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

Endoscopic surveillance alone is feasible and safe in type I gastric neuroendocrine neoplasms less than 10 mm in diameter

PURPOSE

Type I gastric neuroendocrine neoplasms (g-NENs) have a low risk of metastasis and a generally favourable prognosis. Patients with small type I g-NENs (≤10 mm) frequently require no treatment, whereas those with larger polyps usually undergo resection. We evaluated the safety and outcomes of endoscopic surveillance after no initial treatment in selected patients with type I g-NENs.

METHODS

Retrospective analysis of type I g-NEN patients across two European Neuroendocrine Tumour Society Centers of Excellence 2003-2019.

RESULTS

Following initial assessment, 87 of 115 patients with type I g-NEN (75 with polyps ≤10 mm) received no initial treatment and underwent endoscopic surveillance. 79/87 (91%) demonstrated no clinically meaningful change in tumour size or grade over a median 62 month follow up. Only two patients developed NEN progression that required a change in management and two other patients developed gastric adenocarcinoma/high grade dysplasia; all four initially had ≥11 mm g-NENs.

CONCLUSIONS

Patients with ≤10 mm type I g-NENs were unlikely to develop clinically significant tumour progression and in most cases, resection was not needed. The endoscopic surveillance interval could therefore potentially be safely increased to every 2-3 years in such patients. However, lifelong surveillance is still advocated due to the additional risk of developing gastric adenocarcinoma.

Beneficial effects of endoscopic screening on gastric cancer and optimal screening interval: a population-based study

BACKGROUND : The effectiveness of endoscopic screening on gastric cancer has not been widely investigated in China and the screening interval of repeated screening has not been determined. METHODS : In a population-based prospective study, we included 375,800 individuals, 14,670 of whom underwent endoscopic screening (2012-2018). We assessed the associations between endoscopic screening and risk of incident gastric cancer and gastric cancer-specific mortality, and examined changes in overall survival and disease-specific survival following screening. The optimal screening interval for repeated endoscopy for early detection of gastric cancer was explored. RESULTS : Ever receiving endoscopic screening significantly decreased the risk of invasive gastric cancer (age- and sex-adjusted relative risk [RR] 0.69, 95 % confidence interval [CI] 0.52-0.92) and gastric cancer-specific mortality (RR 0.33, 95 %CI 0.20-0.56), particularly for noncardia gastric cancer. Repeated screening strengthened the beneficial effect on invasive gastric cancer-specific mortality of one-time screening. Among invasive gastric cancers, screening-detected individuals had significantly better overall survival (RR 0.18, 95 %CI 0.13-0.25) and disease-specific survival (RR 0.18, 95 %CI 0.13-0.25) than unscreened individuals, particularly for those receiving repeated endoscopy. For individuals with intestinal metaplasia or low grade intraepithelial neoplasia, repeated endoscopy at an interval of < 2 years, particularly within 1 year, significantly enhanced the detection of early gastric cancer, compared with repeated screening after 2 years (P-trend = 0.02). CONCLUSION : Endoscopic screening prevented gastric cancer occurrence and death, and improved its prognosis in a population-based study. Repeated endoscopy enhanced the effectiveness. Screening interval should be based on gastric lesion severity.

Gastric Cancer: Emerging Trends in Prevention, Diagnosis, and Treatment

Gastric adenocarcinoma (GC) is the fourth leading cause of global cancer mortality, and the leading infection-associated cancer. Helicobacter pylori is the dominant risk factor for GC and classified as an IARC class I carcinogen. Surveillance of gastric premalignant conditions is now indicated in high-risk patients. Upper endoscopy is the gold standard for GC diagnosis, and image-enhanced endoscopy increases the detection of gastric premalignant conditions and early gastric cancer (EGC). Clinical staging is crucial for treatment approach, defining early gastric cancer, operable locoregional disease, and advanced GC. Endoscopic submucosal dissection is the treatment of choice for most EGC. Targeted therapies are rapidly evolving, based on biomarkers including MSI/dMMR, HER2, and PD-L1. These advancements in surveillance, diagnostic and therapeutic strategies are expected to improve GC survival rates in the near term.

Family with sequence similarity 153 member B as a potential prognostic biomarker of gastric cancer

Gastric cancer (GC) is one of the most common digestive tumors in Northwest China. Previous sequencing analysis revealed that family with sequence similarity 153 member B (FAM153B) might be the primary driver gene of GC. In this study, we aim to explore the potential roles of FAM153B in GC. Microarray data were firstly obtained from public databases with the aim to evaluate the genetic expression of FAM153B between GC and normal tissues. The results were verified in immunohistochemistry (IHC). We also performed the co-expression network analysis and enrichment analysis to identify underlying mechanisms. A correlation analysis of FAM153B expression and immune infiltration was performed then. Furthermore, two GC cell lines were used to evaluate the effect of FAM153B on gastric cell proliferation by employing MTT and Edu assays. Our findings suggest that FAM153B is downregulated in tumoral tissue, and positively associated with unfavorable survival. The enrichment pathways of FAM153B were regulation of signaling receptor activity, DNA replication, cell cycle transition, chromosomal regulation, and so on. Besides, from the perspective of bioinformatics, the protein expression level of FAM153B is related to the degree of immune cell infiltration. In vitro, overexpression of FAM153B inhibit the proliferation of two cell lines. In summary, this study demonstrates that FAM153B might serve as an effective prognostic and therapeutic biomarker in GC.

Cancer-derived exosomal circ_0038138 enhances glycolysis, growth, and metastasis of gastric adenocarcinoma via the miR-198/EZH2 axis

This study aims to decipher the impact and downstream mechanisms of the bioinformatically identified circ_0038138 delivered by cancer-derived exosomes in gastric adenocarcinoma (GAC). Expression of circ_0038138 in clinical GAC tissues and exosomes (Exos) from clinical plasma samples (plasma-Exos) was predicted by bioinformatics analysis and validated by RT-qPCR. The binding affinity between circ_0038138, miR-198 and EZH2 was identified using luciferase activity, RIP, and RNA pull-down assays. GAC cells (AGS) were co-cultured with Exos isolated from GAC cell supernatant (GC9811-P). After co-culture, the behaviors of GAC cells including proliferation and glycolysis were assessed to identify the biological effect of exosomal circ_0038138. Also, in vivo effects of exosomal circ_0038138 on the tumorigenesis and lung metastasis of GAC cells were evaluated by developing nude mouse xenograft and metastatic models. circ_0038138 upregulation was detected in GAC tissues and plasma-Exos. Exos delivered circ_0038138 to GAC cells and potentiated the proliferative, migratory, invasive, and glycolytic potentials of GAC cells. Mechanistically, circ_0038138 competitively bound to miR-198, which in turn targeted EZH2 by binding to its 3'-UTR. Silencing of EZH2 promoted CXXC4 expression and inhibited Wnt/β-catenin pathway activation, thus repressing the malignancy and glycolysis of GAC cells. In vivo assay confirmed that exosomal circ_0038138 induced tumorigenesis and lung metastasis by regulating the miR-198/EZH2 axis. Collectively, our work suggests that the Exo-mediated transfer of circ_0038138 potentially facilitates the glycolysis, growth and metastasis of GAC cells via miR-198/EZH2 axis, which offers a potential prognostic marker and a therapeutic target for GAC.

Benefit-to-harm ratio and cost-effectiveness of government-recommended gastric cancer screening in China: A modeling study

Objective

Current guidelines recommend the gastric cancer risk score scale (GCRSS) for screening in gastric cancer (GC) high-risk populations in China. This study aimed to estimate the clinical benefits, harms, cost, and cost-effectiveness of the GCRSS screening strategy from a Chinese healthcare system perspective.

Materials and methods

Using a microsimulation model, we evaluated 7 screening scenarios of the GCRSS with varying starting ages. We simulated 100,000 individuals from the age of 20 for each screening scenario. The main outcomes included GC incidence reduction, number of cause-specific deaths, costs, quality-adjusted life year (QALY), incremental cost-effectiveness ratio (ICER), and benefit-to-harm ratio. Deterministic and probabilistic sensitivity analyses were done to explore the robustness of model findings.

Results

Screening with the GCRSS strategy at the age of 40 years (40-GCRSS) provided the greatest reduction of GC incidence by 70.6%, with 7,374 GC deaths averted per 100,000 individuals and the lowest benefit-to-harm ratio of 0.392. Compared with no screening or previous less costly strategy, at a willingness-to-pay (WTP) threshold of $37,655 per QALY, the 40-GCRSS strategy was cost-effective, with ICERs of $12,586 and $29,115 per QALY, respectively. Results were robust across univariate and probabilistic sensitivity analyses. The 40-GCRSS strategy showed a 0.856 probability of being cost-effective at a $37,655 per QALY WTP threshold.

