Precancerous lesions in the stomach: from biology to clinical patient management

Helicobacter pylori cagA, vacA, iceA and babA Genotypes from Peruvian Patients with Gastric Intestinal Metaplasia

We explored the clinical-stage association of gastric intestinal metaplasia (IM) compared to cases of chronic non-atrophic gastritis (CNAG) and its relationship with virulence genotypes of Helicobacter pylori (H. pylori) clinical isolates from patients with dyspepsia in Peru. This study was cross-sectional and included 158 H. pylori clinical isolates; each isolate corresponded to a different Peruvian patient, genotyped by polymerase chain reaction to detect cagA gene and EPIYA motifs, the vacA gene (alleles s1, s2, i1, i2, d1, d2, m1, m2 and subtypes s1a, s1b and s1c), the iceA gene (alleles 1 and 2), and the babA gene (allele 2). We observed that 38.6% presented with IM and that all clinical isolates were CagA positive. The EPIYA-ABC motif was predominant (68.4%), and we observed a high frequency for the vacA gene alleles s1 (94.9%), m1 (81.7%), i1 (63.9%), and d1 (70.9%). Strains with both iceA alleles were also detected (69.6%) and 52.2% were babA2 positive. In addition, it was observed that the cagA+/vacAs1m1 (PR: 2.42, 1.14 to 5.13, p < 0.05) and cagA+/vacAs1am1 (PR: 1.67, 1.13 to 2.45, p < 0.01) genotypes were associated with IM. Our findings revealed the cagA and vacA risk genotypes predominance, and we provided clinically relevant associations between Peruvian patients with H. pylori infection and IM clinical stage.

A comprehensive analysis of the expression, immune infiltration, prognosis and partial experimental validation of CHST family genes in gastric cancer

Previous studies have demonstrated that carbohydrate sulfotransferase family proteins (CHSTs) play a crucial role in the extracellular matrix structural constituent and cancer progression, however, the effect of CHSTs on gastric cancer is still superficial. To investigate these, our study seeks to provide a comprehensive understanding of CHSTs' expression, immune infiltration, and prognostic implications in gastric cancer, utilizing data from the TCGA, GEO and GTEx databases. Furthermore, we conducted experimental validation to elucidate the role of CHST14 specifically in gastric cancer. Our findings suggest that most CHSTs were highly expressed in gastric cancer. Gene copy number variations further indicated prevalent CHSTs amplification in gastric cancer, pointing to its potential relevance in disease progression. Intriguingly, we noted strong positive correlations between most CHSTs and immune cell infiltration. Importantly, most members of CHSTs were related to OS and PFI with gastric cancer, with particular emphasis on CHST14 and CHST9. Multifactorial regression analysis indicates that CHST14 is an independent prognostic factor influencing the overall survival of gastric cancer patients. In further experimental validation, our results demonstrate elevated expression of CHST14 in gastric cancer, and knocking down CHST14 inhibits gastric cancer cell proliferation, invasion, migration and EMT. Additionally, CHST14 may exert its function through the regulation of the Wnt pathway. In summary, our study comprehensively analyzes the hitherto undescribed role of CHSTs in gastric cancer through the analysis of multi-omics data. Importantly, we identify CHST14 as a pivotal promoter in the malignant progression of gastric cancer, offering potential targets for gastric cancer therapy.

Prevalence and temporal trend of gastric preneoplastic lesions in Asia: A systematic review with meta-analysis

BACKGROUND

Gastric cancer is the fifth most common cancer globally, with about 75% of cases occurring in Asia. While chronic atrophic gastritis (CAG) and intestinal metaplasia (IM) are well-recognized preneoplastic gastric lesions, we determined the prevalence and temporal trend of CAG and IM in Asia over the past 50 years.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, MEDLINE, Scopus, and Web of Science for studies reporting the prevalence of CAG and IM in Asia (according to the United Nations geoscheme) published between 1970 and 2022. Heterogeneity was assessed by the I2 index and Cochran Q test. We adopted the random effects model to estimate the pooled prevalence and 95% confidence interval (CI). The slope of prevalence was estimated as a function of time in simple linear regression and weighted meta-regression models to demonstrate the temporal trend. Studies that reported the odds ratio (OR) of Helicobacter pylori infection and CAG/IM were analyzed separately to compile a pooled OR with a 95% CI. This study was registered in INPLASY2022120028.

RESULTS

Of the 81 studies from 19 Asian countries identified, the pooled prevalence for CAG and IM in Asia was 26.1% (95%CI: 22.7-30.0) and 22.9% (95%CI: 19.7-26.6), respectively. Over the past 5 decades, there was a significant decline in the prevalence of IM (slope in adjusted meta-regression models: -0.79 [95%CI: -1.28 to -0.26], P = 0.003), but there was no significant change in the pooled prevalence of CAG. Within Asia, the prevalence varied significantly among different regions. Southern Asia reported the highest pooled prevalence of CAG (42.9%, 95%CI: 27.5%-67.1%), while Western Asia reported the lowest level (12.7%, 95%CI: 5.0%-32.3%). For IM, Eastern Asia reported the highest prevalence (27.1%, 95%CI: 21.1-34.9), with the lowest prevalence reported in Western Asia (3.1%; 95% CI 1.2%-8.0%). H. pylori infection was linked to CAG and IM with OR of 2.16 (95%CI: 2.09-2.22) and 1.64 (95%CI: 1.57-1.72), respectively.

CONCLUSION

This updated meta-analysis showed that up to 26% of study individuals in Asia harbored preneoplastic gastric lesions. There was a declining temporal trend in the prevalence of IM, but not for CAG, in Asia.

Current status of quality control in screening esophagogastroduodenoscopy and the emerging role of artificial intelligence

Esophagogastroduodenoscopy (EGD) screening is being implemented in countries with a high incidence of upper gastrointestinal (UGI) cancer. High-quality EGD screening ensures the yield of early diagnosis and prevents suffering from advanced UGI cancer and minimal operational-related discomfort. However, performance varied dramatically among endoscopists, and quality control for EGD screening remains suboptimal. Guidelines have recommended potential measures for endoscopy quality improvement and research has been conducted for evidence. Moreover, artificial intelligence offers a promising solution for computer-aided diagnosis and quality control during EGD examinations. In this review, we summarized the key points for quality assurance in EGD screening based on current guidelines and evidence. We also outline the latest evidence, limitations, and future prospects of the emerging role of artificial intelligence in EGD quality control, aiming to provide a foundation for improving the quality of EGD screening.

Role of pre-existing incomplete intestinal metaplasia in gastric adenocarcinoma: A retrospective case series analysis

BACKGROUND

Risk stratification for patients with gastric precancerous lesions for endoscopic surveillance remains controversial.

AIM

To analysis of patients having developed gastric adenocarcinoma during the period of follow-up.

METHODS

We conducted a retrospective study on patients having undergone upper endoscopy prior to the development of gastric adenocarcinoma. The presence and stage of precancerous lesions as well as subtype of intestinal metaplasia at the baseline endoscopy got evaluated. Literature mini-review was performed.

RESULTS

Out of 1681 subjects in the Biobank, gastric adenocarcinoma was detected in five cases in whom previous endoscopy data with biopsies either from the corpus or antral part were available. All of the patients had incomplete intestinal metaplasia during the baseline endoscopy; all three subjects in whom intestinal metaplasia subtyping was performed according to Filipe et al, had Type III intestinal metaplasia. Two of the five cases had low Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastritis Intestinal Metaplasia Assessment (OLGIM) stages (I-II) at the baseline.

