Staging of intestinal- and diffuse-type gastric cancers with the OLGA and OLGIM staging systems

Endoscopic Grading and Sampling of Gastric Precancerous Lesions: A Comprehensive Literature Review

Gastric cancer remains a disease with an ominous prognosis, while early gastric cancer has a good-to-excellent prognosis, with 5-year survival rates of up to 92.6% after successful endoscopic resection. In this context, the accurate identification of patients with established gastric precancerous lesions, namely chronic atrophic gastritis and intestinal metaplasia, is the first step in a stepwise approach to minimize cancer risk. Although current guidelines advocate for the execution of random biopsies to stage the extent and severity of gastritis/intestinal metaplasia, modern biopsy protocols are still imperfect as they have limited reproducibility and are susceptible to sampling error. The advent of novel imaging-enhancing modalities, i.e., high-definition with virtual chromoendoscopy (CE), has revolutionized the inspection of gastric mucosa, leading to an endoscopy-based staging strategy for the management of these premalignant changes in the stomach. Nowadays, the incorporation of CE-targeted biopsies in everyday clinical practice offers not only the robust detection of premalignant lesions but also an improvement in quality, by reducing missed diagnoses along with mean biopsies and, thus, the procedural costs and the environmental footprint. In this review, we summarize the recent evidence regarding the endoscopic grading and sampling of gastric precancerous lesions.

Endoscopic and histological risk stratification for gastric cancer using gastric intestinal metaplasia

BACKGROUND AND AIM

Intestinal metaplasia (IM) of the gastric mucosa is strongly associated with the risk of gastric cancer (GC). This study was performed to investigate the usefulness of endoscopic and histological risk stratification for GC using IM.

METHODS

This was a post-hoc analysis of a multicenter prospective study involving 10 Japanese facilities (UMINCTR000027023). The ridge/tubulovillous pattern, light blue crest (LBC), white opaque substance (WOS), endoscopic grading of gastric IM (EGGIM) score using non-magnifying image-enhanced endoscopy, and operative link on gastric IM assessment (OLGIM) were evaluated for their associations with GC risk in all patients.

RESULTS

In total, 380 patients (115 with GC and 265 without GC) were analyzed. The presence of an LBC (limited to antrum: odds ratio [OR] 2.4 [95% confidence interval 1.1-5.0], extended to corpus: OR 3.6 [2.1-6.3]), the presence of WOS (limited to antrum: OR 3.0 [1.7-5.3], extended to corpus: OR 4.2 [2.1-8.2]), and histological IM (limited to antrum: OR 3.2 [1.4-7.4], extended to corpus: OR 8.5 [4.5-16.0]) were significantly associated with GC risk. Additionally, the EGGIM score (5-8 points: OR 8.8 [4.4-16.0]) and OLGIM (stage III/IV: OR 12.5 [6.1-25.8]) were useful for stratification of GC risk. The area under the receiver operating characteristic curve value for GC risk was 0.740 for OLGIM and 0.706 for EGGIM.

CONCLUSIONS

The LBC, WOS, EGGIM, and OLGIM were strongly associated with GC risk in Japanese patients. This finding can be useful for GC risk assessment in daily clinical practice.

Targeting Stem Cells and Dysplastic Features With Dual MEK/ERK and STAT3 Suppression in Gastric Carcinogenesis

BACKGROUNDS & AIMS

Precancerous metaplasia progression to dysplasia can increase the risk of gastric cancers. However, effective strategies to specifically target these precancerous lesions are currently lacking. To address this, we aimed to identify key signaling pathways that are upregulated during metaplasia progression and critical for stem cell survival and function in dysplasia.

METHODS

To assess the response to chemotherapeutic drugs, we used metaplastic and dysplastic organoids derived from Mist1-Kras mice and 20 human precancerous organoid lines established from patients with gastric cancer. Phospho-antibody array analysis and single-cell RNA-sequencing were performed to identify target cell populations and signaling pathways affected by pyrvinium, a putative anticancer drug. Pyrvinium was administered to Mist1-Kras mice to evaluate drug effectiveness in vivo.

RESULTS

Although pyrvinium treatment resulted in growth arrest in metaplastic organoids, it induced cell death in dysplastic organoids. Pyrvinium treatment significantly downregulated phosphorylation of ERK and signal transducer and activator of transcription 3 (STAT3) as well as STAT3-target genes. Single-cell RNA-sequencing data analyses revealed that pyrvinium specifically targeted CD133+/CD166+ stem cell populations, as well as proliferating cells in dysplastic organoids. Pyrvinium inhibited metaplasia progression and facilitated the restoration of normal oxyntic glands in Mist1-Kras mice. Furthermore, pyrvinium exhibited suppressive effects on the growth and survival of human organoids with dysplastic features, through simultaneous blocking of the MEK/ERK and STAT3 signaling pathways.

CONCLUSIONS

Through its dual blockade of MEK/ERK and STAT3 signaling pathways, pyrvinium can effectively induce growth arrest in metaplasia and cell death in dysplasia. Therefore, our findings suggest that pyrvinium is a promising chemotherapeutic agent for reprogramming the precancerous milieu to prevent gastric cancer development.

The Operative Link on Gastritis Assessment (OLGA) system as a marker for gastric cancer and dysplasia in a Colombian population at risk: A multicenter study

Introduction. The OLGA system has been proved to be useful in Asia and Europe as a risk marker of gastric cancer. However, its usefulness in high-risk populations in Colombia is still unknown. Objective. To assess potential associations between the OLGA staging system and an increased risk of gastric cancer and dysplasia in a high-risk Colombian population and to establish diagnostic capacity of the scale to assess the risk. Materials and methods. We carried out a multicenter study including patients with cancer and dysplasia (cases) and patients with atrophy and intestinal metaplasia (controls). A total of 506 patients were recruited from three centers in an area with a high risk population in Colombia. The endoscopic and histopathologic studies were evaluated according to the Sydney system and the OLGA staging system proposed by Rugge. The effect of each variable on the disease (gastric cancer and dysplasia) was evaluated using bivariate and multivariate models. Statistical significance was set considering a p value inferior to 0.05. Results. Advanced stages of the OLGA system (III-IV) were associated with a higher risk of dysplasia and gastric cancer (adjusted OR = 8.71; CI95% = 5.09-14.9; p=0.001), sensitivity=54.9%, specificity=89.3% and positive likelihood ratio=5.17. Conclusions. The OLGA staging system is a risk marker for gastric cancer and dysplasia in the studied population. We recommend its implementation to improve the timely diagnosis and follow-up of patients with the highest cancer risk.

Characteristic analysis of early gastric cancer after Helicobacter pylori eradication: a multicenter retrospective propensity score-matched study

BACKGROUND

Helicobacter pylori (H. pylori) is recognized as a type I carcinogen in gastric cancer (GC). However, GC still occurs after H. pylori eradication, and its diagnosis is more complicated. This study aimed to summarize the characteristics of early GC (EGC) after H. pylori eradication to help accurately identify EGC and avoid missed diagnosis and misdiagnosis.

METHODS

A total of 81 patients of EGC after H. pylori eradication (Hp-eradicated group), resected by endoscopic submucosal dissection (ESD), and 105 cases of H. pylori infection-related EGC (control group) were assessed. After propensity-score matching, the clinical characteristics, endoscopic manifestations, and histopathological features of the 62 matched patients in each group were analyzed. We also conducted specific analyses in combination with endoscopic and histopathological images.

RESULTS

There were more patients in the Hp-eradicated group who received proton pump inhibitor (PPI) for >1 year compared to the control group (p < 0.001). More patients at OLGA stages I-II before the diagnosis of EGC were in the control group (p = 0.045), especially at stage II. The mucosa in the Hp-eradicated group showed more moderate-to-severe atrophy (p = 0.047), map-like redness (p < 0.001) and mild activity (p < 0.001). The predominant histopathological types differed between the two groups (p < 0.001), and the majority of cases in the Hp-eradicated group were high-grade intraepithelial neoplasia (HGIN). Ki-67 expression was lower in the Hp-eradicated group (p = 0.025). But different eradication intervals of H. pylori have little effect on the characteristics of EGC. Furthermore, PPI uses for >1 year (p = 0.005), mucosal map-like redness (p < 0.001), moderate mucosal atrophy (p = 0.017), and mild activity of gastric mucosa (p = 0.005) were independent characteristics of EGC after H. pylori eradication.

CONCLUSION

Our multicenter study revealed that EGC after H. pylori eradication was characterized by long-term PPI use, moderate mucosal atrophy, mucosal map-like redness, the mild activity of gastric mucosa, a higher proportion of HGIN cases, and lower levels of Ki-67.

