Evolution of precancerous lesions in a rural Chinese population at high risk of gastric cancer

Helicobacter pylori and the Human Gastrointestinal Microbiota: A Multifaceted Relationship

Helicobacter pylori is a type of Gram-negative bacteria belonging to the Proteobacteria phylum which is known to cause gastrointestinal disorders such as gastritis and gastric ulcers. Its treatment is based on current eradication regimens, which are composed of combinations of antibiotics such as clarithromycin, metronidazole, levofloxacin and amoxicillin, often combined with a proton pump inhibitor (PPI). With the development of sequencing technologies, it has been demonstrated that not only does the colonization of the gastric and gut environment by H. pylori cause microbial changes, but also the treatment regimens used for its eradication have a significant altering effect on both the gastric and gut microbiota. Here, we review current knowledge on microbiota modulations of current therapies in both environments. We also summarize future perspectives regarding H. pylori infection, the integration of probiotics into therapy and what challenges are being faced on a global basis when we talk about eradication.

Helicobacter pylori Treatment and Gastric Cancer Risk Among Individuals With High Genetic Risk for Gastric Cancer

Importance

Helicobacter pylori treatment and nutrition supplementation may protect against gastric cancer (GC), but whether the beneficial effects only apply to potential genetic subgroups and whether high genetic risk may be counteracted by these chemoprevention strategies remains unknown.

Objective

To examine genetic variants associated with the progression of gastric lesions and GC risk and to assess the benefits of H pylori treatment and nutrition supplementation by levels of genetic risk.

Design, Setting, and Participants

This cohort study used follow-up data of the Shandong Intervention Trial (SIT, 1989-2022) and China Kadoorie Biobank (CKB, 2004-2018) in China. Based on the SIT, a longitudinal genome-wide association study was conducted to identify genetic variants for gastric lesion progression. Significant variants were examined for incident GC in a randomly sampled set of CKB participants (set 1). Polygenic risk scores (PRSs) combining independent variants were assessed for GC risk in the remaining CKB participants (set 2) and in an independent case-control study in Linqu.

Exposures

H pylori treatment and nutrition supplementation.

Main Outcomes and Measures

Primary outcomes were the progression of gastric lesions (in SIT only) and the risk of GC. The associations of H pylori treatment and nutrition supplementation with GC were evaluated among SIT participants with different levels of genetic risk.

Results

Our analyses included 2816 participants (mean [SD] age, 46.95 [9.12] years; 1429 [50.75%] women) in SIT and 100 228 participants (mean [SD] age, 53.69 [11.00] years; 57 357 [57.23%] women) in CKB, with 147 GC cases in SIT and 825 GC cases in CKB identified during follow-up. A PRS integrating 12 genomic loci associated with gastric lesion progression and incident GC risk was derived, which was associated with GC risk in CKB (highest vs lowest decile of PRS: hazard ratio [HR], 2.54; 95% CI, 1.80-3.57) and further validated in the analysis of 702 case participants and 692 control participants (mean [SD] age, 54.54 [7.66] years; 527 [37.80%] women; odds ratio, 1.83; 95% CI, 1.11-3.05). H pylori treatment was associated with reduced GC risk only for individuals with high genetic risk (top 25% of PRS: HR, 0.45; 95% CI, 0.25-0.82) but not for those with low genetic risk (HR, 0.81; 95% CI, 0.50-1.34; P for interaction = .03). Such effect modification was not found for vitamin (P for interaction = .93) or garlic (P for interaction = .41) supplementation.

Conclusions and Relevance

The findings of this cohort study indicate that a high genetic risk of GC may be counteracted by H pylori treatment, suggesting primary prevention could be tailored to genetic risk for more effective prevention.

A noninvasive multianalytical approach establishment for risk assessment and gastric cancer screening

Effective screening and early detection are critical to improve the prognosis of gastric cancer (GC). Our study aims to explore noninvasive multianalytical biomarkers and construct integrative models for preliminary risk assessment and GC detection. Whole genomewide methylation marker discovery was conducted with CpG tandems target amplification (CTTA) in cfDNA from large asymptomatic screening participants in a high-risk area of GC. The methylation and mutation candidates were validated simultaneously using one plasma from patients at various gastric lesion stages by multiplex profiling with Mutation Capsule Plus (MCP). Helicobacter pylori specific antibodies were detected with a recomLine assay. Integrated models were constructed and validated by the combination of multianalytical biomarkers. A total of 146 and 120 novel methylation markers were found in CpG islands and promoter regions across the genome with CTTA. The methylation markers together with the candidate mutations were validated with MCP and used to establish a 133-methylation-marker panel for risk assessment of suspicious precancerous lesions and GC cases and a 49-methylation-marker panel as well as a 144-amplicon-mutation panel for GC detection. An integrated model comprising both methylation and specific antibody panels performed better for risk assessment than a traditional model (AUC, 0.83 and 0.63, P < .001). A second model for GC detection integrating methylation and mutation panels also outperformed the traditional model (AUC, 0.82 and 0.68, P = .005). Our study established methylation, mutation and H. pylori-specific antibody panels and constructed two integrated models for risk assessment and GC screening. Our findings provide new insights for a more precise GC screening strategy in the future.

A multiserological line assay to potentially discriminate current from past Helicobacter pylori infection

OBJECTIVES

Early diagnosis is important in controlling Helicobacter pylori-induced gastritis and progression to gastric malignancy. Serological testing is an efficient non-invasive diagnostic method, but currently does not allow differentiation between active and past infections. To fill this diagnostic gap we investigated the diagnostic value of a panel of ten H. pylori-specific antibodies in individuals with different H. pylori infection status within a German population.

METHODS

We used the recomLine Helicobacter IgG 2.0 immunoblotting assay to analyse ten H. pylori-specific antibodies in serum samples collected from 1108 volunteers. From these, 788 samples were used to build exposure and infection status models and 320 samples for model validation. H. pylori infection status was verified by histological examination. We applied logistic regression to select antibodies correlated to infection status and developed, with independent validation, discriminating models and risk scores. Receiving operating characteristic analysis was performed to assess the accuracy of the discriminating models.

RESULTS

Antibody reactivity against cytotoxin-associated gene A (CagA), H. pylori chaperone (GroEL), and hook-associated protein 2 homologue (FliD) was independently associated with the risk of H. pylori exposure with ORs and 95% CIs of 99.24 (46.50-211.80), 46.17 (17.45-122.17), and 22.16 (8.46-55.04), respectively. A risk score comprising these three selected antibodies differentiated currently H. pylori infected or eradicated participants from negatives with an area under the curve of 0.976 (95% CI: 0.965-0.987) (Model 1). Seropositivity for vacuolating cytotoxin A (VacA), GroEL, FliD, H. pylori adhesin A (HpaA), and γ-glutamyl transpeptidase (gGT) was associated with a current infection with an area under the curve of 0.870 (95% CI: 0.837-0.903), which may help discriminate currently infected patients from eradicated ones (Model 2).

DISCUSSION

The recomLine assay is sensitive and specific in determining H. pylori infection and eradication status and thus represents a valuable tool in the management of H. pylori infection.

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.

Inflammatory microenvironment in gastric premalignant lesions: implication and application

Gastric precancerous lesions (GPL) are a major health concern worldwide due to their potential to progress to gastric cancer (GC). Understanding the mechanism underlying the transformation from GPL to GC can provide a fresh insight for the early detection of GC. Although chronic inflammation is prevalent in the GPL, how the inflammatory microenvironment monitored the progression of GPL-to-GC are still elusive. Inflammation has been recognized as a key player in the progression of GPL. This review aims to provide an overview of the inflammatory microenvironment in GPL and its implications for disease progression and potential therapeutic applications. We discuss the involvement of inflammation in the progression of GPL, highlighting Helicobacter pylori (H. pylori) as a mediator for inflammatory microenvironment and a key driver to GC progression. We explore the role of immune cells in mediating the progression of GPL, and focus on the regulation of inflammatory molecules in this disease. Furthermore, we discuss the potential of targeting inflammatory pathways for GPL. There are currently no specific drugs for GPL treatment, but traditional Chinese Medicine (TCM) and natural antioxidants, known as antioxidant and anti-inflammatory properties, exhibit promising effects in suppressing or reversing the progression of GPL. Finally, the challenges and future perspectives in the field are proposed. Overall, this review highlights the central role of the inflammatory microenvironment in the progression of GPL, paving the way for innovative therapeutic approaches in the future.

