Surveillance of premalignant gastric lesions: a multicentre prospective cohort study from low incidence regions

The value of LCI-based modified Kyoto classification risk scoring system in predicting the risk of early gastric cancer

OBJECTIVE

To study and compare the value of the Kyoto classification risk scoring system and the modified Kyoto classification risk scoring system based on linked color imaging (LCI) in predicting the risk of early gastric cancer.

METHODS

One hundred and fifty patients with pathologically confirmed non-cardia early gastric cancer by endoscopic LCI and 150 non-gastric cancer patients matched for age and gender were included. Basic patient data and whole gastric endoscopic images under LCI were collected, and the images were scored according to the LCI-based Kyoto classification risk scoring system and the LCI-based modified Kyoto classification risk scoring system.

RESULTS

Compared with the LCI-based Kyoto classification risk scoring system, the LCI-based modified Kyoto classification risk scoring system had a higher AUC for predicting the risk of early gastric cancer (0.723 vs. 0.784, p = 0.023), with a score of ≥3 being the best cutoff value for predicting the risk of early gastric cancer (sensitivity 61.33%, specificity 86.00%), and scores of 3 to 5 were significantly associated with early gastric carcinogenesis significantly (OR = 9.032, 95% CI: 4.995-16.330, p < 0.001).

CONCLUSIONS

Compared with the LCI-based Kyoto classification risk scoring system, the LCI-based Kyoto modified classification risk scoring system has a better value for predicting the risk of early gastric cancer, and the score of 3 to 5 is a high-risk factor for the risk of early gastric cancer development, which is more strongly correlated with the risk of early gastric cancer.

Identification of chronic non-atrophic gastritis and intestinal metaplasia stages in the Correa's cascade through machine learning analyses of SERS spectral signature of non-invasively-collected human gastric fluid samples

The progression of gastric cancer involves a complex multi-stage process, with gastroscopy and biopsy being the standard procedures for diagnosing gastric diseases. This study introduces an innovative non-invasive approach to differentiate gastric disease stage using gastric fluid samples through machine-learning-assisted surface-enhanced Raman spectroscopy (SERS). This method effectively identifies different stages of gastric lesions. The XGBoost algorithm demonstrates the highest accuracy of 96.88% and 91.67%, respectively, in distinguishing chronic non-atrophic gastritis from intestinal metaplasia and different subtypes of gastritis (mild, moderate, and severe). Through blinded testing validation, the model can achieve more than 80% accuracy. These findings offer new possibilities for rapid, cost-effective, and minimally invasive diagnosis of gastric diseases.

Non-Invasive Markers for the Detection of Gastric Precancerous Conditions

Gastric cancer (GC) is still one of the most prevalent cancers worldwide, with a high mortality rate, despite improvements in diagnostic and therapeutic strategies. To diminish the GC burden, a modification of the current diagnostic paradigm, and especially endoscopic diagnosis of symptomatic individuals, is necessary. In this review article, we present a broad review and the current knowledge status on serum biomarkers, including pepsinogens, gastrin, Gastropanel®, autoantibodies, and novel biomarkers, allowing us to estimate the risk of gastric precancerous conditions (GPC)-atrophic gastritis and gastric intestinal metaplasia. The aim of the article is to emphasize the role of non-invasive testing in GC prevention. This comprehensive review describes the pathophysiological background of investigated biomarkers, their status and performance based on available data, as well as their clinical applicability. We point out future perspectives of non-invasive testing and possible new biomarkers opportunities.

Current Knowledge about Gastric Microbiota with Special Emphasis on Helicobacter pylori-Related Gastric Conditions

The gastric milieu, because of its very low acidic pH, is very harsh for bacterial growth. The discovery of Helicobacter pylori (H.p.) has opened a new avenue for studies on the gastric microbiota, thus indicating that the stomach is not a sterile environment. Nowadays, new technologies of bacterial identification have demonstrated the existence of other microorganisms in the gastric habitat, which play an important role in health and disease. This bacterium possesses an arsenal of compounds which enable its survival but, at the same time, damage the gastric mucosa. Toxins, such as cytotoxin-associated gene A, vacuolar cytotoxin A, lipopolysaccharides, and adhesins, determine an inflammatory status of the gastric mucosa which may become chronic, ultimately leading to a gastric carcinoma. In the initial stage, H.p. persistence alters the gastric microbiota with a condition of dysbiosis, predisposing to inflammation. Probiotics and prebiotics exhibit beneficial effects on H.p. infection, and, among them, anti-inflammatory, antioxidant, and antibacterial activities are the major ones. Moreover, the association of probiotics with prebiotics (synbiotics) to conventional anti-H.p. therapy contributes to a more efficacious eradication of the bacterium. Also, polyphenols, largely present in the vegetal kingdom, have been demonstrated to alleviate H.p.-dependent pathologies, even including the inhibition of tumorigenesis. The gastric microbiota composition in health and disease is described. Then, cellular and molecular mechanisms of H.p.-mediated damage are clarified. Finally, the use of probiotics, prebiotics, and polyphenols in experimental models and in patients infected with H.p. is discussed.

IL-6 facilitates cross-talk between epithelial cells and tumor- associated macrophages in Helicobacter pylori-linked gastric carcinogenesis

PURPOSE

Helicobacter pylori (H. pylori) is a significant risk factor for development of gastric cancer (GC), one of the deadliest malignancies in the world. However, the mechanism by which H. pylori induces gastric oncogenesis remains unclear. Here, we investigated the function of IL-6 in gastric oncogenesis and macrophage-epithelial cell interactions.

METHODS

We analyzed publicly available datasets to investigate the expression of IL-6 and infiltration of M2 macrophages in GC tissues, and determine the inter-cellular communication in the context of IL-6. Human gastric epithelial and macrophage cell lines (GES-1 and THP-1-derived macrophages, respectively) were used in mono- and co-culture experiments to investigate autocrine-and paracrine induction of IL-6 expression in response to H. pylori or IL-6 stimulation.

RESULTS

We found that IL-6 is highly expressed in GC and modulates survival. M2 macrophage infiltration is predominant in GC and drives an IL-6 mediated communication with gastric epithelium cells. In vitro, IL-6 triggers its own expression in GES-1 and THP-1-derived macrophages cells. In addition, these cell lines are able to upregulate each other's IL-6 levels in an autocrine fashion, which is enhanced by H. pylori stimulation.

CONCLUSION

This study indicates that IL-6 in the tumor microenvironment is essential for intercellular communication. We show that H. pylori enhances an IL-6-driven autocrine and paracrine positive feedback loop between macrophages and gastric epithelial cells, which may contribute to gastric carcinogenesis.

Clinical application of machine learning-based pathomics signature of gastric atrophy

Background

The diagnosis of gastric atrophy is highly subjective, and we aimed to establish a model of gastric atrophy based on pathological features to improve diagnostic consistency.

Methods

We retrospectively collected the HE-stained pathological slides of gastric biopsies and used CellProfiler software for image segmentation and feature extraction of ten representative images for each sample. Subsequently, we employed the Least absolute shrinkage and selection operator (LASSO) to select features and different machine learning (ML) algorithms to construct the diagnostic models for gastric atrophy.

Results

We selected 289 gastric biopsy specimens for training, testing, and external validation. We extracted 464 pathological features and screened ten features by LASSO to establish the diagnostic model for moderate-to-severe atrophy. The range of area under the curve (AUC) for various machine learning algorithms was 0.835-1.000 in the training set, 0.786-0.949 in the testing set, and 0.689-0.818 in the external validation set. LR model had the highest AUC value, with 0.900 (95% CI: 0.852-0.947) in the training set, 0.901 (95% CI: 0.807-0.996) in the testing set, and 0.818 (95% CI: 0.714-0.923) in the external validation set. The atrophy pathological score based on the LR model was associated with endoscopic atrophy grading (Z=-2.478, P=0.013) and gastric cancer (GC) (OR=5.70, 95% CI: 2.63-12.33, P<0.001).

Conclusion

The ML model based on pathological features could improve the diagnostic consistency of gastric atrophy, which is also associated with endoscopic atrophy grading and GC.