CONCLUSION

The presence of incomplete intestinal metaplasia, in particular, that of Type III is a better predictor for gastric adenocarcinoma development than OLGA/OLGIM staging system. Subtyping of intestinal metaplasia have an important role in the risk stratification for surveillance decisions.

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.

Gastric bacteria as potential biomarkers for the diagnosis of atrophic gastritis

BACKGROUND

Identification of the risk factors for atrophic gastritis (AG) and prevention of further deterioration of the gastritis are effective approaches to reduce the incidence of gastric cancer. Previous studies found that dysbiosis has been implicated in a wide range of diseases, while the role of gastric bacteria as a biomarker for AG has not been explored.

METHODS AND RESULTS

Gastric juices from cases with non-atrophic gastritis (NAG) and AG were collected for investigation of bacterial composition and function. The β-diversity of microbiota exhibited a significant reduction in AG samples compared with that in NAG samples. Differential abundance analysis revealed that a total of 23 predicted species changed their distributions; meanwhile, all obligate anaerobic bacteria with a relatively high abundance lowered their contents in AG samples. Additionally, the correlation analysis indicated a clear shift in bacterial correlation pattern between the two groups. Functional interrogation of the gastric microbiota showed that bacterial metabolisms associated with enzyme families, digestive system, and endocrine system were downregulated in AG samples. The compositional dissection of "core microbiota" exhibited that oral pathogens, including Porphyromonas gingivalis, Campylobacter gracilis, and Granulicatella elegans, were magnified in AG samples, suggesting that oral diseases may be a trigger factor for early exacerbation of gastritis. Then, the differentially expressed bacteria were used as diagnostic biomarkers for the random forest classifier model for group prediction.

CONCLUSIONS

The results showed that bacterial biomarkers could distinguish AG patients from NAG cases with an accuracy of 90% at the genus level.

Schlafen family is a prognostic biomarker and corresponds with immune infiltration in gastric cancer

The Schlafen (SLFN) gene family plays an important role in immune cell differentiation and immune regulation. Previous studies have found that the increased SLFN5 expression in patients with intestinal metaplasia correlates with gastric cancer (GC) progression. However, no investigation has been conducted on the SLFN family in GC. Therefore, we systematically explore the expression and prognostic value of SLFN family members in patients with GC, elucidating their possible biological function and its correlation with tumor immune cells infiltration. TCGA database results indicated that the SLFN5, SLFN11, SLFN12, SLFN12L, and SLFN13 expression was significantly higher in GC. The UALCAN and KM plotter databases indicated that enhanced the SLFN family expression was associated with lymph node metastasis, tumor stage, and tumor grade and predicted an adverse prognosis. cBioportal database revealed that the SLFN family had a high frequency of genetic alterations in GC (about 12%), including mutations and amplification. The GeneMANIA and STRING databases identified 20 interacting genes and 16 interacting proteins that act as potential targets of the SLFN family. SLFN5, SLFN11, SLFN12, SLFN12L, and SLFN14 may be implicated in the immunological response, according to Gene Set Enrichment Analysis (GSEA) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Additionally, Timer and TISIDB databases indicate that SLFN5, SLFN11, SLFN12, SLFN12L, and SLFN14 are involved in the immune response. Furthermore, Timer, TCGA, and TISIDB databases suggested that the SLFN5, SLFN11, SLFN12, SLFN12L, and SLFN14 expression in GC is highly linked with immune cell infiltration levels, immune checkpoint, and the many immune cell marker sets expression. We isolated three samples of peripheral blood mononuclear cell (PBMC) and activated T cells; the results showed the expression of SLFN family members decreased significantly when T cell active. In conclusion, the SLFN family of proteins may act as a prognostic indicator of GC and is associated with immune cell infiltration and immune checkpoint expression in GC. Additionally, it may be involved in tumor immune evasion by regulating T cell activation.

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

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

Factors Associated with False Negative Results in Serum Pepsinogen Testing for Precancerous Gastric Lesions in a European Population in the GISTAR Study

The accuracy of plasma pepsinogen (Pg) as a marker for precancerous gastric lesions (PGL) has shown variable results. We aimed to identify factors associated with false negative (FN) cases in Pg testing and to adjust cut-off values for these factors in order to improve Pg yield. Plasma Pg was measured and upper endoscopy with biopsy was performed within the "Multicentric randomized study of Helicobacter pylori eradication and pepsinogen testing for prevention of gastric cancer mortality: the GISTAR study". A multivariable logistic model was built for FN and multiple factors. Values of Pg were compared and sensitivity and specificity were calculated using pre-existing Pg cut-offs for factors showing strong associations with FN. New cut-offs were calculated for factors that showed substantially lower sensitivity. Of 1210 participants, 364 (30.1%) had histologically confirmed PGL, of which 160 (44.0%) were FN. Current smokers, men, and H. pylori positives were more likely FN. Smoking in H. pylori negatives was associated with a higher Pg I/II ratio and substantially lower sensitivity of Pg testing than in other groups. Adjusting Pg cut-offs for current smokers by H. pylori presence improved sensitivity for detecting PGL in this group. Our study suggests that adjusting Pg cut-offs for current smokers by H. pylori status could improve Pg test performance.

Multi-label recognition of cancer-related lesions with clinical priors on white-light endoscopy

Deep learning-based computer-aided diagnosis techniques have demonstrated encouraging performance in endoscopic lesion identification and detection, and have reduced the rate of missed and false detections of disease during endoscopy. However, the interpretability of the model-based results has not been adequately addressed by existing methods. This phenomenon is directly manifested by a significant bias in the representation of feature localization. Good recognition models experience severe feature localization errors, particularly for lesions with subtle morphological features, and such unsatisfactory performance hinders the clinical deployment of models. To effectively alleviate this problem, we proposed a solution to optimize the localization bias in feature representations of cancer-related recognition models that is difficult to accurately label and identify in clinical practice. Optimization was performed in the training phase of the model through the proposed data augmentation method and auxiliary loss function based on clinical priors. The data augmentation method, called partial jigsaw, can "break" the spatial structure of lesion-independent image blocks and enrich the data feature space to decouple the interference of background features on the space and focus on fine-grained lesion features. The annotation-based auxiliary loss function used class activation maps for sample distribution correction and led the model to present localization representation converging on the gold standard annotation of visualization maps. The results show that with the improvement of our method, the precision of model recognition reached an average of 92.79%, an F1-score of 92.61%, and accuracy of 95.56% based on a dataset constructed from 23 hospitals. In addition, we quantified the evaluation representation of visualization feature maps. The improved model yielded significant offset correction results for visualized feature maps compared with the baseline model. The average visualization-weighted positive coverage improved from 51.85% to 83.76%. The proposed approach did not change the deployment capability and inference speed of the original model and can be incorporated into any state-of-the-art neural network. It also shows the potential to provide more accurate localization inference results and assist in clinical examinations during endoscopies.