Conclusions

The findings suggest that the GCRSS strategy is effective and cost-effective in reducing the GC disease burden in China from a Chinese healthcare system perspective. Screening from the age of 40 would be the optimal strategy.

Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report

Helicobacter pyloriInfection is formally recognised as an infectious disease, an entity that is now included in the International Classification of Diseases 11th Revision. This in principle leads to the recommendation that all infected patients should receive treatment. In the context of the wide clinical spectrum associated with Helicobacter pylori gastritis, specific issues persist and require regular updates for optimised management.The identification of distinct clinical scenarios, proper testing and adoption of effective strategies for prevention of gastric cancer and other complications are addressed. H. pylori treatment is challenged by the continuously rising antibiotic resistance and demands for susceptibility testing with consideration of novel molecular technologies and careful selection of first line and rescue therapies. The role of H. pylori and antibiotic therapies and their impact on the gut microbiota are also considered.Progress made in the management of H. pylori infection is covered in the present sixth edition of the Maastricht/Florence 2021 Consensus Report, key aspects related to the clinical role of H. pylori infection were re-evaluated and updated. Forty-one experts from 29 countries representing a global community, examined the new data related to H. pylori infection in five working groups: (1) indications/associations, (2) diagnosis, (3) treatment, (4) prevention/gastric cancer and (5) H. pylori and the gut microbiota. The results of the individual working groups were presented for a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in various clinical fields.

Risk of progression in patients with chronic atrophic gastritis: A retrospective study

Background

Chronic atrophic gastritis (CAG) can progress to gastric cancer (GC) thus requiring endoscopic surveillance. Here, we analyze various aspects of CAG progression, time, and mucosal background, to guide reasonable surveillance.

Methods

CAG patients with three or more endoscopies from 2010–2021 were included. All cases were analyzed for rate and time of progression, and cases with operative link on gastritis assessment (OLGA) staging, operative link on gastric intestinal metaplasia assessment (OLGIM) staging, and Kimura-Takemoto classification were further analyzed. Additional investigation of guideline-defined low-risk patients by reviewing endoscopy in the short-term (1–2 years) after baseline identified several patients as high-risk.

Results

Ninety-seven (10.4%) of the 929 CAG patients progressed to low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN), or GC, during the observation period of 36–129 months (median 53, IQR=24), including 75 (8.1%) cases of LGIN, eight (0.9%) of HGIN, and 14 (1.5%) of GC. Among 170 patients with OLGA/OLGIM at baseline, two (2/2, 100%) GC cases occurred in patients with OLGA/OLGIM III and IV. Of the 236 patients with Kimura-Takemoto classification at baseline, 5/7 (71.4%) cases of GC occurred in patients with C3–O3. Ten, 11, and 25 patients classified as low-risk on the European, British, and Chinese Guidelines, underwent additional endoscopy within 1–2 years, resulting in three (30.0%), four (36.4%), and eight (32.0%) patients being classified as high-risk on these guidelines, respectively.

Conclusion

A minority of CAG patients can progress to GC. OLGA/OLGIM III and IV staging are closely associated with progression. Disease-associated risk may be underestimated in one-third of patients classified as low-risk by initial endoscopy.

Kimura-Takemoto Classification: A Tool to Predict Gastric Intestinal Metaplasia Progression to Advanced Gastric Neoplasia

BACKGROUND AND AIMS

Gastric cancer is a leading cause of morbidity and mortality worldwide. Gastric intestinal metaplasia (GIM) has been described as a key histologic step in the development of gastric adenocarcinoma. However, not all people with GIM develop malignancy. We studied the factors associated with progression to dysplasia and advanced gastric neoplasia (aGN) in patients with baseline GIM.

METHODS

Retrospective cohort analysis of patients with baseline GIM and subsequent endoscopic evaluation at Cleveland Clinic Florida and Ohio Main Campus between 2005 and 2017. Demographic and exposure risk factors, as well as Kimura-Takemoto classification (KTc), were used as variables for hazards ratio (HR) and Kaplan-Meier survival-free analysis for aGN and any form of dysplasia progression.

RESULTS

There were 708 patients identified with GIM; 29 patients (4.1%) progressed to any degree of dysplasia. From these, LGD was present in 12 cases (1.7%), HGD in 4 cases (0.6%), and gastric cancer in 13 cases (1.8%), for a total of 17 aGN cases. KTc was associated with dysplasia and aGN progression (p < 0.001), and no cases progressed if KTc findings were absent. Open-type KTc was associated with aGN (HR 6.36, p < 0.001) and any dysplasia progression (HR 13.34, p < 0.001) compared to closed-type or absent KTc features. No other factors were associated with aGN or dysplasia progression. Open-type KTc was also associated with shorter cancer survival-free progression.

CONCLUSION

Patients with baseline GIM present a higher progression risk to aGN, dysplasia, or cancer if concomitant KTc findings are present, particularly an open-type KTc pattern.

Screening and surveillance for gastric cancer: Does family history play an important role in shaping our strategy?

Family history is an important risk factor of gastric cancer. No guidelines have been developed that target gastric cancer with a family history; only hereditary familial gastric cancer is targeted. We review the available evidence regarding the familial aggregation mechanisms of gastric cancer and a strategy of screening and surveillance for gastric cancer in individuals with a positive family history of the disease. As there is a synergic effect of Helicobacter pylori infection and family history on the increased risk of gastric cancer, Helicobacter pylori eradication should be considered in all infected individuals with a family history of gastric cancer. Currently, there is weak evidence indicating that suitable timing to initiate eradication therapy is at the age of 20, when precancerous lesions, including significant gastric atrophy and intestinal metaplasia, have not been established. Reasonable timing to initiate screening for gastric cancer in individuals with a family history of gastric cancer is 10 years prior to the age of onset of gastric cancer in affected relatives. A 2-year surveillance interval, instead of the 3-year interval recommended in the present guidelines, may be better to detect early gastric cancer in those individuals who have already developed precancerous gastric lesions.

Prevalence of Extensive and Limited Gastric Intestinal Metaplasia and Progression to Dysplasia and Gastric Cancer

BACKGROUND AND AIMS

Guidelines cite extensive gastric intestinal metaplasia (GIM) as a bigger risk factor for gastric cancer (GC) than limited GIM and an indication for endoscopic surveillance. Data on progression of extensive GIM to GC in the USA are limited. This study aimed to estimate the prevalence and progression rates of extensive GIM in a US cohort.

METHODS

This retrospective study assessed the prevalence of extensive GIM between 1/1/1990 and 8/1/2019 at a large academic medical center. Multivariable regression was used to identify predictors of extensive GIM. Incidence of GC on follow-up was calculated as number of new diagnoses divided by person-years of follow-up. Presence of GIM on subsequent follow-up endoscopy was assessed.

RESULTS

Of 1256 individuals with GIM, 352 (28%) had extensive GIM and 904 (72%) had limited GIM. On multivariable analysis, older age (OR 1.01, 95% CI 1.00-1.02) and Hispanic ethnicity (OR 1.55, 95% CI 1.11-2.16) were predictive of extensive GIM. The annual incidence of GC for GIM overall was 0.09%. There was no difference in progression to GC between extensive or limited GIM (IRR 0, 95% CI 0-2.6), or to advanced lesions overall (IRR 0.37, 95% CI 0.04-1.62). 70% of individuals had persistent GIM on follow-up biopsy, and 22% with limited GIM had extensive GIM on follow-up biopsy.

CONCLUSIONS

28% of individuals with GIM have the extensive subtype, and are more likely to be older and of Hispanic ethnicity. There was no difference in progression to GC between extensive and limited GIM. Further research is needed to better assess risk of GIM in the US context.

Clinical utility of GI pathology data: implications for practising pathologists

Gastrointestinal (GI) tract pathology represents one of the largest individual specialties within cellular pathology departments globally. As with other specialties, clear communication with clinicians providing primary care for the patient is of utmost importance for optimal management and for appropriate use of resources such as endoscopy. A wide breadth of neoplastic and inflammatory conditions afflicts the GI tract. Here, we aim to illustrate how pathology reporting of GI tract specimens influences patient management and specifically how precise reporting of key parameters in different specimen types and different disease processes can directly impact patient care. We describe the potential clinical relevance of selected pathology data items pertinent to specific conditions and highlight areas of contention with respect to the significance of some pathology features. Recent guidelines are described where a change, for example, in diagnostic criteria for a condition is described, or criteria influencing further management such as endoscopic surveillance. The aim of this review is to focus on the clinical importance of careful written communication between the pathologist and primary clinician, illustrated by selective clinical scenarios involving the upper and lower GI tracts.