RE.GA.IN.: the Real-world Gastritis Initiative-updating the updates

At the end of the last century, a far-sighted 'working party' held in Sydney, Australia addressed the clinicopathological issues related to gastric inflammatory diseases. A few years later, an international conference held in Houston, Texas, USA critically updated the seminal Sydney classification. In line with these initiatives, Kyoto Global Consensus Report, flanked by the Maastricht-Florence conferences, added new clinical evidence to the gastritis clinicopathological puzzle.The most relevant topics related to the gastric inflammatory diseases have been addressed by the Real-world Gastritis Initiative (RE.GA.IN.), from disease definitions to the clinical diagnosis and prognosis. This paper reports the conclusions of the RE.GA.IN. consensus process, which culminated in Venice in November 2022 after more than 8 months of intense global scientific deliberations. A forum of gastritis scholars from five continents participated in the multidisciplinary RE.GA.IN. consensus. After lively debates on the most controversial aspects of the gastritis spectrum, the RE.GA.IN. Faculty amalgamated complementary knowledge to distil patient-centred, evidence-based statements to assist health professionals in their real-world clinical practice. The sections of this report focus on: the epidemiology of gastritis; Helicobacter pylori as dominant aetiology of environmental gastritis and as the most important determinant of the gastric oncogenetic field; the evolving knowledge on gastric autoimmunity; the clinicopathological relevance of gastric microbiota; the new diagnostic horizons of endoscopy; and the clinical priority of histologically reporting gastritis in terms of staging. The ultimate goal of RE.GA.IN. was and remains the promotion of further improvement in the clinical management of patients with gastritis.

Gastric dysplasia in random biopsies: the influence of Helicobacter pylori infection and alcohol consumption in the presence of a lesion

BACKGROUND

Gastric dysplasia in the absence of an endoscopically defined lesion is rare, usually either a false positive diagnosis or a previously unidentified precancerous lesion during esophagogastroduodenoscopy (EGD).

AIMS

Evaluate factors associated with the presence of an endoscopically visible lesion during follow-up in patients with histologic diagnosis of gastric dysplasia in random biopsies.

METHODS

Retrospective cohort study including patients referred to our institution for gastric dysplasia in random biopsies during Index EGD. Endoscopic evaluation was performed with a high-definition endoscope using narrow band imaging (HD EGD-0). If no lesion was detected, endoscopic surveillance (HD EGD-FU) was conducted within 6 months for high grade dysplasia (HGD) or 12 months for low grade (LGD) or indefinite for dysplasia (IFD).

RESULTS

From a total sample of 96 patients, 5 (5.2%) presented with an endoscopically visible lesion during HD EGD-0, while 10 lesions (10.4%) were identified during HD EGD-FU. Patients with Helicobacter pylori infection at Index EDG and with regular alcohol consumption (≥25 g/day) were 8 and 4 times more likely to have an endoscopically visible lesion on HD EGD-FU (p = 0.012 and p = 0.047). In binary logistic regression, both factors were independent predictors of the presence of gastric lesion on HD EGD-FU (OR 9.284, p = 0.009 and OR 5.025, p = 0.033).

CONCLUSIONS

The presence of an endoscopically visible lesion after the histologic diagnosis of gastric dysplasia in random biopsies was more frequent during HD EGD-FU. H. pylori infection at Index EGD and regular alcohol consumption were significant predictors of the presence of gastric lesion on HD EGD-FU.

The Clinical Impact and Cost-Effectiveness of Surveillance of Incidentally Detected Gastric Intestinal Metaplasia: A Microsimulation Analysis

BACKGROUND & AIMS

Gastric intestinal metaplasia (GIM) is associated with a higher risk of noncardia intestinal gastric adenocarcinoma (GA). The aim of this study was to estimate lifetime benefits, complications, and cost-effectiveness of GIM surveillance using esophagogastroduodenoscopy (EGD).

METHODS

We developed a semi-Markov microsimulation model of patients with incidentally detected GIM, to compare the effectiveness of EGD surveillance with no surveillance at 10-year, 5-year, 3-year, 2-year, and 1-year intervals. We modeled a simulated cohort of 1,000,000 US individuals aged 50 with incidental GIM. Outcome measures were lifetime GA incidence, mortality, number of EGDs, complications, undiscounted life-years gained, and incremental cost-effectiveness ratio with a willingness-to-pay threshold of $100,000/quality-adjusted life-year (QALY).

RESULTS

In the absence of surveillance, the model simulated 32.0 lifetime GA cases and 23.0 lifetime GA deaths per 1000 individuals with GIM, respectively. Among surveilled individuals, simulated lifetime GA incidence (per 1000) decreased with shorter surveillance intervals (10-year to 1-year, 11.2-6.1) as did GA mortality (7.4-3.6). Compared with no surveillance, all modeled surveillance intervals yielded greater life expectancy (87-190 undiscounted life-years gained per 1000); 5-year surveillance provided the greatest number of life-years gained per EGD performed and was the cost-effective strategy ($40,706/QALY). In individuals with risk factors of family history of GA or anatomically extensive, incomplete-type GIM intensified 3-year surveillance was cost-effective (incremental cost-effectiveness ratio $28,156/QALY and $87,020/QALY, respectively).

CONCLUSIONS

Using microsimulation modeling, surveillance of incidentally detected GIM every 5 years is associated with reduced GA incidence/mortality and is cost-effective from a health care sector perspective. Real-world studies evaluating the impact of GIM surveillance on GA incidence and mortality in the United States are needed.

Gastric Intestinal Metaplasia: Real Culprit or Innocent Bystander as a Precancerous Condition for Gastric Cancer?

Gastric intestinal metaplasia (GIM), which denotes conversion of gastric mucosa into an intestinal phenotype, can occur in all regions of the stomach, including cardiac, fundic, and pyloric mucosa. Since the earliest description of GIM, its association with gastric cancer of the differentiated (intestinal) type has been a well-recognized concern. Many epidemiologic studies have confirmed GIM to be significantly associated with subsequent gastric cancer development. Helicobacter pylori, the principal etiologic factor for gastric cancer, plays the most important role in predisposing to GIM. Although the role of GIM in the stepwise progression model of gastric carcinogenesis (the so-called "Correa cascade") has come into question recently, we review the scientific evidence that strongly supports this long-standing model and propose a new progression model that builds on the Correa cascade. Eradication of H pylori is the most important method for preventing gastric cancer globally, but the effect of eradication on established GIM, is limited, if any. Endoscopic surveillance for GIM may, therefore, be necessary, especially when there is extensive corpus GIM. Recent advances in image-enhanced endoscopy with integrated artificial intelligence have facilitated the identification of GIM and neoplastic lesions, which will impact preventive strategies in the near future.

Therapeutic effects and potential mechanisms of endoscopic submucosal injection of mesenchymal stem cells on chronic atrophic gastritis

Previous studies have demonstrated the rejuvenating and restorative actions of mesenchymal stem cells (MSCs) in multiple diseases, but their role in reversing chronic atrophic gastritis (CAG) is not well understood owing to their low efficiency in homing to the stomach. In this work, we investigated the therapeutic effect of umbilical cord-derived MSCs (UC-MSCs) on CAG by endoscopic submucosal injection and preliminarily explored possible mechanisms in vitro. MSCs and normal saline (NS) were injected into the submucosa of the stomach in randomly grouped CAG rabbits. Therapeutic effects on serum indices and histopathology of the gastric mucosa were analyzed in vivo at 30 and 60 days after MSCs injection. GES-1 cells were co-cultured with MSCs in vitro using a Transwell system and cell viability, proliferation, and migration ability were detected. Additionally, in view of the potential mechanisms, the relative protein expression levels of apoptosis, autophagy and inflammation in vitro were explored by Western Blotting. We found that submucosal injection of MSCs up-regulated serum indices (G-17, PGI and PGI/PGII) and alleviated histopathological damage to the gastric mucosa in CAG rabbits. Co-culture of GES-1 cells with MSCs improved cell viability, proliferation, and migration ability, while suppressing apoptosis. We also observed a reduction in the expression of apoptosis indicators, including Bax and cleaved caspase-3, in GES-1 cells after co-culture with MSCs in vitro. Our findings suggest that submucosal injection of MSCs is a promising approach for reversing CAG, and attenuating apoptosis plays a potential role in this process.

U-Net deep learning model for endoscopic diagnosis of chronic atrophic gastritis and operative link for gastritis assessment staging: a prospective nested case-control study

Background

The operative link for the gastritis assessment (OLGA) system can objectively reflect the stratification of gastric cancer risk in patients with chronic atrophic gastritis (CAG).