Incidence and Predictors of Gastric Neoplastic Lesions in Corpus-Restricted Atrophic Gastritis: A Single-Center Cohort Study

INTRODUCTION

Corpus-restricted atrophic gastritis is a chronic inflammatory disorder leading to possible development of type 1 neuroendocrine tumors (T1gNET), intraepithelial neoplasia (IEN), and gastric cancer (GC). We aimed to assess occurrence and predictors of gastric neoplastic lesions in patients with corpus-restricted atrophic gastritis at long-term follow-up.

METHODS

A prospective single-center cohort of patients with corpus-restricted atrophic gastritis adhering to endoscopic-histological surveillance was considered. Follow-up gastroscopies were scheduled according to the management of epithelial precancerous conditions and lesions of the stomach guidelines. In case of new/worsening of known symptoms, gastroscopy was anticipated. Cox regression analyses and Kaplan-Meier survival curves were obtained.

RESULTS

Two hundred seventy-five patients with corpus-restricted atrophic gastritis (72.0% female, median age 61 [23-84] years) were included. At a median follow-up of 5 (1-17) years, the annual incidence rate person-year was 0.5%, 0.6%, 2.8%, and 3.9% for GC/high-grade IEN, low-grade IEN, T1gNET, and all gastric neoplastic lesions, respectively. All patients showed at baseline operative link for gastritis assessment (OLGA)-2, except 2 low-grade (LG) IEN patients and 1 T1gNET patient with OLGA-1. Age older than 60 years (hazard ratio [HR] 4.7), intestinal metaplasia without pseudopyloric metaplasia (HR 4.3), and pernicious anemia (HR 4.3) were associated with higher risk for GC/HG-IEN or LG-IEN development and shorter mean survival time for progression (13.4, 13.2, and 11.1, respectively, vs 14.7 years, P = 0.01). Pernicious anemia was an independent risk factor for T1gNET (HR 2.2) and associated with a shorter mean survival time for progression (11.7 vs 13.6 years, P = 0.04) as well as severe corpus atrophy (12.8 vs 13.6 years, P = 0.03).

DISCUSSION

Patients with corpus-restricted atrophic gastritis are at increased risk for GC and T1gNET despite low-risk OLGA scores, and those aged older than 60 years with corpus intestinal metaplasia or pernicious anemia seem to display a high-risk scenario.

Staging of operative link on gastritis assessment and operative link on gastric intestinal metaplasia systems for risk assessment of early gastric cancer: a case-control study

AIMS

Operative link on gastritis assessment (OLGA) and operative link on gastric intestinal metaplasia assessment (OLGIM) systems are histological staging systems of gastritis for gastric cancer (GC) risk estimation. Intermediate OLGA/OLGIM stages are of concern in a region with high incidence of GC. This study aimed to validate OLGA and OLGIM staging systems for early GC (EGC) in Chinese population.

METHODS

This single-centre, case-control study included 196 patients with EGC and 196 age-matched and sex-matched health screening control subjects. OLGA and OLGIM systems, and other clinical parameters were evaluated using logistic regression analysis.

RESULTS

OLGA and OLGIM stages II/III/IV were more prevalent in patients with EGC than in the control subjects. Multivariable analysis revealed family history of GC, previous Helicobacter pylori (H. pylori) infection, OLGA stages II and III-IV, OLGIM stages II and III-IV as independent risk factors for EGC (ORs, 4.04, 1.87, 2.52, 6.79, 4.11 and 10.78, respectively). Area under the receiver operating characteristic curve on EGC risk estimation was improved for OLGIM compared with OLGA (0.78 vs 0.71, p<0.001). Autoantibody seropositivity of gastric mucosa was not associated with EGC risk stratified by H. pylori status.

CONCLUSIONS

Surveillance of intermediate-risk patients (OLGA/OLGIM II) should be emphasised in our region. The OLGIM may be preferred over the OLGA for EGC risk estimation.

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.

Real-time assessment of H. pylori during the endoscopic assessment of individuals with gastric intestinal metaplasia: a possible way to reduce the burden of care

OBJECTIVES

The management of individuals with gastric intestinal metaplasia (GIM) includes biopsies for its staging and to diagnose Helicobacter pylori (Hp ). Advanced-stage GIM can be estimated by endoscopy through EGGIM, and a new device permits the real-time assessment of ammonia for the identification of Hp infection. The aim of this study was to assess the simultaneous use of EGGIM and real-time assessment of ammonia to avoid biopsies and reduce the burden of care in clinical practice.

METHODS

A multicentre study involving 101 consecutively enrolled patients [52% male; 65(18-85) years]. During endoscopy, gastric juice was aspirated and analysed; EGGIM was determined in real-time. Targeted biopsies were performed and histopathological assessment was used as gold standard.

RESULTS

Advanced-stage GIM were detected in 14.9% of patients and Hp infection in 18.8%. EGGIM showed for advanced-stage GIM a sensitivity, specificity and NPV of 86.7%, 84.9% and 97.3%, whilst real-time assessment of ammonia, 83.3%, 78.2% and 95.4%, respectively. Gastric juice was insufficient in 5 (5.0%). Overall, 64 (67%) patients were correctly diagnosed by EGGIM and real-time assessment of ammonia. If the 47 (49%) patients negative to both assessments would have avoided biopsies, only 4 (4.2%) would have been missed: two with advanced-stage GIM and two with Hp infection.

CONCLUSION

The combination of endoscopic assessment and real-time analysis of Hp allows the exclusion of advanced-stage GIM or Hp infection without the need of biopsies in a significant proportion of individuals. This may allow in specific situations to abstain from biopsies reducing the burden of care.

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.

Histopathological Evaluation of Gastric Mucosal Atrophy for Predicting Gastric Cancer Risk: Problems and Solutions

Patients suffering from chronic gastritis and developing gastric mucosa atrophy are at increased risk of the development of gastric cancer. The diagnosis of chronic atrophic gastritis (CAG) is a complex procedure involving a detailed history taking, a thorough physical examination and the use of laboratory and instrumental diagnostic methods among which the endoscopy of the upper digestive tract is the cornerstone because it allows the assessment of the topography of gastritis and identification of erosions and areas of intestinal metaplasia with the use of NBI endoscopy. However, the diagnosis of CAG requires morphological examination of the gastric mucosa. So, in addition to assessing macroscopic changes in the gastric mucosa, it is necessary to take biopsy specimens in accordance with the protocols for their morphological and immunohistochemical examination. In the absence of specific diagnostic stigmas of CAG, close cooperation between a clinician, endoscopist and pathologist is necessary. The article presents systematized data on the histopathological assessment of the gastric mucosa atrophy to predict the risk of gastric cancer.

Risk assessment of metachronous gastric cancer development using OLGA and OLGIM systems after endoscopic submucosal dissection for early gastric cancer: a long-term follow-up study

BACKGROUND

Metachronous gastric cancer (MGC) may develop in patients undergoing curative endoscopic submucosal dissection for early gastric cancer. As gastritis and intestinal metaplasia are notable precursors to gastric cancer, we assessed MGC risk using the Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia assessment (OLGIM) systems.

METHODS

This retrospective cohort study classified the OLGA and OLGIM stages for 916 patients who had undergone endoscopic submucosal dissection for early gastric cancer between 2005 and 2015. MGC development was followed up until 2020 and risk factors were evaluated using the Cox proportional hazards regression analysis.

RESULTS

During a median follow-up of 94 months, MGC developed in 120 subjects. OLGA stages II ~ IV were significantly associated with increased MGC risk (hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.05-3.19; HR 2.31, 95% CI 1.22-4.38; HR 2.36, 95% CI 1.16-4.78) in multivariable analysis, even after adjusting for the well-known positive predictor of Helicobacter pylori eradication. OLGIM stages II ~ IV also showed significant association (HR 2.86, 95% CI 1.29-6.54; HR 2.94, 95% CI 1.34-6.95; HR 3.64, 95% CI 1.60-8.29). 5-year cumulative incidence increased with each stage. Helicobacter pylori-eradicated patients with OLGIM stages 0 ~ II had significantly less MGC than non-eradicated patients (4.5% vs 11.8%, p = 0.022), which was not observed with OLGIM stages III ~ IV.

CONCLUSIONS

High OLGA and OLGIM stages are independent risk factors for metachronous gastric cancer, with the OLGIM staging system being a better predictor. Patients with OLGIM stages 0 ~ II are a subgroup that may benefit more from Helicobacter pylori eradication.