Gastric Cancer Screening in Japan: A Narrative Review

Gastric cancer is the second leading cause of cancer incidence in Japan, although gastric cancer mortality has decreased over the past few decades. This decrease is attributed to a decline in the prevalence of H. pylori infection. Radiographic examination has long been performed as the only method of gastric screening with evidence of reduction in mortality in the past. The revised 2014 Japanese Guidelines for Gastric Cancer Screening approved gastric endoscopy for use in population-based screening, together with radiography. While endoscopic gastric cancer screening has begun, there are some problems associated with its implementation, including endoscopic capacity, equal access, and cost-effectiveness. As H. pylori infection and atrophic gastritis are well-known risk factors for gastric cancer, a different screening method might be considered, depending on its association with the individual's background and gastric cancer risk. In this review, we summarize the current status and problems of gastric cancer screening in Japan. We also introduce and discuss the results of gastric cancer screening using H. pylori infection status in Hoki-cho, Tottori prefecture. Further, we review risk stratification as a system for improving gastric cancer screening in the future.

Comparison between Endoscopic Submucosal Dissection and Surgery in Patients with Early Gastric Cancer

Simple Summary

Conventional gastrectomy combined with regional lymph node dissection has been the standard treatment for early gastric cancer (EGC). This retrospective case–control study aimed to compare the clinical outcomes of endoscopic submucosal dissection (ESD) and surgical resection for EGC in China. After propensity score-matching, there were no significant differences between the two groups for OS, RFS, and DSS. Additionally, with similar R0 resection and recurrence rates, the ESD group showed less blood loss, fewer adverse events, lower hospital cost, and a shorter operative time and hospital duration than the surgery group. Therefore, ESD can be a first-line treatment of EGC in addition to surgery.

Abstract

Background: Endoscopic submucosal dissection (ESD) has become a preferred treatment option for early gastric cancer (EGC). This study aimed to compare the clinical outcomes of ESD and surgical resection for EGC. Methods: This was a retrospective case–control study. Patients with a diagnosis of EGC who underwent ESD or surgery in our hospital from 2011 to 2020 were enrolled. We compared the clinical characteristics and treatment outcomes of these two groups according to propensity score-matching. The primary outcome comparison was overall survival (OS). Secondary outcomes were disease-specific survival (DSS), recurrence-free survival (RFS), and treatment-related events. Results: In the matched cohort, the ESD group showed comparable OS, RFS, and DSS with the surgery group. Statistical differences were shown in blood loss and adverse events. Furthermore, the ESD group showed lower hospital cost, as well as a shorter operative time and hospital duration than the surgery group. The R0 resection and recurrence rates were similar between the two groups. In Cox regression analysis, age, tumor size, poor differentiation, and lymphovascular invasion were regarded as independent factors of OS. Conclusions: With sufficient safety and advantages, ESD can be a first-line treatment of EGC. Preoperative evaluation is vital to the appropriate treatment and prognosis.

Normal Gastrointestinal Mucosa at Biopsy and Overall Mortality: Nationwide Population-Based Cohort Study

BACKGROUND

Normal gastrointestinal (GI) mucosa on endoscopy has been linked to a lower risk of colorectal cancer (CRC) but its association to overall death is unknown.

METHODS

We identified 466,987 individuals with a first GI biopsy 1965-2016 with normal mucosa (60.6% upper GI and 39.4% lower GI) through all Swedish pathology departments (n = 28). They were individually matched to 2,321,217 reference individuals without a GI biopsy and also compared to 505,076 full siblings. Flexible parametric models were applied to estimate hazard ratio (HRs) and 95% confidence interval (95% CI) for death.

RESULTS

During a median follow-up of ~11 years, 85,859 (18.39%) of individuals with normal mucosa and 377,653 (16.27%) of reference individuals died. This corresponded to incidence rates of 147.56/10,000 vs 127.90/10,000 person-years respectively (rate difference: 19.66/10,000 person-years), with the multivariable-adjusted HR of 1.21 (95% CI: 1.20-1.22). Excess mortality was seen for both upper and lower biopsy with normal mucosa. Particularly higher HRs for death were seen in males, individuals biopsied when aged <40 years, those without a prior record of GI disease, and those with high education. Mortality risk was most increased in the first five years after biopsy (HR = 1.34; 95% CI: 1.32-1.36) but decreased thereafter. Having a GI biopsy with normal mucosa was associated with excess mortality from cardiovascular (CVD)disease (HR = 1.02; 95% CI: 1.01-1.03), cancer (HR = 1.58; 95% CI: 1.56-1.61), GI disease (HR = 1.65; 95% CI: 1.58-1.71), and other causes (HR = 1.10; 95% CI: 1.08-1.11). Sibling comparisons yielded similar results.

CONCLUSION

Compared with individuals without a GI biopsy, those with a normal GI biopsy due to clinical symptoms had a higher mortality particularly in the first five years after biopsy, and especially from GI disease and cancer.

LncRNA HOXC-AS1 Sponges miR-99a-3p and Upregulates MMP8, Ultimately Promoting Gastric Cancer

Simple Summary

Long noncoding RNAs, including the HOXC Cluster Antisense RNA 1 (HOXC-AS1), are reported to be critical during the occurrence and progression of gastric cancer. We examined cells and tissues for the expression of HOXC-AS1 and correlated the expression levels with the disease specific survival of the gastric cancer patients. We also identified the interaction between HOXC-AS1 and miR-99a-3p, as well as matrix metalloproteinase 8 (MMP8) by dual-luciferase reporter gene assays. Western blot and qRT-PCR were conducted to verify the alteration in expression levels, while Cell Counting Kit-8 assay and colony formation assay were performed to explore the influences on gastric cancer cells. Overexpression of HOXC-AS1 would accordingly sponge greater quantities of miR-99a-3p, leading to the upregulation of MMP8, eventually facilitating the progress of gastric cancer.

Abstract

Gastric cancer (GC) is among the most lethal tumors worldwide. Long noncoding RNAs (lncRNAs) are reported to be critical during the occurrence and progression of malignancies. The HOXC cluster antisense RNA 1 (HOXC-AS1) has been suggested to participate in the genesis and development of GC. Therefore, we examined GC cells and tissues for the expression of HOXC-AS1 and correlated the expression levels with the disease specific survival of the patients, finding that HOXC-AS1 was overexpressed and probably had a tendency of leading to a poor prognosis. The Cell Counting Kit-8 assay and colony formation assay were then performed under knockdown of HOXC-AS1, revealing that cell proliferation of GC was distinctly decreased. Afterwards, miR-99a-3p was predicted to bind with HOXC-AS1 by DIANA tools. We carried out dual-luciferase reporter gene assays to identify the interaction between them. After knockdown of HOXC-AS1, miR-99a-3p was clearly overexpressed in GC cells. In addition, matrix metalloproteinase 8 (MMP8) was shown to be combined with miR-99a-3p using TargetScan. Similar experiments, along with western blot, were conducted to validate the correlation between miR-99a-3p and MMP8. Finally, rescue experiments for CCK-8 were completed, disclosing that HOXC-AS1 promoted cell progression of GC through sponging miR-99a-3p followed by subsequent upregulation of MMP8.

Assessment of Serum Pepsinogens with and without Co-Testing with Gastrin-17 in Gastric Cancer Risk Assessment-Results from the GISTAR Pilot Study

Introduction−−Serum pepsinogen tests for gastric cancer screening have been debated for decades. We assessed the performance of two pepsinogen assays with or without gastrin-17 for the detection of different precancerous lesions alone or as a composite endpoint in a Latvian cohort. Methods−−Within the intervention arm of the GISTAR population-based study, participants with abnormal pepsinogen values by ELISA or latex-agglutination tests, or abnormal gastrin-17 by ELISA and a subset of subjects with all normal biomarker values were referred for upper endoscopy with biopsies. Performance of biomarkers, corrected by verification bias, to detect five composite outcomes based on atrophy, intestinal metaplasia, dysplasia or cancer was explored. Results−−Data from 1045 subjects were analysed, of those 273 with normal biomarker results. Both pepsinogen assays showed high specificity (>93%) but poor sensitivity (range: 18.4−31.1%) that slightly improved when lesions were restricted to corpus location (40.5%) but decreased when dysplasia and prevalent cancer cases were included (23.8%). Adding gastrin-17 detection, sensitivity reached 33−45% while specificity decreased (range: 61.1−62%) and referral rate for upper endoscopy increased to 38.6%. Conclusions−−Low sensitivity of pepsinogen assays is a limiting factor for their use in population-based primary gastric cancer screening, however their high specificity could be useful for triage.