Objectives

We developed a real-time video monitoring model for the endoscopic diagnosis of CAG and OLGA staging based on U-Net deep learning (DL). To further validate and improve its performance, we designed a study to evaluate the diagnostic evaluation indices.

Design

A prospective nested case-control study.

Methods

Our cohort consisted of 1306 patients from 31 July 2021 to 31 January 2022. According to the pathological results, patients in the cohort were divided into the CAG group and the chronic non-atrophic gastritis group to evaluate the diagnostic evaluation indices. Each atrophy lesion was automatically labeled and the atrophy severity was assessed by the model. Propensity score matching was used to minimize selection bias.

Results

The diagnostic evaluation indices and the consistency between OLGA staging and pathological diagnosis of the model were superior to those of endoscopists [sensitivity (89.31% versus 67.56%), specificity (90.46% versus 70.23%), positive predictive value (90.35% versus 69.41%), negative predictive value (89.43% versus 68.40%), accuracy rate (89.89% versus 68.89%), Youden index (79.77% versus 37.79%), odd product (79.23 versus 4.91), positive likelihood ratio (9.36 versus 2.27), negative likelihood ratio (0.12 versus 0.46)], areas under the curves (AUC) (95% CI) (0.919 (0.893-0.945) versus 0.749 (0.707-0.792), p < 0.001) and kappa (0.816 versus 0.291)].

Conclusion

Our study demonstrated that the DL model can assist endoscopists in real-time diagnosis of CAG during gastroscopy and synchronous identification of high-risk OLGA stage (OLGA stages III and IV) patients.

Trial registration

ChiCTR2100044458.

SERPINB5 is a novel serum diagnostic biomarker for gastric high-grade intraepithelial neoplasia and plays a role in regulation of macrophage phenotypes

BACKGROUND

Gastric cancer (GC) develops from gastric precancerous lesions (GPL), and early diagnosis and treatment at the premalignant stage may achieve a higher benefit‒cost ratio with a reduced necessity for surgery. However, reliable noninvasive screening biomarkers of GPL are currently lacking.

METHODS

The marker genes of GPL encoding extracellular proteins were identified by bioinformatics analysis and further verified by immunofluorescence and immunohistochemistry assays. Serum samples were collected to measure the levels of SERPINB5, the diagnostic efficacy of which was assessed by the area under the receiver operating characteristic (ROC) curve (AUC). Finally, the effect of SERPINB5 on the phenotypic conversion of macrophages was verified by public data and in vitro experiments.

RESULTS

SERPINB5 was identified as an extracellular biomarker of GPL that had good diagnostic efficacy. High expression of SERPINB5 was observed in the epithelial cells and adjacent extracellular matrix on sections of gastric high-grade intraepithelial neoplasia (HGIN). Importantly, SERPINB5 determined in serum was significantly increased in the HGIN group, and the AUC for discriminating between HGIN and chronic gastritis or low-grade intraepithelial neoplasia was 0.9936 and 0.9750, respectively. Moreover, SERPINB5 expression was positively correlated with macrophage infiltration, and M1 marker NOS2 expression, but negatively correlated with M2 marker CSF1R expression. In THP-1-derived macrophages, SERPINB5 upregulated expression of M1-related cytokines TNF-α and IL-12, and M1 marker CD86, but suppressed production of M2-related cytokines TGF-β and IL-10.

CONCLUSIONS

Our study provides evidence that SERPINB5 may serve as a promising noninvasive serum biomarker for gastric HGIN screening and regulate macrophage phenotype conversion.

The prediction model of operative link on gastric intestinal metaplasia stage III-IV: A multicenter study

Purpose

Intestinal metaplasia plays a crucial role in the risk stratification of gastric cancer development. The objective of the study was to develop a prediction model for Operative Link on Gastric Intestinal Metaplasia (OLGIM) Stage III-IV.

Methods

We analyzed 7945 high-risk gastric cancer individuals from 115 hospitals who underwent questionnaires and gastroscope. The participants were assigned to either the development or validation cohort randomly. Demographics and clinical characteristics were obtained. The outcome measurement was OLGIM III-IV. Univariate logistic regression was used for feature selection and multivariate logistic analysis was performed to develop the nomogram. Area under the curves, calibration plots, decision curve and clinical impact analysis were used to assess the performance of the nomogram.

Results

4600 individuals and 3345 individuals were included in the development and validation cohort, of which 124 and 86 individuals were diagnosed with OLGIM III-IV, respectively. Parameters in the training validation cohort matched well and there was no significant difference between two cohorts. A nomogram model for predicting OLGIM Stage III-IV consisted of 4 significantly associated variables, including age, gender, PG I and G-17 (AUC 0.723 and 0.700 for the 2 cohorts). The nomogram demonstrated excellent performance in the calibration curve. Decision curve and clinical impact analysis suggested clinical benefit of the prediction model.

Conclusions

This reliable individualized nomogram might contribute to more accurate management for patients with OLGIM III-IV. Therefore, we suggest that this study be used as an incentive to promote the application.

Intestinal Metaplasia Associated with Symptoms of Dyspepsia

Background

Peptic ulcer disease (PUD) and Helicobacter pylori (HP) are associated with dyspepsia, but the role of gastric intestinal metaplasia (IM) has not been described. The objective of this study is to examine the association between gastric IM and dyspepsia.

Methods

We developed a cohort of consecutive patients referred to gastroenterology between Jan 2019 and July 2020 for dyspepsia and iron deficiency anemia (IDA) and completed an upper endoscopy with biopsies in a safety-net health system. The primary outcome was the prevalence of gastric IM in patients with dyspepsia compared to IDA. Secondary outcomes included prevalence of HP, chronic gastritis (CG) and chronic active gastritis (CAG) in the dyspepsia and IDA groups. A multivariable analysis was performed to assess the independent association between gastric IM and dyspepsia.

Results

Compared to the IDA cohort (n = 366), patients with dyspepsia (n = 349) were more likely to be female (65% vs. 47%, p < 0.01), harbor gastric IM (20.3% vs. 14.2%, p = 0.03), and less likely to have CAG (12.0% vs. 26.5%, p < 0.01) or HP (10.9% vs. 21.3%, p < 0.01). After adjusting for pathological findings, race, ethnicity, gender and age, the association strengthened between IM and dyspepsia (adj OR 1.81 from OR 1.54, 95% CI 1.19-2.76, p < 0.01).

Conclusions

We observed a significant relationship between the presence of gastric IM and dyspepsia symptoms, which increased after adjusting for confounding factors. Future studies should verify the relationship between IM and dyspepsia, the effect of IM regression, and possible mediators of gastric IM on symptoms.

Increased Prevalence of Autoimmune Gastritis in Patients with a Gastric Precancerous Lesion

Background: Autoimmune gastritis (AIG), characterized with the presence of anti-parietal-cell antibodies (APCA), is a risk factor for gastric cancer. However, AIG may go underdiagnosed, especially in the case of H. pylori infection and the presence of gastric precancerous lesions (GPL), due to the ambiguous pathology and delayed symptom onset. Aim: Investigate the prevalence and characteristics of AIG in GPL patients. Methods: Prevalence of AIG was determined with the presence of APCA in patients with GPL (n = 256) and the control group (n = 70). Pathological characteristics and levels of gastrin 17 (G17), pepsinogen (PG) I and II and anti-Helicobacter pylori IgG were assessed in GPL cases, and the severity of intestinal metaplasia and gastric atrophy was scored by expert pathologists. Results: APCA positivity was observed in 18% of cases vs. 7% of controls (p = 0.033). Only 3/256 patients were previously diagnosed with AIG. The presence of APCA was associated with corpus-limited and extended GPL. A receiver operating curve analysis demonstrated that the G17 and PGI/II ratio could identify APCA-positive patients within GPL cases (AUC: 0.884). Conclusions: The prevalence of AIG is higher in patients with GPL but goes undiagnosed. Using G17 and PG I/II as diagnostic markers can help to identify patients with AIG and improve surveillance programs for patients with GPL.

A spatially mapped gene expression signature for intestinal stem-like cells identifies high-risk precursors of gastric cancer

Objective

Gastric intestinal metaplasia (GIM) is a precancerous lesion that increases gastric cancer (GC) risk. The Operative Link on GIM (OLGIM) is a combined clinical-histopathologic system to risk-stratify patients with GIM. The identification of molecular biomarkers that are indicators for advanced OLGIM lesions may improve cancer prevention efforts.