Effect of Helicobacter pylori Eradication Treatment on Metachronous Gastric Neoplasm Prevention Following Endoscopic Submucosal Dissection for Gastric Adenoma

The long-term effect of Helicobacter pylori eradication on metachronous gastric neoplasm prevention after endoscopic submucosal dissection (ESD) of gastric adenoma is unclear. This study included patients with confirmed H. pylori infection after ESD with curative resection for gastric adenoma. Patients were divided based on the success of H. pylori eradication treatment into two groups: eradication and non-eradication. Patients with any newly detected lesion within 1 year after ESD and recurrence at the ESD site were excluded from the analysis. Further, 1:1 propensity score matching was also performed to eliminate baseline differences between the two groups. H. pylori eradication treatment was administered to 673 patients after ESD (163 in the successful eradication group and 510 in the non-eradication group). During the median follow-up periods of 25 and 39 months in the eradication and non-eradication groups, metachronous gastric neoplasm was identified in 6 (3.7%) and 22 patients (4.3%), respectively. Adjusted Cox analysis revealed that H. pylori eradication was not associated with increased risk of metachronous gastric neoplasm after ESD. Kaplan-Meier analysis in the matched population yielded similar findings (p = 0.546). H. pylori eradication treatment was not associated with metachronous gastric neoplasm after ESD with curative resection for gastric adenoma.

The application of new gastric cancer screening score system for gastric cancer screening and risk assessment of gastric precancerous lesions in China

Objective: To evaluate the value of new gastric cancer screening score system for risk assessment of gastric precancerous lesions.Methods: A total of 520 patients were enrolled after the examination of endoscopy at Endoscopy Center, Department of Gastroenterology, from June 2018 to December 2021. The patients were divided into three groups according to age, gender, serum helicobacter pylori antibody test, pepsinogen I (PGI), pepsinogen II (PGII), pepsinogen I/II ratio (PGR) and gastrin-17 test results before endoscopy: Group A defined as low-risk group (0-11 points), Group B defined as middle-risk group (12-16 points), Group C defined as high-risk group (17-23 points). The detection rates of gastric cancer and atrophic gastritis in three groups were analyzed. According to the range and degree of atrophy/intestinal metaplasia, patients were divided into five groups on the basis of OLGA/OLGIM staging system. The levels of PG I, PG II and PGR were compared between different groups, and the correlation between new gastric cancer screening score system and OLGA/OLGIM staging system were evaluated. Statistical analysis was accomplished by ANOVA, chi-square test and Gamma coefficient analysis.Results: A total of 520 patients were enrolled. 268 patients were classified into group A,222 patients into group B and 30 patients into group C, respectively. According to the pathological results, 281 cases were non-atrophic gastritis, 230 cases atrophic gastritis and 9 cases gastric cancer. For OLGA staging system, 281 patients were divided into stage-0 group, 121 patients into stage-I group, 72 patients into stage-II group, 33 patients into stage-III group and 13 patients into stage-IV groups. The PGI and PGR level correlated inversely with the rising OLGA stages (F = 3.028, p = .016, F = 6.036, p < .001). For OLGIM staging system, 252 patients were divided into stage-0 group, 137 patients into stage-I group, 80 patients into stage-II group, 36 patients into stage-III group and 15 patients into stage-IV group. The PGR level correlated inversely with the rising OLGIM stages (F = 3.466, p＝.007). The detection rates of gastric cancer and atrophic gastritis in Group C were much higher than other groups. (X² = 14.727, p < .001; X² = 51.280, p < .001). Gamma coefficient analysis showed significant correlations between OLGA/OLGIM and the new gastric cancer screening score system (p < .001).Conclusions: The new gastric cancer screening score system is closely linked with histological OLGA/OLGIM staging system in the risk assessment of gastric precancerous lesions. The role of new gastric cancer screening score system in future gastric precancerous lesions screening and high risk population identifying was promising.

Endoscopic Grading of Gastric Intestinal Metaplasia Using Magnifying and Nonmagnifying Narrow-Band Imaging Endoscopy

Several endoscopic findings obtained by magnifying image-enhanced endoscopy (IEE) are reportedly correlated with gastric intestinal metaplasia (IM); however, the differences between magnifying and nonmagnifying IEE for the diagnosis of gastric IM remain unknown. This study included 100 consecutive patients who underwent narrow-band imaging endoscopy. Four areas of the stomach were evaluated using nonmagnifying and magnifying IEE. Light-blue crest (LBC), white opaque substance (WOS), and endoscopic grading of the gastric IM (EGGIM) were assessed. The concordance rates between nonmagnifying and magnifying IEE were 80.5% for LBC and 93.3% for WOS. The strength of agreement between each observation technique showed good reproducibility, with a kappa value of 0.69 and 0.83 for LBC and WOS, respectively. The individual EGGIM score indicated a good correlation between nonmagnifying and magnifying IEE (concordance rate, 75%; kappa value, 0.67). The prevalence of a high EGGIM score in patients with and without gastric cancer (GC) showed a significant difference both with nonmagnifying IEE (odds ratio (OR), 3.3; 95% confidence interval (CI), 1.2-9.0), and magnifying IEE (OR, 3.1; 95% CI, 1.1-8.9). Nonmagnifying IEE has the potential to stratify the individual risk of GC, similar to magnifying IEE, warranting further investigation with histological assessment.

Histopathologically defined intestinal metaplasia in lesser curvature of corpus prior to Helicobacter pylori eradication is a risk factor for gastric cancer development

BACKGROUND AND AIM

Helicobacter pylori eradication has been shown to reduce the risk of gastric cancer (GC), with the number of eradication therapy cases on the rise. However, GC can still occur after successful treatment, and the histological differences prior to eradication in patients with and without GC are unclear. This study investigated the pre-treatment histological risk factors for GC development following eradication therapy.

METHODS

We retrospectively enrolled consecutive adult patients diagnosed as having H. pylori infection between April 2004 and December 2018. Atrophy and intestinal metaplasia (IM) were histologically assessed according to the updated Sydney System. The operative link on gastritis assessment and the operative link on gastric intestinal metaplasia (OLGIM) were evaluated as well.

RESULTS

Of the 247 patients analyzed in this study, 11 (4.5%) experienced GC after eradication therapy. Histological IM scores in the GC group were significantly higher at all gastric biopsy sites (p < .05), and the proportion of OLGIM III/IV stage was significantly greater in GC patients (81.8% vs. 31.8%, p < .01). For GC prediction, the area under the receiver operating characteristic curve for IM score at the lesser curvature of the corpus was the highest among all biopsy sites and not inferior to OLGIM results.

CONCLUSIONS

Patients with histological IM prior to H. pylori eradication, especially at the lesser curvature of the corpus, may be at elevated risk for GC development after eradication therapy and require close surveillance.

Linked color imaging-based endoscopic grading of gastric intestinal metaplasia and histological gastritis staging in the assessment of gastric cancer risk

OBJECTIVE

To evaluate the value and compare the effectiveness of linked color imaging-based endoscopic grading of gastric intestinal metaplasia (LCI-EGGIM) and operative link on gastric intestinal metaplasia (OLGIM) in risk stratification of early gastric cancer (EGC).

METHODS

Eighty-one patients with EGC who underwent endoscopic submucosal dissection were included. The general data and EGC-related risk factors of all participants were recorded. LCI-EGGIM and OLGIM were used for both groups.

RESULTS

The number of patients with LCI-EGGIM score ≥ 5 was significantly higher in the EGC group than in the control group (58.02% vs. 12.35%, p < .001). Furthermore, the number of patients with OLGIM stage III/IV in the EGC group was significantly higher than that in the control group (56.79% vs. 7.41%, p < .001). Multivariate analysis showed that OLGIM stage III/IV (adjusted odds ratio [AOR]: 29.74, 95% CI: 7.49-117.94) and LCI-EGGIM score ≥ 5 (AOR: 12.33, 95% CI: 3.71-41.02) were significantly associated with EGC. There was no significant difference in the area under the receiver operating characteristic curve between LCI-EGGIM and OLGIM in predicting the risk of EGC (0.74 vs. 0.77, p = .1116).

CONCLUSION

OLGIM and LCI-EGGIM can be used and have the same value for predicting the risk stratification of EGC in patients with gastric intestinal metaplasia.

Endoscopic scoring system for gastric atrophy and intestinal metaplasia: correlation with OLGA and OLGIM staging: a single-center prospective pilot study in Korea

BACKGROUND/AIMS

We aimed to develop an endoscopic scoring system to evaluate gastric atrophy and intestinal metaplasia using narrow-band imaging (NBI) and near focus mode (NFM) to compare endoscopic scores with the Operative link for gastritis assessment (OLGA) and the Operative link for gastric intestinal metaplasia assessment (OLGIM).

