Helicobacter pylori Eradication for Prevention of Metachronous Recurrence after Endoscopic Resection of Early Gastric Cancer

Risk Assessment of Metachronous Gastric Neoplasm after Endoscopic Resection for Early Gastric Cancer According to Age at Helicobacter pylori Eradication

Background/Aims

Helicobacter pylori eradication can reduce the incidence of metachronous gastric neoplasm (MGN) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study evaluated the risk of developing MGN after ESD for EGC based on age at H. pylori eradication.

Methods

Data of patients who underwent curative ESD for EGC with H. pylori infection between 2005 and 2018 were retrospectively analyzed. The patients were allocated to four groups according to age at H. pylori eradication: group 1 (<50 years), group 2 (50-59 years), group 3 (60-69 years), and group 4 (≥70 years).

Results

All patients were followed up for at least 5 years after ESD. The 5-year cumulative incidence of MGN was 2.1%, 7.0%, 8.7%, and 16.7% in groups 1, 2, 3, and 4, respectively (p<0.001), and groups 3 and 4 showed a significant increase in the risk of MGN (hazard ratio [HR], 4.66; 95% confidence interval [CI], 1.09 to 19.92 and HR, 10.75; 95% CI, 2.45 to 47.12). After adjustments for moderate to severe intestinal metaplasia based on the updated Sydney system, groups 3 and 4 remained significantly associated with MGN (HR, 4.40; 95% CI, 1.03 to 18.84 and HR, 10.14; 95% CI, 2.31 to 44.57).

Conclusions

The incidence of MGN after ESD for EGC increased with age at H. pylori eradication. Age at H. pylori eradication ≥60 years was an independent risk factor for MGN, even after adjusting for the presence of advanced intestinal metaplasia.

Maintaining H. pylori Negativity After Eradication Can Consolidate Its Benefit in Gastric Cancer Prevention: A Meta-Analysis

INTRODUCTION

Several studies have reported the role of Helicobacter pylori eradication in gastric cancer (GC) prevention. However, for individuals with unsatisfactory management of their H. pylori infection status after eradication, the risk of GC remains unclear.

METHODS

An exhaustive search strategy of the incidence of GC (including primary gastric cancer and metachronous gastric cancer) incidence in patients with unsuccessful eradication or H. pylori reinfection was implemented in the PubMed, Embase, Cochrane Library, and Web of Science. The hazard ratios (HRs) and cumulative incidence of total GC in patients with failed eradication or H. pylori reinfection (FE-Hp (+)) group were compared with that in patients with successful eradication and no H. pylori reinfection (SE-Hp (-)) group and patients with noneradication (NE) group.

RESULTS

Seven eligible studies (including 8,767 patients with H. pylori infection) were identified. In the FE-Hp (+) group, the total GC risk was 1.86-fold of that in the SE-Hp (-) group (HR = 1.86, 95% confidence interval [CI]: 1.14-3.04, P = 0.013). The total GC risk in the NE group was also higher than that in the FE-Hp (+) group (HR = 1.98, 95% CI: 1.11-3.52, P = 0.002). On further analysis with different end points showed that the pooled GC risk increased over time (5-year follow-up: HR = 2.92, 1.34-6.34; 10-year follow-up: HR = 4.04, 2.56-6.37).

DISCUSSION

Compared with the SE-Hp (-) group, the FE-Hp (+) group had a higher risk of gastric carcinoma. Long-term monitoring of H. pylori infection status could consolidate the benefit of eradicating H. pylori for preventing GC prevention in patients after eradication.

Characteristic endoscopic findings in Helicobacter pylori diagnosis in clinical practice

INTRODUCTION

Helicobacter pylori is a major risk factor for gastric cancer. In addition to eradication therapy, early-phase detection of gastric cancer through screening programs using high-vision endoscopy is also widely known to reduce mortality. Although European and US guidelines recommend evaluation of atrophy and intestinal metaplasia by high-vision endoscopy and pathological findings, the guideline used in Japan - the Kyoto classification of gastritis - is based on endoscopic evaluation, and recommends the grading of risk factors. This system requires classification into three endoscopic groups: H. pylori-negative, previous H. pylori infection (inactive gastritis), and current H. pylori infection (active gastritis). Major endoscopic findings in active gastritis are diffuse redness, enlarged folds, nodularity, mucosal swelling, and sticky mucus, while those in H pylori-related gastritis - irrespective of active or inactive status - are atrophy, intestinal metaplasia, and xanthoma.