Methods

This study was based on clinical and genomic data from four cohorts: 1) GAPS, a GIM cohort with detailed OLGIM severity scoring (N=303 samples); 2) the Cancer Genome Atlas (N=198); 3) a collation of in-house and publicly available scRNA-seq data (N=40), and 4) a spatial validation cohort (N=5) consisting of annotated histology slides of patients with either GC or advanced GIM. We used a multi-omics pipeline to identify, validate and sequentially parse a highly-refined signature of 26 genes which characterize high-risk GIM.

Results

Using standard RNA-seq, we analyzed two separate, non-overlapping discovery (N=88) and validation (N=215) sets of GIM. In the discovery phase, we identified 105 upregulated genes specific for high-risk GIM (defined as OLGIM III-IV), of which 100 genes were independently confirmed in the validation set. Spatial transcriptomic profiling revealed 36 of these 100 genes to be expressed in metaplastic foci in GIM. Comparison with bulk GC sequencing data revealed 26 of these genes to be expressed in intestinal-type GC. Single-cell profiling resolved the 26-gene signature to both mature intestinal lineages (goblet cells, enterocytes) and immature intestinal lineages (stem-like cells). A subset of these genes was further validated using single-molecule multiplex fluorescence in situ hybridization. We found certain genes (TFF3 and ANPEP) to mark differentiated intestinal lineages, whereas others (OLFM4 and CPS1) localized to immature cells in the isthmic/crypt region of metaplastic glands, consistent with the findings from scRNAseq analysis.

Conclusions

using an integrated multi-omics approach, we identified a novel 26-gene expression signature for high-OLGIM precursors at increased risk for GC. We found this signature localizes to aberrant intestinal stem-like cells within the metaplastic microenvironment. These findings hold important translational significance for future prevention and early detection efforts.

Epidemiology, Risk Factors for Gastric Cancer and Surveillance of Premalignant Gastric Lesions: A Prospective Cohort Study of Central Saudi Arabia

(1) Background: Saudi Arabia (SA) is a country with a low incidence of gastric cancer (GC). In this study, we sought to assess the epidemiology of GC, its clinicopathological profiles, and its association with risk factors as well as to identify premalignant gastric lesions (PGL) and examine neoplastic progression. (2) Methods: This five-year prospective study screened for GC and PGL in asymptomatic Saudi patients, aged 45-75 years (n = 35,640) and living in Al Kharj, Riyadh province in central SA. Those who were positive in a high-sensitivity guaiac fecal occult blood test (HSgFOBT+) and had negative results in colonoscopy offered to undergo upper GI endoscopy (n = 1242). Factors associated with GC were examined. (3) Results: The five-year participation rate was 87% (1080/1242). The incidence rate of GC was 26.9 new cases per 100,000 population per year (9.6 new cases per year/total population at risk-35,640), and it was 8.9 cases per 1000 persons per year among the 1080 subjects with HSgFOBT+ and negative colonoscopy results. The five-year mortality rate was 67% among patients with GC (n = 48), 3.0% among participants in the gastric screening program (n = 1080) and 0.09% among the original population participating in the colorectal screening program (n = 35,640). Intestinal-type adenocarcinoma was the most frequent type (77%), with the tumor most commonly located in the antrum (41%). Overall, 334 participants had PGL, and seven of them (2.1%) showed neoplastic progression to GC during the follow-up. Factors associated with GC were age, Helicobacter pylori (HP) infection, obesity (body mass index BMI > 30), smoking, a diet of salty preserved foods, low income and a family history of GC. (4) Conclusions: The incidence of GC is low in central SA, but screening for PGL and GC among patients with HSgFOBT+ and negative colonoscopy may prevent or result in the early treatment of GC. HP eradication, normal body weight, not smoking and adhering to a healthy diet can reduce the risk of GC. The resulting data provide important input for the improvement of national guidelines.

Clinical Management of Patients with Gastric MALT Lymphoma: A Gastroenterologist's Point of View

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas (GML) are non-Hodgkin lymphomas arising from the marginal zone of the lymphoid tissue of the stomach. They are usually induced by chronic infection with Helicobacter pylori (H. pylori); however, H. pylori-negative GML is of increasing incidence. The diagnosis of GML is based on histological examination of gastric biopsies, but the role of upper endoscopy is crucial since it is the first step in the diagnostic process and, with currently available novel endoscopic techniques, may even allow an in vivo diagnosis of GML per se. The treatment of GML, which is usually localized, always includes the eradication of H. pylori, which should be performed even in H. pylori-negative GML. In the case of GML persistence after eradication of the bacteria, low-dose radiotherapy may be proposed, while systemic treatments (immunochemotherapy) should be reserved for very rare disseminated cases. In GML patients, at diagnosis but even after complete remission, special attention must be paid to an increased risk of gastric adenocarcinoma, especially in the presence of associated gastric precancerous lesions (gastric atrophy and gastric intestinal metaplasia), which requires adequate endoscopic surveillance of these patients.

A systematic review and meta-analysis on the relative and attributable risk of Helicobacter pylori infection and cardia and non-cardia gastric cancer

INTRODUCTION

This study aimed to update the association between Helicobacter pylori (H. pylori) infection and gastric cancer (GC).

METHODS

We searched PubMed, Embase, and Cochrane Library from 1990 to December 2021 to identify prospective studies. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were summarized to validate the relationship between H. pylori infection and GC.

RESULTS

Including 27 studies, findings indicated a strong link between H. pylori and non-cardia gastric cancer (NCGC) in both Europe/North America (OR=5.37, 95%CI:4.39-6.57) and Asia (OR = 2.50, 95%CI:1.89-3.32), and a positive association with cardia gastric cancer (CGC) in Asia (OR = 1.74, 95%CI:1.38-2.19), but an inverse association in European/American populations (OR = 0.64, 95%CI: 0.51 to 0.79). Furthermore, the strength of association was greater in studies that detected H. pylori by immunoblotting versus ELISA, and also in studies testing for H. pylori detection further back in time prior to cancer diagnosis (Ptrend<0.05). Approximately 79% of NCGC in Asia and 87% in Europe/North America, along with 62% of CGC in Asia, could be attributable to H. pylori infection.

CONCLUSIONS

The meta-analysis supports the significant attributable risk of H. pylori infection for GC and underscores the potential impact of targeting H. pylori in GC prevention programs.

PROSPERO REGISTRATION

CRD42021274120.

Clinical Practice Guideline for Gastritis in Korea

Gastritis is a disease characterized by inflammation of the gastric mucosa. It is very common and has various classification systems such as the updated Sydney system. As there is a lot of evidence that Helicobacter pylori infection is associated with the development of gastric cancer and that gastric cancer can be prevented by eradication, H. pylori gastritis has been emphasized recently. The incidence rate of gastric cancer in Korea is the highest in the world, and due to the spread of screening endoscopy, atrophic gastritis and intestinal metaplasia are commonly diagnosed in the general population. However, there have been no clinical guidelines developed in Korea for these lesions. Therefore, this clinical guideline has been developed by the Korean College of Helicobacter and Upper Gastrointestinal Research for important topics that are frequently encountered in clinical situations related to gastritis. Evidence-based guidelines were developed through systematic review and de novo processes, and eight recommendations were made for eight key questions. This guideline needs to be periodically revised according to the needs of clinical practice or as important evidence about this issue is published in the future.

Controlling Gastric Cancer in a World of Heterogeneous Risk

Gastric cancer (GC) is a leading cause of global mortality but also a cancer whose footprint is highly unequal. This review aims to define global disease epidemiology, critically appraise strategies of prevention and disease attenuation, and assess how these strategies could be applied to improve outcomes from GC in a world of variable risk and disease burden. Strategies of primary prevention focus on improving the detection and eradication of the main environmental risk factor, Helicobacter pylori. In certain countries of high incidence, endoscopic or radiographic screening of the asymptomatic general population has been adopted as a means of secondary prevention. By contrast, identification and targeted surveillance of individuals with precancerous lesions (such as intestinal metaplasia) is being increasingly embraced in nations of low incidence. This review also highlights existing knowledge gaps in GC prevention as well as the role of emerging technologies for early detection and risk stratification.