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.

Endoscopic resection of gastric low-grade dysplasia with high risk factors is associated with decreased advanced neoplasia: a single-center retrospective cohort study

BACKGROUND

The natural course of gastric low-grade dysplasia (LGD) remains unclear, and there are inconsistent management recommendations among guidelines and consensus.

OBJECTIVE

This study aimed to investigate the incidence of advanced neoplasia in patients with gastric LGD and identify the related risk factors.

METHODS

Cases of biopsy demonstrated LGD (BD-LGD) at our center from 2010 to 2021 were reviewed retrospectively. Risk factors related to histological progression were identified, and outcomes of patients based on risk stratification were evaluated.

RESULTS

Ninety-seven (23.0%) of 421 included BD-LGD lesions were diagnosed as advanced neoplasia. Among 409 superficial BD-LGD lesions, lesion in the upper third of the stomach, H. pylori infection, larger size, and narrow band imaging (NBI)-positive findings were independent risk factors of progression. NBI-positive lesions and NBI-negative lesions with or without other risk factors had 44.7%, 1.7%, and 0.0% risk of advanced neoplasia, respectively. Invisible lesions, visible lesions (VLs) without a clear margin, and VLs with a clear margin and size ≤ 10 mm, or > 10 mm had 4.8%, 7.9%, 16.7%, and 55.7% risk of advanced neoplasia, respectively. In addition, endoscopic resection decreased the risk of cancer (P < 0.001) and advanced neoplasia (P < 0.001) in patients with NBI-positive lesions, but not in NBI-negative patients. Similar results were found in patients with VLs with clear margin and size > 10 mm. Moreover, NBI-positive lesions had higher sensitivity and lower specificity for predicting advanced neoplasia than VLs with a clear margin and size > 10 mm determined by white-light endoscopy (97.6% vs. 62.7%, P < 0.001; and 63.0% vs. 85.6%, P < 0.001, respectively).

CONCLUSION

Progression of superficial BD-LGD is associated with NBI-positive lesions, as well as with VLs with a clear margin (size > 10 mm) if NBI is unavailable, and selective resection of those lesions offers benefits for patients by decreasing the risk of advanced neoplasia.

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.

Feasibility of olfactomedin 4 as a molecular biomarker for early diagnosis of gastric neoplasia after intestinal metaplasia

OBJECTIVES

This study discusses whether olfactomedin 4 (OLFM4) could be used as a sensitive and specific biomarker in the early diagnosis of gastric cancer (GC) after gastric intestinal metaplasia (GIM).

METHODS

An integrative analysis combining data derived from the Gene Expression Omnibus (GEO) and cBioPortal databases was performed to investigate the potential molecular biomarker. Immunohistochemistry and quantitative real-time polymerase chain reactions were used to measure the expression of messenger ribonucleic acid (mRNA) and protein by OLFM4. In combination with the gastroscopic findings and the OLFM4 expression in GIM-GC, a predictive model was established. The receiver operator characteristic curve (ROC) was applied to assess the diagnostic value of the model for GIM-GC.

RESULTS

According to the GEO and cBioPortal databases, OLFM4 was identified as a key gene in the diagnosis of GIM-GC. Higher protein expression of OLFM4 was found in GIM and GIM-GC compared with chronic superficial gastritis (GS) (p < 0.05). The positive expression rate of OLFM4 in paracancerous tissue (GCP) was higher than in GIM (p > 0.05). There was no significant difference between GIM-GC and GCP (p > 0.05). The mRNA expression of OLFM4 was similar to the protein expression, and the positive expression rate was higher in early GIM-GC than in GIM (p < 0.05).

CONCLUSION

Olfactomedin 4 could be used as a biomarker for the early diagnosis of GIM-GC, and the logistic predictive model could be an effective tool for increasing the early diagnostic rate.

Allium vegetable intake associated with the risk of incident gastric cancer: a continuous follow-up study of a randomized intervention trial

BACKGROUND

Allium vegetable components have antibacterial, antioxidative, and immune modulation properties, thus potentially exhibiting antitumor effects. Despite evidence from case-control studies, prospective studies linking allium vegetables with gastric cancer (GC) have been sparse.

OBJECTIVE

In a prospective study, we examined whether allium vegetable intake would change the risk of GC occurrence and whether the associations would be modified by vitamin supplementation, garlic supplementation, and Helicobacter pylori (H. pylori) treatment.

METHODS

The study was conducted on the basis of the Shandong Intervention Trial, a randomized, placebo-controlled, factorial-designed trial (1995-2003) in a well-recognized high-risk area for GC in China. Participants were continuously followed up to December 2017 for 22.3 y (1995-2017). A total of 3229 subjects were included, with information on the intake of allium vegetables (garlic vegetables and scallions), collected by structured questionnaires in 1994. The associations of total and individual allium vegetable intake with the risk of GC were examined, respectively.

RESULTS

During the follow-up, 144 incident cases of GC were identified. Garlic vegetable intake was associated with a decreased risk of incident GC (P-trend = 0.02; OR: 0.83; 95% CI: 0.70, 0.98, per 1 kg/y increment), whereas scallion intake showed no association (P-trend = 0.80). An inverse association of the risk of GC with total allium vegetable and garlic vegetable intake was particularly stronger among those receiving the placebo for vitamin supplementation or garlic supplementation, indicating potential effect modifications by nutritional supplementation on allium vegetable intake and the risk of developing GC. Similar findings were found for analyses of the combined prevalence of dysplasia or GC.

CONCLUSIONS

We found a significant reduction in the risk of developing GC with increasing dietary intake of allium vegetables, particularly garlic vegetables. The findings add to the literature on the potential inverse association of garlic vegetable intake with the risk of GC, therefore holding public health implications for dietary recommendations. This trial was registered at clinicaltrials.gov as NCT00339768.

Bile reflux and bile acids in the progression of gastric intestinal metaplasia

ABSTRACT

Gastric intestinal metaplasia (GIM) is a precancerous lesion of gastric cancer (GC) and is considered an irreversible point of progression for GC. Helicobacter pylori infection can cause GIM, but its eradication still does not reverse the process. Bile reflux is also a pathogenic factor in GIM and can continuously irritate the gastric mucosa, and bile acids in refluxed fluid have been widely reported to be associated with GIM. This paper reviews in detail the relationship between bile reflux and GIM and the mechanisms by which bile acids induce GIM.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Endoscopic features and clinical importance of autoimmune gastritis

Autoimmune gastritis (AIG) is a special type of chronic gastritis characterized by autoimmune disorders caused by cellular immunity, resulting in the destruction of parietal cells and production of antiparietal cell antibodies. Endoscopic findings of AIG are mainly characterized by corpus-dominant advanced atrophy. The antral area is generally considered to have no or mild atrophy; however, there are cases wherein the gastric mucosa is red or faded due to past infection with Helicobacter pylori or bile reflux. Currently, there are no diagnostic criteria for AIG in Japan, and it is important to make a diagnosis based on the presence of gastric autoantibodies and characteristic endoscopic and histological findings. AIG is associated with gastric cancer, neuroendocrine tumors (NETs), and other autoimmune diseases, such as thyroid diseases, anemia, and neurological symptoms due to impaired absorption of iron and vitamin B₁₂ , and thus requires systemic treatment. The significance of diagnosing AIG is to include patients as a high-risk group for the development of gastric cancer and gastric NETs, provide an opportunity to detect autoimmune endocrine diseases, and initiate therapeutic intervention before anemia and neurological symptoms develop. It is important to pay close attention to the occurrence of AIG comorbidities not only at the time of AIG diagnosis but also during follow-up after detection.

