) and gastric cancer has been reported widely in recent years. However, previous studies have focused mainly on circRNAs from gastric cancer tissue. The objectives of the present study were to detect dysregulated circRNAs from both tissue and plasma of patients with gastric cancer and to explore their potential roles in the pathogenesis of gastric cancer. Expression profiles of circRNAs were obtained from the Gene Expression Omnibus (GEO) and analyzed using the GEO2R tool to identify differential expressed circRNAs. The significance threshold was set as |log2 (fold change)| > 2 and adjusted P < .05. The microRNA (miRNA) binding sites of the differentially expressed circRNAs were predicted using the Circular RNA Interactome web tool. TargetScan and the miRNet database were used to predict the miRNA target genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed using Database for Annotation Visualization and Integrated Discovery. Hub genes were identified and a network was constructed with Cytoscape. The overall survival rates for the selected miRNAs and messenger RNAs were evaluated by Kaplan-Meier Plotter. A total of three downregulated circRNAs (hsa_circ_0001190, hsa_circ_0036287, and hsa_circ_0048607) were identified in this study. Six miRNAs and eight hub genes met the significance criteria and were selected for further analysis. A circRNA-miRNA-hub gene network was constructed based on three circRNAs, six miRNAs, and eight hub genes. Evaluation of overall survival rates for the hub genes showed that low expression levels of GADD45A, PPP1CB, PJA2, and KLF2 were associated with poor overall survival. This study identified potential novel plasma circRNA biomarkers and provides insights into the underlying mechanisms of gastric cancer pathogenesis.

Endoscopic Kyoto classification of Helicobacter pylori infection and gastric cancer risk diagnosis

Recent advances in endoscopic technology allow detailed observation of the gastric mucosa. Today, endoscopy is used in the diagnosis of gastritis to determine the presence/absence of Helicobacter pylori (H. pylori) infection and evaluate gastric cancer risk. In 2013, the Japan Gastroenterological Endoscopy Society advocated the Kyoto classification, a new grading system for endoscopic gastritis. The Kyoto classification organized endoscopic findings related to H. pylori infection. The Kyoto classification score is the sum of scores for five endoscopic findings (atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness with or without regular arrangement of collecting venules) and ranges from 0 to 8. Atrophy, intestinal metaplasia, enlarged folds, and nodularity contribute to gastric cancer risk. Diffuse redness and regular arrangement of collecting venules are related to H. pylori infection status. In subjects without a history of H. pylori eradication, the infection rates in those with Kyoto scores of 0, 1, and ≥ 2 were 1.5%, 45%, and 82%, respectively. A Kyoto classification score of 0 indicates no H. pylori infection. A Kyoto classification score of 2 or more indicates H. pylori infection. Kyoto classification scores of patients with and without gastric cancer were 4.8 and 3.8, respectively. A Kyoto classification score of 4 or more might indicate gastric cancer risk.

Previous Helicobacter pylori infection-induced atrophic gastritis: A distinct disease entity in an understudied population without a history of eradication

Individuals with chronic atrophic gastritis who are negative for active H. pylori infection with no history of eradication therapy have been identified in clinical practice. By excluding false-negative and autoimmune gastritis cases, it can be surmised that most of these patients have experienced unintentional eradication of H. pylori after antibiotic treatment for other infectious disease, unreported successful eradication, or H. pylori that spontaneously disappeared. These patients are considered to have previous H. pylori infection-induced atrophic gastritis. In this work, we define these cases based on the following criteria: absence of previous H. pylori eradication; atrophic changes on endoscopy or histologic confirmation of glandular atrophy; negative for a current H. pylori infection diagnosed in the absence of proton-pump inhibitors or antibiotics; and absence of localized corpus atrophy, positivity for autoantibodies, or characteristic histologic findings suggestive of autoimmune gastritis. The risk of developing gastric cancer depends on the atrophic grade. The reported rate of developing gastric cancer is 0.31%-0.62% per year for successfully eradicated severely atrophic cases (pathophysiologically equal to unintentionally eradicated cases and unreported eradicated cases), and 0.53%-0.87% per year for spontaneously resolved cases due to severe atrophy. Therefore, for previous H. pylori infection-induced atrophic gastritis cases, we recommend endoscopic surveillance every 3 years for high-risk patients, including those with endoscopically severe atrophy or intestinal metaplasia. Because of the difficulty involved in the endoscopic diagnosis of gastric cancer in cases of previous infection, appropriate monitoring of the high-risk subgroup of this understudied population is especially important.