Missed Opportunities for Screening or Surveillance Among Patients with Newly Diagnosed Non-cardia Gastric Adenocarcinoma

BACKGROUND

Screening for gastric cancer is not recommended despite rising rates in certain U.S.

POPULATIONS

We determined possible missed opportunities for the detection and surveillance of preneoplastic lesions among gastric cancer patients in a VA hospital.

METHODS

This retrospective cohort study included consecutive, newly diagnosed non-cardia gastric adenocarcinoma patients from 11/2007 to 10/2018 at the Houston VA Hospital. We identified missed opportunities for screening based on risk factors (non-White race, smoking, alcohol, Helicobacter pylori infection, gastric ulcers, family history of gastric cancer). We additionally determined missed opportunities for surveillance of known high-risk lesions. Associations between receipt of prior endoscopy for screening or surveillance and cancer-related outcomes (stage, treatment, survival) were determined using logistic regression models.

RESULTS

Among 91 gastric cancer patients, 95.6% were men, 51.6% were black, 12.1% were Hispanic, with mean age of 68.0 years (standard deviation 10.8 years). The most common risk factors included non-white race (68.1%), smoking (76.9%), alcohol use (59.3%) and prior H. pylori (12.1%). Most patients had ≥ 1 risk factor for gastric cancer (92.6%), and 76.9% had ≥ 2 risk factors. Only 25 patients (27.5%) had undergone endoscopy prior to cancer diagnosis. Of 14 with known high-risk lesions (i.e., gastric intestinal metaplasia, dysplasia, ulcer), only 2 (14.3%) underwent surveillance endoscopy. Receipt of prior endoscopy was not associated with differences in cancer outcomes.

CONCLUSIONS

Most patients with newly diagnosed gastric cancer had ≥ 2 known risk factors for gastric cancer but never received prior screening endoscopy. Among the few with known prior preneoplastic lesions, endoscopic surveillance was not consistently performed.

A Global Perspective on Gastric Cancer Screening: Which Concepts Are Feasible, and When?

BACKGROUND

Gastric cancer (GC) remains the fifth most common cancer and the third most common cause of cancer-related death globally. In 2022, GC fell into the scope of the updated EU recommendations for targeted cancer screening. Given the growing awareness of the GC burden, we aimed to review the existing screening strategies for GC in high-risk regions and discuss potentially applicable modalities in countries with low-to-intermediate incidence.

METHODS

The references for this Review article were identified through searches of PubMed with the search terms "gastric cancer", "stomach cancer", "Helicobacter pylori", and "screening" over the period from 1995 until August 2022.

RESULTS

As Helicobacter pylori (H. pylori)-induced gastritis is the primary step in the development of GC, the focus on GC prevention may be directed toward testing for and treating this infection. Such a strategy may be appealing in countries with low- and intermediate- GC incidence. Other biomarker-based approaches to identify at-risk individuals in such regions are being evaluated. Within high-incidence areas, both primary endoscopic screening and population-based H. pylori "test-and-treat" strategies represent cost-effective models.

CONCLUSIONS

Given the significant variations in GC incidence and healthcare resources around the globe, screening strategies for GC should be adjusted to the actual conditions in each region. While several proven tools exist for accurate GC diagnosis, a universal modality for the screening of GC populations remains elusive.

Cancer risk stratification system and classification of gastritis: Perspectives

Kyoto global consensus reports that the current ICD-10 classification for gastritis is obsolete. The Kyoto classification of gastritis states that severe mucosal atrophy has a high risk of gastric cancer, while mild to moderate atrophy has a low risk. The updated Kimura-Takemoto classification of atrophic gastritis considers five histological types of multifocal corpus atrophic gastritis according to stages C2 to O3. This method of morphological diagnosis of atrophic gastritis increases sensitivity by 2.4 times for severe atrophy compared to the updated Sydney system. This advantage should be considered when stratifying the high risk of gastric cancer. The updated Kimura-Takemoto classification of atrophic gastritis should be used as a reference standard (gold standard) in studies of morpho-functional relationships to identify serological markers of atrophic gastritis with evidence-based effectiveness. The use of artificial intelligence in the serological screening of atrophic gastritis makes it possible to screen a large number of the population. During serological screening of atrophic gastritis and risk stratification of gastric cancer, it is advisable to use the Kyoto classification of gastritis with updated Kimura-Takemoto classification of atrophic gastritis.

Histopathologic Diagnosis Discrepancies Between Preoperative Endoscopic Forceps Biopsies and Specimens Resected by Endoscopic Submucosal Dissection in Superficial Gastric Neoplasms

BACKGROUND

The standard of practice when a superficial lesion was identified during upper GI endoscopy is to take an endoscopic forceps biopsy (EFB) of the lesion. The histopathologic findings then will determine the management plan. Endoscopic submucosal dissection (ESD) enables en-bloc resection for early neoplasms of the gastrointestinal tract and provides an adequate specimen that permits a more reliable histopathologic assessment. The objective of this study was to determine the rate of histopathologic discrepancy between EFB and specimens resected by ESD, and to identify the predisposing risk factors for this discordance.

MATERIALS AND METHODS

This is a retrospective study, enrolling patients with superficial gastric neoplasms that underwent EFB followed by ESD. We divided cases to concordant or discordant group according to the histopathologic diagnosis of EFB and ESD specimens. We also analyzed the features that may have influenced the occurrence of histopathologic discordance and the association between discordant samples of adenocarcinoma and neoplastic invasion to deeper layers.

RESULTS

A total of 115 gastric ESD procedures were performed with 84 patients meeting the inclusion criteria. Histopathologic discordance between EFB and ESD specimens were observed in 35.8% of cases (30/84 lesions). The univariant-bivariant analysis and multivariate logistic regression analysis showed that histologic discordance was closely related to the size of the lesions ( P =0.028).

CONCLUSION

Histopathologic discrepancy between EFB and ESD specimens may occur in approximately one-third of cases, particularly for lesions over 20 mm, which may lead to crucial delays in gastric cancer precise diagnosis and treatment.

Chinese integrated guideline on the management of gastric precancerous conditions and lesions

The standardized diagnosis and management of gastric precancerous conditions and lesions are important to prevent gastric cancer. This guideline, created by 5 traditional Chinese medicine and Western medicine associations, based on the current morbidity and diagnosis and treatment of gastric precancerous conditions and lesions, provides specific key points and strategies for diagnosis and treatment in the following five aspects: definition and epidemiology, diagnosis and stage, surveillance, treatment and efficacy evaluation. It is hoped that these aspects, assessed by integrating Western medicine and traditional Chinese medicine and involving multidisciplinary participation, will play a guiding role in clinical diagnosis and treatment and achieve effective secondary prevention of gastric cancer.

Clinical and endoscopic predictors of gastric precancerous conditions: a large population case control study

BACKGROUND

Atrophic gastritis (AG) and gastric intestinal metaplasia (GIM) are well defined intermediate precancerous conditions (PCCs) in the gastric cancer cascade. The diagnosis of PCCs may be suspected based on endoscopic findings but is established by histology. Estimates of the global prevalence of PCCs vary widely but simple clinical or endoscopic predictors of their diagnosis are ill defined. We aimed to evaluate the prevalence of gastric PCCs in our practice and to identify predictors for its diagnosis.

METHODS

We analyzed electronic reports of patients referred for gastroscopy procedures over a 5-year period and included those for whom gastric biopsies were performed. We investigated demographic, clinical, and endoscopic findings to identify possible association with histologic detection of gastric PCCs and performed multivariate analysis to identify predictors of its diagnosis.

RESULTS

A total of 4930 patients with full endoscopic and histologic data were included for the final analysis. Of these, 806 (16.3%) patients had a histologic diagnosis of gastric PCCs. Demographic and clinical variables including male sex (51.4% vs. 45.7%; P=0.003), age over 60 (69.8% vs. 45.2%; P<0.001), and anemia indication for gastroscopy (17.6% vs. 14.8%; P=0.04) were significantly associated with gastric PCCs diagnosis. Likewise, endoscopic findings of Barret's esophagus (2.6% vs. 1.3%; P=0.006), atrophic gastritis according to endoscopist's judgment (12.9% vs. 3.5%; P<0.01) and corpus predominant gastritis (22.5% vs. 14.7%; P=0.02) were significantly associated with gastric PCCs. In multivariate analysis, age>60 (please explain all acronyms HR 2.51, 95% CI 2.12-2.96), male sex (HR 1.235, 95% CI 1.05-1.44), corpus predominant (HR 1.284, 95% CI 1.04-1.57), and atrophic gastritis (HR 4, 95% CI 3.07-5.21) were independent predictors for PCCs diagnosis.