METHODS

A total of 51 patients who underwent diagnostic esophagogastroduodenoscopy were prospectively enrolled and endoscopic scoring using NBI and NFM was performed. Four areas (the lesser and greater curvatures of the antrum and the lesser and greater curvature side of the corpus) were observed and biopsies were taken. The degree of atrophy was scored from 0 to 2 according to the Kimura-Takemoto classification. The degree of intestinal metaplasia was scored from 0 to 4 according to the location and the extent of the intestinal metaplasia.

RESULTS

The correlation coefficient for atrophy between the endoscopic and histologic scores was 0.70 (95% CI: 0.52-0.81 p < .001) and for intestinal metaplasia, it was 0.75 (95% CI: 0.60-0.85; p < .001). For atrophic gastritis, an endoscopic score >1 correlated with OLGA stage III and IV with a sensitivity, specificity, positive predictive value, negative predictive value, and agreement of 88, 74, 75, 87, and 80.4%, respectively, and for intestinal metaplasia, an endoscopic score >1 correlated with high OLGIM stage III and IV with 100, 59, 69, 100, and 78.4%, respectively.

CONCLUSIONS

Endoscopic scoring for gastric atrophy and intestinal metaplasia using NBI-NFM likely correlates with histologic staging in Korea, a high-risk region for gastric cancer.

Detection and Characterization of Early Gastric Cancer

In this review, we would like to focus on risk stratification and quality indicators of diagnostic upper gastrointestinal endoscopy in the detection and characterization of early gastric cancer. Preparation of the upper gastrointestinal tract with mucolytic agents or simethicone is often overlooked in the west, and this inexpensive step prior to endoscopy can greatly improve the quality of imaging of the upper digestive tract. Risk stratification based on epidemiological features including family history, Helicobacter pylori infection status, and tobacco smoking is often overlooked but may be useful to identify a subgroup of patients at higher risk of developing gastric cancer. Quality indicators of diagnostic upper gastrointestinal endoscopy are now well defined and include: minimal inspection time of 3 min, adequate photographic documentation of upper gastrointestinal landmarks, utilization of advanced endoscopic imaging technology including narrow band imaging and blue laser imaging to detect intestinal metaplasia and characterize early gastric cancer; and standardized biopsy protocols allow for histological evaluation of gastric mucosa and detection of atrophic gastritis and intestinal metaplasia. Finally, endoscopic and histologic classifications such as the Kimura–Takemoto Classification of atrophic gastritis and the OLGA–OLGIM classifications may help stratify patients at a higher risk of developing early gastric cancer.

Tumorigenic mechanisms of estrogen and Helicobacter pylori cytotoxin-associated gene A in estrogen receptor α-positive diffuse-type gastric adenocarcinoma

BACKGROUND

Diffuse-type gastric cancer (DGC), for which Helicobacter pylori infection is a causal factor, is associated with poor prognosis among young women, possibly due to female hormones such as estrogen. We aimed to identify the carcinogenesis induced by estrogen and H. pylori in DGC.

METHODS

We screened and selected estrogen receptor alpha (ERα)-positive (MKN45) and ERα-negative (SNU5) DGC cell lines. H. pylori strain 60190 and its isogenic mutant strain lacking cytotoxin-associated gene A (60190ΔCagA) were used to infect MKN45 cells. And the cytotoxin-related gene A (CagA) cDNA which was cloned into pSP65-SR-HA (cagA-pSP65SRa) vector was used to transfect MKN45 cells. Tumor samples were used for DGC organoid culture.

RESULTS

In MKN45 cells, we found that estradiol promotes epithelial-mesenchymal transition (EMT) and stemness phenotypes via HOTAIR expression. These effects were further enhanced by the addition of CagA secreted by H. pylori but were reversed by co-treatment with fulvestrant (ICI 182,780), a selective ER degrader. We also validated the effect of estrogen on DGC organoids. ERα expression was associated with tumor invasion and HOTAIR expression in DGC patients with overt H. pylori infection.

CONCLUSIONS

These findings may explain the rapid DGC progression in young women with physiologically high levels of estrogen and suggest that fulvestrant with ovarian function suppression could serve as a tumor-suppressive agent in premenopausal patients with DGC.

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.

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.

Kyoto classification risk scoring system and endoscopic grading of gastric intestinal metaplasia for gastric cancer: Multicenter observation study in Japan

OBJECTIVES

The usefulness of endoscopic and histological risk assessment for gastric cancer (GC) has not been fully investigated in Japanese clinical practice.

METHODS

In this multicenter observation study, GC and non-GC patients were prospectively enrolled in 10 Japanese facilities. The Kyoto classification risk scoring system, the Kimura-Takemoto endoscopic atrophy classification, the endoscopic grading of gastric intestinal metaplasia (EGGIM), the operative link on gastritis assessment (OLGA) and the operative link on gastric intestinal metaplasia assessment (OLGIM) were applied to all patients. The strength of an association with GC risk was compared. In addition, important endoscopic findings in the Kyoto classification were identified.

RESULTS

Overall, 115 GC and 265 non-GC patients were analyzed. Each risk stratification method had a significant association with GC risk in univariate analysis. In multivariate analysis, OLGIM stage III/IV (odds ratio [OR] 2.8 [95% CI 1.5-5.3]), high EGGIM score (OR 1.8 [1.0-3.1]) and opened-type Kimura-Takemoto (OR 2.5 [1.4-4.5]) had significant associations with GC risk. In the Kyoto classification, opened-type endoscopic atrophy, invisible regular arrangement of collecting venules (RAC), extensive (>30%) intestinal metaplasia in the corpus in image-enhanced endoscopy, and map-like redness in the corpus were independent high-risk endoscopic findings. The modified Kyoto classification risk scoring system using these four findings demonstrated a better area under the receiver operating characteristic curve value (0.750, P = 0.052) than that of the original Kyoto classification (0.706).

CONCLUSIONS

The OLGIM stage III/IV, high EGGIM score and open-typed Kimura-Takemoto had strong association with GC risk in Japanese patients. The modified Kyoto classification risk scoring system may be useful for GC risk assessment, which warrants further validation. (UMIN000027023).

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.

The OLGA-OLGIM staging and the interobserver agreement for gastritis and preneoplastic lesion screening: a cross-sectional study

Stomach cancer (SC) incidence and mortality are relevant public health issues worldwide. In Colombia, screening for preneoplastic lesions (PNL) and the presence of H. pylori is not routinely performed. Therefore, the aim of this study was to evaluate OLGA-OLGIM staging and the interobserver agreement in gastritis and preneoplastic lesions in patients with gastroduodenal symptoms from Colombia. A cross-sectional study was conducted in 272 patients with gastroduodenal symptoms. Gastric biopsies were taken following the Updated Sydney System with the OLGA-OLGIM classification, and the results were evaluated by two pathologists. Chronic gastritis and PNL were reported in 76% and 24% of the patients, respectively. Furthermore, 25% of the patients with PNL displayed gastric atrophy (GA) and 75% intestinal metaplasia (IM). Agreement in the histopathological reading for IM was good, whereas for OLGA was variable, and for the H. pylori quantity was poor. OLGA-OLGIM stages 0-II were the most frequent (96%), while stage III (4%) and SC (4%) were the least frequent. Age and coffee consumption were associated with a higher prevalence of PNL. This work determined that 4% of the population is at high risk of developing SC and would benefit from follow-up studies. Reinforcement of training programs to improve the agreement in histopathology readings is required.

Current Evidence for a Paradigm Shift in Gastric Cancer Prevention From Endoscopic Screening to Helicobacter pylori Eradication in Korea

Gastric cancer is prevalent in Korea and ranked as the third most common cancer in 2019, followed by lung and thyroid cancers. The National Cancer Screening Program (NCSP) for gastric cancer has been implemented in adults aged ≥40 since 1999 and involves endoscopic screening every 2 years. The beneficial effects of the current NCSP on early cancer detection, cost-effectiveness, and mortality reduction are evident. However, the screening program results in a large socioeconomic burden and the consumption of medical resources, as it focuses solely on secondary prevention (early detection) rather than primary prevention of cancer. Helicobacter pylori is defined as a group I carcinogen by the International Agency for Research on Cancer. Hence, its eradication has been suggested as an important primary gastric cancer prevention strategy. Well-designed randomized controlled trials involving high-risk groups (post-endoscopic resection of early gastric cancer and family history of gastric cancer) and long-term follow-up studies in the general population have provided high-quality evidence regarding the effects of H. pylori eradication on gastric cancer prevention. In this review, we discussed the evidences for a possible modification of the current gastric cancer secondary prevention strategy by introducing primary prevention through H. pylori eradication. Areas for future research to optimize primary prevention strategies were also suggested.