AREAS COVERED

This review describes the endoscopic characteristics of current H. pylori infection, and how characteristic endoscopic findings should be evaluated.

EXPERT OPINION

Although the correct evaluation of endoscopic findings related to H. pylori remains necessary, if findings of possible infection are observed, it is important to diagnose infection by detection methods with high sensitivity and specificity, including the stool antigen test and urea breath test.

Curative criteria for endoscopic treatment of gastric cancer

Endoscopic treatment, particularly endoscopic submucosal dissection, has become the primary treatment for early gastric cancer. A comprehensive optical assessment, including white light endoscopy, image-enhanced endoscopy, and magnification, are the cornerstones for clinical staging and determining the resectability of lesions. This paper discusses factors that influence the indication for endoscopic resection and the likelihood of achieving a curative resection. Our review stresses the critical need for interpreting the histopathological report in accordance with clinical guidelines and the imperative of tailoring decisions based on the patients' and lesions' characteristics and preferences. Moreover, we offer guidance on managing complex scenarios, such as those involving non-curative resection. Finally, we identify future research avenues, including the role of artificial intelligence in estimating the depth of invasion and the urgent need to refine predictive scores for lymph node metastasis and metachronous lesions.

Early gastric cancer recurrence after endoscopic submucosal dissection: Not to be ignored!

This editorial comments on the article "Efficacy of multi-slice spiral computed tomography in evaluating gastric cancer recurrence after endoscopic submucosal dissection". We focus on the importance of paying more attention to post-endoscopic submucosal dissection (ESD) gastric cancer recurrence in patients with early gastric cancer (EGC) and how to manage it effectively. ESD has been a well-known treatment and the mainstay for EGC, with the advantages of less invasion and fewer complications when compared with traditional surgical procedures. Despite a lower local recurrence rate after ESD, the problem of postoperative recurrence in patients with EGC has become increasingly non-ignorable with the global popularization of ESD technology and the increasing number of post-ESD patients.

Early gastric cancer recurrence after endoscopic submucosal dissection: Not to be ignored!

This editorial comments on the article "Efficacy of multi-slice spiral computed tomography in evaluating gastric cancer recurrence after endoscopic submucosal dissection". We focus on the importance of paying more attention to post-endoscopic submucosal dissection (ESD) gastric cancer recurrence in patients with early gastric cancer (EGC) and how to manage it effectively. ESD has been a well-known treatment and the mainstay for EGC, with the advantages of less invasion and fewer complications when compared with traditional surgical procedures. Despite a lower local recurrence rate after ESD, the problem of postoperative recurrence in patients with EGC has become increasingly non-ignorable with the global popularization of ESD technology and the increasing number of post-ESD patients.

Clinical Decision Support System for All Stages of Gastric Carcinogenesis in Real-Time Endoscopy: Model Establishment and Validation Study

BACKGROUND

Our research group previously established a deep-learning-based clinical decision support system (CDSS) for real-time endoscopy-based detection and classification of gastric neoplasms. However, preneoplastic conditions, such as atrophy and intestinal metaplasia (IM) were not taken into account, and there is no established model that classifies all stages of gastric carcinogenesis.

OBJECTIVE

This study aims to build and validate a CDSS for real-time endoscopy for all stages of gastric carcinogenesis, including atrophy and IM.

METHODS

A total of 11,868 endoscopic images were used for training and internal testing. The primary outcomes were lesion classification accuracy (6 classes: advanced gastric cancer, early gastric cancer, dysplasia, atrophy, IM, and normal) and atrophy and IM lesion segmentation rates for the segmentation model. The following tests were carried out to validate the performance of lesion classification accuracy: (1) external testing using 1282 images from another institution and (2) evaluation of the classification accuracy of atrophy and IM in real-world procedures in a prospective manner. To estimate the clinical utility, 2 experienced endoscopists were invited to perform a blind test with the same data set. A CDSS was constructed by combining the established 6-class lesion classification model and the preneoplastic lesion segmentation model with the previously established lesion detection model.