CONCLUSIONS

Not uncommonly encountered in our practice, a judicious performance of gastric biopsies to detect gastric PCCs should be adopted especially in older, male patients with endoscopic findings of corpus predominant and/or gastric atrophy.

Evolution of the Correa's cascade steps: A long-term endoscopic surveillance among non-ulcer dyspepsia and gastric ulcer after H. pylori eradication

BACKGROUND

This study is aimed toward investigating the evolution of each Correa's step after Helicobacter pylori eradication in a long-term follow-up and exploring the factors correlated with a high-risk of gastric cancer.

METHODS

A total of 1824 H. pylori-infected subjects were enrolled to receive screening endoscopy. Among them, 491 received surveillance endoscopy. The patients were divided into Correa's steps I to VI, from normal to gastric cancer. A group-based trajectory model was used to classify patients as persistent high-risk status or not.

RESULTS

The prevalence rates of positive corpus-predominant gastritis index (CGI) were 20%-40% in all age groups and Correa's steps IV-V increased >35% after 50 years based on screening endoscopy. Successful eradication of H. pylori regressed CGI after the 1st year-and-thereafter (P < 0.05) and decreased Correa's step progression (Relative risk 0.66 [95% CI 0.49-0.89], P = 0.01); however, it did not regress OLGA and OLGIM. Not only in steps IV-V, but also in step III, the patients had a risk of developing gastric cancer (11.13-76.41 and 4.61 per 1000 person-years). Age (Hazard ratio 1.012 [1.003-1.020], P = 0.01), OLGA stages ≥ I (2.127 [1.558-2.903], P < 0.001), and OLGIM stages ≥ I (1.409 [1.119-1.774], P = 0.004) were correlated independently with a persistent high-risk status.

CONCLUSION

The patients in Correa's steps III-V, but not I-II, were at risk of gastric cancer after H. pylori eradication. Age, OLGA stages ≥ I, and OLGIM stages ≥ I were independent factors correlated to a persistent high-risk of gastric cancer. The data may be useful when scheduling surveillance endoscopy for subjects in each Correa's step (NCT04527055).

Constitutive programmed death ligand 1 expression protects gastric G-cells from Helicobacter pylori-induced inflammation

INTRODUCTION

Gastric intestinal metaplasia (GIM) is a premalignant lesion, highly associated with Helicobacter pylori infection. Previous studies have shown that H. pylori is able to induce the expression of programmed death ligand 1 (PD-L1), an inhibitory immune modulator, in gastric cells. Our aim was to investigate whether tissues from GIM patients may exploit PD-L1 expression upon H. pylori infection to evade immunosurveillance.

METHODS

Immunohistochemistry was performed for PD-L1 and enteroendocrine markers somatostatin and gastrin on samples derived from a cohort of patients with known GIM, both before and after H. pylori eradication. To determine the identity of any observed PD-L1-positive cells, we performed multiplex immunofluorescent staining and analysis of single-cell sequencing data.

RESULTS

GIM tissue was rarely positive for PD-L1. In normal glands from GIM patients, PD-L1 was mainly expressed by gastrin-positive G-cells. While the D-cell and G-cell compartments were both diminished 2-fold (p = .015 and p = .01, respectively) during H. pylori infection in the normal antral tissue of GIM patients, they were restored 1 year after eradication. The total number of PD-L1-positive cells was not affected by H. pylori, but the percentage of PD-L1-positive G-cells was 30% higher in infected subjects (p = .011), suggesting that these cells are preferentially rescued from destruction.

CONCLUSIONS

Antral G-cells frequently express PD-L1 during homeostasis. G-cells seem to be protected from H. pylori-induced immune destruction by PD-L1 expression. GIM itself does not express PD-L1 and is unlikely to escape immunosurveillance via expression of PD-L1.

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.

Recommendations for endoscopic surveillance after esophageal atresia repair in adults

BACKGROUND

Endoscopic surveillance of adults with esophageal atresia is advocated, but the optimal surveillance strategy remains uncertain. This study aimed to provide recommendations on appropriate starting age and intervals of endoscopic surveillance in adults with esophageal atresia.

METHODS

Participants underwent standardized upper endoscopies with biopsies. Surveillance intervals of 3-5 years were applied, depending on age and histopathological results. Patient's age and time to development of (pre)malignant lesions were calculated.

RESULTS

A total of 271 patients with esophageal atresia (55% male; median age at baseline endoscopy 26.7 (range 15.6-68.5) years; colon interposition n = 17) were included. Barrett's esophagus was found in 19 (7%) patients (median age 32.3 (17.8-56.0) years at diagnosis). Youngest patient with a clinically relevant Barrett's esophagus was 20.9 years. Follow-up endoscopies were performed in 108 patients (40%; median follow-up time 4.6 years). During surveillance, four patients developed Barrett's esophagus but no dysplasia or cancer was found. One 45-year-old woman with a colon interposition developed an adenoma with high-grade dysplasia which was radically removed. Two new cases of esophageal carcinoma were diagnosed in patients (55 and 66 years old) who were not under surveillance. One of them had been curatively treated for esophageal carcinoma 13 years ago.

CONCLUSIONS

This study shows that endoscopic screening of patients with esophageal atresia, including those with a colon interposition, can be started at 20 years of age. Up to the age of 40 years a surveillance interval of 10 years appeared to be safe. Endoscopic surveillance may also be warranted for patients after curative esophageal cancer treatment.

Sociodemographic disparities in gastric cancer and the gastric precancerous cascade: A population-based study

BACKGROUND

Gastric carcinogenesis is a multistep process initiating with chronic gastritis and progressing through atrophy, intestinal metaplasia, and dysplasia to carcinoma. This study aims to comprehensively investigate sociodemographic disparities in each stage of gastric carcinogenesis and estimate to what extent the inequalities could be ascribed to risk factors of gastric cancer (GC).

METHODS

We used the baseline data from a community-based study in China's high-risk areas, totalling 27094 participants. Gastric mucosa status was ascertained by endoscopy and biopsies. An overall socioeconomic status (SES) variable was generated by latent class analysis. We calculated relative risks (RRs) and 95% confidence intervals (CIs) using modified Poisson regression to assess associations of sociodemographic factors with each cascade stage. We estimated the percentage of the excess risk for neoplastic lesions among vulnerable populations that can be explained by established risk factors.

RESULTS

Age and sex showed associations with all gastric lesions, whose RRs increased with lesion progressing. Compared with individuals without schooling, the RRs of neoplastic lesions for people with primary, secondary, and post-secondary education were 0·86 (95% CI 0·76-0·97), 1·00 (95% CI 0·88-1·13), and 0·70 (95% CI 0·47-1·03), respectively. Participants with medium SES had a lower risk of neoplastic lesions than people in the low SES group (RR 0·83, 95% CI 0·74-0·93). GC risk factors could explain 33·6% of the excess risk of neoplastic lesions among men and a small proportion of the disparities among SES groups.

INTERPRETATION

Age and sex were essential sociodemographic factors for GC and precursor diseases. Individuals with low educational levels or SES were more likely to have neoplastic lesions. About one-third of the sex difference and a slight fraction of the socioeconomic inequalities could be attributed to included risk factors.

FUNDING

Sanming Project of Medicine in Shenzhen, National Natural Science Foundation, and Special Project of Bejing-Tianjin-Hebei Basic Research Cooperation.

Long-Term Outcome of Gastric Mild-Moderate Dysplasia: A Real-World Clinical Experience

BACKGROUND & AIMS

The natural course of gastric mild-moderate dysplasia in a country with high incidence of gastric cancer (GC) is relatively unknown. We aimed to determine the long-term cumulative incidence of and risk factors for advanced neoplasia in patients with gastric dysplasia.

METHODS

This was a single-center observational study including all consecutive patients diagnosed with gastric mild-moderate dysplasia between 2000 and 2017. Follow-up data were collected until December 2019. We determined the cumulative incidence of advanced neoplasia and identified risk factors with Cox regression.