Gastric Corpus Mucosal Hyperplasia and Neuroendocrine Cell Hyperplasia, but not Spasmolytic Polypeptide-Expressing Metaplasia, Is Prevented by a Gastrin Receptor Antagonist in H+/K+ATPase Beta Subunit Knockout Mice

Proton pump inhibitor use is associated with an increased risk of gastric cancer, which may be mediated by hypergastrinemia. Spasmolytic polypeptide-expression metaplasia (SPEM) has been proposed as a precursor of gastric cancer. We have examined the effects of the gastrin receptor antagonist netazepide (NTZ) or vehicle on the gastric corpus mucosa of H⁺/K⁺ATPase beta subunit knockout (KO) and wild-type (WT) mice. The gastric corpus was evaluated by histopathology, immunohistochemistry (IHC), in situ hybridization (ISH) and whole-genome gene expression analysis, focusing on markers of SPEM and neuroendocrine (NE) cells. KO mice had pronounced hypertrophy, intra- and submucosal cysts and extensive expression of SPEM and NE cell markers in the gastric corpus, but not in the antrum. Numerous SPEM-related genes were upregulated in KO mice compared to WT mice. NTZ reduced hypertrophia, cysts, inflammation and NE hyperplasia. However, NTZ neither affected expression of SPEM markers nor of SPEM-related genes. In conclusion, NTZ prevented mucosal hypertrophy, cyst formation and NE cell hyperplasia but did not affect SPEM. The presence of SPEM seems unrelated to the changes caused by hypergastrinemia in this animal model.

Recent advances in diagnostic upper endoscopy

BACKGROUND

Esophageo-gastro-duodenoscopy (EGD) is an important procedure used for detection and diagnosis of esophago-gastric lesions. There exists no consensus on the technique of examination.

AIM

To identify recent advances in diagnostic EGDs to improve diagnostic yield.

METHODS

We queried the PubMed database for relevant articles published between January 2001 and August 2019 as well as hand searched references from recently published endoscopy guidelines. Keywords used included free text and MeSH terms addressing quality indicators and technological innovations in EGDs. Factors affecting diagnostic yield and EGD quality were identified and divided into the follow segments: Pre endoscopy preparation, sedation, examination schema, examination time, routine biopsy, image enhanced endoscopy and future developments.

RESULTS

We identified 120 relevant abstracts of which we utilized 67 of these studies in our review. Adequate pre-endoscopy preparation with simethicone and pronase increases gastric visibility. Proper sedation, especially with propofol, increases patient satisfaction after procedure and may improve detection of superficial gastrointestinal lesions. There is a movement towards mandatory picture documentation during EGD as well as dedicating sufficient time for examination improves diagnostic yield. The use of image enhanced endoscopy and magnifying endoscopy improves detection of squamous cell carcinoma and gastric neoplasm. The magnifying endoscopy simple diagnostic algorithm is useful for diagnosis of early gastric cancer.

CONCLUSION

There is a steady momentum in the past decade towards improving diagnostic yield, quality and reporting in EGDs. Other interesting innovations, such as Raman spectroscopy, endocytoscopy and artificial intelligence may have widespread endoscopic applications in the near future.

Feedback regulation between phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1 and transforming growth factor β1 and prognostic value in gastric cancer

BACKGROUND

Phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1 (PREX1) was reported to be overexpressed in some cancers and involved in cancer development, but its expression and significance in gastric cancer remain unclear.

AIM

To evaluate the expression of PREX1 in gastric cancer and its significance in the development of gastric cancer, especially to evaluate the potential mechanism of PREX1 in gastric cancer.

METHODS

Bioinformatic analysis was performed in order to examine the expression of PREX1 in gastric cancer. The relationship between the survival rate of gastric cancer patients and PREX1 expression was assessed by Kaplan Meier portal. The Gene Set Enrichment Analysis and the correlation between PREX1 and transforming growth factor (TGF) β1 pathway-related mediators were evaluated by cBioPortal for Cancer Genomics. Western blotting and reverse transcriptase polymerase chain reaction assay were used to test the role of TGFβ1 on the expression of PREX1. Western blotting and dual-luciferase reporter system was used to evaluate the effect of PREX1 on the activation of TGFβ1 pathway. Wound healing and Transwell assay were used to assess the effect of PREX1 on the metastasis activity of gastric cancer cells.