RESULTS

The overall lesion classification accuracy (95% CI) was 90.3% (89%-91.6%) in the internal test. For the performance validation, the CDSS achieved 85.3% (83.4%-97.2%) overall accuracy. The per-class external test accuracies for atrophy and IM were 95.3% (92.6%-98%) and 89.3% (85.4%-93.2%), respectively. CDSS-assisted endoscopy showed an accuracy of 92.1% (88.8%-95.4%) for atrophy and 95.5% (92%-99%) for IM in the real-world application of 522 consecutive screening endoscopies. There was no significant difference in the overall accuracy between the invited endoscopists and established CDSS in the prospective real-clinic evaluation (P=.23). The CDSS demonstrated a segmentation rate of 93.4% (95% CI 92.4%-94.4%) for atrophy or IM lesion segmentation in the internal testing.

CONCLUSIONS

The CDSS achieved high performance in terms of computer-aided diagnosis of all stages of gastric carcinogenesis and demonstrated real-world application potential.

Single-cell Profiling Uncovers a Muc4-Expressing Metaplastic Gastric Cell Type Sustained by Helicobacter pylori-driven Inflammation

Mechanisms for Helicobacter pylori (Hp)-driven stomach cancer are not fully understood. In a transgenic mouse model of gastric preneoplasia, concomitant Hp infection and induction of constitutively active KRAS (Hp+KRAS+) alters metaplasia phenotypes and elicits greater inflammation than either perturbation alone. Gastric single-cell RNA sequencing showed that Hp+KRAS+ mice had a large population of metaplastic pit cells that expressed the intestinal mucin Muc4 and the growth factor amphiregulin. Flow cytometry and IHC-based immune profiling revealed that metaplastic pit cells were associated with macrophage and T-cell inflammation. Accordingly, expansion of metaplastic pit cells was prevented by gastric immunosuppression and reversed by antibiotic eradication of Hp. Finally, MUC4 expression was significantly associated with proliferation in human gastric cancer samples. These studies identify an Hp-associated metaplastic pit cell lineage, also found in human gastric cancer tissues, whose expansion is driven by Hp-dependent inflammation.

Significance

Using a mouse model, we have delineated metaplastic pit cells as a precancerous cell type whose expansion requires Hp-driven inflammation. In humans, metaplastic pit cells show enhanced proliferation as well as enrichment in precancer and early cancer tissues, highlighting an early step in the gastric metaplasia to cancer cascade.

Endoscopic Resection of Early Gastric Cancer and Pre-Malignant Gastric Lesions

Early gastric cancer comprises gastric malignancies that are confined to the mucosa or submucosa, irrespective of lymph node metastasis. Endoscopic resection is currently pivotal for the management of such early lesions, and it is the recommended treatment for tumors presenting a very low risk of lymph node metastasis. In general, these lesions consist of two groups of differentiated mucosal adenocarcinomas: non-ulcerated lesions (regardless of their size) and small ulcerated lesions. Endoscopic submucosal dissection is the technique of choice in most cases. This procedure has high rates of complete histological resection while maintaining gastric anatomy and its functions, resulting in fewer adverse events than surgery and having a lesser impact on patient-reported quality of life. Nonetheless, approximately 20% of resected lesions do not fulfill curative criteria and demand further treatment, highlighting the importance of patient selection. Additionally, the preservation of the stomach results in a moderate risk of metachronous lesions, which underlines the need for surveillance. We review the current evidence regarding the endoscopic treatment of early gastric cancer, including the short-and long-term results and management after resection.

Clinical Practice Guidelines of Russian Gastroenterological Association, Scientific Society for the Clinical Study of Human Microbiome, Russian Society for the Prevention of Non-Communicable Diseases, Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy for <i>H. pylori</i> Diagnostics and Treatment in Adults

Aim: bring to the attention of practitioners indications for anti-Helicobacter therapy, methods and procedure for diagnostics and eradication therapy ofН. pyloriinfection.