Clinical Recommendations of Russian Gastroenterological Association and RENDO Endoscopic Society on Diagnosis and Treatment of Gastritis and Duodenitis

Aim.The clinical guidelines are intended to supplement specialty decision-making for improved aid quality in patients with gastritis and duodenitis though acknowledging the latest clinical evidence and principles of evidencebased medicine.Key points.Gastritis is an inflammatory disease of stomach mucosa, with a separate definition of acute and chronic gastritis. Chronic gastritis is a cohort of chronic diseases uniting a typical morphology of persistent inflammatory infiltration, impaired cellular renewal with emergent intestinal metaplasia, atrophy and epithelial dysplasia of gastric mucosa. Oesophagogastroduodenoscopy (OGDS) or high-resolution OGDS with magnified or non-magnified virtual chromoendoscopy, including targeted biopsy for atrophy and intestinal metaplasia grading and neoplasia detection, are recommended to verify gastritis and duodenitis, precancer states and/or gastric mucosal changes. All chronic gastritis patients positive for H. рylori should undergo eradication therapy as aetiological and subsidiary for gastric cancer prevention. Chronic gastritis patients with symptoms of dyspepsia (epigastric pain, burning and congestion, early satiety), also combined with functional dyspepsia, are recommended proton pump inhibitors, prokinetics, rebamipide and bismuth tripotassium dicitrate in symptomatic treatment. With focal restricted intestinal metaplasia, follow-up is not required in most cases, mainly when advanced atrophic gastritis is ruled out in high-quality endoscopy with biopsy. However, a familial history of gastric cancer, incomplete intestinal metaplasia and persistent H. pylori infection render endoscopy monitoring with chromoendoscopy and targeted biopsy desirable once in three years. Patients with advanced atrophic gastritis should have high-quality endoscopy every 3 years, and once in 1–2 years if complicated with a familial history of gastric cancer.Conclusion.The recommendations condense current knowledge on the aetiology and pathogenesis of gastritis and duodenitis, as well as laboratory and instrumental diagnostic techniques, main approaches to aetiological H. pylori eradication and treatment of dyspeptic states.

High-risk individuals for gastric cancer would be missed for surveillance without subtyping of intestinal metaplasia

The use of Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastritis Assessment based on Intestinal Metaplasia (OLGIM) staging system is recommended for identifying subjects at risk for developing gastric cancer; usually high-risk lesions are considered only as stages III and IV. Accumulating evidence suggests that incomplete intestinal metaplasia (IM) is important in the development of gastric cancer. Our aim has been to identify the prevalence of incomplete IM in patients with low-risk OLGA/OLGIM stages among a high-risk general population. Healthy adult volunteers aged 40-64 years were invited to undergo upper endoscopy within a regional GISTAR pilot study in Kazakhstan (n = 166). Gastric lesions were staged according to OLGA/OLGIM staging system. High iron diamine-alcian blue (HID-AB) was used for subtyping IM. IM prevalence overall was 45.8%. Incomplete IM was present in 52.6% (type II in 30.3% and type III in 22.3%), whereas complete IM was found in 47.4% individuals. The prevalence of OLGIM I and II stage were 39.8 and 4.8%, respectively, whereas OLGIM III was observed in 1.2%. The prevalence of incomplete IM in patients stratified to OLGIM I was 54.5% (type II in 31.8% and type III in 22.7%). High prevalence of incomplete IM was detected not only in subjects with extensive IM, but in those stratified as at the OLGIM I stage. Without IM subtyping, patients with high risk of gastric cancer development would be missed for surveillance.

HELICOBACTER PYLORI CHRONIC GASTRITIS ON PATIENTS WITH PREMALIGNANT CONDITIONS: OLGA AND OLGIM EVALUATION AND SERUM BIOMARKERS PERFORMANCE

BACKGROUND

H. pylori chronic atrophic gastritis is a premalignant lesion, and its staging, according to OLGA and OLGIM systems aims to identify patients at increased risk of developing gastric cancer and optimize their follow-up. GastroPanel®, serum biomarkers panel including pepsinogen I (PGI), pepsinogen II (PGII), Gastrin 17 (G17) and anti- H. pylori antibodies is a noninvasive test for adenocarcinoma risk assessment in chronic H. pylori gastritis patients.

OBJECTIVE

Prospective study to evaluate the concordance between OLGA and OLGIM grading systems, as well as to evaluate GastroPanel´s performance in patients with premalignant lesions secondary to H. pylori chronic gastritis in Brazil.

METHODS

Patients with H. pylori chronic gastritis with premalignant lesions confirmed by histology were recruited from the gastrointestinal clinic of a University Hospital. All participants underwent endoscopic examination with biopsies which were reported according to updated Sydney system and premalignant lesions grading systems (OLGA and OLGIM). Blood samples were collected for biomarkers serological analysis (GastroPanel®, Biohit, Helsinki, Finland). The cut off values used to define high risk patients were those recommended by the manufacturer: PGI ≤30 µm/L and PGI/PGII ≤3.

RESULTS

41 patients were recruited: 28 women, 13 men, mean age 67.3 (47-89, SD: 9.6) years. By OLGA system, were obtained: OLGA 0 (n=1), OLGA I (n=7), OLGA II (n=17), OLGA III (n=9), and OLGA IV (n=7). By OLGIM system, were obtained: OLGIM 0 (n=14), OLGIM I (n=5), OLGIM II (n=10), OLGIM III (n=10), and OLGIM IV (n=2). Regarding histological staging among patients staged as low risk (OLGA/OLGIM 0, I and II) and high risk (OLGA/OLGIM III and IV) for gastric cancer development, the concordance rate found between both classifications was 85.4%. Considering high risk patients, those patients thus included in at least one of the systems the final distribution of our sample considered 24 low-risk and 17 high-risk patients for the development of gastric cancer. To determine by GastroPanel® whether the patient would be at low or high risk of developing gastric cancer, PGI showed a sensitivity, specificity and accuracy of 0.47 (95%CI: 0.26-0.69), 0.67 (95%CI: 0.47-0.82), and 0.58 (95%CI: 0.43-0.72), respectively, while PGI/PGII showed sensitivity, specificity and accuracy of 0.06 (95%CI: 0.01-0.27), 0.83 (95%CI: 0.64-0.93) and 0.51 (95%CI: 0.36-0.66), respectively.

CONCLUSION

The histological classifications OLGA and OLGIM presented a substantial concordance rate among themselves. Simultaneous use of both histological classification systems increased the identification's rate of high-risk patients. Biomarker analysis was not effective to distinguish low to high risk patients in the studied population. Further studies are needed to validate its use in clinical practice in Brazil.

Endoscopic surveillance at 3 years after diagnosis, according to European guidelines, seems safe in patients with atrophic gastritis in a low-risk region

BACKGROUND

Autoimmune and multifocal atrophic gastritis (AG) are at risk for gastric neoplastic lesions. European guidelines recommend surveillance with high-quality endoscopy every 3 years.

AIM

To prospectively investigate the occurrence of gastric neoplastic lesions at the 3-year follow-up in patients with autoimmune and multifocal AG.

METHODS

Longitudinal cohort study conducted between 2011 and 2019: consecutive patients with histological diagnosis of autoimmune or multifocal AG underwent follow-up gastroscopy 3 years after diagnosis with high-resolution-narrow-band-imaging endoscopes.

RESULTS

Overall, 160 patients were included(F117(73.0%);median age 66(35-87)years). Autoimmune and multifocal AG were present in 122(76.3%) and 38(23.7%) patients, respectively. At the 3-year follow-up, 16(10.0%) patients presented 16 gastric neoplastic lesions: 3(18.7%) gastric cancers, 4(25.0%) low-grade dysplasia, 2(12.5%) low-grade dysplasia adenomas, 7(43.7%) type-1 neuroendocrine tumours. In these patients, OLGA and OLGIM III/IV stages were present in 4(25.0)% and 1(6.3%), respectively; 11(69.0%) presented autoimmune AG, and all but one(93.7%) had parietal cells antibodies positivity (p = 0.026 vs patients without lesions). All lesions were endoscopically(87.5%) or surgically(12.5%) treated with favourable outcome. Age>70 years was associated with a 9-fold higher probability of developing gastric epithelial neoplastic lesions (OR 9.6,95CI% 1.2-79.4,p = 0.0359).