Usefulness of optical enhancement endoscopy combined with magnification to improve detection of intestinal metaplasia in the stomach

Background and study aims  The light blue crest observed in narrow band imaging endoscopy has high diagnostic accuracy for diagnosis of gastric intestinal metaplasia (GIM). The objective of this prospective study was to evaluate the diagnostic accuracy of magnifying i-scan optical enhancement (OE) imaging for diagnosing the LBC sign in patients with different levels of risk for gastric cancer in a Mexican clinical practice. Patients and methods  Patients with a history of peptic ulcer and symptoms of dyspepsia or gastroesophageal reflux disease were enrolled. Diagnosis of GIM was made at the predetermined anatomical location and white light endoscopy and i-scan OE Mode 1 were captured at the two predetermined biopsy sites (antrum and pyloric regions). Results  A total of 328 patients were enrolled in this study. Overall GIM prevalence was 33.8 %. The GIM distribution was 95.4 % in the antrum and 40.5 % in the corpus. According to the Operative Link on Gastritis/Intestinal-Metaplasia Assessment staging system, only two patients (1.9 %) were classified with high-risk stage disease. Sensitivity, specificity, positive​ and negative predictive values, positive and negative likelihood ratios, and accuracy of both methods (95 % C. I.) were 0.50 (0.41-0.60), 0.55 (0.48-0.62), 0.36 (0.31-0.42), 0.68 (0.63-0.73), 1.12 (0.9-1.4), 0.9 (0.7-1.1), and 0.53 (0.43-0.60) for WLE, and 0.96 (0.90-0.99), 0.91 (0.86-0.94), 0.84 (0.78-0.89), 0.98 (0.94-0.99), 10.4 (6.8-16), 0.05 (0.02-0.12), and 0.93 (0.89-0.95), respectively. The kappa concordance was 0.67 and the reliability coefficient was 0.7407 for interobserver variability. Conclusions  Our study demonstrated the high performance of magnifying i-scan OE imaging for endoscopic diagnosis of GIM in Mexican patients.

Rejuvenation of Helicobacter pylori-Associated Atrophic Gastritis Through Concerted Actions of Placenta-Derived Mesenchymal Stem Cells Prevented Gastric Cancer

Chronic Helicobacter pylori infection causes gastric cancer via the progression of precancerous chronic atrophic gastritis (CAG). Therefore, repairing gastric atrophy could be a useful strategy in preventing H. pylori-associated gastric carcinogenesis. Although eradication of the bacterial pathogen offers one solution to this association, this study was designed to evaluate an alternative approach using mesenchymal stem cells to treat CAG and prevent carcinogenesis. Here, we used human placenta-derived mesenchymal stem cells (PD-MSCs) and their conditioned medium (CM) to treat H. pylori-associated CAG in a mice/cell model to explore their therapeutic effects and elucidate their molecular mechanisms. We compared the changes in the fecal microbiomes in response to PD-MSC treatments, and chronic H. pylori-infected mice were given ten treatments with PD-MSCs before being sacrificed for end point assays at around 36 weeks of age. These animals presented with significant reductions in the mean body weights of the control group, which were eradicated following PD-MSC treatment (p < 0.01). Significant changes in various pathological parameters including inflammation, gastric atrophy, erosions/ulcers, and dysplastic changes were noted in the control group (p < 0.01), but these were all significantly reduced in the PD-MSC/CM-treated groups. Lgr5+, Ki-67, H⁺/K⁺-ATPase, and Musashi-1 expressions were all significantly increased in the treated animals, while inflammatory mediators, MMP, and apoptotic executors were significantly decreased in the PD-MSC group compared to the control group (p < 0.001). Our model showed that H. pylori-initiated, high-salt diet-promoted gastric atrophic gastritis resulted in significant changes in the fecal microbiome at the phylum/genus level and that PD-MSC/CM interventions facilitated a return to more normal microbial communities. In conclusion, administration of PD-MSCs or their conditioned medium may present a novel rejuvenating agent in preventing the progression of H. pylori-associated premalignant lesions.

Helicobacter pylori-Induced Inflammation: Possible Factors Modulating the Risk of Gastric Cancer

Chronic inflammation and long-term tissue injury are related to many malignancies, including gastric cancer (GC). Helicobacter pylori (H. pylori), classified as a class I carcinogen, induces chronic superficial gastritis followed by gastric carcinogenesis. Despite a high prevalence of H. pylori infection, only about 1–3% of people infected with this bacterium develop GC worldwide. Furthermore, the development of chronic gastritis in some, but not all, H. pylori-infected subjects remains unexplained. These conflicting findings indicate that clinical outcomes of aggressive inflammation (atrophic gastritis) to gastric carcinogenesis are influenced by several other factors (in addition to H. pylori infection), such as gut microbiota, co-existence of intestinal helminths, dietary habits, and host genetic factors. This review has five goals: (1) to assess our current understanding of the process of H. pylori-triggered inflammation and gastric precursor lesions; (2) to present a hypothesis on risk modulation by the gut microbiota and infestation with intestinal helminths; (3) to identify the dietary behavior of the people at risk of GC; (4) to check the inflammation-related genetic polymorphisms and role of exosomes together with other factors as initiators of precancerous lesions and gastric carcinoma; and (5) finally, to conclude and suggest a new direction for future research.

Development and Validation of Nomograms to Predict Operative Link for Gastritis Assessment Any-Stage and Stages III-IV in the Chinese High-Risk Gastric Cancer Population

Purpose: It is very essential to diagnose gastric atrophy in the area with high prevalence of gastric cancer. Operative link for gastritis assessment (OLGA) was developed to detect the severity of gastric atrophy. The aim of this study was to develop and validate nomograms for predicting OLGA any-stage and stages III-IV in the Chinese high-risk gastric cancer population. Methods: We retrospectively analyzed 7,945 participants obtained by a multicenter cross-sectional study. We randomly selected 55% individuals (4,370 participants, training cohort) to analyze and generate the prediction models and validated the models on the remaining individuals (3,575 participants, validation cohort). A multivariate logistic regression model was used to select variables in the training cohort. The corresponding nomograms were developed to predict OLGA any-stage and stages III-IV, respectively. The area under the receiver operating characteristic curves and the GiViTI calibration belts were used to estimate the discrimination and calibration of the prediction models. Results: There were 1,226 (28.05%) participants in the training sample and 970 (27.13%) in the validation sample who were diagnosed with gastric atrophy. The nomogram predicting OLGA any-stage had an area under the curve (AUC) of 0.610 for the training sample and 0.615 for the validation sample, with favorable calibrations in the overall population. Similarly, the nomogram predicting OLGA stages III-IV had an AUC of 0.702 and 0.714 for the training and validation samples, respectively, with favorable calibrations in the overall population. Conclusions: The prediction model can early identify the occurrence of gastric atrophy and the severity stage of gastric atrophy to some extent.

Recent Advances in Digestive Tract Tumors: Updates From the 5th Edition of the World Health Organization "Blue Book"

CONTEXT.—

The World Health Organization Classification of Tumours: Digestive System Tumors, 5th edition, was published in 2019 and shows several impactful changes as compared with the 4th edition published in 2010. Changes include a revised nomenclature of serrated lesions and revamping the classification of neuroendocrine neoplasms. Appendiceal goblet cell adenocarcinoma is heavily revised, and intrahepatic cholangiocarcinoma is split into 2 subtypes. New subtypes of colorectal carcinoma and hepatocellular carcinoma are described. Precursor lesions are emphasized with their own entries, and both dysplastic and invasive lesions are generally recommended to be graded using a 2-tier system. Hematolymphoid tumors, mesenchymal tumors, and genetic tumor syndromes each have their own sections in the 5th edition. New hematolymphoid lesions include monomorphic epitheliotropic intestinal T-cell lymphoma; duodenal-type follicular lymphoma; intestinal T-cell lymphoma, not otherwise specified; and indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. This paper will provide an in-depth look at the changes in the 5th edition as compared with the 4th edition.