Key points. Chronic gastritis caused byН. pyloriinfection, including asymptomatic persons, may be considered as an indication for eradication therapy of Н. pylori as etiological therapy and opportunistic screening for gastric cancer prevention. Indications, for obligatory anti-Helicobacter therapy include peptic ulcer, gastric MALT lymphoma, early gastric cancer (EGC) with endoscopic resection. H. pylori primary diagnostics methods include13C-urea breath test,H. pyloristool antigen lab test, rapid urease test and serological method. The serological method cannot be used after anti-Helicobacter therapy.

In RussiaH. pyloristrains' resistance to clarithromycin does not exceed 15 % in most regional studies. The first line therapy forН. pyloriinfection eradication is the standard triple therapy including a proton pump inhibitor (PPI), clarithromycin and amoxicillin, enhanced with bismuthate tripotassium dicitrate. A classic four-component therapy based on bismuthate tripotassium dicitrate or quadrotherapy without bismuth drug products which includes PPI, amoxicillin, clarithromycin and metronidazole, may be used as alternative to the first line eradication therapy. The standard triple therapy may be prescribed for 14 days only in those regions, where it has been proven to be effective. Quadrotherapy with bismuthate tripotassium dicitrate is also used as main second line therapy in case of standard triple therapy, bismuth enhanced standard triple therapy or combined therapy failure. Another second line therapy includes PPI, levofloxacin and amoxicillin, to which a bismuth-containing drug product may be added. The third line therapy is selected individually based on previously used treatment settings.

Conclusion. In each case ofH. pyloriinfection the decision for eradication therapy should be made, which is especially relevant as eradication ofH. pylorihas been recognized as an effective measure for the prevention of gastric cancer.

Clinical Practice Guidelines of Russian Gastroenterological Association, Scientific Society for the Clinical Study of Human Microbiome, Russian Society for the Prevention of Non-Communicable Diseases, Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy for <i>H. pylori</i> Diagnostics and Treatment in Adults

Aim: bring to the attention of practitioners indications for anti-Helicobacter therapy, methods and procedure for diagnostics and eradication therapy ofН. pyloriinfection.

Key points. Chronic gastritis caused byН. pyloriinfection, including asymptomatic persons, may be considered as an indication for eradication therapy of Н. pylori as etiological therapy and opportunistic screening for gastric cancer prevention. Indications, for obligatory anti-Helicobacter therapy include peptic ulcer, gastric MALT lymphoma, early gastric cancer (EGC) with endoscopic resection. H. pylori primary diagnostics methods include13C-urea breath test,H. pyloristool antigen lab test, rapid urease test and serological method. The serological method cannot be used after anti-Helicobacter therapy.

In RussiaH. pyloristrains' resistance to clarithromycin does not exceed 15 % in most regional studies. The first line therapy forН. pyloriinfection eradication is the standard triple therapy including a proton pump inhibitor (PPI), clarithromycin and amoxicillin, enhanced with bismuthate tripotassium dicitrate. A classic four-component therapy based on bismuthate tripotassium dicitrate or quadrotherapy without bismuth drug products which includes PPI, amoxicillin, clarithromycin and metronidazole, may be used as alternative to the first line eradication therapy. The standard triple therapy may be prescribed for 14 days only in those regions, where it has been proven to be effective. Quadrotherapy with bismuthate tripotassium dicitrate is also used as main second line therapy in case of standard triple therapy, bismuth enhanced standard triple therapy or combined therapy failure. Another second line therapy includes PPI, levofloxacin and amoxicillin, to which a bismuth-containing drug product may be added. The third line therapy is selected individually based on previously used treatment settings.

Conclusion. In each case ofH. pyloriinfection the decision for eradication therapy should be made, which is especially relevant as eradication ofH. pylorihas been recognized as an effective measure for the prevention of gastric cancer.