Neutrophil extracellular traps participate in the development of cancer-associated thrombosis in patients with gastric cancer

BACKGROUND

The development of venous thromboembolism (VTE) is associated with high mortality among gastric cancer (GC) patients. Neutrophil extracellular traps (NETs) have been reported to correlate with the prothrombotic state in some diseases, but are rarely reported in GC patients.

AIM

To investigate the effect of NETs on the development of cancer-associated thrombosis in GC patients.

METHODS

The levels of NETs in blood and tissue samples of patients were analyzed by ELISA, flow cytometry, and immunofluorescence staining. NET generation and hypercoagulation of platelets and endothelial cells (ECs) in vitro were observed by immunofluorescence staining. NET procoagulant activity (PCA) was determined by fibrin formation and thrombin–antithrombin complex (TAT) assays. Thrombosis in vivo was measured in a murine model induced by flow stenosis in the inferior vena cava (IVC).

RESULTS

NETs were likely to form in blood and tissue samples of GC patients compared with healthy individuals. In vitro studies showed that GC cells and their conditioned medium, but not gastric mucosal epithelial cells, stimulated NET release from neutrophils. In addition, NETs induced a hypercoagulable state of platelets by upregulating the expression of phosphatidylserine and P-selectin on the cells. Furthermore, NETs stimulated the adhesion of normal platelets on glass surfaces. Similarly, NETs triggered the conversion of ECs to hypercoagulable phenotypes by downregulating the expression of their intercellular tight junctions but upregulating that of tissue factor. Treatment of normal platelets or ECs with NETs augmented the level of plasma fibrin formation and the TAT complex. In the models of IVC stenosis, tumor-bearing mice showed a stronger ability to form thrombi, and NETs abundantly accumulated in the thrombi of tumor-bearing mice compared with control mice. Notably, the combination of deoxyribonuclease I, activated protein C, and sivelestat markedly abolished the PCA of NETs.

CONCLUSION

GC-induced NETs strongly increased the risk of VTE development both in vitro and in vivo. NETs are potential therapeutic targets in the prevention and treatment of VTE in GC patients.

Academy of Medicine, Singapore clinical guideline on endoscopic surveillance and management of gastric premalignant lesions

Gastric cancer (GC) has a good prognosis, if detected at an early stage. The intestinal subtype of GC follows a stepwise progression to carcinoma, which is treatable with early detection and intervention using high-quality endoscopy. Premalignant lesions and gastric epithelial polyps are commonly encountered in clinical practice. Surveillance of patients with premalignant gastric lesions may aid in early diagnosis of GC, and thus improve chances of survival. An expert professional workgroup was formed to summarise the current evidence and provide recommendations on the management of patients with gastric premalignant lesions in Singapore. Twenty-five recommendations were made to address screening and surveillance, strategies for detection and management of gastric premalignant lesions, management of gastric epithelial polyps, and pathological reporting of gastric premalignant lesions.

Somatic Mutation of FAT Family Genes Implicated Superior Prognosis in Patients With Stomach Adenocarcinoma

FAT family genes encode protocadherin, which regulates tumor cell proliferation and migration. Although transcriptional levels of FAT family members had been reported in multiple malignant tumors, the association between mutation and prognosis of the FAT family in stomach adenocarcinoma (STAD) has not been investigated. Herein, we performed a multi-omics integrative bioinformatics analysis using genomic and mRNA expression data to explore the role of gene mutations across the FAT family on clinical outcomes of STAD. The results showed that FAT mutations occurred in 174 of 435 (40%) of the samples. Patients with FAT mutations possessed significantly better progression-free survival (P = 0.019) and overall survival (P = 0.034) than those with non-FAT mutations, and FAT mutations exhibited significantly higher tumor mutational burden (TMB) and microsatellite instability. Notably, FAT mutations had a greater effect on somatic single-nucleotide variation than copy number variation and resulted in more abundant DNA damage repair (DDR) mutations. Further investigation demonstrated that FAT mutations contributed to an inflammatory tumor microenvironment (TME), as indicated by significantly increased numbers of activated CD4 and CD8 T cells, and significantly decreased numbers of mast cell, plasmacytoid dendritic cell, type 2 T helper cell, and high expression of immune-promoting genes. Moreover, biological process antigen processing and presentation, DNA replication, and DDR-related pathways were significantly upregulated in patients with FAT mutations. Collectively, FAT mutations significantly improved the survival of patients with STAD by enhancing tumor immunogenicity (e.g., TMB and DDR mutations) and an inflamed TME, indicating that the FAT family might be a potential prognostic and therapeutic biomarker for STAD.

Study on the Mechanism of Sancao Tiaowei Decoction in the Treatment of MNNG-Induced Precancerous Lesions of Gastric Carcinoma Through Hedgehog Signaling Pathway

Sancao Tiaowei Decoction (SCTWD), a traditional Chinese medicine created by Professor Chen Weijian, has been used in the prevention and treatment of precancerous lesions of gastric carcinoma (PLGC). However, its mechanism has not been made clear. This study aimed to evaluate the therapeutic effect of SCTWD on 1-methyl-3-nitro-1-nitrosoguanidine-induced PLGC in rats and the mechanism of this effect. We found that SCTWD effectively repaired gastric mucosal injury, reversed the process of PLGC, and inhibited the occurrence of gastric cancer to some extent. In the results of hematoxylin-eosin (HE) staining, the number and arrangement of mucosal glands and the number of mononuclear cells in the lamina propria were improved in varying degrees; the enzyme-linked immunosorbent assay (ELISA) showed that the PG I and PGR of the medication treatment group were significantly higher; a Reverse Transcription-Polymerase Chain Reaction (RT-PCR) test showed that SCTWD could significantly upregulate the expression levels of Shh, Ptch, and Gli-1 in the gastric tissue of rats. The immunohistochemical method showed that SCTWD could significantly upregulate the protein expressions of Shh, Gli-1, Smo, cyclin D1, CDKN2A/p16INK4a, and NF-κBP65 and could reduce the expression of Ptch at the same time. Through the preliminary analysis of 75 compounds screened by UPLC-Q-TOF-MS, the main components, such as organic acids, esters and anhydrides, flavonoids, phenols, tanshinones, and so on, have anti-inflammatory and anti-tumor pharmacological effects. The results of KEGG enrichment analysis showed that 5 signaling pathways related to this project were found, and 33 differential genes were presented to construct the interaction network. These results suggested that SCTWD had a good regulatory effect on PLGC and thus may have a multi-targeted effect; SCTWD can not only significantly improve the pathological changes of gastric mucosa in rats with PLGC but also exert a strong effect of the regulation of the hedgehog signaling pathway.

Cytosponge-TFF3 Testing can Detect Precancerous Mucosal Changes of the Stomach

Gastric intestinal metaplasia (GIM) and gastric atrophy (GA) are associated with increased risk of gastric cancer and are indications for endoscopic surveillance when affecting the proximal stomach.1 Endoscopic screening is not cost-effective in areas with low-moderate incidence of gastric cancer2; noninvasive methods to detect GIM/GA are currently lacking.3.

From part to whole, operative link on to endoscopic grading of gastric intestinal metaplasia, pathology to endoscopy: gastric intestinal metaplasia graded by endoscopy

Objective: To conduct a systematic review and meta-analysis on the prediction of severity of gastric intestinal metaplasia (GIM) in localized and entire gastric mucosa using endoscopy. Methods: The authors searched Web of Science, PubMed, Embase and Cochrane Central Register of Controlled Trials and performed systematic searches on endoscopic grading of GIM of the entire stomach using Meta-DiSc and Stata. Results: Sensitivity and specificity for the stratified prediction of overall GIM were 0.91 (95% CI: 0.85-0.95) and 0.91 (95% CI: 0.88-0.93), respectively. Sensitivity in predicting the different grades of GIM was higher in operative link on GIM assessment grades 0, III and IV but lower in grades I and II. Conclusion: Digital chromoendoscopy is well suited to predicting the severity of localized and overall GIM.

Comparison of endoscopic treatments for small gastric adenomas

BACKGROUND

Gastric adenomas can be successfully treated with endoscopic resection, including endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR). The aim of this study was to evaluate and compare the efficacy of ESD and EMR with circumferential precutting (EMR-P) in the treatment of small gastric adenomas.

METHODS

This study included 1014 gastric adenomas ≤ 15 mm in diameter treated with ESD or EMR-P from 2012 to 2019, retrospectively. Propensity score matching between the ESD and EMR-P groups (1:1 to 3:1) was performed according to age, sex, tumor size, tumor location (upper, middle, and lower thirds), morphology, and preprocedural histology. The procedure time and the rates of en bloc resection, complete resection, adverse events, and local recurrence were compared between the two groups.