OBJECTIVE.—

To provide a comprehensive, in-depth update on the World Health Organization classification of digestive tumors, including changes to nomenclature, updated diagnostic criteria, and newly described entities.

DATA SOURCES.—

The 5th edition of the World Health Organization Classification of Tumours: Digestive System Tumours, as well as the 4th edition.

CONCLUSIONS.—

The World Health Organization has made many key changes in its newest update on tumors of the digestive system. Pathologists should be aware of these changes and incorporate them into their practice as able or necessary.

Deep learning for diagnosis of precancerous lesions in upper gastrointestinal endoscopy: A review

Upper gastrointestinal (GI) cancers are the leading cause of cancer-related deaths worldwide. Early identification of precancerous lesions has been shown to minimize the incidence of GI cancers and substantiate the vital role of screening endoscopy. However, unlike GI cancers, precancerous lesions in the upper GI tract can be subtle and difficult to detect. Artificial intelligence techniques, especially deep learning algorithms with convolutional neural networks, might help endoscopists identify the precancerous lesions and reduce interobserver variability. In this review, a systematic literature search was undertaken of the Web of Science, PubMed, Cochrane Library and Embase, with an emphasis on the deep learning-based diagnosis of precancerous lesions in the upper GI tract. The status of deep learning algorithms in upper GI precancerous lesions has been systematically summarized. The challenges and recommendations targeting this field are comprehensively analyzed for future research.

Research progress on gut microbiota in patients with gastric cancer, esophageal cancer, and small intestine cancer

The pathogenesis of gut microbiota in humans can be indicated due to the wide application of techniques, such as 16S rRNA sequencing. Presently, several studies have found a significant difference in fecal flora between normal individuals and patients with gastric cancer. Although clinical research on the feedback mechanism of gastric flora and gut microbiota is lacking, clarifying the relationship between gut microbiota and the characteristics of cancer is significant for the early diagnosis of gastric cancer. This study was conducted to review the results of several studies in the past 5 years and analyze the intestinal bacteria in patients with gastric cancer and compare them with those in patients with esophageal and small intestine cancers. It was found that the gut microbiota in patients with gastric cancer was similar to that in patients with esophageal cancer. However, making an analysis and comparing the gut microbiota in patients with small intestine and gastric cancers was impossible due to the low incidence of small intestinal cancer. Our review summarized the research progress on using the gut microbiota for early screening for gastric cancer, and the results of this study will provide a further direction in this field. KEY POINTS: • We reviewed several relative mechanisms of the gut microbiota related to gastric cancer. • The gut microbiota in gastric, esophageal, and small intestine cancers are significantly different in types and quantity, and we have provided some tips for further research. • A prospective review of sequencing methods and study results on the gut microbiota in gastric, esophageal, and small intestine cancers was described.

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.

Vorsorgegastroskopie in Deutschland – erste Ergebnisse der Pilotphase der Prä-GIT-Studie

Im Rahmen der Prä-GIT-Studie sollen Informationen zur Prävalenz und zum Verlauf von präkanzerösen und frühmalignen Läsionen im oberen Gastrointestinaltrakt (OGIT) gewonnen sowie Hochrisikogruppen identifiziert werden. Studienteilnehmer erhalten im Rahmen einer regulären Vorsorgekoloskopie nach vorangegangener Einverständniserklärung in derselben Sitzung eine standardisierte hochauflösende Gastroskopie. Für die Hauptphase der Studie ist geplant, 5000 Teilnehmer in 30 gastroenterologischen Praxen in Bayern einzuschließen. Zur Vorbereitung wurde diese Pilotstudie durchgeführt, um die Machbarkeit des Studienprotokolls, die Akzeptanz der Untersuchung sowie die Durchführung in der „Praxis“-Realität zu prüfen.

Methodik Drei gastroenterologische Praxen in Bayern nahmen an der dreimonatigen Pilotphase von 10/2018 bis 12/2018 teil. Nach entsprechender Aufklärung wurde Patienten, die sich zur Vorsorgekoloskopie in diesen Praxen vorstellten, zusätzlich eine diagnostische Gastroskopie angeboten. Die Gastroskopien erfolgten nach einer vorgegebenen Arbeitsanweisung (Standard Operating Procedure, SOP). Zusätzlich erfolgten eine Datenerhebung zu Ernährung und Lebensstil anhand eines Selbstausfüllfragebogens sowie die Sammlung von Bioproben.

Ergebnisse Innerhalb von 3 Monaten wurden 52 Probanden in drei Praxen in Bayern in die Studie eingeschlossen. Das durchschnittliche Alter lag bei 63,4 Jahren. Die durchschnittliche Untersuchungszeit lag bei 11 Minuten, Komplikationen traten keine auf. Ein Teilnehmer zeigte einen Polyp im Bereich des Recessus piriformis, 21 Teilnehmer zeigten eine Refluxösophagitis, vier Teilnehmer einen Barrett-Ösophagus, davon einer histologisch einen Barrett-Ösophagus mit LGIEN, ein Teilnehmer wies einen Ösophaguspolyp mit leichtgradiger Plattenepitheldysplasie auf, 12 Teilnehmer eine mit Helicobacter pylori assoziierte Gastritis. Eine korpusdominante Atrophie wurde in einem Fall und ein Duodenal-Adenom mit LGIEN in zwei Fällen beschrieben. 100 % bzw. 89 % der Teilnehmer stellten eine Blut- bzw. eine Stuhlprobe für weitere Untersuchungen zur Verfügung. Alle Teilnehmer füllten zudem den Patientenfragebogen aus.

Zusammenfassung Durch die Prä-GIT-Studie soll erstmals für Deutschland eine solide Datenbasis generiert werden, um die Häufigkeiten verschiedener prämaligner und frühkanzeröser Veränderungen im oberen Gastrointestinaltrakt valide schätzen zu können. Die jetzige Pilotphase liefert wichtige Erkenntnisse zur Machbarkeit sowie zur Verbesserung der Prozesse im Rahmen der Hauptphase der Studie. Erfreulicherweise zeigte sich eine sehr große Akzeptanz der Teilnahme an der Studie.

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.

Autoantibodies Toward ATP4A and ATP4B Subunits of Gastric Proton Pump H+,K+-ATPase Are Reliable Serological Pre-endoscopic Markers of Corpus Atrophic Gastritis

INTRODUCTION

Noninvasive assessment of corpus atrophic gastritis (CAG), a condition at increased risk of gastric cancer, is based on the measurement of pepsinogens, gastrin, and Helicobacter pylori antibodies. Parietal cell autoantibodies (PCAs) against the gastric proton pump (ATP4) are potential serological biomarkers of CAG. The purpose of this study was to compare the diagnostic performance of PCA and pepsinogen I tests in patients with clinical suspicion of CAG with the histopathological evaluation of gastric biopsies as reference standard.