JAK-STAT1 Signaling Pathway Is an Early Response to Helicobacter pylori Infection and Contributes to Immune Escape and Gastric Carcinogenesis

Helicobacter pylori infection induces a number of pro-inflammatory signaling pathways contributing to gastric inflammation and carcinogenesis and has been identified as a major risk factor for the development of gastric cancer (GC). Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling mediates immune regulatory processes, including tumor-driven immune escape. Programmed death ligand 1 (PD-L1) expressed on gastric epithelium can suppress the immune system by shutting down T cell effector function. In a human cohort of subjects with gastric lesions and GC analyzed by proteomics, STAT1 increased along the cascade of progression of precancerous gastric lesions to GC and was further associated with a poor prognosis of GC (Hazard Ratio (95% confidence interval): 2.34 (1.04-5.30)). We observed that STAT1 was activated in human H. pylori-positive gastritis, while in GC, STAT1, and its target gene, PD-L1, were significantly elevated. To confirm the dependency of H. pylori, we infected gastric epithelial cells in vitro and observed strong activation of STAT1 and upregulation of PD-L1, which depended on cytokines produced by immune cells. To investigate the correlation of immune infiltration with STAT1 activation and PD-L1 expression, we employed a mouse model of H. pylori-induced gastric lesions in an Rnf43-deficient background. Here, phosphorylated STAT1 and PD-L1 were correlated with immune infiltration and proliferation. STAT1 and PD-L1 were upregulated in gastric tumor tissues compared with normal tissues and were associated with immune infiltration and poor prognosis based on the TCGA-STAD database. H. pylori-induced activation of STAT1 and PD-L1 expression may prevent immune surveillance in the gastric mucosa, allowing premalignant lesions to progress to gastric cancer.

E2F1/2/4 mRNA is associated with immune infiltration and are potential biomarkers for the prognosis of human gastric carcinoma

Background

E2Fs are genes that regulate DNA synthesis and the cell cycle by encoding a family of transcription factors. Increasing experimental evidence has revealed that E2Fs play key roles in tumor progression in various types of cancer.

Methods

We investigated the survival, expression and transcriptional data of E2F1/2/4 in gastric cancer (GC) patients using the immunohistochemistry assay, Kaplan-Meier Plotter, cBioPortal, String, and GEPIA databases. The plasma of GC patients was analyzed using the real-time reverse transcription polymerase chain reaction (RT-PCR) assay. The correlation between E2F1/2/4 expression and clinical features was analyzed using the quartile method. As well, the correlation between E2F1/2/4 and GC immune infiltration was also investigated using the TIMER database. Database of Immune Cell Expression (DICE) was also used to analyze correlations between SOX4 and immune responses.

Results

RT-PCR and tissue immunohistochemistry confirmed that E2F1/2/4 was highly expressed in serum and GC tissue samples of GC patients, the expression of which was not affected by patient age and gender. Also, the survival analysis revealed that low levels of E2F1/2/4 expression were significantly associated with a longer overall survival (OS) in GC patients. E2F1/2/4 was correlated with patient prognosis and immune cell infiltration, including B cells, CD8⁺ T cells, CD4⁺ T cells, macrophages, neutrophils, and DCs in GC. Our findings indicated that E2F1/2/4 could be used as a prognostic biomarker and indicator of immune infiltration in GC.

Conclusions

This study revealed that E2F1/2/4 could be a promising indicator for tumor-associated immune infiltration and prognosis in GC patients.

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

Simple Summary

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

Abstract

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

Proteomic profiling identifies signatures associated with progression of precancerous gastric lesions and risk of early gastric cancer

Background

Molecular features underlining the multistage progression of gastric lesions and development of early gastric cancer (GC) are poorly understood, restricting the ability to GC prevention and management.

Methods

We portrayed proteomic landscape and explored proteomic signatures associated with progression of gastric lesions and risk of early GC. Tissue proteomic profiling was conducted for a total of 324 subjects. A case-control study was performed in the discovery stage (n=169) based on populations from Linqu, a known high-risk area for GC in China. We then conducted two-stage validation, including a cohort study from Linqu (n = 56), with prospective follow-up for progression of gastric lesions (280–473 days), and an independent case-control study from Beijing (n = 99).

Findings

There was a clear distinction in proteomic features for precancerous gastric lesions and GC. We derived four molecular subtypes of gastric lesions and identified subtype-S4 with the highest progression risk. We found 104 positively-associated and 113 inversely-associated proteins for early GC, with APOA1BP, PGC, HPX and DDT associated with the risk of gastric lesion progression. Integrating these proteomic signatures, the ability to predict progression of gastric lesions was significantly strengthened (areas-under-the-curve=0.88 (95%CI: 0.78–0.99) vs. 0.56 (0.36–0.76), Delong's P = 0.002). Immunohistochemistry assays and examination at mRNA level validated the findings for four proteins.

Interpretation

We defined proteomic signatures for progression of gastric lesions and risk of early GC, which may have translational significance for identifying particularly high-risk population and detecting GC at an early stage, improving potential for targeted GC prevention.

Funding

The funders are listed in the Acknowledgement.

Chemical constituents and medicinal properties of Allium species

Allium species, belonging to Alliaceae family, are among the oldest cultivated vegetables used as food. Garlic, onions, leeks and chives, which belong to this family, have been reported to have medicinal properties. The Allium species constituents have been shown to have antibacterial and antioxidant activities, and, in addition, other biological properties. These activities are related to their rich organosulfur compounds. These organosulfur compounds are believed to prevent the development of cancer, cardiovascular, neurological, diabetes, liver diseases as well as allergy and arthritis. There have also been reports on toxicities of these compounds. The major active compounds of Allium species includes, diallyl disulfide, diallyl trisulfide, diallyl sulfide, dipropyl disulfide, dipropyl trisulfide, 1-propenylpropyl disulfide, allyl methyl disulfide and dimethyl disulfide. The aim of this review is to focus on a variety of experimental and clinical reports on the effectiveness, toxicities and possible mechanisms of actions of the active compounds of garlic, onions, leek and chives.

Expert-level classification of gastritis by endoscopy using deep learning: a multicenter diagnostic trial

Background and study aims Endoscopy plays a crucial role in diagnosis of gastritis. Endoscopists have low accuracy in diagnosing atrophic gastritis with white-light endoscopy (WLE). High-risk factors (such as atrophic gastritis [AG]) for carcinogenesis demand early detection. Deep learning (DL)-based gastritis classification with WLE rarely has been reported. We built a system for improving the accuracy of diagnosis of AG with WLE to assist with this common gastritis diagnosis and help lessen endoscopist fatigue.

Methods We collected a total of 8141 endoscopic images of common gastritis, other gastritis, and non-gastritis in 4587 cases and built a DL -based system constructed with UNet + + and Resnet-50. A system was developed to sort common gastritis images layer by layer: The first layer included non-gastritis/common gastritis/other gastritis, the second layer contained AG/non-atrophic gastritis, and the third layer included atrophy/intestinal metaplasia and erosion/hemorrhage. The convolutional neural networks were tested with three separate test sets.

Results Rates of accuracy for classifying non-atrophic gastritis/AG, atrophy/intestinal metaplasia, and erosion/hemorrhage were 88.78 %, 87.40 %, and 93.67 % in internal test set, 91.23 %, 85.81 %, and 92.70 % in the external test set ,and 95.00 %, 92.86 %, and 94.74 % in the video set, respectively. The hit ratio with the segmentation model was 99.29 %. The accuracy for detection of non-gastritis/common gastritis/other gastritis was 93.6 %.

Conclusions The system had decent specificity and accuracy in classification of gastritis lesions. DL has great potential in WLE gastritis classification for assisting with achieving accurate diagnoses after endoscopic procedures.

Identification and Validation of Plasma Metabolomic Signatures in Precancerous Gastric Lesions That Progress to Cancer

IMPORTANCE

Metabolic deregulation plays an important role in gastric cancer (GC) development. To date, no studies have comprehensively explored the metabolomic profiles along the cascade of gastric lesions toward GC.

OBJECTIVE

To draw a metabolic landscape and define metabolomic signatures associated with the progression of gastric lesions and risk of early GC.

DESIGN, SETTING, AND PARTICIPANTS

A 2-stage, population-based cohort study was initiated in 2017 in Linqu County, Shandong Province, China, a high-risk area for GC. Prospective follow-up was conducted during the validation stage (June 20, 2017, to May 27, 2020). A total of 400 individuals were included based on the National Upper Gastrointestinal Cancer Early Detection Program in China. The discovery stage involved 200 individuals with different gastric lesions or GC (high-grade intraepithelial neoplasia or invasive GC). The validation stage prospectively enrolled 152 individuals with gastric lesions who were followed up for 118 to 1063 days and 48 individuals with GC.

EXPOSURES

Metabolomic profiles and metabolite signatures were examined based on untargeted plasma metabolomics assay.

MAIN OUTCOMES AND MEASURES

The risk of GC overall and early GC (high-grade intraepithelial neoplasia), and progression of gastric lesions.