RESULTS

After propensity score matching, 478 lesions (ESD: 295, EMR-P: 183) were analyzed. The rates of en bloc resection (94.9% vs. 93.4%, p = 0.498), complete resection (93.6% vs. 90.2%, p = 0.177), bleeding (8.1% vs. 3.8%, p = 0.063), and local recurrence (0.0% vs. 1.4%, p = 0.185) did not significantly differ between the two groups. The procedure time was significantly longer for ESD than for EMR-P (p < 0.001). In the EMR-P group, the complete resection rate was significantly lower in the upper third than in the middle and lower thirds (p < 0.001).

CONCLUSION

EMR-P is as effective as ESD for the treatment of small gastric adenomas. However, the efficacy of EMR-P is lower for gastric adenomas in the proximal stomach.

Interobserver agreement of estimating the extent of intestinal metaplasia in patients with chronic atrophic gastritis

The extent of gastric intestinal metaplasia (GIM) can be used to determine the risk of gastric cancer. Eleven international gastrointestinal expert pathologists estimated the extent of GIM on haematoxylin and eosin (H&E)- and Alcian blue-Periodic acid Schiff (AB-PAS)-stained slides of 46 antrum biopsies in 5% increments. Interobserver agreement was tested with the intraclass correlation coefficient (ICC). Correlation between standard deviation and extent of GIM was evaluated with the Spearman correlation. The interobserver agreement was very good (ICC = 0.983, 95% confidence interval (CI) 0.975-0.990). The use of AB-PAS did not increase the agreement (ICC = 0.975, 95% CI 0.961-0.985). Cases with a higher amount of metaplastic epithelium demonstrated a higher standard deviation (rs = 0.644; p < 0.01), suggesting lower diagnostic accuracy in cases with extensive GIM. In conclusion, estimating the extent of GIM on H&E-stained slides in patients with chronic atrophic gastritis can be achieved satisfactorily with high interobserver agreement, at least among international expert gastrointestinal pathologists.

The Incidence-Based Mortality and Survival Trends in Patients with Gastric Signet Ring Cell Carcinoma

Background and Aim. Gastric signet ring cell carcinoma (SRC) is a distinct subtype of gastric cancer. This study aims to analyze the incidence-based mortality and survival trends in patients with gastric SRC over the past decades. Materials and Methods. The patients from the Surveillance, Epidemiology, and End Results (SEER) database were recruited to explore the incidence-based mortality and survival trends from 2000 to 2017. We further analyzed the differences in mortality and survival trends in these patients by sex and stage. We also used joinpoint software to evaluate the trends in annual percentage change (APC) for statistical significance. Results. 14916 patients were collected, including 7801 (52.3%) male and 7115 (47.7%) female. We identified a single joinpoint at 2002. The overall incidence-based mortality of gastric SRC declined in America after 2002 (APC = −1.21, $P<0.05$ ). In stratified analysis by sex and stage, the incidence-based mortality rate was higher in males than females. After 2002, the mortality rate decreased significantly in male (APC = −1.68, $P<0.05$ ) and M0-stage patients (APC = −1.75, $P<0.05$ ). In survival trend analysis, the 2-year relative survival improved in M0-stage gastric SRC, especially for males (APC = 1.14, $P<0.05$ ). As for M1-stage patients, the 2-year relative survival significantly elevated in both male (APC = 3.87, $P<0.05$ ) and female (APC = 5.63, $P<0.05$ ) patients. Conclusions. The incidence-based mortality of gastric SRC has declined, and survival has improved in America over time. These optimistic trends may be attributed to cancer screening implementation and advances in novel treatments in the past decades.

Dynamics of Oxidative Stress in Helicobacter pylori-Positive Patients with Atrophic Body Gastritis and Various Stages of Gastric Cancer

Gastric cancer is a global health problem. The pathogenesis of this disease remains unclear. This study included 198 H. pylori (+) men aged 45 to 60 years old. Group A included 63 practically healthy men, group B included 45 men with severe atrophic body gastritis, group C included 37 men with epithelial gastric cancer stages I-II according to TNM, and group D included 54 men with epithelial gastric cancer stages III-IV according to the TNM scale. The content of malondialdehyde (MDA), diene conjugates (DCs), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPO) was detected using an enzyme immunoassay (ELISA) or spectrophotometric methods in the blood plasma. The concentrations of MDA and DC were increased in the patients of group B compared with group A, and in patients of groups C and D compared with groups A and B. The ratio of MDA/SOD and MDA/CAT was decreased in the patients in group D compared with the patients in group C, and was significantly higher compared with group A. The ratios of MDA/GPO and MDA/GST increased linearly and were at a maximum in groups C and D. Our work determined that indicators of oxidative stress may be the biochemical substrate, which brings together the various stages of the Correa cascade, and may explain disease progression. The dynamics of changes in the content of SOD and CAT in the plasma in patients with gastric cancer may be a target of future investigations.

Real-time semantic segmentation of gastric intestinal metaplasia using a deep learning approach

Background/Aims

Previous artificial intelligence (AI) models attempting to segment gastric intestinal metaplasia (GIM) areas have failed to be deployed in real-time endoscopy due to their slow inference speeds. Here, we propose a new GIM segmentation AI model with inference speeds faster than 25 frames per second that maintains a high level of accuracy.

Methods

Investigators from Chulalongkorn University obtained 802 histological-proven GIM images for AI model training. Four strategies were proposed to improve the model accuracy. First, transfer learning was employed to the public colon datasets. Second, an image preprocessing technique contrast-limited adaptive histogram equalization was employed to produce clearer GIM areas. Third, data augmentation was applied for a more robust model. Lastly, the bilateral segmentation network model was applied to segment GIM areas in real time. The results were analyzed using different validity values.

Results

From the internal test, our AI model achieved an inference speed of 31.53 frames per second. GIM detection showed sensitivity, specificity, positive predictive, negative predictive, accuracy, and mean intersection over union in GIM segmentation values of 93%, 80%, 82%, 92%, 87%, and 57%, respectively.

Conclusions

The bilateral segmentation network combined with transfer learning, contrast-limited adaptive histogram equalization, and data augmentation can provide high sensitivity and good accuracy for GIM detection and segmentation.

Severity of gastric intestinal metaplasia predicts the risk of gastric cancer: a prospective multicentre cohort study (GCEP)

OBJECTIVE

To investigate the incidence of gastric cancer (GC) attributed to gastric intestinal metaplasia (IM), and validate the Operative Link on Gastric Intestinal Metaplasia (OLGIM) for targeted endoscopic surveillance in regions with low-intermediate incidence of GC.

METHODS

A prospective, longitudinal and multicentre study was carried out in Singapore. The study participants comprised 2980 patients undergoing screening gastroscopy with standardised gastric mucosal sampling, from January 2004 and December 2010, with scheduled surveillance endoscopies at year 3 and 5. Participants were also matched against the National Registry of Diseases Office for missed diagnoses of early gastric neoplasia (EGN).

RESULTS

There were 21 participants diagnosed with EGN. IM was a significant risk factor for EGN (adjusted-HR 5.36; 95% CI 1.51 to 19.0; p<0.01). The age-adjusted EGN incidence rates for patients with and without IM were 133.9 and 12.5 per 100 000 person-years. Participants with OLGIM stages III-IV were at greatest risk (adjusted-HR 20.7; 95% CI 5.04 to 85.6; p<0.01). More than half of the EGNs (n=4/7) attributed to baseline OLGIM III-IV developed within 2 years (range: 12.7-44.8 months). Serum trefoil factor 3 distinguishes (Area Under the Receiver Operating Characteristics 0.749) patients with OLGIM III-IV if they are negative for H. pylori. Participants with OLGIM II were also at significant risk of EGN (adjusted-HR 7.34; 95% CI 1.60 to 33.7; p=0.02). A significant smoking history further increases the risk of EGN among patients with OLGIM stages II-IV.

CONCLUSIONS

We suggest a risk-stratified approach and recommend that high-risk patients (OLGIM III-IV) have endoscopic surveillance in 2 years, intermediate-risk patients (OLGIM II) in 5 years.

CD10 and Das1: a biomarker study using immunohistochemistry to subtype gastric intestinal metaplasia

Background

Intestinal metaplasia (IM) is considered a key pivot point in the Correa model of gastric cancer (GC). It is histologically subtyped into the complete and incomplete subtypes, the latter being associated with a greater risk of progression. However, the clinical utility of IM subtyping remains unclear, partially due to the absence of reliable defining biomarkers.