METHODS

A prospective case-finding study was performed on 218 naive adult patients (131 women, median age 65 years) who underwent gastric biopsies to confirm/exclude CAG. Patients with histopathological CAG were defined as cases, conversely as controls. Autoantibodies against the individual alpha (ATP4A) and beta (ATP4B) subunits of ATP4 were measured by luciferase immunoprecipitation, and global PCA and pepsinogen I by enzyme-linked immunosorbent assay.

RESULTS

Histopathology classified 107 subjects (49%) as cases (CAG+, autoimmune 81.2%, and multifocal extensive 18.8%) and 111 subjects (51%) as controls (CAG-). In cases, ATP4A, ATP4B, and PCA titers were increased compared with controls, whereas pepsinogen I was reduced (P < 0.0001 for all). ATP4B, ATP4A, and pepsinogen I tests showed sensitivities of 77%, 75%, and 73% and specificities of 88%, 88%, and 80%, respectively. The receiver operating characteristic (ROC) area under the ROC curve (AUC) of these serological biomarkers confirmed their ability to discriminate cases from controls (ATP4B = 0.838, ATP4A = 0.826, pepsinogen I = 0.775, and PCA = 0.805), whereas the partial ROC-pAUC90 analysis showed that the ATP4B test had the best diagnostic performance (P = 0.008 vs ATP4; P = 0.0002 vs pepsinogen I). The presence of autoimmune or extensive gastritis was not significantly different between ATP4B positive or negative cases (P = 0.217).

DISCUSSION

PCAs are promising serological biomarkers for the identification of CAG in high-risk individuals, particularly in an autoimmune pattern but also in an extensive-multifocal atrophy pattern.

Diagnostic value of macrophage inhibitory cytokine 1 as a novel prognostic biomarkers for early gastric cancer screening

BACKGROUND

Early diagnosis is very important to improve the survival rate of patients with gastric cancer (GC), especially in asymptomatic participants. However, low sensitivity of common biomarkers has caused difficulties in early screening of GC. In this study, we explored whether MIC-1 can improve the detection rate of early GC.

METHODS

We screened 8257 participants based on risk factors such as age, gender, and family history for physical examination including gastroscopy. Participant blood samples were taken for measure MIC-1, CA-199, CA72-4, and PG1/PG2 levels. The diagnostic performance of MIC-1 was assessed and compared with CA-199, CA72-4, and PG1/PG2, and its role in early GC diagnosis and the assessment of the risk of precancerous lesions have also been studied.

RESULTS

Based on endoscopic and histopathological findings, 55 participants had GC, 566 participants had low-grade neoplasia, and 2605 participants had chronic gastritis. MIC-1 levels were significantly elevated in GC serum samples as compared to controls (P < .001). The sensitivity of serum MIC-1 for GC diagnosis was much higher than that of CA-199 (49.1% vs 20.0%) with similar specificities. Moreover, receiver operating characteristic (ROC) curve analysis also showed that serum MIC-1 had a better performance compared with CA-199, CA72-4, and PG1/PG2 in distinguishing early-stage GC (AUC: 72.9% vs 69.5%, 67.5%, 44.0%, respectively).

CONCLUSIONS

Serum MIC-1 is significantly elevated in most patients with early GC. MIC-1 can serve as a novel diagnostic marker of early GC and value the risk of GC.

Autoimmune gastritis

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

[Screening gastroscopy in Germany - first results of the pilot phase of the Prä-GIT study]

The primary aim of the Prä-GIT study is to collect information on the prevalence and course of precancerous and early malignant lesions in the upper GIT (uGIT) as well as risk factors associated with these lesions in asymptomatic individuals. Study participants presenting for a screening colonoscopy will undergo an additional endoscopic examination of the uGIT in the same session. 5000 participants in 30 endoscopy clinics in Bayern will be included. The pilot study presented here was performed to test the main study protocol as well as the acceptance of an additional uGIT endoscopic examination.

METHODS

 Three endoscopy clinics in Bayern took part in the three-month pilot study between October and December 2018. Patients presenting for a screening colonoscopy in these clinics were offered an additional endoscopic examination of the uGIT which was performed according to a standard operating procedure (SOP). Furthermore, data on dietary habits and lifestyle, as well as biological samples, were collected.

RESULTS

 52 participants were included in three clinics in Altötting, Augsburg and Regensburg. The average age was 63.4 years. The average time spent per uGIT endoscopy was 11 minutes. No complications occurred. One participant showed a polyp of the recessus piriformis. Refluxesophagitis was seen in 21 participants, four participants had Barrett's esophagus with histological evidence of low-grade dysplasia in one patient, and an esophageal polyp with low-grade dysplasia was seen in one participant. Helicobacter-pylori gastritis was documented in 12 participants. Corpus-dominant atrophy was described in one participant, while a duodenal adenoma with low-grade dysplasia was seen in two participants. 100 % and 89 % of study participants gave a blood or a stool sample, respectively. All participants answered the questionnaire on dietary and lifestyle habits.

CONCLUSION

 The Prä-GIT study was designed to generate a database for premalignant and early cancerous lesions of the uGIT in Germany in asymptomatic individuals presenting for a regular screening colonoscopy. The current pilot study has delivered important insights into the feasibility of the main study protocol. Additionally, the pilot study has shown a high rate of acceptance of an additional uGIT examination in this study population.

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.

Diagnosis and Management of Gastric Intestinal Metaplasia: Current Status and Future Directions

Gastric intestinal metaplasia (GIM) is a known premalignant condition of the human stomach along the pathway to gastric cancer (GC). Histologically, GIM represents the replacement of normal gastric mucosa by mucin-secreting intestinal mucosa. Helicobacter pylori infection is the most common etiologic agent of GIM development worldwide. The prevalence of GIM is heterogeneous among different regions of the world and correlates with the population endemicity of H. pylori carriage, among other environmental factors. GC remains the third leading cause of cancer-related mortality globally. GIM is usually diagnosed by upper endoscopy with biopsy, and histologic scoring systems have been developed to risk-stratify patients at highest risk for progression to GC. Several recent endoscopic imaging modalities may improve the optical detection of GIM and early GC. Appropriate surveillance of GIM may be cost effective and represents an opportunity for the early diagnosis and therapy of GC. Certain East Asian nations have established population-level programs for the screening and surveillance of GIM; guidelines regarding GIM surveillance have also recently been published in Europe. By contrast, few data exist regarding the appropriateness of surveillance of GIM in the United States. In this review, we discuss the pathogenesis, epidemiology, diagnosis, and management of GIM with an emphasis on the role of appropriate endoscopic surveillance.

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.

Prevalence of Atrophic Gastritis in Kazakhstan and the Accuracy of Pepsinogen Tests to Detect Gastric Mucosal Atrophy

BACKGROUND

Atrophic gastritis is considered precursor condition for gastric cancer. There is so far limited evidence on the performance of pepsinogens for atrophy detection in Central Asia. The aim of our study was to detect the prevalence of atrophic gastritis in the asymptomatic adult population in Kazakhstan as well as address the accuracy of pepsinogen testing in atrophy detection.

METHODS

Healthy individuals aged 40-64 were included. Upper endoscopy and pepsinogens (PG) evaluation were performed. PG were analysed in plasma by latex agglutination. Cut off values were used to define decreased PG values (PGR ≤ 3 and PG I ≤ 70 ng/mL); severely decreased PG values (PGR ≤ 2 and PG I ≤ 30 ng/mL). Biopsies were analyzed and obtained according to the updated Sydney System. PG test sensitivity, specificity and overall accuracy were assessed using the histological diagnosis as the "gold standard".