RESULTS

Of the 400 participants, 124 of 200 (62.0%) in the discovery set were men; mean (SD) age was 56.8 (7.5) years. In the validation set, 136 of 200 (68.0%) were men; mean (SD) age was 57.5 (8.1) years. Distinct metabolomic profiles were noted for gastric lesions and GC. Six metabolites, including α-linolenic acid, linoleic acid, palmitic acid, arachidonic acid, sn-1 lysophosphatidylcholine (LysoPC)(18:3), and sn-2 LysoPC(20:3) were significantly inversely associated with risk of GC overall and early GC (high-grade intraepithelial neoplasia). Among these metabolites, the first 3 were significantly inversely associated with gastric lesion progression, especially for the progression of intestinal metaplasia (α-linolenic acid: OR, 0.42; 95% CI, 0.18-0.98; linoleic acid: OR, 0.43; 95% CI, 0.19-1.00; and palmitic acid: OR, 0.32; 95% CI, 0.13-0.78). Compared with models including only age, sex, Helicobacter pylori infection, and gastric histopathologic findings, integrating these metabolites significantly improved the performance for predicting the progression of gastric lesions (area under the curve [AUC], 0.86; 95% CI, 0.70-1.00 vs AUC, 0.69; 95% CI, 0.50-0.88; P = .02) and risk of early GC (AUC, 0.83; 95% CI, 0.58-1.00 vs AUC, 0.61; 95% CI, 0.31-0.91; P = .03).

CONCLUSIONS AND RELEVANCE

This study defined metabolite signatures that might serve as meaningful biomarkers for assessing high-risk populations and early diagnosis of GC, possibly advancing targeted GC prevention and control.

Suppression of Helicobacter pylori infection by daily cranberry intake: A double-blind, randomized, placebo-controlled trial

BACKGROUND AND AIM

Dietary strategies that contribute to reducing incidence of Helicobacter pylori infection without negative side effects are highly desirable owing to worldwide bacterial prevalence and carcinogenesis potential. The aim of this study was to determine dosage effect of daily cranberry consumption on H. pylori suppression over time in infected adults to assess the potential of this complementary management strategy in a region with high gastric cancer risk and high prevalence of H. pylori infection.

METHODS

This double-blind, randomized, placebo-controlled trial on 522 H. pylori-positive adults evaluated dose-response effects of proanthocyanidin-standardized cranberry juice, cranberry powder, or their placebos on suppression of H. pylori at 2 and 8 weeks by ¹³ C-urea breath testing and eradication at 45 days post-intervention.

RESULTS

H. pylori-negative rates in placebo, low-proanthocyanidin, medium-proanthocyanidin, and high-proanthocyanidin cranberry juice groups at week 2 were 13.24%, 7.58%, 1.49%, and 13.85% and at week 8 were 7.35%, 7.58%, 4.48%, and 20.00%, respectively. Consumption of high-proanthocyanidin juice twice daily (44 mg proanthocyanidin/240-mL serving) for 8 weeks resulted in decreased H. pylori infection rate by 20% as compared with other dosages and placebo (P < 0.05). Percentage of H. pylori-negative participants increased from 2 to 8 weeks in subjects who consumed 44 mg proanthocyanidin/day juice once or twice daily, showing a statistically significant positive trend over time. Encapsulated cranberry powder doses were not significantly effective at either time point. Overall trial compliance was 94.25%. Cranberry juice and powder were well-tolerated.

CONCLUSIONS

Twice-daily consumption of proanthocyanidin-standardized cranberry juice may help potentiate suppression of H. pylori infection.

TRIAL REGISTRATION

ChiCTR1800017522, per WHO ICTRP.

Intestinal metaplasia of the urinary tract harbors potentially oncogenic genetic variants

In the urinary tract, there is an uncertain relationship between intestinal metaplasia (IM), primary adenocarcinoma, and urothelial carcinoma. Although IM is usually found adjacent to concurrent urothelial carcinoma or adenocarcinoma, small retrospective series have shown that most bladder biopsies with only IM do not subsequently develop cancer. However, IM with dysplasia does seem to be associated with a higher risk of concurrent malignancy or progressing to cancer. Since the molecular landscape of these lesions has remained largely unexplored, there are significant uncertainties about the oncogenic potential of IM in the bladder and urethra. This study investigated the presence of potentially oncogenic genetic variants in cases of IM with and without dysplasia. Twenty-three (23) cases of IM (3 urethra, 20 bladder) were sequenced using a solid tumor next-generation sequencing panel. Of these, five contained IM with high-grade dysplasia (including a case with paired IM-adenocarcinoma and another with paired IM-urothelial carcinoma) and 18 lacked dysplasia. Oncogenic genetic variants were found in all cases of IM with high-grade dysplasia and in five non-dysplastic IM cases, including mutations and copy number variants commonly seen in primary adenocarcinoma of the bladder and urothelial carcinoma. This study demonstrates that IM can harbor potentially oncogenic genetic variants, suggesting that it might represent a cancer precursor or a marker of increased cancer risk in a subset of cases.

Endoscopy for Gastric Cancer Screening Is Cost Effective for Asian Americans in the United States

BACKGROUND & AIMS

Endoscopic screening for gastric cancer is routine in some countries with high incidence and is associated with reduced gastric cancer-related mortality. Immigrants from countries of high incidence to low incidence of gastric cancer retain their elevated risk, but no screening recommendations have been made for these groups in the United States. We aimed to determine the cost effectiveness of different endoscopic screening strategies for noncardia gastric cancer, compared with no screening, among Chinese, Filipino, Southeast Asian, Vietnamese, Korean, and Japanese Americans.

METHODS

We generated a decision-analytic Markov model to simulate a cohort of asymptomatic 50-year-old Asian Americans. The cost effectiveness of 2 distinct strategies for endoscopic gastric cancer screening was compared with no screening for each group, stratified by sex. Outcome measures were reported in incremental cost-effectiveness ratios (ICERs), with a willingness-to-pay threshold of $100,000/quality-adjusted life-year (QALY). Extensive sensitivity analyses were performed.

RESULTS

Compared with performing no endoscopic gastric cancer screening, performing a 1-time upper endoscopy with biopsies, with continued endoscopic surveillance if gastric intestinal metaplasia was identified, was cost effective, whereas performing ongoing biennial endoscopies, even for patients with normal findings from endoscopy and histopathology, was not. The lowest ICERs were observed for Chinese, Japanese, and Korean Americans (all <$73,748/QALY).

CONCLUSIONS

Endoscopic screening for gastric cancer with ongoing surveillance of gastric preneoplasia is cost effective for Asian Americans ages 50 years or older in the United States. The lowest ICERs were for Chinese, Japanese, and Korean Americans (all <$73,748/QALY).

Initial results from a multi-center population-based cluster randomized trial of esophageal and gastric cancer screening in China

Background

We initiated the first multi-center cluster randomized trial of endoscopic screening for esophageal cancer and gastric cancer in China. The objective of the study was to report the baseline screening findings in this trial.

Methods

We recruited a total of 345 eligible clusters from seven screening centers. In the intervention group, participants from high-risk areas were screened by endoscopy; in non-high-risk areas, high-risk individuals were identified using a questionnaire and advised for endoscopy. Lugol’s iodine staining in esophagus and indigo carmine dye in stomach were performed to aid in the diagnosis of suspicious lesions. The primary outcomes of this study were the detection rate (proportion of positive cases among individuals who underwent endoscopic screening) and early detection rate (the proportion of positive cases with stage 0/I among all positive cases).

Results

A total of 149,956 eligible subjects were included. The detection rate was 0.7% in esophagus and 0.8% in stomach, respectively. Compared with non-high-risk areas, the detection rates in high-risk areas were higher, both in esophagus (0.9% vs. 0.1%) and in stomach (0.9% vs. 0.3%). The same difference was found for early-detection rate (esophagus: 92.9% vs. 53.3%; stomach: 81.5% vs. 33.3%).

Conclusions

The diagnostic yield of both esophagus and stomach were higher in high-risk areas than in non-high-risk areas, even though in non-high-risk areas, only high-risk individuals were screened. Our study may provide important clues for evaluating and improving the effectiveness of upper-endoscopic screening in China.

Trial registration: Protocol Registration System in Chinese Clinical Trial Registry, ChiCTR-EOR-16008577. Registered 01 June 2016-Retrospectively registered, http://www.chictr.org.cn/showprojen.aspx?proj=14372

Increased Risk of Progression to Gastric Adenocarcinoma in Patients with Non-dysplastic Gastric Intestinal Metaplasia Versus a Control Population

AIM

In previous studies, the 5-year progression rate of gastric intestinal metaplasia to gastric adenocarcinoma has varied substantially. We investigated the incidence rate of dysplasia and gastric adenocarcinoma and the rate of progression among a cohort of patients with non-dysplastic gastric intestinal metaplasia.