CONCLUSIONS

The first endoscopic surveillance 3 years after diagnosis seems safe for autoimmune and multifocal AG patients and should be offered to elderly patients who are at higher risk for gastric neoplasia.

Predictive value of risk score using Kyoto classification of gastritis a few years prior to diagnosis of early gastric cancer

Background and Aim

Based on past diagnostic classifications of gastritis, the Kyoto classification of gastritis adopts simpler, more objective gastritis findings according to Helicobacter pylori infection status and evaluates the risk of gastric cancer. To clarify whether this score can predict future gastric cancer, we retrospectively examined risk scores obtained using the Kyoto classification of gastritis a few years prior to the diagnosis of early gastric cancer.

Methods

We reviewed data from 50 individuals who had undergone upper gastrointestinal endoscopy 2–3 years prior to the diagnosis of early gastric cancer in our hospital. Two expert endoscopists evaluated and compared risk scores obtained using the Kyoto classification of gastritis between cancer and control groups.

Results

With regard to the risk score obtained using the Kyoto classification of gastritis in all cases, atrophy, intestinal metaplasia, diffuse redness, and total score were significantly higher among gastric cancer cases. Among H. pylori‐eradicated cases, atrophy score was higher in the gastric cancer group. Among patients for whom H. pylori had been eradicated for >3 years at first endoscopy, atrophy score was still higher in the gastric cancer group.

Conclusion

This retrospective study suggested that the risk score obtained using the Kyoto classification of gastritis was useful for predicting the onset of gastric cancer. In particular, patients with a high atrophy score even after H. pylori eradication may be at high risk of developing gastric cancer.

Gastric intestinal metaplasia assessment between linked color imaging based on endoscopy and pathology

OBJECTIVE

Cumulative evidence suggests that linked color imaging (LCI) can be used to identify gastric intestinal metaplasia (GIM). We aimed to develop endoscopic grading for GIM (EGGIM) with LCI.

METHODS

Two hundred and seventy-seven patients who underwent high-resolution white-light gastroscopy followed by LCI for EGGIM estimation were included. LCI was performed for the entire mucosa, and images of five areas each were recorded from the lesser and greater curvatures of the antrum and corpus, and for the incisura. For each area, scores of 0 (no GIM), 1 (focal GIM, ≤30% of the area), and 2 (extensive GIM, >30% of the area) were attributed for 10 points. If GIM was suspected based on endoscopy findings, targeted biopsies were performed; if GIM was not evident, random biopsies were performed according to the Sydney system to estimate the operative link on GIM (OLGIM).

RESULTS

GIM was staged as OLGIM 0, I, II, III, and IV in 136, 70, 37, 28, and 6 patients, respectively. For OLGIM III/IV diagnosis, the area under the receiver operating curve was 0.949 (95% CI 0.916-0.972). EGGIM of 4, with sensitivity and specificity of 94.12% (95% CI 80.3%-99.3%) and 86.42% (95% CI 81.5%-90.5%), respectively, was determined the best cut-off value for identifying OLGIM III/IV patients.

CONCLUSIONS

Our findings demonstrated the ability of EGGIM for diagnosing the extent of intestinal metaplasia and showed that EGGIM is related to OLGIM staging. EGGIM of 4 was the best cut-off value for identifying OLGIM III/IV patients.

Gastric cancer screening in low incidence populations: Position statement of AEG, SEED and SEAP

This positioning document, sponsored by the Asociación Española de Gastroenterología, the Sociedad Española de Endoscopia Digestiva and the Sociedad Española de Anatomía Patológica, aims to establish recommendations for the screening of gastric cancer (GC) in low incidence populations, such as the Spanish. To establish the quality of the evidence and the levels of recommendation, we used the methodology based on the GRADE system (Grading of Recommendations Assessment, Development and Evaluation). We obtained a consensus among experts using a Delphi method. The document evaluates screening in the general population, individuals with relatives with GC and subjects with GC precursor lesions (GCPL). The goal of the interventions should be to reduce GC related mortality. We recommend the use of the OLGIM classification and determine the intestinal metaplasia (IM) subtype in the evaluation of GCPL. We do not recommend to establish endoscopic mass screening for GC or Helicobacter pylori. However, the document strongly recommends to treat H.pylori if the infection is detected, and the investigation and treatment in individuals with a family history of GC or with GCPL. Instead, we recommend against the use of serological tests to detect GCPL. Endoscopic screening is suggested only in individuals that meet familial GC criteria. As for individuals with GCPL, endoscopic surveillance is only suggested in extensive IM associated with additional risk factors (incomplete IM and/or a family history of GC), after resection of dysplastic lesions or in patients with dysplasia without visible lesion after a high quality gastroscopy with chromoendoscopy.

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

OBJECTIVES

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

DESIGN

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

RESULTS

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

CONCLUSION

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

Comparison of operative link for gastritis assessment, operative link on gastric intestinal metaplasia assessment, and TAIM stagings among men with atrophic gastritis

BACKGROUND

Gastric cancer is the world’s third most lethal malignancy. Most gastric cancers develop through precancerous states of atrophic gastritis and intestinal metaplasia. Two staging systems, operative link for gastritis assessment (OLGA) and operative link on gastric intestinal metaplasia assessment (OLGIM), have been developed to detect high gastric cancer risk. European guidelines recommend surveillance for high-risk OLGA/OLGIM patients (stages III–IV), and for those with advanced stage of atrophic gastritis in the whole stomach mucosa. We hypothesize, that by combining atrophy and intestinal metaplasia into one staging named TAIM, more patients with increased gastric cancer risk could be detected.

AIM

To evaluate the clinical value of the OLGA, OLGIM, and novel TAIM stagings as prognostic indicators for gastric cancer.

METHODS

In the Helsinki Gastritis Study, 22346 elderly male smokers from southwestern Finland were screened for serum pepsinogen I (PGI). Between the years 1989 and 1993, men with low PGI values (PGI < 25 μg/L), were invited to undergo an oesophagogastroduodenoscopy. In this retrospective cohort study, 1147 men that underwent gastroscopy were followed for gastric cancer for a median of 13.7 years, and a maximum of 27.3 years. We developed a new staging system, TAIM, by combining the topography with the severity of atrophy or intestinal metaplasia in gastric biopsies. In TAIM staging, the gastric cancer risk is classified as low or high.

RESULTS

Twenty-eight gastric cancers were diagnosed during the follow-up, and the incidence rate was 1.72 per 1000 patient-years. The cancer risk associated positively with TAIM [Hazard ratio (HR) 2.70, 95%CI: 1.09–6.69, P = 0.03]. The risk increased through OLGIM stages 0-IV (0 vs IV: HR 5.72, 95%CI: 1.03–31.77, P for trend = 0.004), but not through OLGA stages 0–IV (0 vs IV: HR 5.77, 95%CI: 0.67–49.77, P for trend = 0.10). The sensitivities of OLGA and OLGIM stages III–IV were low, 21% and 32%, respectively, whereas that of TAIM high-risk was good, 79%. On the contrary, OLGA and OLGIM had high specificity, 85% and 81%, respectively, but TAIM showed low specificity, 42%. In all three staging systems, the high-risk men had three- to four-times higher gastric cancer risk compared to the general male population of the same age.

CONCLUSION

OLGIM and TAIM stagings show prognostic value in assessing gastric cancer risk in elderly male smokers with atrophic gastritis.

Current Perspectives in Atrophic Gastritis

PURPOSE OF THE REVIEW

Atrophic gastritis is a complex syndrome with gastric atrophy as a common trait. Helicobacter pylori infection and autoimmunity are the two main contexts in which it develops. It is slightly symptomatic, affects various aspects of general health, and remains a predisposing factor for gastric cancer. This review will update current knowledge and progress on atrophic gastritis.

RECENT FINDINGS

Atrophic gastritis affects mostly adults with persistent dyspepsia, deficient anemia, autoimmunity disease, long-term proton pump inhibitor use, and a family history of gastric cancer. Gastric biopsies, expressed as Sydney system grade and OLGA/OLGIM classifications, represent the gold standard for diagnosis and cancer risk stage, respectively. Recently, electronic chromoendoscopy has allowed "targeted biopsies" of intestinal metaplasia. The associated hypochlorhydria affects the gastric microbiota composition suggesting that non-Helicobacter pylori microbiota may participate in the development of gastric cancer. Physicians should be aware of multifaceted clinical presentation of atrophic gastritis. It should be endoscopically monitored by targeted gastric biopsies. Autoimmune and Helicobacter pylori-induced atrophic gastritis are associated with different gastric microbial profiles playing different roles in gastric tumorigenesis.