RESULTS

Altogether 157 individuals - female 40,1% and male 59,9% were included. Histologically, moderate to severe corpus atrophy, was present only in 1,3% cases. From all study subjects, 26,8% had decreased plasma PG values with cut-off values PGR ≤ 3 and PG I ≤ 70 ng/mL. The sensitivity of the PG test with this cut-off values was 50,0%, specificity 73,5%, overall accuracy 73,2% for detection of moderate to severe atrophy in the corpus. The sensitivity of PG test with cut-off values PGR ≤ 2 and PG I ≤30 ng/mL was 50,0%, specificity 90,9% and overall accuracy 90,4%.

CONCLUSIONS

The prevalence of gastric mucosal atrophy was low in the Kazakh population. Serological PG test screening nevertheless can play an important role in the diagnosis of gastric precancerous lesions. However, the diagnostic accuracy of the PG test is mainly dependent on the cut-off values for positive results.

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.

Helicobacter pylori and cytokine gene variants as predictors of premalignant gastric lesions

Gastric cancer remains the third leading cause of mortality from cancer worldwide and carries a poor prognosis, due largely to late diagnosis. The importance of the interaction between Helicobacter pylori (H. pylori) infection, the main risk factor, and host-related genetic factors has been studied intensively in recent years. The genetic predisposition for non-hereditary gastric cancer is difficult to assess, as neither the real prevalence of premalignant gastric lesions in various populations nor the environmental risk factors for cancer progression are clearly defined. For non-cardiac intestinal-type cancer, identifying the factors that modulate the progression from inflammation toward cancer is crucial in order to develop preventive strategies. The role of cytokines and their gene variants has been questioned in regard to non-self-limiting H. pylori gastritis and its evolution to gastric atrophy and intestinal metaplasia; the literature now includes various and non-conclusive results on this topic. The influence of the majority of cytokine single nucleotide polymorphisms has been investigated for gastric cancer but not for preneoplastic gastric lesions. Among the investigated gene variants onlyIL10T-819C, IL-8-251, IL-18RAP917997, IL-22 rs1179251, IL1-B-511, IL1-B-3954, IL4R-398 and IL1RN were identified as predictors for premalignant gastric lesions risk. One of the most important limiting factors is the inhomogeneity of the studies (e.g., the lack of data on concomitant H. pylori infection, methods used to assess preneoplastic lesions, and source population). Testing the modifying effect of H. pylori infection upon the relationship between cytokine gene variants and premalignant gastric lesions, or even testing the interaction between H. pylori and cytokine gene variants in multivariable models adjusted for potential covariates, could increase generalizability of results.

Endoscopic Upper GI Screening

The rationale behind endoscopic screening of the upper gastrointestinal tract (GIT) in the West is different from Asian countries with a high prevalence of gastric cancer. If epidemiological data on upper GIT cancer in the Western world is considered, then endoscopic screening of the upper GIT must target premalignant conditions as well and, furthermore, lay emphasis on the assessment of the entire upper GIT in high-risk individuals from the mouth till the duodenum. Although data on the incidence, prevalence, and further development of premalignant conditions in the upper GIT is lacking, a risk-based approach to endoscopic screening will be more cost-effective than a general screening approach. Finally, endoscopists need to be educated and trained in the assessment of the upper GIT during screening endoscopy.

Gastric cancer prevention targeted on risk assessment: Gastritis OLGA staging

Gastric cancer (GC) ranks among the most lethal epithelial malignancies, and its striking mortality rate prompts a global prevention strategy. Helicobacter pylori (H. pylori) gastritis is the main GC promoter, and the 2014 Global Kyoto conference recognized H. pylori gastritis as a (treatable) infectious disease. It is therefore plausible that any large-scale intervention for H. pylori eradication would result in cleansing the world of the fifth cause of cancer-related death. Atrophic gastritis is the cancerization field in which GCs (both intestinal and diffuse histotypes) mainly develop. Discontinuing the inflammatory cascade triggered by H. pylori is tantamount to preventing GC. For patients (still infected or eradicated) who have already developed gastric atrophy, the severity/topography of the atrophic changes correlates with their cancer risk. Gastritis OLGA (Operative Link for Gastritis Assessment) staging consistently ranks the atrophy-associated cancer risk, providing a solid clinical/biological rationale for establishing patient-specific surveillance programs. By combining primary and secondary prevention strategies, gastric cancer is a preventable disease.

H. pylori infection induced BMAL1 expression and rhythm disorder aggravate gastric inflammation

BACKGROUND

Rhythm abnormalities are crucial for diverse diseases. However, their role in disease progression induced by Helicobacter pylori (H. pylori) remains elusive.

METHODS

H. pylori infection was used in in vivo and in vitro experiments to examine its effect on rhythmic genes. The GEO database was used to screen H. pylori affecting rhythm genes, and the effect of rhythm genes on inflammatory factors. Chromatin immunoprecipitation and dual luciferase assays were used to further find out the regulation between molecules. Animal models were used to confirm the relationship between rhythm genes and H. pylori-induced inflammation.

FINDINGS

BMAL1 disorders aggravate inflammation induced by H. pylori. Specifically, H. pylori induce BMAL1 expression in vitro and in vivo through transcriptional activation of LIN28A, breaking the circadian rhythm. Mechanistically, LIN28A binds to the promoter region of BMAL1 and directly activates its transcription under H. pylori infection. BMAL1 in turn functions as a transcription factor and enhances the expression of proinflammatory cytokine TNF-α, thereby promoting inflammation. Of note, BMAL1 dysfunction in the rhythm disorder animal model aggravates inflammatory response induced by H. pylori infection in vivo.

INTERPRETATION

These findings in this study imply the pathogenic relationship between BMAL1 and H. pylori. BMAL1 may serve as a potential diagnostic marker and therapeutic target for the early diagnosis and treatment of diseases related to H. pylori infection. FUND: National Natural Science Foundation of China.

Gastritis staging in the endoscopic follow-up for the secondary prevention of gastric cancer: a 5-year prospective study of 1755 patients

OBJECTIVE

Operative link on gastritis assessment (OLGA) staging for gastritis ranks the risk for gastric cancer (GC) in progressive stages (0-IV). This prospective study aimed at quantifying the cancer risk associated with each gastritis stage.

DESIGN

A cohort of 1755 consecutive patients with dyspepsia underwent initial (T-0) oesophagogastroduodenoscopy with mapped gastric biopsies, OLGA staging and assessment of Helicobacter pylori infection. Patients were followed for 55 months (median); patients with stages II III and IV underwent a second endoscopy/restaging (T-1), and those with stages 0 and I were followed clinically and through in-depth clinical and record checking. Endpoints were OLGA stage at T-1 and development of gastric epithelial neoplasia.

RESULTS

At T-0, 77.6% of patients had stage 0, 14.4% stage I, 5.1% stage II, 2.1% stage III and 0.85% stage IV. H. pylori infection was detected in 603 patients at T-0 and successfully eradicated in 602 of them; 220 had a documented history of H. pylori eradication; and 932 were H. pylori naïve-negative. Incident neoplastic lesions (prevalence=0.4%; low-grade intraepithelial neoplasia (IEN)=4; high-grade IEN=1; GC=2) developed exclusively in patients with stages III-IV. The risk for epithelial neoplasia was null in patients at stages 0, I and II (95% CI 0 to 0.4), 36.5 per 1000 person-years in patients at stage III (95% CI 13.7 to 97.4) and 63.1 per 1000 person-years in patients at stage IV (95% CI 20.3 to 195.6).