METHODS

This is a single-center, single-cohort retrospective study. Patients who had undergone an EGD with biopsies from 01/01/1993 to 12/31/2013 were included. The primary outcome of interest was the composite of low-grade dysplasia, high-grade dysplasia, or adenocarcinoma. Time to progression and risk factor subgroup analyses were performed.

RESULTS

A total of 1628 subjects were screened, of whom 358 met the inclusion criteria. A total of 21 first-time events were recorded. The annual incidence rate of low-grade dysplasia was 2.1 (95% CI 1.3-3.5) cases per 1000 person-years, 0.5 (95% 0.2-1.3) per 1000 person-years for high-grade dysplasia, and 0.8 (95% CI 0.3-1.6) cases per 1000 person-years for gastric adenocarcinoma. The historical control group had an annual adenocarcinoma incidence rate of 0.07 per 1000 person-years. The event rate in Asians was also noted to be significantly higher between years 0-8 as compared with patients of non-Asian race, and extensive intestinal metaplasia was an independent risk factor (HR = 4.06 (95% CI 1.45-11.34), p = 0.007).

CONCLUSIONS

Patients with non-dysplastic gastric intestinal metaplasia may progress to dysplasia and gastric adenocarcinoma. The incidence rate of gastric adenocarcinoma is higher than that of the historical control population (0.07 per 1000 person-years). The presence of extensive intestinal metaplasia was a risk factor for progression of disease. Triennial EGD may be warranted in patients with non-dysplastic gastric intestinal metaplasia.

Effect and cost-effectiveness of national gastric cancer screening in Japan: a microsimulation modeling study

BACKGROUND

A national endoscopic screening program for gastric cancer was rolled out in Japan in 2015. We used a microsimulation model to estimate the cost-effectiveness of current screening guidelines and alternative screening strategies in Japan.

METHODS

We developed a microsimulation model that simulated a virtual population corresponding to the Japanese population in risk factor profile and life expectancy. We evaluated 15 endoscopic screening scenarios with various starting ages, stopping ages, and screening intervals. The primary outcomes were quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratio. Cost-effective screening strategies were determined using a willingness-to-pay threshold of $50,000 per QALY gained. One-way sensitivity and probabilistic sensitivity analyses were done to explore model uncertainty.

RESULTS

Using the threshold of $50,000 per QALY, a triennial screening program for individuals aged 50 to 75 years was the cost-effective strategy, with an incremental cost-effectiveness ratio of $45,665. Compared with no endoscopic screening, this strategy is predicted to prevent 63% of gastric cancer mortality and confer 27.2 QALYs gained per 1000 individuals over a lifetime period. Current screening guidelines were not on the cost-effectiveness efficient frontier. The results were robust on one-way sensitivity analyses and probabilistic sensitivity analysis.

CONCLUSIONS

This modeling study suggests that the endoscopic screening program in Japan would be cost-effective when implemented between age 50 and 75 years, with the screening repeated every 3 years. These findings underscore the need for further evaluation of the current gastric cancer screening recommendations.

Novel treatment for gastric intestinal metaplasia, a precursor to cancer

BACKGROUND AND AIM

Gastric intestinal metaplasia (GIM) is precancerous with a worldwide prevalence of 25%. Eradicating Helicobacter pylori prevented about half of gastric cancers; failure to prevent the rest was attributed to GIM. GIM is irreversible and often extensive. There is no treatment. Existing endoscopic mucosal resection (EMR) is designed to treat early gastric cancer of usually <2 cm. We designed a two-endoscope technique of EMR for extensive lesions such as GIM.

METHODS

Forty patients with histologically confirmed moderate to severe GIM (operative link on GIM [OLGIM] classification) received the treatment in a daycare center. Chromoendoscopy with methylene blue was first performed to indicate the GIM. Submucosal saline injections were used to lift the stained mucosa to form multiple safety cushions, which were transformed into artificial polyps by suction and ligation, using a cap familiar to gastroenterologists for ligation of esophageal varices. EMRs were then achieved by snare polypectomy. By rotating two gastroscopes, one was designated to perform lift and snare and the other to perform suction and ligation; cycles of lift-ligate-snare were performed until all stained mucosa was removed. Assessment chromoendoscopy with ≥seven biopsies was performed at 6 months.

RESULTS

A total of 227 EMRs were performed, with a median of 3.5 per patient. Bleeding was uncommon and minimal. Gastric perforation ascribable to loss of a safety cushion occurred in one patient. Chromoendoscopy at 6 months in 36 willing patients showed no recurrence of GIM.

CONCLUSION

The two-endoscope technique of EMR for GIM was essentially safe and effective, with no recurrence at 6 months. It could be performed by endoscopists with standard skills.

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

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

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.

Association Between Lifestyle Factors, Vitamin and Garlic Supplementation, and Gastric Cancer Outcomes: A Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

The associations of lifestyle factors with gastric cancer (GC) are still underexplored in populations in China. Long-term nutritional supplementation may prevent GC in high-risk populations, but the possible effect modification by lifestyle factors remains unknown.

OBJECTIVE

To evaluate how lifestyle factors, including smoking, alcohol intake, and diet, may change the risk of GC incidence and mortality and whether the effects of vitamin and garlic supplementation on GC are associated with major lifestyle factors.

DESIGN, SETTING, AND PARTICIPANTS

This is a secondary analysis of the Shandong Intervention Trial, a masked, randomized, placebo-controlled trial that aimed to assess the effect of vitamin and garlic supplementations and Helicobacter pylori treatment on GC in a factorial design with 22.3 years of follow-up. The study took place in Linqu County, Shandong province, China, a high-risk area for GC. Data were collected from Jully 1995 to December 2017. Overall, 3365 participants aged 35 to 64 years identified in 13 randomly selected villages who agreed to undergo gastroscopy were invited to participate in the trial and were included in the analysis. Data analysis was conducted from March to May 2019.

INTERVENTIONS

Participants received vitamin and garlic supplementation for 7.3 years, H pylori treatment for 2 weeks (among participants with H pylori ), or placebo.

MAIN OUTCOMES AND MEASURES

The primary outcomes were GC incidence and GC mortality (1995-2017). We also examined the progression of gastric lesions (1995-2003) as a secondary outcome.

RESULTS

Of the 3365 participants (mean [SD] age, 47.1 [9.2] years; 1639 [48.7%] women), 1677 (49.8%) were randomized to receive active vitamin supplementation, with 1688 (50.2%) receiving placebo, and 1678 (49.9%) receiving active garlic supplementation, with 1687 (50.1%) receiving placebo. Overall, 151 GC cases (4.5%) and 94 GC deaths (2.8%) were identified. Smoking was associated with increased risk of GC incidence (odds ratio, 1.72; 95% CI, 1.003-2.93) and mortality (hazard ratio [HR], 2.01; 95% CI, 1.01-3.98). Smoking was not associated with changes to the effects of vitamin or garlic supplementation. The protective effect on GC mortality associated with garlic supplementation was observed only among those not drinking alcohol (never drank alcohol: HR, 0.33; 95% CI, 0.15-0.75; ever drank alcohol: HR, 0.92; 95% CI, 0.55-1.54; P for interaction = .03), and significant interactions were only seen among participants with H pylori (never drank alcohol: HR, 0.31; 95% CI, 0.12-0.78; ever drank alcohol: HR, 0.91; 95% CI, 0.52-1.60; P for interaction = .04). No significant interactions between vitamin supplementation and lifestyle factors were found.

CONCLUSIONS AND RELEVANCE

In this secondary analysis of a randomized clinical trial, smoking was associated with an increased risk of GC incidence and mortality. Not drinking alcohol was associated with a stronger beneficial effect of garlic supplementation on GC prevention. Our findings provide new insights into lifestyle intervention for GC prevention, suggesting that mass GC prevention strategies may need to be tailored to specific population subgroups to maximize the potential beneficial effect.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00339768.