Significance of Helicobacter pylori Eradication on Atrophic Gastritis and Intestinal Metaplasia

There has been an accumulation of data regarding the chemopreventive effects of <i>Helicobacter pylori</i> (<i>H. pylori</i>) eradication. However, it remains unclear how <i>H. pylori</i> infection causes gastric cancer (GC) and how <i>H. pylori</i> eradication can prevent GC. Atrophic gastritis (AG) and intestinal metaplasia (IM) are known as precancerous lesions which mainly lead to intestinal-type GC but to some extent, can also lead to diffuse-type GC. The most important mechanism of AG/IM is <i>H. pylori</i>-induced chronic gastritis. Thus, the reversibility of AG and IM by <i>H. pylori</i> eradication therapy is very important in the prevention of GC. There have been many studies providing data supporting the improvement of AG by the eradication of <i>H. pylori</i> to some extent. In contrast, IM has been regarded as “the point of no return.” However, more recent studies have implied the improvement of IM after eradication, suggesting the importance of early eradication therapy in reversible histological status. In this review, we focused on the reversibility of AG and IM by <i>H. pylori</i> eradication and tried to investigate the predicting factors for the improvement of AG and IM including age, sex, smoking, and diet, as well as <i>H. pylori</i> infection.

Pepsinogen Serology and Gastritis OLGA Staging in Mucosal Atrophy Assessment: A Cross-Sectional Study Involving East China Endoscopy Population

The histological gastric stage (OLGA) plays an important role in evaluating gastric atrophy, a symptom which suggests a risk of gastric cancer (GC). However, gastroscopy is an invasive examination, which has limited application in populations undergoing physical examination. Serum pepsinogen (PG) and gastin-17 (G-17) levels are noninvasive indexes which are recommended when screening for GC. We aim to explore the correlation between PG/G-17 and OLGA stage, in order to provide reliable indexes for GC screening. The study included 453 asymptomatic individuals from East China undergoing physical examination, who then underwent endoscopy including collection of biopsy samples. Assays for serum PG, G-17, and Helicobacter pylori (Hp) were performed. Atrophy of gastric mucosa was graded according to OLGA for each individual. 453 participants, average age 52.46 ± 10.30 years, 253 male and 200 female, were included. In the asymptomatic physical examination population, serum PGI, PGII, and PGR levels decreased with increasing OLGA scores. PGI and PGR were inversely correlated with increasing OLGA stage in both Hp-positive and Hp-negative groups. The levels of serum PGI, PGII, and G-17 in the Hp-positive group were higher than those in the Hp-negative group; conversely, the PGR levels were lower. Furthermore, OLGA scores increased with age in the Hp-positive group. In conclusion, there is a significant correlation between OLGA stage and serum PG in populations from East China undergoing physical examination. Serum PG and G-17 combined with Hp test plays an important role in evaluating gastric atrophy.

A current clinical overview of atrophic gastritis

Introduction: Atrophic gastritis (AG) is a complex syndrome which arises as a consequence of H. pylori infection or in the context of gastric autoimmunity. It often deserves a benign course but may lead to potentially life-threatening complications: cancer and anemia. This review aims to address traditional and innovative knowledge on this often under-diagnosed disorder.Areas covered: This review covers clinical presentation, risk factors, diagnosis, and management of AG and provides an updated resource for clinicians to get insight into this challenging disorder. Updated literature was searched in PubMed. Manual search from reference lists of publications was performed.Expert opinion: A case-finding strategy may be beneficial in individuals with anemia, dyspepsia, autoimmune thyropaties and type 1 diabetes, and family history of gastric cancer. AG is linked to gastric cancer risk and endoscopic surveillance is indicated according to topography of gastric atrophy and risk factors. The direction for future research in AG is summarized.

Effects of eradicating Helicobacter pylori on metachronous gastric cancer prevention: A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (H pylori) infection is closely associated with the incidence of gastric cancer. However, whether H pylori eradication prevents metachronous gastric cancer remains uncertain. The aim of our study is to assess how eradicating H pylori influences metachronous gastric cancer onset following treatment of early stage gastric cancer via endoscopic resective surgery.

PATIENTS AND METHODS

We performed a systematic review and meta-analysis by searching PubMed, Embase, Web of Science, and the Cochrane Library. Cohort studies and randomized controlled trials that compared individuals receiving H pylori eradication with individuals receiving placebo/nontreatment and evaluated the subsequent onset of metachronous gastric cancer as the main outcome were eligible for our study. Two authors reviewed articles and extracted data independently. Integrated results for all data were presented as risk ratio.

RESULTS

Thirteen studies containing 3863 patients were consistent with study inclusion criteria. Of the 2480 individuals in whom H pylori was successfully eradicated, 163 (6.57%) developed metachronous gastric cancer, as compared with 176 (12.73%) out of 1383 persistently infected individuals. The pooled risk ratio of metachronous gastric cancer for these studies was 0.46 (95% CI, 0.37-0.57, P < .001), providing support for the therapeutic elimination of H pylori. Subgroup analyses yielded similar results.

CONCLUSION

Eradicating H pylori via therapeutic treatment can effectively reduce rates of metachronous gastric cancer, and as such, it should be implemented in H pylori-infected individuals recently treated for early stage gastric cancers via endoscopic resection.

LINC00319 acts as a microRNA-335-5p sponge to accelerate tumor growth and metastasis in gastric cancer by upregulating ADCY3

Gastric cancer (GC) is one of the most common cancers in the world and remains a heavy burden of health worldwide. Adenylate cyclase 3 (ADCY3) is a widely expressed membrane-associated protein in human tissues and has been identified to be a new molecular target of GC. Long noncoding RNAs have a substantial influence on tumorigenesis and progression of tumors by binding to microRNAs. Therefore, this study is to clarify the mechanism by which LINC00319 sponges micro RNA-335-5p (miR-335-5p) to influence the development of GC. Initially, microarray analysis identified GC-related differentially expressed LINC00319 and ADCY3 for this study. The interaction was confirmed that LINC00319 interacted with miR-335-5p to regulate ADCY3. Next, SGC-7901 cells presenting with the lowest LINC00319 expression and the highest miR-335-5p expression were transfected with LINC00319, miR-335-5p inhibitor, or ADCY3 vector to examine their roles in growth and metastasis of GC cells, which was further ascertained by in vivo experiments. LINC00319 was upregulated and miR-335-5p was downregulated in GC cells. LINC00319 overexpression, miR-335-5p inhibitor, or ADCY3 overexpression was shown to significantly elevate the expression of cyclin-dependent kinase 4 and metastasis associated 1, decrease that of growth arrest-specific 1, and promote tumor growth and metastasis by increasing proliferation and migration and reducing cell apoptosis. Importantly, it was found that overexpressed miR-335-5p exerted its tumor suppressive role in GC through downregulating ADCY3. Collectively, LINC00319 expedited growth and metastasis of GC by upregulating miR-335-5p-mediated ADCY3.NEW & NOTEWORTHY This study is carried out based on in vivo and in vitro studies in mice and gastric cancer (GC) cells with the aim of clarifying the role of LINC00319 on GC growth and metastasis, which associated with micro RNA-335-5p-mediated adenylate cyclase 3. Altogether, we identified LINC00319 to be a potential therapy to treat GC.

Chronic atrophic gastritis: Natural history, diagnosis and therapeutic management. A position paper by the Italian Society of Hospital Gastroenterologists and Digestive Endoscopists [AIGO], the Italian Society of Digestive Endoscopy [SIED], the Italian Society of Gastroenterology [SIGE], and the Italian Society of Internal Medicine [SIMI]

Chronic atrophic gastritis (CAG) is an underdiagnosed condition characterised by translational features going beyond the strict field of gastroenterology as it may manifest itself by a variable spectrum of gastric and extra-gastric symptoms and signs. It is relatively common among older adults in different parts of the world, but large variations exist. Helicobacter pylori-related CAG [multifocal] and autoimmune CAG (corpus-restricted) are apparently two different diseases, but they display overlapping features. Patients with cobalamin and/or iron deficiency anaemia or autoimmune disorders, including autoimmune thyroiditis and type 1 diabetes mellitus, should be offered screening for CAG. Pepsinogens, gastrin-17, and anti-H. pylori antibodies serum assays seem to be reliable non-invasive screening tools for the presence of CAG, helpful to identify individuals to refer to gastroscopy with five standard gastric biopsies in order to obtain histological confirmation of diagnosis. Patients with CAG are at increased risk of developing gastric cancer, and they should be estimated with histological staging systems (OLGA or OLGIM). H. pylori eradication may be beneficial by modifying the natural history of atrophy, but not that of intestinal metaplasia. Patients with advanced stages of CAG (Stage III/IV OLGA or OLGIM) should undergo endoscopic surveillance every three years, those with autoimmune CAG every three-five years. In patients with CAG, a screening for autoimmune thyroid disease and micronutrient deficiencies, including iron and vitamin B₁₂, should be performed. The optimal treatment for dyspeptic symptoms in patients with CAG remains to be defined. Proton pump inhibitors are not indicated in hypochlorhydric CAG patients.