CONCLUSIONS

This prospective study confirms that OLGA staging reliably predicts the risk for development of gastric epithelial neoplasia. Although no neoplastic lesions arose in H. pylori-naïve patients, the H. pylori eradication in subjects with advanced stages (III-IV) did not abolish the risk for neoplastic progression.

OLGA Gastritis Staging for the Prediction of Gastric Cancer Risk: A Long-term Follow-up Study of 7436 Patients

OBJECTIVES

Gastritis OLGA-staging ranks the risk for gastric cancer (GC) in progressive stages (0-IV). This long-term follow-up study quantifies the GC risk associated with each OLGA stage.

METHODS

Consecutive patients (7436) underwent esophagogastroscopy (T-0), with mapped gastric biopsies, OLGA staging, and H. pylori status assessment. Patients with neoplastic lesion (invasive or non-invasive) at the index endoscopy (and/or within 12 months) were excluded. All patients were followed-up (T-1) by combining different sources of clinical/pathological information (Regional Registries of: (i) esophagogastroduodenoscopies; (ii) pathology reports; (iii) cancer, (iv) mortality). The endpoint was histologically documented development of gastric epithelial neoplasia.

RESULTS

At T-0, the patients' distribution by OLGA stage was: Stage 0 = 80.8%; Stage I = 12.6%; Stage II = 4.3%; Stage III = 2.0%; Stage IV = 0.3%; H. pylori infection was detected in 25.9% of patients. At the end of the follow-up (mean/median = 6.3/6.6 years), 28 incident neoplasia were documented (overall prevalence = 0.60 per 10³/person-years; low-grade intraepithelial neoplasia = 17/28; high-grade intraepithelial neoplasia = 4/28; GC = 7/28). By OLGA stage at the enrollment, the rate of incident neoplasia was: Stage 0 = 1 case; rate/10³ person-years = 0.03; 95%CI: 0.004-0.19; Stage I = 2 cases; rate/10³ person-years = 0.34; 95%CI: 0.09-1.36; Stage II = 3 cases; rate/10³ person-years = 1.48; 95%CI: 0.48-4.58; Stage III = 17 cases; rate/10³ person-years = 19.1; 95%CI: 11.9-30.7; Stage IV = 5 cases; rate/10³ person-years = 41.2; 95%CI: 17.2-99.3. Multivariate analysis including gender, age, H. pylori status, and OLGA stage at enrollment only disclosed OLGA stage as predictor of neoplastic progression (OLGA stage III: HR = 712.4, 95%CI = 92.543-5484.5; OLGA stage IV: HR = 1450.7, 95%CI = 166.7-12626.0).

CONCLUSIONS

Among 7436 patients, OLGA stages at the enrollment correlated significantly with different risk for gastric neoplasia. Based on the obtained results, gastritis staging is a critical adjunct in endoscopy follow-up protocols aimed at GC secondary prevention.

Occurrence and predictors of metaplastic atrophic gastritis in a nation-wide consecutive endoscopic population presenting with upper gastrointestinal symptoms

OBJECTIVES

The frequency of metaplastic atrophic gastritis in noninvestigated dyspepsia and its associated symptoms pattern are not known. This study aimed to assess the occurrence and clinical predictors of metaplastic atrophic gastritis in a consecutive endoscopic population presenting with upper gastrointestinal symptoms.

PATIENTS AND METHODS

A post-hoc cross-sectional study was carried out on endoscopic-histological data from 668 patients (64% women, age: 58 years) with upper gastrointestinal symptoms obtained during a multicenter study. Patients with dyspeptic (46%), reflux-like symptoms (22%), and both (32%) as indications for gastroscopy were included. Gastroscopy with biopsies (Sydney System) was performed. Clinical data and symptoms were collected using a structured questionnaire.

RESULTS

Metaplastic atrophic gastritis was detected in 201 (30.1%) patients: 22.3% antrum-restricted, 4.5% corpus-restricted, and 3.3% extensive. Postprandial fullness was more frequent in patients with metaplastic atrophic gastritis compared with those without metaplastic atrophic gastritis (29.8 vs. 18.8%, P=0.002); epigastric pain/burning, early satiety, and reflux symptoms occurred similarly in both groups. At multivariate logistic regression, metaplastic atrophic gastritis (any site) was associated with age older than 55 years [odds ratio (OR): 1.86, 95% confidence interval (CI): 1.26-2.73], Helicobacter pylori (OR: 1.66, 95% CI: 1.1-2.39), postprandial fullness (OR: 1.62, 95% CI: 1.03-2.54), and smoking (OR: 1.53, 95% CI: 1.02-2.31). Corpus-restricted atrophic gastritis was associated with postprandial fullness (OR: 4.16, 95% CI: 1.79-9.63) and NSAIDs (OR: 2.98, 95% CI: 1.01-8.88), extensive and antrum-restricted atrophic gastritis was associated with age older than 55 (OR 3.6, 95% CI: 1.20-12.67 and OR: 1.63, 95% CI: 1.06-2.49).

CONCLUSION

Metaplastic atrophic gastritis, a preneoplastic condition, may be found in about one of three patients undergoing endoscopy for upper gastrointestinal symptoms, and clinical predictors are age older than 55 years, smoking, H. pylori infection, and postprandial fullness, especially for corpus-restricted metaplastic atrophic gastritis. An accurate pre-endoscopic characterization of patients with upper gastrointestinal symptoms with easily achievable clinical information may help to better address an endoscopic investigation.

Role of gastroscopic biopsy of gastric ulcer margins and healed sites in the diagnosis of early gastric cancer: A clinical controlled study of 513 cases

The present case study aimed to evaluate the effect of gastroscopic biopsy of gastric ulcer margins and healed sites in the diagnosis of early gastric cancer. A total of 513 patients who were diagnosed with gastric ulcers using gastroscopy between January 1999 and December 2013 were included in the present study and were divided into either the experimental or the control group. In the control group, samples were only taken from the ulcer margin, whereas in the experimental group samples were taken from the ulcer margin and from the ulcer base. In the experimental group, a routine biopsy of the ulcer margin was performed on first examination, and recheck by gastroscopy was performed from the second week. For ulcers that remained unhealed, a biopsy of the ulcer margin was subsequently conducted; however, for healed or almost healed ulcers, a biopsy of the ulcer base was conducted. The duration of follow-up by gastroscopy ranged between 1 week and 24 months. For the control group, a biopsy of the ulcer margin was conducted using the conventional method. The detection rate of the experimental group was 3.88% (9/232), with 4 cases of gastric cancer confirmed from examinations of the ulcer base. The detection rate of the control group was 1.07% (3/281), which was significantly decreased compared with that of the experimental group (P=0.0345). Overall, patients who underwent regular follow-up gastroscopy following treatment exhibited a markedly increased detection rate of early gastric cancer, suggesting that early cancer may occur in healed gastric ulcer sites.