Methods

Based on gene expression data and existing literature, we selected CD10 and Das1 as candidate biomarkers to distinguish complete and incomplete IM glands in tissues from patients without GC (IM-GC) and patients with GC (IM + GC). Immunohistochemical staining of individually subtyped IM glands was scored after blinding by two researchers using tissue belonging to both IM-GC and IM + GC patients. Whole tissue Das1 staining was further assessed using digital image quantification (cellSens Dimension, Olympus).

Results

Across both cohorts CD10 stained the IM brush border and was shown to have a high sensitivity (87.5% and 94.9% in IM-GC and IM + GC patients respectively) and specificity (100.0% and 96.7% respectively) with an overall AUROC of 0.944 for complete IM glands. By contrast Das1 stained mainly goblet cells and the apical membrane of epithelial cells, mostly of incomplete IM glands with a low sensitivity (28.6% and 29.3% in IM-GC and IM + GC patients respectively) but high specificity (98.3% and 85.1% respectively) and an overall AUROC of 0.603 for incomplete IM glands. A combined logistic regression model showed a significant increase in AUROC for detecting complete IM glands (0.955 vs 0.970). Whole tissue digital quantification of Das1 staining showed a significant association with incomplete IM compared to complete IM, both in IM-GC and in IM + GC patients (p = 0.016 and p = 0.009 respectively, Mann–Whitney test and unpaired t test used). Additionally, complete IM in IM + GC patients exhibited significantly more Das1 staining than in IM-GC patients (p = 0.019, Mann–Whitney test).

Conclusions

These findings suggest that CD10 is an outstanding biomarker for complete IM and Das1 may be useful as a secondary biomarker for IM glands at greater risk of progression irrespective of IM subtype. Overall, the clinical use of these biomarkers could lead to improved patient stratification and targeted surveillance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02268-z.

Pernicious Anemia: The Hematological Presentation of a Multifaceted Disorder Caused by Cobalamin Deficiency

Pernicious anemia is still a neglected disorder in many medical contexts and is underdiagnosed in many patients. Pernicious anemia is linked to but different from autoimmune gastritis. Pernicious anemia occurs in a later stage of autoimmune atrophic gastritis when gastric intrinsic factor deficiency and consequent vitamin B₁₂ deficiency may occur. The multifaceted nature of pernicious anemia is related to the important role of cobalamin, which, when deficient, may lead to several dysfunctions, and thus, the proteiform clinical presentations of pernicious anemia. Indeed, pernicious anemia may lead to potentially serious long-term complications related to micronutrient deficiencies and their consequences and the development of gastric cancer and type 1 gastric neuroendocrine tumors. When not recognized in a timely manner or when pernicious anemia is diagnosed with delay, these complications may be potentially life-threatening and sometimes irreversible. The current review aimed to focus on epidemiology, pathogenesis, and clinical presentations of pernicious anemia in an attempt to look beyond borders of medical specialties. It aimed to focus on micronutrient deficiencies besides the well-known vitamin B₁₂ deficiency, the diagnostic approach for pernicious anemia, its long-term complications and optimal clinical management, and endoscopic surveillance of patients with pernicious anemia.

Endoscopic diagnosis of gastric intestinal metaplasia in patients with autoimmune gastritis using narrow-band imaging: does pseudopyloric metaplasia muddy the waters?

Background and study aims  In autoimmune atrophic gastritis (AAG), associated with intestinal (IM) and/or pseudopyloric metaplasia (PPM), endoscopic surveillance is recommended for gastric cancer risk mainly linked to IM. Endoscopic Grading of Gastric Intestinal Metaplasia (EGGIM) reliably identifies IM, but has not been assessed in AAG. We aimed to assess the performance of EGGIM (index test) versus histology (reference test) of corpus IM in AAG. Patients and methods  This was a cross-sectional study of 210 AAG patients undergoing surveillance gastroscopy with narrow-band imaging (NBI): corpus IM scored according to EGGIM, histology according to updated Sydney system, and morphological criteria. Results  NBI identified corpus IM in 88.6 % of AAG patients: EGGIM were 0, 1, 2, 3, 4 in 11.4 %, 0.5 %, 33.3 %, 1.9 %, and 52.9 %, respectively. Histology identified corpus IM in 78.1 % and PPM in 79.5 % of patients. PPM was present with IM in 57.6 % and without IM in 21.9 % patients, 20.5 % had IM without PPM. EGGIM, compared to histology, correctly classified 76.2 % of patients, showing high sensitivity (91.5 %, 95 %CI 86.1-95.3). EGGIM correctly classified 93 % of patients with IM without PPM, 90.9 % with both metaplasias, and 21.7 % with PPM without IM yielding low specificity (21.7 %, 95 %CI 10.9-36.4). Conclusions  In AAG, EGGIM showed high accuracy and sensitivity identifying > 90 % of patients with histological corpus IM. EGGIM overestimated IM when PPM without IM was present, yielding low specificity. These findings raise the question of whether in AAG, PPM and IM may display similar endoscopic features on NBI.

Performance status of targeted biopsy alone versus Sydney protocol by non-NBI expert gastroenterologist in gastric intestinal metaplasia diagnosis

Background and study aims  According to a recent guideline, patients with gastric intestinal metaplasia (GIM) should have at least five biopsies performed under the Sydney protocol to evaluate for risk of extensive GIM. However, only narrow-band imaging (NBI)-targeted biopsy may be adequate to diagnose extensive GIM. Patients and methods  A cross-sectional study was conducted between November 2019 and October 2020. Patients with histology-proven GIM were enrolled. All patients underwent standard esophagogastroduodenoscopy performed by a gastroenterology trainee. The performing endoscopists took biopsies from either a suspected GIM area (NBI-targeted biopsy) or randomly (if negative for GIM read by NBI) to complete five areas of the stomach as per the Sydney protocol. The gold standard for GIM diagnosis was pathology read by two gastrointestinal pathologists with unanimous agreement. Results  A total of 95 patients with GIM were enrolled and 50 (52.6%) were men with a mean age of 64 years. Extensive GIM was diagnosed in 43 patients (45.3%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of NBI-targeted biopsy vs. the Sydney protocol were 88.4% vs.100 %, 90.3% vs. 90.3%, 88.4% vs. 89.6%, 90.3% vs. 100%, and 89.5% vs. 94.7%, respectively. The number of specimens from NBI-targeted biopsy was significantly lower than that from Sydney protocol (311vs.475, P  < 0.001). Conclusions  Both NBI-targeted biopsy and Sydney protocol by a gastroenterologist who was not an expert in NBI and who has experience with diagnosis of at least 60 cases of GIM provided an NPV higher than 90%. Thus, targeted biopsy alone with NBI, which requires fewer specimens, is an alternative option for extensive GIM diagnosis.

Proposal of minimum elements for screening and diagnosis of gastric cancer by an international Delphi consensus

The World Endoscopy Organization Stomach and Duodenal Diseases Committee extracted minimum elements for screening and diagnosis of gastric cancer (GC) in aim to support countries that do not have national guidelines on screening and diagnosis of GC. Current national or international guidelines were collected worldwide and recommendations were classified according to the quality of evidence and were finalized through a modified Delphi method. The minimum elements consist of seven categories: [1] Extraction of high-risk patients of GC before esophagogastroduodenoscopy (EGD), [2] Patients who need surveillance of GC, [3] Method to ensure quality of EGD for detection of GC, [4] Individual GC risk assessment by EGD, [5] Extraction of high-risk patients of GC after EGD [6] Qualitative or differential diagnosis of GC by EGD, and [7] Endoscopic assessment to choose the therapeutic strategy for GC. These minimum elements will be a guide to promote the elimination of GC among countries with a high incidence of GC who lack national guidelines or screening programs.

Deep learning model can improve the diagnosis rate of endoscopic chronic atrophic gastritis: a prospective cohort study

BACKGROUND AND AIMS

Chronic atrophic gastritis (CAG) is a precancerous form of gastric cancer. However, with pathological diagnosis as the gold standard, the sensitivity of endoscopic diagnosis of atrophy is only 42%. We developed a deep learning (DL)-based real-time video monitoring diagnostic model for endoscopic CAG and conducted a prospective cohort study to verify whether this diagnostic model could improve the diagnosis rate of endoscopic CAG compared with that of endoscopists.

METHODS

A U-NET network was used to build a real-time video monitoring diagnostic model for endoscopic CAG based on DL. We enrolled 431 patients who underwent gastroscopy from October 1, 2020, to December 1, 2020. To keep the baseline data of enrolled patient uniform and control for confounding factors, we applied a paired design and included the same patients in both the DL and the endoscopist group.