RESULTS

PREX1 was overexpressed in the gastric tumors, and the expression levels were positively associated with the development of gastric cancer. Also, the high expression of PREX1 revealed poor prognosis, especially for those advanced and specific intestinal gastric cancer patients. PREX1 was closely involved in the positive regulation of cell adhesion and positively correlated with TGFβ1-related mediators. Furthermore, TGFβ1 could induce the expression of PREX1 at both the protein and mRNA level. Also, PREX1 could activate the TGFβ1 pathway. The induced PREX1 could increase the migration and invasion activity of gastric cancer cells.

CONCLUSION

PREX1 is overexpressed in gastric cancer, and the high level of PREX1 predicts poor prognosis. PREX1 is closely associated with TGFβ signaling and promotes the metastasis of gastric cancer cells.

Incidence of Stomach and Esophageal Cancers in Mongolia: Data from 2009 to 2018

Introduction

Digestive organ cancer is a major public health issue both in Asia and in Mongolia. The most prevalent cancer-related deaths in Mongolia are registered as caused by the stomach, esophagus, and liver. There is a lack of study which investigated the accurate incidence of digestive organ cancer nationwide.

Purpose

We aimed to investigate the incidence of stomach and esophageal cancers in Mongolian population.

Materials and methods

Epidemiologic data were collected between 2009 and 2018 through the oncology departments of hospitals and medical centers in all provinces, soums (the smallest unit of provinces), and major districts of the capital city. We used appropriate statistical methods in SPSS software.

Results

The incidence of esophageal cancer in last 10 years (2009–2018) was 10.09 in 100,000 populations and the highest incidence was registered in Uvs (38.13), Bayan-Ulgii (24.15), and Zavkhan (18.18) provinces, respectively. The incidence of stomach cancer was 20.33 in 100,000 populations and the highest incidences were registered in Uvs (53.01), Khovd (46.02), and Darkhan-Uul (40.50) provinces, respectively.

Conclusion

The incidences of these cancers have increased last 10 years in some provinces. Stomach and esophageal cancers incidence in Mongolia is considerably higher compared to the other Asian countries. The nationwide targeted prevention program is needed.

How to cite this article

Lonjid T, Sambuu T, Tumurbat N, et al. Incidence of Stomach and Esophageal Cancers in Mongolia: Data from 2009 to 2018. Euroasian J Hepato-Gastroenterol 2020;10(1):16–21.

Accuracy of endoscopic staging and targeted biopsies for routine gastric intestinal metaplasia and gastric atrophy evaluation study protocol of a prospective, cohort study: the estimate study

INTRODUCTION

Patients with chronic atrophic gastritis (CAG) and intestinal metaplasia (IM) are at risk of developing gastric adenocarcinoma. Their diagnosis and management currently rely on histopathological guidance after random endoscopic biopsy sampling (Sydney biopsy strategy). This approach has significant flaws such as under-diagnosis, poor reproducibility and poor correlation between endoscopy and histology. This prospective, international multicentre study aims to establish whether endoscopy-led risk stratification accurately and reproducibly predicts CAG and IM extent and disease stage.

METHODS AND ANALYSIS

Patients with CAG and/or IM on standard white light endoscopy (WLE) will be prospectively identified and invited to undergo a second endoscopy performed by an expert endoscopist using enhanced endoscopic imaging techniques with virtual chromoendoscopy. Extent of CAG/IM will be endoscopically staged with enhanced imaging and compared with standard WLE. Histopathological risk stratification through targeted biopsies will be compared with endoscopic disease staging and to random biopsy staging on WLE as a reference. At least 234 patients are required to show a 10 % difference in sensitivity and accuracy between enhanced imaging endoscopy-led staging and the current biopsy-led staging protocol of gastric atrophy with a power (beta) of 80 % and a 0.05 probability of a type I error (alpha).

ETHICS AND DISSEMINATION

The study was approved by the respective Institutional Review Boards (Netherlands: MEC-2018-078; UK: 19/LO/0089). The findings will be published in peer-reviewed journals and presented at scientific meetings.

TRIAL REGISTRATION NUMBER

NTR7661; Pre-results.