Risk of metachronous gastric neoplasm occurrence during intermediate-term follow-up period after endoscopic submucosal dissection for gastric dysplasia

After endoscopic resection (ER) of gastric dysplasia, metachronous gastric neoplasm (MGN) appears to have an incidence rate similar to that detected after ER of early gastric cancer (EGC). We investigated whether the risk of MGN after ER for gastric dysplasia is different between patients with low-grade dysplasia (LGD) and high-grade dysplasia (HGD). Between March 2011 and December 2016, 198 patients with LGD (LGD group) and 46 patients with HGD (HGD group) who underwent ER were included in the study. During a median follow-up of 2.5 years, MGNs developed in 21 patients (10.6%) in the LGD group and in 6 patients (13.0%) in the HGD group. Hazard ratios (HRs) for MGNs (HR, 1.45; P = 0.425) and for metachronous HGD or gastric cancer (HR, 2.41; P = 0.214) in the HGD group were not different than those of the LGD group. However, considering patients without Helicobacter pylori infection, those in the HGD group had a significantly increased risk of metachronous HGD or gastric cancer compared to those in the LGD group (HR in HGD-group, 5.23; P = 0.044). These results indicate that meticulous surveillance endoscopy is needed to detect MGNs after ER of gastric dysplasia, especially in patients with HGD, including those without H. pylori infection.

Burden of Gastric Cancer

Gastric cancer is a global health problem, with more than 1 million people newly diagnosed with gastric cancer worldwide each year. Despite its worldwide decline in incidence and mortality over the past 5 decades, gastric cancer remains the third leading cause of cancer-related death. Knowledge of global as well as regional epidemiology and risk factors for gastric cancer is essential for the practicing gastroenterologist to make personalized decisions about risk stratification, screening, and prevention. In this article, we review the epidemiology of gastric cancer as well as screening and prevention efforts to reduce global morbidity and mortality from gastric cancer. First, we discuss the descriptive epidemiology of gastric cancer, including its incidence, mortality, survival, and secular trends. We combine a synthesis of published studies with an analysis of data from the International Agency for Research on Cancer GLOBOCAN project to describe the global burden of gastric cancer and data from the US Cancer Statistics registry to discuss the change in incidence of gastric cancer in the United States. Next, we summarize current knowledge of risk factors for gastric cancer. Finally, we discuss prevention strategies and screening efforts for gastric cancer.

Incidence Rate of Gastric Cancer Adenocarcinoma in Patients With Gastric Dysplasia: A Systematic Review and Meta-Analysis

Several studies have reported the risk of progression to gastric adenocarcinoma (GAC) in patients with gastric dysplasia (GD); however, the findings are controversial. We performed a systematic review and meta-analysis to study the incidence rate of GAC among patients with GD. Using a comprehensive search strategy, we systematically searched online databases including PubMed, Scopus, EMBASE, Cochrane Library, and Web of Science databases for identifying all relevant original articles through inception until July 2018. Cochran Q and I tests were used to assess heterogeneities between included studies. The incidence rates of GAC and their corresponding 95% confidence intervals (CIs) were pooled using random-effect or fixed-effect models. Of the 1980 retrieved records, 30 eligible articles (61 studies) were included. The overall pooled incidence rate of GAC was 40.36 (95% CI, 27.08-55.71; I, 96.0%) cases per 1000 person-years in patients with GD. Subgroup analysis according to the type of GD indicated the highest incidence rate of GAC was 186.40 (95% CI, 106.63-285.60; I, 94.6%) per 1000 person-years among patients with high-grade dysplasia (HGD) lesions. Although the incidence rates of GAC in low-grade dysplasia (LGD) lesions and in nonclassified lesions were 11.25 (95% CI, 3.91-21.22; I, 89.3%), and 1.40 (95% CI, 0.00-9.71; I, 78.8%), respectively. Compared with patients with LGD lesions, progression rate from GD to GAC was roughly 16 times greater in patients with HGD lesions. As the majority of patients with GAC are diagnosed in an advanced stage our study suggests strict management of HGD lesions to prevent GAC.

Effects of Helicobacter pylori treatment and vitamin and garlic supplementation on gastric cancer incidence and mortality: follow-up of a randomized intervention trial

OBJECTIVE

To assess the effects of Helicobacter pylori treatment, vitamin supplementation, and garlic supplementation in the prevention of gastric cancer.

DESIGN

Blinded randomized placebo controlled trial.

SETTING

Linqu County, Shandong province, China.

PARTICIPANTS

3365 residents of a high risk region for gastric cancer. 2258 participants seropositive for antibodies to H pylori were randomly assigned to H pylori treatment, vitamin supplementation, garlic supplementation, or their placebos in a 2×2×2 factorial design, and 1107 H pylori seronegative participants were randomly assigned to vitamin supplementation, garlic supplementation, or their placebos in a 2×2 factorial design.

INTERVENTIONS

H pylori treatment with amoxicillin and omeprazole for two weeks; vitamin (C, E, and selenium) and garlic (extract and oil) supplementation for 7.3 years (1995-2003).

MAIN OUTCOME MEASURES

Primary outcomes were cumulative incidence of gastric cancer identified through scheduled gastroscopies and active clinical follow-up through 2017, and deaths due to gastric cancer ascertained from death certificates and hospital records. Secondary outcomes were associations with other cause specific deaths, including cancers or cardiovascular disease.

RESULTS

151 incident cases of gastric cancer and 94 deaths from gastric cancer were identified during 1995-2017. A protective effect of H pylori treatment on gastric cancer incidence persisted 22 years post-intervention (odds ratio 0.48, 95% confidence interval 0.32 to 0.71). Incidence decreased significantly with vitamin supplementation but not with garlic supplementation (0.64, 0.46 to 0.91 and 0.81, 0.57 to 1.13, respectively). All three interventions showed significant reductions in gastric cancer mortality: fully adjusted hazard ratio for H pylori treatment was 0.62 (95% confidence interval 0.39 to 0.99), for vitamin supplementation was 0.48 (0.31 to 0.75), and for garlic supplementation was 0.66 (0.43 to 1.00). Effects of H pylori treatment on both gastric cancer incidence and mortality and of vitamin supplementation on gastric cancer mortality appeared early, but the effects of vitamin supplementation on gastric cancer incidence and of garlic supplementation only appeared later. No statistically significant associations were found between interventions and other cancers or cardiovascular disease.

CONCLUSIONS

H pylori treatment for two weeks and vitamin or garlic supplementation for seven years were associated with a statistically significant reduced risk of death due to gastric cancer for more than 22 years. H pylori treatment and vitamin supplementation were also associated with a statistically significantly reduced incidence of gastric cancer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00339768.

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

Gastric adenocarcinoma carries a poor prognosis, in part due to the late stage of diagnosis. Risk factors include Helicobacter pylori infection, family history of gastric cancer-in particular, hereditary diffuse gastric cancer and pernicious anaemia. The stages in the progression to cancer include chronic gastritis, gastric atrophy (GA), gastric intestinal metaplasia (GIM) and dysplasia. The key to early detection of cancer and improved survival is to non-invasively identify those at risk before endoscopy. However, although biomarkers may help in the detection of patients with chronic atrophic gastritis, there is insufficient evidence to support their use for population screening. High-quality endoscopy with full mucosal visualisation is an important part of improving early detection. Image-enhanced endoscopy combined with biopsy sampling for histopathology is the best approach to detect and accurately risk-stratify GA and GIM. Biopsies following the Sydney protocol from the antrum, incisura, lesser and greater curvature allow both diagnostic confirmation and risk stratification for progression to cancer. Ideally biopsies should be directed to areas of GA or GIM visualised by high-quality endoscopy. There is insufficient evidence to support screening in a low-risk population (undergoing routine diagnostic oesophagogastroduodenoscopy) such as the UK, but endoscopic surveillance every 3 years should be offered to patients with extensive GA or GIM. Endoscopic mucosal resection or endoscopic submucosal dissection of visible gastric dysplasia and early cancer has been shown to be efficacious with a high success rate and low rate of recurrence, providing that specific quality criteria are met.

Gastric cancer in patients with gastric atrophy and intestinal metaplasia: A systematic review and meta-analysis

AIM

Intestinal metaplasia (IM) and gastric atrophy (GA) are precancerous lesions in the stomach. There is a large debate on natural course of these lesions and surveillance strategy in these patients. This meta-analysis was aimed to find the most appropriate follow up and the rate of progression from IM and GA to GC.