Treatment of Helicobacter pylori infection in atrophic gastritis

Helicobacter pylori (Hp) is a major human pathogen causing chronic, progressive gastric mucosal damage and is linked to gastric atrophy and cancer. Hp-positive individuals constitute the major reservoir for transmission of infection. There is no ideal treatment for Hp. Hp infection is not cured by a single antibiotic, and sometimes, a combined treatment with three or more antibiotics is ineffective. Atrophic gastritis (AG) is a chronic disease whose main features are atrophy and/or intestinal metaplasia of the gastric glands, which arise from long-standing Hp infection. AG is reportedly linked to an increased risk for gastric cancer, particularly when extensive intestinal metaplasia is present. Active or past Hp infection may be detected by conventional methods in about two-thirds of AG patients. By immunoblotting of sera against Hp whole-cell protein lysates, a previous exposure to Hp infection is detected in all AG patients. According to guidelines, AG patients with Hp positivity should receive eradication treatment. The goals of treatment are as follows: (1) Cure of infection, resolution of inflammation and normalization of gastric functions; (2) possible reversal of atrophic and metaplastic changes of the gastric mucosa; and (3) prevention of gastric cancer. An ideal antibiotic regimen for Hp should achieve eradication rates of approximately 90%, and complex multidrug regimens are required to reach this goal. Amongst the factors associated with treatment failure are high bacterial load, high gastric acidity, Hp strain, smoking, low compliance, overweight, and increasing antibiotic resistance. AG, when involving the corporal mucosa, is linked to reduced gastric acid secretion. At a non-acidic intra-gastric pH, the efficacy of the common treatment regimens combining proton pump inhibitors with one or more antibiotics may not be the same as that observed in patients with Hp gastritis in an acid-producing stomach. Although the efficacy of these therapeutic regimens has been thoroughly tested in subjects with Hp infection, there is a paucity of evidence in the subgroup of patients with AG. Bismuth-based therapy may be an attractive treatment in the specific setting of AG, and specific studies on the efficacy of bismuth-based therapies are needed in patients with AG.

Cancer-associated fibroblasts in tumor microenvironment - Accomplices in tumor malignancy

There is much cellular heterogeneity in the tumor microenvironment. The tumor epithelia and stromal cells co-evolve, and this reciprocal relationship dictates almost every step of cancer development and progression. Despite this, many anticancer therapies are designed around druggable features of tumor epithelia, ignoring the supportive role of stromal cells. Cancer-associated fibroblasts (CAFs) are the dominant cell type within the reactive stroma of many tumor types. Numerous previous studies have highlighted a pro-tumorigenic role for CAFs via secretion of various growth factors, cytokines, chemokines, and the degradation of extracellular matrix. Recent works showed that CAFs secrete H₂O₂ to effect stromal-mediated field cancerization, transform primary epithelial cells, and aggravate cancer cell aggressiveness, in addition to inflammatory and mitogenic factors. Molecular characterization of CAFs also underscores the importance of Notch and specific nuclear receptor signaling in the activation of CAFs. This review consolidates recent findings of CAFs and highlights areas for future investigations.

Gastritis staging as a clinical priority

The elective background for gastric adenocarcinoma is the atrophic transformation of the gastric mucosa. The extent of mucosal atrophy basically parallels the risk of developing gastric cancer. This means that either noninvasive (serology) or invasive (endoscopy/histology) methods enabling the atrophic transformation to be quantified can be used theoretically to assess a given patient's gastric cancer risk. This review aims to focus on the reliability of histology gastritis Operative Link for Gastritis Assessment -staging system for assessing the 'personalized' cancer risk in individuals with (atrophic) gastritis.

Precancer in ulcerative colitis: the role of the field effect and its clinical implications

Cumulative evidence indicates that a significant proportion of cancer evolution may occur before the development of histological abnormalities. While recent improvements in DNA sequencing technology have begun to reveal the presence of these early preneoplastic clones, the concept of 'premalignant field' was already introduced by Slaughter more than half a century ago. Also referred to as 'field effect', 'field defect' or 'field cancerization', these terms describe the phenomenon by which molecular alterations develop in normal-appearing tissue and expand to form premalignant patches with the potential to progress to dysplasia and cancer. Field effects have been well-characterized in ulcerative colitis, an inflammatory bowel disease that increases the risk of colorectal cancer. The study of the molecular alterations that define these fields is informative of mechanisms of tumor initiation and progression and has provided potential targets for early cancer detection. Herein, we summarize the current knowledge about the molecular alterations that comprise the field effect in ulcerative colitis and the clinical utility of these fields for cancer screening and prevention.

Gastric Cancer as Preventable Disease

Gastric cancer, 1 of the 5 most common causes of cancer death, is associated with a 5-year overall survival rate less than 30%. A minority of cancers occurs as part of syndromic diseases; more than 90% of adenocarcinomas are considered as the ultimate consequence of a longstanding mucosal inflammation. Helicobacter pylori infection is the leading etiology of non-self-limiting gastritis, which may result in atrophy of the gastric mucosa and impaired acid secretion. Gastric atrophy establishes a field of cancerization prone to further molecular and phenotypic changes, possibly resulting in cancer growth. This well-understood natural history provides the clinicopathologic rationale for primary and secondary cancer prevention strategies. A large body of evidence demonstrates that combined primary (H pylori eradication) and secondary (mainly endoscopy) prevention efforts may prevent or limit the progression of gastric oncogenesis. This approach, which is tailored to different country-specific gastric cancer incidence, socioeconomic, and cultural factors, requires that the complementary competences of gastroenterologists, oncologists, and pathologists be amalgamated into a common strategy of health policy.

The potential value of serum pepsinogen for the diagnosis of atrophic gastritis among the health check-up populations in China: a diagnostic clinical research

BACKGROUND

The aim of this study is to assess the validity of the measurement of pepsinogen as a screening test for chronic atrophic gastritis (AG) in health check-up populations in China.

METHODS

Patients from consecutive regular health check-up were enrolled from January 2014 to June 2015. Endoscopy, combined with monitoring the Helicobacter pylori (Hp) infections, and measuring the serum pepsinogen (PG) were used to determine the diagnostic accuracy of PG for the screening of atrophic gastritis. Histopathology was assessed by the Operative Link on Gastritis Assessment (OLGA) system. Statistical analysis was performed using SPSS statistical software.

RESULTS

The total Hp infection rate was 40%. Based on pathology, the 996 participants were divided into three groups: non-atrophic (NAG), mild-moderate atrophic (MAG): stage I and II of the OLGA classification, and severe atrophic (SAG): stage III and IV of the OLGA classification. Compared with NAG and MAG groups, PGR decreased significantly in SAG group (p < 0.05). PGI and PGII levels were significantly elevated in Hp-positive group, while the PGR was markedly decreased (p < 0.01). When MAG and SAG groups were combined and compared with NAG group, the best cutoff value for atrophy diagnosis was PGI ≤50.3 ng/ml; the cutoff value in Hp-negative group was absolutely higher than in Hp-positive group. When NAG and MAG groups were combined and compared with the SAG group, the best cutoff value for diagnosis of severe atrophy was at PGR ≤4.28. The cutoff values in Hp-negative and Hp-positive groups were calculated at PGR ≤6.28 and ≤4.28, respectively.

CONCLUSIONS

Pepsinogens play an important role in the identification of patients with atrophic gastritis and severe AG. Use of different cutoff values of PG for Hp-negative and Hp-positive groups may offer greater efficacy in the diagnosis of AG.