RESULTS

The DL model improved the diagnosis rate of endoscopic CAG compared with that of endoscopists. Compared with diagnoses by endoscopists, the proportions of moderate and severe CAG in the atrophy patients diagnosed by the DL model were significantly larger, the proportion of "type O" CAG was significantly larger, the number of atrophy sites found was significantly increased, and the number of biopsies was significantly decreased. Compared with diagnoses by endoscopists, in the atrophic lesions diagnosed by the DL model, the proportions of severe atrophy and severe intestinal metaplasia were significantly increased.

CONCLUSIONS

Our study suggested the DL model could improve the diagnosis rate of endoscopic CAG compared with that of endoscopists.

TRIAL REGISTRATION

ChiCTR2100044458, 18/03/2020.

Roles of Plasmacytoid Dendritic Cells in Gastric Cancer

Gastric cancer (GC) is the fifth most common neoplasm and the third most deadly cancer in humans worldwide. Helicobacter pylori infection is the most important causative factor of gastric carcinogenesis, and activates host innate and adaptive immune responses. As key constituents of the tumor immune microenvironment, plasmacytoid dendritic cells (pDCs) are increasingly attracting attention owing to their potential roles in immunosuppression. We recently reported that pDCs have vital roles in the development of immunosuppression in GC. Clarifying the contribution of pDCs to the development and progression of GC may lead to improvements in cancer therapy. In this review, we summarize current knowledge regarding immune modulation in GC, especially the roles of pDCs in GC carcinogenesis and treatment strategies.

Recent insights into the use of immune checkpoint inhibitors in gastric cancer

Gastric cancer (GC) is the fifth most incident and the fourth deadliest cancer worldwide. GC is a heterogeneous disease from the histological and molecular standpoints. This malignancy is mostly diagnosed at advanced stages of the disease, where the available therapeutic interventions are not effective. The emergence of immunotherapy has transformed the landscape of cancer treatment, including GC, and currently immune checkpoint inhibitors have been approved for the treatment of patients with recurrent/metastatic GC. This review summarizes the main clinical trials evaluating the use of immune checkpoint inhibitors in GC. It also highlights the potential of biomarkers for patient selection for GC immune checkpoint inhibition therapy, including programmed cell death ligand 1 expression and tumor mutational burden, and characteristics of the GC molecular classification, such as microsatellite instability status and Epstein-Barr virus infection, as predictors of response to blockade of the programmed cell death 1/programmed cell death ligand 1 axis.

A Bibliometric Analysis of Atrophic Gastritis From 2011 to 2021

Background

Atrophic gastritis (AG), which is characterized by a decreased number or disappearance of the glandular structures and secretory dysfunction, is linked to chronically inflamed stomach. It has been estimated that the annual incidence of gastric cancer (GC) is 0.1% for patients with AG. Early eradication of Helicobacter pylori (H. pylori) can reduce the risk of GC development. Additionally, the follow-up and management of AG are necessary to prevent GC. Exploring novel methods of the automatized analysis of data for apprehending knowledge in any medical field is encouraged, especially when a body of literature suggests the necessity of doing so. Accordingly, herein, we aim to systematically review the current foci and status of AG research using bibliometric analysis.

Methods

Articles and reviews related to AG published from 2011 to 2021 in the Web of Science Core Collection were retrieved. Microsoft Office Excel 2019 and GraphPad Prism were used to show the annual number of publications and scientific productivity of authors through time. CiteSpace and VOSviewer were used to generate network maps about the collaborations among countries, institutions, and authors as well as reveal hotspots of AG research. The relationships among the author's keywords, cited references, and the top authors were summarized by a Sankey plot (three-fields plot).

Results

A total of 1,432 publications were included in the present study. China remained the most productive country, with the highest number of publications (377, 26.32%). Vanderbilt University contributed the most publications of any single institution (56, 3.91%). James R Goldenring was the most active and influential scholar, with the highest number of publications and greatest centrality. The most prolific journal in this field was World Journal of Gastroenterology (62, 4.32%). Gastroenterology (997, 69.62%) was the most co-cited journal. Exploring the origin of gastric metaplasia, especially spasmolytic polypeptide-expressing metaplasia (SPEM) was a major topic in AG research.

Conclusions

This bibliometric study provides a comprehensive analysis of the scientific progress of AG over the past decade. Metaplasia is a hot topic and could be a promising area of research in the coming years.

Block of Proliferation 1 Promotes Proliferation, Invasion and Epithelial Mesenchymal Transformation in Gastric Cancer

Background

Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide nowadays. Block of proliferation 1 (BOP1), a nucleolar protein involved in rRNA processing and ribosome assembly, is associated with tumor development in certain cancers of digestive system. Therefore, we hypothesized that BOP1 might play an important role in gastric cancer development.

Methods

Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA) were used to identify the differentially expressed genes and their clinical relevance. qPCR and western blot were performed further to examine the levels of BOP1 mRNA and protein, respectively. Cell viability, apoptosis, migration and invasion were investigated in gastric cancer cell lines with BOP1 silencing or overexpression. The epithelial mesenchymal transition (EMT) associated proteins, including E-cadherin and N-cadherin, were measured using immunoblotting. Finally, the downstream pathway of BOP1 were explored using bioinformatic analysis and qPCR.

Results

BOP1 was found up-regulated in gastric tumor tissues compared with paired normal tissues (P < 0.0001). Its expression was associated with more advanced pathological grades (P = 0.0006) and tumor location (P = 0.002), as well as a poor survival (HR 1.27, P = 0.015). BOP1 expression was increased in 4 kind of tumor cell lines compared with the normal group. The overexpression of BOP1 promoted cell proliferation and inhibit cell apoptosis, while silencing BOP1 showed a reversed trend. Immunoblotting results suggested that BOP enhanced N-cadherin, a mesenchymal marker, while reduced E-cadherin, an epithelial marker. Finally, bioinformatic prediction showed that the cell cycle could be a downstream pathway of BOP1.

Conclusions

The present study demonstrated that BOP1 contributed to the development of gastric cancer by promoting proliferation, invasion and epithelial mesenchymal transformation, which could be a biomarker or therapeutic target in GC.

Gastric epithelial histology and precancerous conditions

The most common histological type of gastric cancer (GC) is gastric adenocarcinoma arising from the gastric epithelium. Less common variants include mesenchymal, lymphoproliferative and neuroendocrine neoplasms. The Lauren scheme classifies GC into intestinal type, diffuse type and mixed type. The WHO classification includes papillary, tubular, mucinous, poorly cohesive and mixed GC. Chronic atrophic gastritis (CAG) and intestinal metaplasia are recommended as common precancerous conditions. No definite precancerous condition of diffuse/poorly/undifferentiated type is recommended. Chronic superficial inflammation and hyperplasia of foveolar cells may be the focus. Presently, the management of early GC and precancerous conditions mainly relies on endoscopy including diagnosis, treatment and surveillance. Management of precancerous conditions promotes the early detection and treatment of early GC, and even prevent the occurrence of GC. In the review, precancerous conditions including CAG, metaplasia, foveolar hyperplasia and gastric hyperplastic polyps derived from the gastric epithelium have been concluded, based on the overview of gastric epithelial histological organization and its renewal.

Construction of a circRNA-miRNA-mRNA network based on differentially co-expressed circular RNA in gastric cancer tissue and plasma by bioinformatics analysis

BACKGROUND

Increasing evidence implicates circular RNAs (circRNAs) have been involved in human cancer progression. However, the mechanism remains unclear. In this study, we identified novel circRNAs related to gastric cancer and constructed a circRNA-miRNA-mRNA network.

METHODS

Microarray datasets GSE83521 and GSE93541 were obtained from the Gene Expression Omnibus (GEO). Then, we used computational biology to identify circRNAs that were differentially expressed in both GC tissue and plasma compared to normal controls; then, we detected the expression of the selected circRNAs in gastric cell lines by quantitative real-time polymerase chain reaction (qRT-PCR). We also identified circRNA-related candidate miRNAs and their target genes with online tools. Combining the predicted miRNAs and target mRNAs, a competing endogenous RNA regulatory network was established. Functional and pathway enrichment analyses were performed, and interactions between proteins were predicted by using String and Cytoscape. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to elucidate the possible functions of these differentially expressed circRNAs. The regulatory network constructed using the microarray datasets (GSE83521 and GSE93541) contained three differentially co-expressed circRNAs (DECs). A circRNA-miRNA-mRNA network was constructed based on 3 circRNAs, 43 miRNAs and 119 mRNAs.