METHODS

This meta-analysis is followed and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic databases including EMBASE, PubMed, Web of Science databases, Scopus, and the Cochrane Library were searched until July 2018. Cochran's Q test and I-square (I2) test were used to examine heterogeneity across included studies. We pooled data using random-effect or fixed effect models indicated as incidence rate or proportion with 95% confidence intervals (CI). The variables of study included demographic data, endoscopy interval, follow up interval and time, GA and IM type and GC stage. Moreover, incidence rate of GC and progress rate, regress and persistence proportion in both GA and IM patients were assessed.

RESULTS

Overall, 68 original articles out of 32981 citations were included in our meta-analysis. The pooled GC incidence rate in patients with GA was 1.24 (95% CI, 0.80, 1.76; I2: 83.6%) cases per 1,000 person-years. The rates of later diagnosis of IM and gastric dysplasia in patients with GA were estimated as 41.42 (95% CI, 3.11, 64.45; I2: 95.6%) and 6.23 (95% CI, 2.34, 11.46; I2: 83.0%) cases per 1,000 person-years, respectively. The pooled regressed proportion was 32.23 (95% CI, 18.07-48.02; I2: 94.0%) and the persistence proportion was 38.83 (95% CI, 20.20-59.13; I2: 97.0%) per 100 observations in GA patients. In IM studies, the pooled incidence rate of GC was 3.38 (95% CI, 2.13, 4.85; I2: 93.4%) cases per 1,000 person-years. The progressed rate to dysplasia in IM patient was estimated to be 12.51 (95% CI, 5.45, 22.03; I2: 95.1%) cases per 1,000 person-years. The pooled regressed proportion was 31.83 (95% CI, 25.48-38.51; I2: 91.0%) and the persistence proportion was 43.46 (95% CI, 32.52-54.71; I2: 96.0%) per 100 observations in IM patients.

CONCLUSION

Overall, the incidence of GC in patients with IM and GA are low but there is heterogeneity in data with the highest rate in Asian, males with those with incomplete IM. There is probability of regression or persistence without progression in patients with IM and GA who receive appropriate management.

Risk of gastric cancer among patients with gastric intestinal metaplasia

Plenty of studies have assessed the association between intestinal metaplasia (IM) and gastric cancer risk, while the results were inconsistent. We aimed to assess the risk of gastric cancer among patients with IM. Systematic literature searches were conducted in PubMed, Embase and Cochrane databases. Baseline characteristics and outcomes from the included studies were extracted independently by two investigators. Either a fixed-effects or a random-effects model was used to composite the pooled OR for gastric cancer risk. Finally, a total of 21 studies, which comprised 402,636 participants and 4,535 gastric cancer patients, were finally included in the current meta-analysis. Compared with those participants without IM, IM patients were at a higher risk of gastric cancer (pooled OR = 3.58, 95% CI 2.71-4.73). We observed that incomplete IM (pooled OR = 9.48, 95% CI 4.33-20.78) but not complete IM (pooled OR = 1.55, 95% CI 0.91-2.65) was significantly associated with a higher gastric cancer risk. Besides, it appeared that gastric cancer risk was higher among patients with IM in the corpus (pooled OR = 7.39, 95% CI 4.94-11.06) than those with IM in the antrum only (pooled OR = 4.06, 95% CI 2.79-5.91). And the pooled ORs for gastric noncardia cancer and gastric cardia cancer were 4.98 (95% CI 3.12-7.95) and 1.93 (95% CI 1.15-3.24), respectively. In conclusion, patients with IM were at a higher risk of gastric cancer, especially for incomplete IM and IM in the corpus. The current evidence supports the use of IM subtypes in the surveillance of gastric cancer.

The evolving role of endoscopy in the diagnosis of premalignant gastric lesions

Gastric adenocarcinoma is a disease that is often detected late, at a stage when curative treatment is unachievable. This must be addressed through changes in our approach to the identification of patients at increased risk by improving the detection and risk assessment of premalignant changes in the stomach, including chronic atrophic gastritis and intestinal metaplasia. Current guidelines recommend utilising random biopsies in a pathology-led approach in order to stage the extent and severity of gastritis and intestinal metaplasia. This random method is poorly reproducible and prone to sampling error and fails to acknowledge recent advances in our understanding of the progression to gastric cancer as a non-linear, branching evolutionary model. Data suggest that recent advances in endoscopic imaging modalities, such as narrow band imaging, can achieve a high degree of accuracy in the stomach for the diagnosis of these premalignant changes. In this review, we outline recent data to support a paradigm shift towards an endoscopy-led approach to diagnosis and staging of premalignant changes in the stomach. High-quality endoscopic interrogation of the chronically inflamed stomach mucosa, supported by targeted biopsies, will lead to more accurate risk assessment, with reduced rates of under or missed diagnoses.

Association of gastric intestinal metaplasia and East Asian ethnicity with the risk of gastric adenocarcinoma in a U.S. population

BACKGROUND AND AIMS

Although the incidence of gastric cancer is higher than that of esophageal cancer in the United States, no screening or surveillance guidelines exist. The aim of this study is to evaluate the association between gastric intestinal metaplasia and the risk of gastric cancer in a U.S. tertiary care system with a large immigrant population.

METHODS

This is a retrospective case-control study with cases of biopsy-proven gastric cancer matched (by age and gender) to controls without gastric cancer who had undergone EGD. The presence of gastric intestinal metaplasia was ascertained from pathology reports. Other potential risk factors for gastric cancer were abstracted from medical records as follows: country of origin, Helicobacter pylori infection, family history of gastric cancer, alcohol consumption, smoking, and history of partial gastrectomy (Billroth I or II). Conditional logistic regression was used to identify independent risk factors for gastric cancer.

RESULTS

One hundred fifty-two cases of gastric cancer were compared with 456 age- and gender-matched controls. The mean age was 66 years, and 57% were male. Multivariable analysis identified 2 significant predictors of gastric cancer: the presence of gastric intestinal metaplasia (odds ratio [OR], 9.3; 95% confidence interval [CI], 4.5-18.9; P < .001) and East Asian ethnicity (OR, 15.9; 95% CI, 5.8-43.6; P < .001).

CONCLUSION

The presence of gastric intestinal metaplasia on endoscopy and East Asian ethnicity were significant risk factors for gastric cancer. Screening East Asian immigrants and surveying patients with gastric intestinal metaplasia may improve the rates of early detection of gastric cancer in the United States.

Helicobacter pylori-induced gastric pathology: insights from in vivo and ex vivo models

Gastric colonization with Helicobacter pylori induces diverse human pathological conditions, including superficial gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric adenocarcinoma and its precursors. The treatment of these conditions often relies on the eradication of H. pylori, an intervention that is increasingly difficult to achieve and that does not prevent disease progression in some contexts. There is, therefore, a pressing need to develop new experimental models of H. pylori-associated gastric pathology to support novel drug development in this field. Here, we review the current status of in vivo and ex vivo models of gastric H. pylori colonization, and of Helicobacter-induced gastric pathology, focusing on models of gastric pathology induced by H. pylori, Helicobacter felis and Helicobacter suis in rodents and large animals. We also discuss the more recent development of gastric organoid cultures from murine and human gastric tissue, as well as from human pluripotent stem cells, and the outcomes of H. pylori infection in these systems.

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.

HCRP1 downregulation confers poor prognosis and induces chemoresistance through regulation of EGFR-AKT pathway in human gastric cancer

The current study aims to investigate the biological roles and clinical significance of HCRP1 in human gastric cancer. The expression pattern of HCRP1 in gastric cancer tissue and adjacent non-cancerous tissue was detected by immunohistochemistry. HCRP1 downregulation was found in 57 of 137 human gastric cancer samples and correlated with advanced TNM stage, positive nodal status, and relapse. Log-rank test showed that HCRP1 downregulation also correlated with poor overall survival and reduced relapse-free survival. In addition, we found that HCRP1 overexpression inhibited proliferation, colony formation, and invasion in HGC-27 cells. On the other hand, HCRP1 depletion by small interfering RNA promoted proliferation, colony formation, and invasion in SGC-7901 cells. We also treated gastric cancer cells with cisplatin. MTT and Annexin V/PI analysis were carried out to examine change of chemoresistance. We found that HCRP1 overexpression sensitized HGC-27 cells to cisplatin while its depletion reduced sensitivity in SGC-7901 cells. Moreover, we found that HCRP1 overexpression negatively regulated cyclin D1, MMP-2, p-EGFR, p-ERK, and p-AKT. HCRP1 depletion showed the opposite effects. In conclusion, our results suggest that HCRP1 downregulation might serve as an indicator for poor prognosis in gastric cancer patients. HCRP1 reduces drug resistance through regulation of EGFR-AKT signaling.