RESULTS

A total of 3489 consecutive participants were followed for a median of 4.19 years from initial mild-moderate dysplasia diagnosis. The median surveillance interval between index endoscopy and next follow-up endoscopy was 1.08 years, and more than half of patients had at least 3 surveillance gastroscopies. During the study period, the majority of participants did not show disease progression, either with dysplasia not detected (51.4%) or with persistent dysplasia (46.1%). There were 88 (2.9%) patients (5.13 per 1000 patient-years) who progressed to advanced neoplasia within a median of 4.3 years. The annual incidence of advanced neoplasia and GC were 0.43% and 0.26%, respectively, within 5 years of mild-moderate dysplasia diagnosis. Increasing age, male sex, moderate dysplasia, dysplasia detected in fundus or cardia at index endoscopy, and persistent Helicobacter pylori infection during follow-up were independent risk factors for developing advanced neoplasia.

CONCLUSIONS

Even in a country with high incidence of GC, the majority of patients with gastric mild-moderate dysplasia did not experience disease progression in the long term. Intensified surveillance during the first 5 years after mild-moderate dysplasia detection is suggested.

Toll-Like Receptor 1 Locus Re-examined in a Genome-Wide Association Study Update on Anti-Helicobacter pylori IgG Titers

BACKGROUND & AIMS

A genome-wide significant association between anti-Helicobacter pylori (H pylori) IgG titers and Toll-like receptor (TLR1/6/10) locus on 4p14 was demonstrated for individuals of European ancestry, but not uniformly replicated. We re-investigated this association in an updated genome-wide association study (GWAS) meta-analysis for populations with low gastric cancer incidence, address potential causes of cohort heterogeneity, and explore functional implications of genetic variation at the TLR1/6/10 locus.

METHODS

The dichotomous GWAS (25% individuals exhibiting highest anti-H pylori IgG titers vs remaining 75%) included discovery and replication sampls of, respectively, n = 15,685 and n = 9676, all of European ancestry. Longitudinal analysis of serologic data was performed on H pylori-eradicated subjects (n = 132) and patients under surveillance for premalignant gastric lesions (n = 107). TLR1/6/10 surface expression, TLR1 mRNA, and cytokine levels were measured in leukocyte subsets of healthy subjects (n = 26) genotyped for TLR1/6/10 variants.

RESULTS

The association of the TLR1/6/10 locus with anti-H pylori IgG titers (rs12233670; β = -0.267 ± SE 0.034; P = 4.42 × 10^-15) presented with high heterogeneity and failed replication. Anti-H pylori IgG titers declined within 2-4 years after eradication treatment (P = 0.004), and decreased over time in patients with premalignant gastric lesions (P < 0.001). Variation at the TLR1/6/10 locus affected TLR1-mediated cytokine production and TLR1 surface expression on monocytes (P = 0.016) and neutrophils (P = 0.030), but not mRNA levels.

CONCLUSIONS

The association between anti-H pylori IgG titers and TLR1/6/10 locus was not replicated across cohorts, possibly owing to dependency of anti-H pylori IgG titers on therapy, clearance, and antibody decay. H pylori-mediated immune cell activation is partly mediated via TLR1 signaling, which in turn is affected by genetic variation.

Coding and non-coding co-expression network analysis identifies key modules and driver genes associated with precursor lesions of gastric cancer

BACKGROUND

Helicobacter pylori infection is the most important risk factor for gastric cancer (GC). Human gastric adenocarcinoma develops after long-term H. pylori infection via the Correa cascade. This carcinogenic pathway describes the progression from gastritis to atrophy, intestinal metaplasia (IM), dysplasia and GC. Patients with atrophy and intestinal metaplasia are considered to have precancerous lesions of GC (PLGC). H. pylori eradication and endoscopy surveillance are currently the only interventions for preventing GC. Better knowledge of the biology of human PLGC may help find stratification markers and contribute to better understanding of biological mechanisms. One way to achieve this is by using co-expression network analysis. Weighted gene co-expression network analysis (WGCNA) is often used to identify modules from co-expression networks and relate them to clinical traits. It also allows identification of driver genes that may be critical for PLGC.

AIM

The purpose of this study was to identify co-expression modules and differential gene expression in dyspeptic patients at different stages of the Correa pathway.

METHODS

We studied 96 gastric biopsies from 78 patients that were clinically classified as: non-active (n = 10) and chronic-active gastritis (n = 20), atrophy (n = 12), and IM (n = 36). Gene expression of coding RNAs was determined by microarrays and non-coding RNAs by RNA-seq. The WGCNA package was used for network construction, module detection, module preservation and hub and driver gene selection.

RESULTS

WGCNA identified 20 modules for coding RNAs and 4 for each miRNA and small RNA class. Modules were associated with antrum and corpus gastric locations, chronic gastritis and IM. Notably, coding RNA modules correlated with the Correa cascade. One was associated with the presence of H. pylori. In three modules, the module eigengene (ME) gradually increased in the stages toward IM, while in three others the inverse relationship was found. One miRNA module was negatively correlated to IM and was used for a mRNA-miRNA integration analysis. WGCNA also uncovered driver genes. Driver genes show both high connectivity within a module and are significantly associated with clinical traits. Some of those genes have been previously involved in H. pylori carcinogenesis, but others are new. Lastly, using similar external transcriptomic data, we confirmed that the discovered mRNA modules were highly preserved.

CONCLUSION

Our analysis captured co-expression modules that provide valuable information to understand the pathogenesis of the progression of PLGC.

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.

Serum Pepsinogens Combined with New Biomarkers Testing Using Chemiluminescent Enzyme Immunoassay for Non-Invasive Diagnosis of Atrophic Gastritis: A Prospective, Multicenter Study

Background: Analysis of serum biomarkers for the assessment of atrophic gastritis (AG), a gastric precancerous lesion, is of growing interest for identification of patients at increased risk of gastric cancer. The aim was to analyze the diagnostic performance of serum pepsinogen testing using another method, chemiluminescent enzyme immunoassay (CLEIA), as well as of other new potential biomarkers. Material and Methods: The sera of patients considered at increased risk of gastric cancer and undergoing upper endoscopy collected in our previous prospective, multicenter study were tested for pepsinogen I (PGI) and II (PGII), interleukin-6 (IL-6), human epididymal protein 4 (HE-4), adiponectin, ferritin and Krebs von den Lungen (KL-6) using the CLEIA. The diagnostic performance for the detection of AG was calculated by taking histology as the reference. Results: In total, 356 patients (162 men (46%); mean age 58.6 (±14.2) years), including 152 with AG, were included. For the detection of moderate to severe corpus AG, sensitivity and specificity of the pepsinogen I/II ratio were of 75.0% (95%CI 57.8–87.9) and 92.6% (88.2–95.8), respectively. For the detection of moderate to severe antrum AG, sensitivity of IL-6 was of 72.2% (95%CI 46.5–90.3). Combination of pepsinogen I/II ratio or HE-4 showed a sensitivity of 85.2% (95%CI 72.9–93.4) for the detection of moderate to severe AG at any location. Conclusion: This study shows that PG testing by CLEIA represents an accurate assay for the detection of corpus AG. Additionally, IL-6 and HE-4 may be of interest for the detection of antrum AG. Mini-abstract: Pepsinogens testing by chemiluminescent enzyme immunoassay is accurate for the detection of corpus atrophic gastritis. IL-6 and HE-4 maybe of interest for the detection of antrum atrophic gastritis.

Autophagy mediates ER stress and inflammation in Helicobacter pylori-related gastric cancer

Autophagy is a cellular degradation mechanism, which is triggered by the bacterium Helicobacter pylori. A single nucleotide polymorphism (SNP) in the autophagy gene ATG16L1 (rs2241880, G-allele) has been shown to dysregulate autophagy and increase intestinal endoplasmic reticulum (ER) stress. Here, we investigate the role of this SNP in H.pylori-mediated gastric carcinogenesis and its molecular pathways. ATG16L1 rs2241880 was genotyped in subjects from different ethnic cohorts (Dutch and Australian) presenting with gastric (pre)malignant lesions of various severity. Expression of GRP78 (a marker for ER stress) was assessed in gastric tissues. The effect of ATG16L1 rs2241880 on H.pylori-mediated ER stress and pro-inflammatory cytokine induction was investigated in organoids and CRISPR/Cas9 modified cell lines. Development of gastric cancer was associated with the ATG16L1 rs2241880 G-allele. Intestinal metaplastic cells in gastric tissue of patients showed increased levels of ER-stress. In vitro models showed that H.pylori increases autophagy while reducing ER stress, which appeared partly mediated by the ATG16L1 rs2241880 genotype. H.pylori-induced IL-8 production was increased while TNF-α production was decreased, in cells homozygous for the G-allele. The ATG16L1 rs2241880 G-allele is associated with progression of gastric premalignant lesions and cancer. Modulation of H.pylori-induced ER stress pathways and pro-inflammatory mediators by ATG16L1 rs2441880 may underlie this increased risk.