Natural history of autoimmune atrophic gastritis: a prospective, single centre, long-term experience

BACKGROUND

Autoimmune atrophic gastritis (AAG) is an immune-mediated disorder characterised by destruction of gastric oxyntic mucosa AIM: To explore gastric histopathological evolution in a cohort of AAG patients over a prolonged follow-up METHODS: Single centre prospective study enrolling consecutive patients with histologically confirmed AAG between 2000 and 2018. All AAG patients undergoing endoscopic follow-up every 1-3 years were classified as having stages 1, 2 or 3 according to atrophy severity (mild, moderate and severe). AAG patients with either glandular or neuroendocrine dysplasia/neoplasia were classified as having stage 4. Disease stage progression, and changes in serum anti-parietal cell antibody (PCA), chromogranin A and gastrin-17 were assessed.

RESULTS

In total, 282 AAG patients (mean age 60.3 years; F:M ratio 2.4:1; median follow-up 3 years, interquartile range 1-7) were enrolled. All patients with stages 1 or 2 progressed to stage 2 or 3 over time with a steady trend (P = .243) and regression from a severe to a milder stage was never noticed. Disease progression of patients with stages 1 or 2 occurred within the first 3 years. PCA positivity rate did not change over time. Stage 3 patients had higher gastrin-17 levels compared to patients with stages 1 and 2 (median 606 vs 295 pg/mL; P < .001). In stage 3, the hazard ratio for the risk of developing stage 4 was 6.6 (95% CI 1.5-29; P = .001).

CONCLUSIONS

AAG is a steadily progressive disease, in which stages 1 and 2 always progress to stage 3. The risk of developing a complicated disease stage is greater in patients with more severe gastric lesions.

The clinical meaning of the "indefinite for atrophy" lesions within gastric mucosa biopsy specimens in a region with a high prevalence of gastric cancer

BACKGROUND

The diagnosis of gastric atrophy is important in the regions where the prevalence of Helicobacter pylori (H. pylori) is high. The assessment of gastric atrophy is impossible in subjects with severe gastric inflammation or inadequate biopsy samples, leading these cases to be categorized as indefinite for atrophy. The aim of this study was to evaluate clinical characteristics of cases reported as indefinite for atrophy.

MATERIALS AND METHODS

We reviewed 3192 gastric biopsies obtained at a single medical center between 2003 and 2017. Cases categorized as indefinite atrophy (n = 1,292) were compared with three groups, the absent atrophy group (n = 755), Operative Link on Gastric Atrophy (OLGA) I-II group (n = 925), and OLGA III-IV group (n = 220), by considering age, sex, smoking, alcohol drinking, salty and spicy food diet, ABO blood type, family history of gastric cancer (GC), and H. pylori infection that are known atrophic gastritis-associated risk factors.

RESULTS

Subjects aged ≥65 years (34.9% vs 26.4%, P < 0.001), male (58.9% vs 49.1%, P < 0.001), and H. pylori infected subjects (82.5% vs 63.3%, P < 0.001) were significantly more likely to be categorized into the indefinite atrophy group than absent atrophy group. Subjects with family history of GC (21.9% vs 25.7%, P = 0.031) and positive H. pylori infection (82.5% vs 86.2%, P = 0.019) were significantly less likely to be in the indefinite atrophy group than low-risk OLGA group. Subjects aged ≥65 years (34.9% vs 52.3%, P < 0.001) and current/past smoker (50.9% vs 70.0%, P < 0.001) were significantly more likely to be in the high-risk OLGA group than indefinite atrophy group.

CONCLUSIONS

The pathological report of indefinite for atrophy suggests a higher plausibility of gastric atrophy than nonassessment due to a simple technical error.

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

NTR7661; Pre-results.

CDX1 Expression Induced by CagA-Expressing Helicobacter pylori Promotes Gastric Tumorigenesis

Intestinal-type gastric cancer often results from Helicobacter pylori infection through intestinal metaplasia, a transdifferentiated premalignant phenotype. Because H. pylori virulence factor CagA has been associated with aberrant expression of the transcription factor CDX1, which regulates intestinal differentiation, we explored its relationship with H. pylori infection and function during gastric carcinogenesis in normal gastric epithelial cells and gastric cancer cell lines. Infection of HFE 145 cells with CagA⁺ H. pylori increased expression of CDX1, as well as the epithelial-to-mesenchymal transition (EMT) markers Snail and Slug, increased invasion and migration, but those effects were not found in HFE 145 cells infected with CagA-deficient H. pylori. CDX1 overexpression increased expression of the intestinal markers Villin, sucrose isomaltase (SI), and MUC2, induced spheroid formation, and enhanced expression of the stem cell markers CD44, SOX2, Oct4, and Nanog, while CDX1 knockdown inhibited proliferation and intestinal stemness. Treatment of CDX1-expressing cells with metformin, an antidiabetic drug known to decrease the risk of gastric cancer, decreased expression of EMT and stemness markers, and reduced spheroid formation. In a murine xenograft model, combining metformin or shCDX1 with cisplatin reduced tumor growth, increased caspase-3 cleavage, and reduced expression of CD44 and MMP-9 to a greater degree than cisplatin alone. Patients with more advanced intestinal metaplasia staging exhibited higher CDX1 expression than those with earlier intestinal metaplasia staging (P = 0.039), and those with H. pylori tended to have more CDX1 expression than noninfected patients (P = 0.061). Finally, human tissue samples with higher CDX1 levels showed prominent CD44/SOX2 expression. Our findings indicate CagA⁺ H. pylori-induced CDX1 expression may enhance gastric cancer tumorigenesis and progression, and support therapeutic targeting of CDX1 in gastric cancer. IMPLICATIONS: This study shows that CDX1 contributes to the tumorigenesis and progression of gastric cancer and suggests the potential of targeting CDX1 to treat this malignancy.

KMT2C Mutations in Diffuse-Type Gastric Adenocarcinoma Promote Epithelial-to-Mesenchymal Transition

PURPOSE

Lauren diffuse-type gastric adenocarcinomas (DGAs) are generally genomically stable. We identified lysine (K)-specific methyltransferase 2C (KMT2C) as a frequently mutated gene and examined its role in DGA progression.

EXPERIMENTAL DESIGN

We performed whole exome sequencing on tumor samples of 27 patients with DGA who underwent gastrectomy. Lysine (K)-specific methyltransferase 2C (KMT2C) was analyzed in DGA cell lines and in patient tumors.

RESULTS

KMT2C was the most frequently mutated gene (11 of 27 tumors [41%]). KMT2C expression by immunohistochemistry in tumors from 135 patients with DGA undergoing gastrectomy inversely correlated with more advanced tumor stage (P = 0.023) and worse overall survival (P = 0.017). KMT2C shRNA knockdown in non-transformed HFE-145 gastric epithelial cells promoted epithelial-to-mesenchymal transition (EMT) as demonstrated by increased expression of EMT-related proteins N-cadherin and Slug. Migration and invasion in gastric epithelial cells following KMT2C knockdown increased by 47- to 88-fold. In the DGA cell lines MKN-45 and SNU-668, which have lost KMT2C expression, KMT2C re-expression decreased expression of EMT-related proteins, reduced cell migration by 52% to 60%, and reduced cell invasion by 50% to 74%. Flank xenografts derived from KMT2C-expressing DGA organoids, compared with wild-type organoids, grew more slowly and lost their infiltrative leading edge. EMT can lead to the acquisition of cancer stem cell (CSC) phenotypes. KMT2C re-expression in DGA cell lines reduced spheroid formation by 77% to 78% and reversed CSC resistance to chemotherapy via promotion of DNA damage and apoptosis.

CONCLUSIONS

KMT2C is frequently mutated in certain populations with DGA. KMT2C loss in DGA promotes EMT and is associated with worse overall survival.