Combined Detection of Plasma ZIC1, HOXD10 and RUNX3 Methylation is a Promising Strategy for Early Detection of Gastric Cancer and Precancerous Lesions

We try to explore the value of aberrant DNA methylation of several cancer-related genes in plasma as non-invasive biomarkers for gastric cancer (GC) and precancerous lesions. By using methylation-specific polymerase chain reaction assay we determined the methylation status of three selected genes ZIC1, HOXD10 and RUNX3 in blood samples from patients with GC and precancerous lesions. We discovered that the methylation rate of ZIC1, HOXD10 and RUNX3 increased significantly in the progression of gastric carcinogenesis. Methylation of ZIC1 was associated with positive serum CA19-9, while that of HOXD10 was related to H. pylori status, serum CA19-9 and CEA levels and tumor invasion depth. The Odds ratios (ORs) of ZIC1, HOXD10 and RUNX3 methylation for predicting GC were 4.285 (95%CI: 2.435-7.542), 3.133 (95%CI: 1.700-5.775) and 2.674 (95%CI: 1.441-4.960), while for predicting "gastric cancer and intraepithelial neoplasia" (GnI), the ORs were 12.011 (95%CI: 0.050-28.564), 9.174 (95%CI: 3.220-26.135) and 12.794 (95%CI: 4.115-39.778), respectively. In terms of combined detection of these three genes, the sensitivity was 91.6% for GC and 89.8% for GnI, with the highest Youden index in both GC and GnI determination. Conclusively, combined detection of ZIC1, HOXD10 and RUNX3 promoter hypermethylation might be a promising strategy for early detection of GC and precancerous lesions.

Clinicopathological characteristics of patients who underwent additional gastrectomy after incomplete endoscopic resection for early gastric cancer

To evaluate the clinicopathological characteristics and factors that lead to residual tumors in patients who underwent additional gastrectomy for incomplete endoscopic resection (ER) for early gastric cancer (EGC).Between 2003 and 2013, the medical records of patients underwent additional gastrectomy after incomplete ER were retrospectively reviewed. Those diagnosed with the presence of histologic residual tumor in specimens obtained by gastrectomy were assigned to the residual tumor (RT) group (n = 47); those diagnosed with the absence of histologic residual tumor were assigned to the nonresidual tumor (NRT) group (n = 33).In the multivariate analysis, endoscopic piecemeal resection, Helicobacter pylori infection, large tumor size (>2 cm), and both (lateral and vertical) marginal involvement were independent factors of the presence of residual tumor in additional gastrectomy after incomplete resection ER for EGC and the rates of independent factors were significantly higher in the RT group than in the NRT group (P < 0.05).Before ER, preexamination to accurately determine the GC invasion depth and the presence of LN metastasis is very important. During ER, surgeons should attempt to perform en bloc resection and to resect the mucous membrane with adequate safety margins to prevent tumor invasion into the lateral and vertical margins.

Risk Factors for Metachronous Gastric Neoplasms in Patients Who Underwent Endoscopic Resection of a Gastric Neoplasm

Background/Aims

To identify the risk factors for metachronous gastric neoplasms in patients who underwent an endoscopic resection of a gastric neoplasm.

Methods

We prospectively collected clinicopathologic data and measured the methylation levels of HAND1, THBD, APC, and MOS in the gastric mucosa by methylation-specific real-time polymerase chain reaction in patients who underwent endoscopic resection of gastric neoplasms.

Results

A total of 257 patients with gastric neoplasms (113 low-grade dysplasias, 25 high-grade dysplasias, and 119 early gastric cancers) were enrolled. Metachronous gastric neoplasm developed in 7.4% of patients during a mean follow-up of 52 months. The 5-year cumulative incidence of metachronous gastric neoplasm was 4.8%. Multivariate analysis showed that moderate/severe corpus intestinal metaplasia and family history of gastric cancer were independent risk factors for metachronous gastric neoplasm development; the hazard ratios were 4.12 (95% confidence interval [CI], 1.23 to 13.87; p=0.022) and 3.52 (95% CI, 1.09 to 11.40; p=0.036), respectively. The methylation level of MOS was significantly elevated in patients with metachronous gastric neoplasms compared age- and sex-matched patients without metachronous gastric neoplasms (p=0.020).

Conclusions

In patients who underwent endoscopic resection of gastric neoplasms, moderate/severe corpus intestinal metaplasia and a family history of gastric cancer were independent risk factors for metachronous gastric neoplasm, and MOS was significantly hypermethylated in patients with metachronous gastric neoplasms.

The Incidence of Gastric Adenocarcinoma Among Patients With Gastric Intestinal Metaplasia: A Long-term Cohort Study

BACKGROUND AND AIMS

Gastric intestinal metaplasia (IM) has been known as a premalignant condition, but estimates of its cancer risk vary widely. We aimed to analyze cancer risk of gastric IM by a long-term cohort study.

METHODS

We conducted a hospital-based study that included all patients with gastric IM between 1992 and 2010, and the development of gastric adenocarcinoma was evaluated until July 2011. Patients developing gastric cancer ≤180 days after the index diagnosis of IM were excluded. The incidence rate, the cumulative incidence, and the standardized incidence ratio (SIR) of gastric cancer were determined, and hazard ratios (HRs) of risk factors were calculated.

RESULTS

We identified 7059 patients with a median follow-up duration of 5.1 years, and 81 patients developed gastric adenocarcinoma during the study period. The 5-, 10-, and 15-year cumulative incidences of gastric cancer were 0.9% [95% confidence interval (CI), 0.6-1.1), 2.0% (95% CI, 1.5-2.6), and 3.0% (95% CI, 2.0-4.0), respectively. On multivariate analysis, older age (eg, 75 y and above; HR=7.4; 95% CI, 2.8-19.6), low-grade dysplasia (HR=4.0; 95% CI, 2.1-7.9), and high-grade dysplasia (HR=18.8; 95% CI, 9.0-39.5) were independent risk factors. As compared with the risk in the general population, the SIR of gastric cancer among patients with gastric IM was 2.5 (95% CI, 2.0-3.1). However, the SIR was only 2.0 (95% CI, 1.5-2.6) in the nondysplasia subgroup, but was up to 35.2 (95% CI, 15.2-69.4) in the high-grade dysplasia subgroup.

CONCLUSIONS

Gastric IM is an important risk factor for gastric cancer, but surveillance should be arranged only for those at an especially high risk.

Risks and Predictors of Gastric Adenocarcinoma in Patients with Gastric Intestinal Metaplasia and Dysplasia: A Population-Based Study

OBJECTIVES

Gastric intestinal metaplasia and dysplasia are precursor lesions for adenocarcinoma. The risks of progression to malignancy from these lesions are not well characterized, particularly in the US populations.

METHODS

We identified 4,331 Kaiser Permanente Northern California members who were diagnosed with gastric intestinal metaplasia or dysplasia between 1997 and 2006 and followed them through December 2013. The incident rates of gastric adenocarcinoma, relative risks in comparison with the Kaiser Permanente general population, and predictors of progression to malignancy were investigated.

RESULTS

Among 4,146 individuals with gastric intestinal metaplasia and 141 with low-grade dysplasia with 24,440 person-years follow-up, 17 and 6 cases of gastric adenocarcinoma were diagnosed, respectively, after 1 year from the index endoscopy. The incidence rate of gastric adenocarcinoma was 0.72/1,000 person-years in patients with intestinal metaplasia, with a relative risk of 2.56 (95% confidence interval (CI) 1.49-4.10) compared with the Kaiser Permanente member population, and 7.7/1,000 person-years for low-grade dysplasia, with a relative risk of 25.6 (95% CI, 9.4-55.7). The median time for gastric intestinal metaplasia to progress to adenocarcinoma was 6.1 years, and for low-grade dysplasia, 2.6 years. Hispanic race/ethnicity and history of dysplasia were associated with significantly higher risk of progression to gastric adenocarcinoma.

CONCLUSIONS

Gastric intestinal metaplasia and dysplasia are significant predictors for gastric adenocarcinoma. The low risk for malignancy associated with intestinal metaplasia does not support routine endoscopic surveillance. However, surveillance should be considered in patients at higher risks, including those with suspicious endoscopic features, presence of dysplasia, and Hispanic race/ethnicity.