Mapping the genomic diaspora of gastric cancer

Gastric cancer (GC) is a leading contributor to global cancer incidence and mortality. Pioneering genomic studies, focusing largely on primary GCs, revealed driver alterations in genes such as ERBB2, FGFR2, TP53 and ARID1A as well as multiple molecular subtypes. However, clinical efforts targeting these alterations have produced variable results, hampered by complex co-alteration patterns in molecular profiles and intra-patient genomic heterogeneity. In this Review, we highlight foundational and translational advances in dissecting the genomic cartography of GC, including non-coding variants, epigenomic aberrations and transcriptomic alterations, and describe how these alterations interplay with environmental influences, germline factors and the tumour microenvironment. Mapping of these alterations over the GC life cycle in normal gastric tissues, metaplasia, primary carcinoma and distant metastasis will improve our understanding of biological mechanisms driving GC development and promoting cancer hallmarks. On the translational front, integrative genomic approaches are identifying diverse mechanisms of GC therapy resistance and emerging preclinical targets, enabled by technologies such as single-cell sequencing and liquid biopsies. Validating these insights will require specifically designed GC cohorts, converging multi-modal genomic data with longitudinal data on therapeutic challenges and patient outcomes. Genomic findings from these studies will facilitate 'next-generation' clinical initiatives in GC precision oncology and prevention.

The risk of diffuse-type gastric cancer following diagnosis with gastric precancerous lesions: a systematic review and meta-analysis

PURPOSE

Gastric cancers are classified as diffuse-type (DTGC) or intestinal-type (ITGC). DTGCs have distinct clinical and histopathologic features, and carry a worse overall prognosis compared to ITGCs. Atrophic gastritis (AG) and intestinal metaplasia (IM) are known precursors to ITGC. It is unknown if AG and IM increase risk for DTGC.

METHODS

We performed a systematic review to identify studies reporting on the association of AG/IM and DTGC. We extracted the odds ratio (OR) of the association from studies, and performed pool analysis. Subgroup analysis was performed on studies reporting histologic severity (using operative link systems) to assess if histologic severity of AG/IM was associated with higher risk.

RESULTS

We identified six case-control and eight cohort studies for inclusion. Both AG (pooled OR = 1.9, 95% CI 1.5 to 2.4, p < 0.001) and IM (pooled OR = 2.3, 95% CI 1.9 to 2.9, p < 0.001) demonstrated an association with DTGC. High AG severity was associated with increased risk for DTGC compared to low AG severity (OR = 1.7, 95% CI 1.2 to 2.3, p = 0.002). Similarly, high IM severity was associated with increased risk compared to low IM severity (OR = 1.9, 95% CI 1.3 to 2.7, p = 0.001).

CONCLUSION

Both AG and IM are associated with DTGC. Increasing histologic severity of both AG and IM increases risk for DTGC. There may exist a common pathway between ITGC and some DTGCs mediated through mucosal precursor lesions. These data may inform future strategies of cancer risk attenuation and control.

Advances in the Aetiology & Endoscopic Detection and Management of Early Gastric Cancer

Simple Summary

Gastric adenocarcinoma has remained a highly lethal disease. Awareness and recognition of preneoplastic conditions (including gastric atrophy and intestinal metaplasia) using high-resolution white-light endoscopy as well as chromoendoscopy is therefore essential. Helicobacter pylori, a class I carcinogen, remains the main contributor to the development of sporadic distal gastric neoplasia. Management of early gastric neoplasia with endoscopic resections should be in line with standard indications. A multidisciplinary approach to any case of an early gastric neoplasia is imperative. Hereditary forms of gastric cancer require a tailored approach and individua-lized surveillance.

Abstract

The mortality rates of gastric carcinoma remain high, despite the progress in research and development in disease mechanisms and treatment. Therefore, recognition of gastric precancerous lesions and early neoplasia is crucial. Two subtypes of sporadic gastric cancer have been recognized: cardia subtype and non-cardia (distal) subtype, the latter being more frequent and largely associated with infection of Helicobacter pylori, a class I carcinogen. Helicobacter pylori initiates the widely accepted Correa cascade, describing a stepwise progression through precursor lesions from chronic inflammation to gastric atrophy, gastric intestinal metaplasia and neoplasia. Our knowledge on He-licobacter pylori is still limited, and multiple questions in the context of its contribution to the pathogenesis of gastric neoplasia are yet to be answered. Awareness and recognition of gastric atrophy and intestinal metaplasia on high-definition white-light endoscopy, image-enhanced endoscopy and magnification endoscopy, in combination with histology from the biopsies taken accurately according to the protocol, are crucial to guiding the management. Standard indications for endoscopic resections (endoscopic mucosal resection and endoscopic submucosal dissection) of gastric dysplasia and intestinal type of gastric carcinoma have been recommended by multiple societies. Endoscopic evaluation and surveillance should be offered to individuals with an inherited predisposition to gastric carcinoma.

Surveillance of premalignant gastric cardia lesions: A population-based prospective cohort study in China

In our study, we aimed to assess the long-term risk of gastric cardia adenocarcinoma (GCA) for patients with different histological cardia lesions to inform future guidelines for GCA screening in China. We conducted a population-based prospective study among 9740 subjects who underwent upper endoscopy screening during 2005 to 2009 and followed until December 2017. Cumulative incidence and mortality rates of GCA were calculated by the baseline histological diagnoses, and the hazard ratios (HRs), overall and by age and sex, were analyzed by Cox proportional hazards models. During a median follow-up of 10 years, we identified 123 new GCA cases (1.26%) and 31 GCA deaths (0.32%). The age-standardized incidence and mortality rates of GCA were 128.71/100 000 and 35.69/100 000 person-years, and cumulative incidence rate in patients with cardia high-grade dysplasia (CHGD), cardia low-grade dysplasia (CLGD) and atrophic carditis (AC)/cardia intestinal metaplasia (CIM) was 25%, 3.05% and 1.58%, respectively. The progression rate and cancer risk of GCA increased monotonically with each step in Correa's cascade. Individuals aged 50 to 69 years had 4.4 times higher GCA incidence than those aged 40 to 49 years. Patients with CLGD had a significantly higher 3-year GCA incidence than the normal group, while patients with AC/CIM had a comparable GCA risk during 3-year follow-up but a higher risk at 5-year intervals. Our results suggested a postponed starting age of 50 years for GCA screening, immediate treatment for patients with CHGD, a 3-year surveillance interval for patients with CLGD, and a lengthened surveillance interval of 5 years for patients with AC/CIM.

Gastric intestinal metaplasia: when to treat? How to treat?

PURPOSE OF REVIEW

Gastric intestinal metaplasia (GIM) is an attractive target for surveillance and treatment as it can progress to gastric adenocarcinoma (GAC). Yet, GIM remains a challenging area for clinicians as most patients do not progress to cancer, and there are conflicting data regarding the benefits of surveillance and therapy. This review aims to summarize recently published GIM surveillance guidelines, to discuss, which patients with GIM may benefit from treatment, and to review pivotal and recent literature on GIM therapy.

RECENT FINDINGS

Guidelines published by American, British, and European gastroenterology societies do not recommend universal surveillance, but do suggest endoscopic surveillance in patients with risk factors for progression to GAC. Although light examination for at least 7 min and mapping biopsies may increase yield for dysplasia and GAC. In randomized trials, Helicobacter pylori eradication reduced risk of dysplasia and cancer. In GIM with visible dysplasia and early-stage GAC, endoscopic resection improves quality of life without reducing survival compared with surgery. Endoscopic ablation therapies have shown promise for invisible or extensive dysplasia.

SUMMARY

Endoscopic resection is appropriate for visible dysplasia and early-stage GAC without high-risk features that persists despite H. pylori eradication therapy. Prospective studies are needed to assess the utility of endoscopic ablation in GIM.