RESULTS

GO and KEGG analysis showed that the regulation of apoptotic signaling pathway and PI3K-Akt signaling pathway were highest degrees of enrichment respectively. We established a protein-protein interaction (PPI) network consisting of 165 nodes and 170 edges and identified hub genes by using MCODE plugin in Cytoscape. Furthermore, a core circRNA-miRNA-mRNA network was constructed based on hub genes. Hsa_circ_0001013 was finally determined to play an important role in the pathogenesis of GC according to the core circRNA-miRNA-mRNA network.

CONCLUSIONS

We propose a new circRNA-miRNA-mRNA network that is associated with the pathogenesis of GC. The network may become a new molecular biomarker and could be used to develop potential therapeutic strategies for gastric cancer.

A novel DNA methylation signature associated with lymph node metastasis status in early gastric cancer

Background

Lymph node metastasis (LNM) is an important factor for both treatment and prognosis of early gastric cancer (EGC). Current methods are insufficient to evaluate LNM in EGC due to suboptimal accuracy. Herein, we aim to identify methylation signatures for LNM of EGC, facilitate precision diagnosis, and guide treatment modalities.

Methods

For marker discovery, genome-wide methylation sequencing was performed in a cohort (marker discovery) using 47 fresh frozen (FF) tissue samples. The identified signatures were subsequently characterized for model development using formalin-fixed paraffin-embedded (FFPE) samples by qPCR assay in a second cohort (model development cohort, n = 302, training set: n = 151, test set: n = 151). The performance of the established model was further validated using FFPE samples in a third cohorts (validation cohort, n = 130) and compared with image-based diagnostics, conventional clinicopathology-based model (conventional model), and current standard workups.

Results

Fifty LNM-specific methylation signatures were identified de novo and technically validated. A derived 3-marker methylation model for LNM diagnosis was established that achieved an AUC of 0.87 and 0.88, corresponding to the specificity of 80.9% and 85.7%, sensitivity of 80.6% and 78.1%, and accuracy of 80.8% and 83.8% in the test set of model development cohort and validation cohort, respectively. Notably, this methylation model outperformed computed tomography (CT)-based imaging with a superior AUC (0.88 vs. 0.57, p < 0.0001) and individual clinicopathological features in the validation cohort. The model integrated with clinicopathological features demonstrated further enhanced AUCs of 0.89 in the same cohort. The 3-marker methylation model and integrated model reduced 39.4% and 41.5% overtreatment as compared to standard workups, respectively.

Conclusions

A novel 3-marker methylation model was established and validated that shows diagnostic potential to identify LNM in EGC patients and thus reduce unnecessary gastrectomy in EGC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01219-x.

Consistency between the endoscopic Kyoto classification and pathological updated Sydney system for gastritis: A cross-sectional study

BACKGROUND

Two methods are used to evaluate gastritis: the updated Sydney system (USS) with pathology and Kyoto classification, a new endoscopy-based diagnostic criterion for which evidence is accumulating. However, the consistency of their results is unclear. This study investigated the consistency of their results.

METHODS

Patients who underwent esophagogastroduodenoscopy and were evaluated for Helicobacter pylori infection for the first time were eligible. The association between corpus and antral USS scores (neutrophil activity, chronic inflammation, atrophy, and intestinal metaplasia) and Kyoto classification scores (atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness) was assessed.

RESULTS

Seven-hundred-seventeen patients (mean age, 49.2 years; female sex, 57.9%; 450 H. pylori-positive and 267 H. pylori-negative patients) were enrolled. All endoscopic gastritis cases in the Kyoto classification were associated with high corpus and antral USS scores for neutrophil activity and chronic inflammation. A subanalysis was performed for H. pylori-positive patients. Regarding atrophy and intestinal metaplasia, endoscopic findings were associated with USS scores. Enlarged folds, nodularity, and diffuse redness were associated with high corpus USS scores for neutrophil activity and chronic inflammation, but with low antral USS scores for atrophy and intestinal metaplasia. The Kyoto classification scores were also associated with the pathological topographic distribution of neutrophil activity and intestinal metaplasia.

CONCLUSIONS

Among H. pylori-positive individuals, endoscopic and pathological diagnoses were consistent with atrophy and intestinal metaplasia. Enlarged folds, nodularity, and diffuse redness were associated with pathological inflammation (neutrophil activity and chronic inflammation) of the corpus; however, they were inversely associated with pathological atrophy and intestinal metaplasia. The endoscopy-based Kyoto classification of gastritis partially reflects pathology.

Real-time artificial intelligence for detecting focal lesions and diagnosing neoplasms of the stomach by white-light endoscopy (with videos)

BACKGROUND AND AIMS

White-light endoscopy (WLE) is the most pivotal tool to detect gastric cancer in an early stage. However, the skill among endoscopists varies greatly. Here, we aim to develop a deep learning-based system named ENDOANGEL-LD (lesion detection) to assist in detecting all focal gastric lesions and predicting neoplasms by WLE.

METHODS

Endoscopic images were retrospectively obtained from Renmin Hospital of Wuhan University (RHWU) for the development, validation, and internal test of the system. Additional external tests were conducted in 5 other hospitals to evaluate the robustness. Stored videos from RHWU were used for assessing and comparing the performance of ENDOANGEL-LD with that of experts. Prospective consecutive patients undergoing upper endoscopy were enrolled from May 6, 2021 to August 2, 2021 in RHWU to assess clinical practice applicability.

RESULTS

Over 10,000 patients undergoing upper endoscopy were enrolled in this study. The sensitivities were 96.9% and 95.6% for detecting gastric lesions and 92.9% and 91.7% for diagnosing neoplasms in internal and external patients, respectively. In 100 videos, ENDOANGEL-LD achieved superior sensitivity and negative predictive value for detecting gastric neoplasms from that of experts (100% vs 85.5% ± 3.4% [P = .003] and 100% vs 86.4% ± 2.8% [P = .002], respectively). In 2010 prospective consecutive patients, ENDOANGEL-LD achieved a sensitivity of 92.8% for detecting gastric lesions with 3.04 ± 3.04 false positives per gastroscopy and a sensitivity of 91.8% and specificity of 92.4% for diagnosing neoplasms.

CONCLUSIONS

Our results show that ENDOANGEL-LD has great potential for assisting endoscopists in screening gastric lesions and suspicious neoplasms in clinical work. (Clinical trial registration number: ChiCTR2100045963.).

Identifying the pre-malignant stomach: from guidelines to practice

Gastric adenocarcinoma develops after stepwise progression from normal mucosa through to adenocarcinoma most commonly after being triggered by Helicobacter pylori (H. pylori) infection. As disease is often diagnosed late, the prognosis for gastric adenocarcinoma is poor. Identifying pre-malignant mucosal lesions such as atrophic gastritis, intestinal metaplasia and dysplasia is one strategy adopted by clinicians to reduce cancer related mortality. Surveillance of high-risk individuals and endoscopic resection of dysplastic lesions is recommended by international and UK guidelines. The early detection and endoscopic management reduce the need for invasive surgery. The advancement of image enhanced endoscopy technology, endoscopic training, risk stratification and histological assessment has proven pivotal to the management of pre-malignant lesions. In this review we outline the development of a high-risk stomach, endoscopic assessment and review practical guidelines on identifying pre-malignant gastric mucosa.

JAG consensus statements for training and certification in oesophagogastroduodenoscopy

INTRODUCTION

Training and quality assurance in oesophagogastroduodenoscopy (OGD) is important to ensure competent practice. A national evidence-based review was undertaken to update and develop standards and recommendations for OGD training and certification.

METHODS

Under the oversight of the Joint Advisory Group (JAG), a modified Delphi process was conducted with stakeholder representation from British Society of Gastroenterology, Association of Upper Gastrointestinal Surgeons, trainees and trainers. Recommendations on OGD training and certification were formulated following literature review and appraised using Grading of Recommendations Assessment, Development and Evaluation. These were subjected to electronic voting to achieve consensus. Accepted statements were incorporated into the updated certification pathway.

RESULTS

In total, 32 recommendation statements were generated for the following domains: definition of competence (4 statements), acquisition of competence (12 statements), assessment of competence (10 statements) and post-certification support (6 statements). The consensus process led to following certification criteria: (1) performing ≥250 hands-on procedures; (2) attending a JAG-accredited basic skills course; (3) attainment of relevant minimal performance standards defined by British Society of Gastroenterology/Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland, (4) achieving physically unassisted D2 intubation and J-manoeuvre in ≥95% of recent procedures, (5) satisfactory performance in formative and summative direct observation of procedural skills assessments.

CONCLUSION

The JAG standards for diagnostic OGD have been updated following evidence-based consensus. These standards are intended to support training, improve competency assessment to uphold standards of practice and provide support to the newly-independent practitioner.