Risk factors for gastric metachronous lesions after endoscopic or surgical resection: a systematic review and meta-analysis

INTRODUCTION : Metachronous gastric lesions (MGL) are a significant concern after both endoscopic and surgical resection for early gastric cancer. Identification of risk factors for MGL could help to individualize surveillance schedules and potentially reduce the burden of care, but data are inconclusive. We aimed to identify risk factors for MGL and compare the incidence after endoscopic resection (ER) and subtotal gastrectomy. METHODS : We conducted a systematic review by searching PubMed, ISI, and Scopus, and performed meta-analysis. RESULTS : 52 studies were included. Pooled cumulative MGL incidence after ER was 9.3 % (95 % confidence interval [CI] 7.7 % to 11.0 %), significantly higher than after subtotal gastrectomy (1.2 %, 95 %CI 0.5 % to 2.2 %). After adjusting for mean follow-up, predicted MGL at 5 years was 9.5 % after ER and 0.7 % after subtotal gastrectomy. Older age (mean difference 1.08 years, 95 %CI 0.21 to 1.96), male sex (odds ratio [OR] 1.43, 95 %CI 1.22 to 1.66), family history of gastric cancer (OR 1.88, 95 %CI 1.03 to 3.41), synchronous lesions (OR 1.72, 95 %CI 1.30 to 2.28), severe gastric mucosal atrophy (OR 2.77, 95 %CI 1.22 to 6.29), intestinal metaplasia in corpus (OR 3.15, 95 %CI 1.67 to 5.96), persistent Helicobacter pylori infection (OR 2.08, 95 %CI 1.60 to 2.72), and lower pepsinogen I/II ratio (mean difference -0.54, 95 %CI -0.86 to -0.22) were significantly associated with MGL after ER. Index lesion characteristics were not significantly associated with MGL. ER treatment was possible in 83.2 % of 914 MGLs (95 %CI 72.2 to 91.9 %). CONCLUSION : Follow-up schedules should be different after ER and subtotal gastrectomy, and individualized further based on diverse risk factors.

An Immune Signature for Risk Stratification and Therapeutic Prediction in Helicobacter pylori-Infected Gastric Cancer

Helicobacter pylori (HP) infection is the greatest risk factor for gastric cancer (GC). Increasing evidence has clarified that tumor immune microenvironment (TIME) is closely related to the prognosis and therapeutic efficacy of HP-positive (HP+) GC patients. In this study, we aimed to construct a novel immune-related signature for predicting the prognosis and immunotherapy efficacy of HP+ GC patients. A total of 153 HP+ GC from three different cohorts were included in this study. An Immune-Related prognostic Signature for HP+ GC patients (IRSHG) was established using Univariate Cox regression, the LASSO algorithm, and Multivariate Cox regression. Univariate and Multivariate analyses proved IRSHG was an independent prognostic predictor for HP+ GC patients, and an IRSHG-integrated nomogram was established to quantitatively assessthe prognostic risk. The low-IRSHG group exhibited higher copy number load and distinct mutation profiles compared with the high-IRSHG group. In addition, the difference of hallmark pathways and immune cells infiltration between the two groups was investigated. Notably, tumor immune dysfunction and exclusion (TIDE) analysis indicated that the low-IRSHG group had a higher sensitivity to anti-PD-1 immunotherapy, which was validated by an external pabolizumab treatment cohort. Moreover, 98 chemotherapeutic drugs and corresponding potential biomarkers were identified for two groups, and several drugs with potential ability to reverse IRSHG score were identified using CMap analysis. Collectively, IRSHG may serve as a promising biomarker for survival outcome as well as immunotherapy efficacy. Furthermore, it can also help to prioritize potential therapeutics for HP+ GC patients, providing new insight for the personalized treatment of HP-infected GC.

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

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

Novel "High-dose Quad" Salvage Therapy Approach for Helicobacter pylori Infection: A Case Report

Purpose: This case report outlines the successful eradication of chronic Helicobacter pylori (H. pylori) infection using a novel, "high-dose quad" salvage therapy approach. Gastroenterologists may consider using this approach for patients who have previously failed first- and second-line treatment regimens, as recommended by the American College of Gastroenterology (ACG). Summary: H. pylori infection is associated with multiple chronic gastrointestinal diseases, and patients who test positive for H. pylori should undergo treatment until eradication is achieved. Unfortunately, increasing antibiotic resistance to clarithromycin, metronidazole, and levofloxacin makes eradication of H. pylori challenging. This case describes an 84-year-old American woman with chronic H. pylori gastritis who failed two first-line treatment regimens (bismuth quadruple therapy and concomitant therapy), but responded to a novel, "high-dose quad" salvage regimen consisting of high-dose levofloxacin, amoxicillin, metronidazole, and high-dose acid suppression. Conclusion: This is the first time the "high-dose quad" regimen has been reviewed in the literature and is not FDA approved, but may be considered as an alternative salvage therapy in certain patients, based on the efficacy and safety observed in this case.

[Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer]

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Preventing Metachronous Gastric Cancer after the Endoscopic Resection of Gastric Epithelial Neoplasia: Roles of Helicobacter pylori Eradication and Aspirin

Whether Helicobacter pylori eradication actually reduces the risk of metachronous gastric cancer (MGC) development remains a controversial question. In this review, we addressed this topic by reviewing the results of clinical investigations and molecular pathological analyses of the roles of H. pylori eradication and aspirin administration in the prevention of MGC. In regard to the clinical studies, the results of meta-analyses and randomized control trials differ from those of retrospective studies: the former trials show that H. pylori eradication has a preventive effect on MGC, while the latter studies do not. This discrepancy may be at least partly attributable to differences in the follow-up periods: H. pylori eradication is more likely to prevent MGC over a long-term follow-up period (≥5 years) than over a short-term follow-up period. In addition, many studies have shown that aspirin may have an additive effect on MGC-risk reduction after H. pylori eradication has been achieved. Both H. pylori eradication and aspirin use induce molecular alterations in the atrophic gastritis mucosa but not in the intestinal metaplasia. Unfortunately, the molecular pathological analyses of these interventions have been limited by short follow-up periods. Therefore, a long-term prospective cohort is needed to clarify the changes in molecular events caused by these interventions.

RAI14 Regulated by circNFATC3/miR-23b-3p axis Facilitates Cell Growth and Invasion in Gastric Cancer

Circular RNAs (circRNAs) have been proved to act crucial roles in multiple malignancies including gastric cancer (GC). Retinoic acid induced 14 (RAI14) acts as an oncogene in human cancers, but the underlying mechanisms by which RAI14 is regulated by circRNA/miRNA axis remain elusive. The clinical value of RAI14, miR-23b-3p and circNFATC3 was estimated by The Cancer Genome Atlas and fluorescence in situ hybridization. The interplay between miR-23b-3p and RAI14 or circNFATC3 was determined by qRT-PCR, Western blot, luciferase gene report and RIP assays. Biological function assays and a subcutaneous xenograft model were executed to unveil the role of circNFATC3/miR-23b-3p/RAI14 axis in GC cells. As a consequence, upregulation of RAI14 and circNFATC3 or downregulation of miR-23b-3p was associated with poor prognosis in patients with GC. Restored miR-23b-3p depressed cell proliferation, colony formation, and cell invasion by targeting RAI14, whereas RAI14 facilitated cell progression and reversed the anti-tumor effects of miR-23b-3p in GC cells. Then, circNFATC3 had a co-localization with miR-23b-3p in the cytoplasm in GC tissue cells and could act as a sponge of miR-23b-3p in GC cell line. Silencing of circNFATC3 inhibited cell growth and in vivo tumorigenesis by upregulating miR-23b-3p and downregulating RAI14. In conclusion, our findings indicated that RAI14 facilitated cell growth and invasion and was regulated by circNFATC3/miR-23b-3p axis in GC.

Clinical practice guideline for endoscopic resection of early gastrointestinal cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer (second edition)

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society, in collaboration with the Japanese Gastric Cancer Association, produced "Guidelines for Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Early Gastric Cancer" in 2014, as a set of basic guidelines in accordance with the principles of evidence-based medicine. At the time, a number of statements had to be established by consensus (the lowest evidence level), as evidence levels remained low for many specific areas in this field. However, in recent years, the number of well-designed clinical studies has been increasing. Based on new findings, we have issued the revised second edition of the above guidelines that cover the present state of knowledge. These guidelines are divided into the following seven categories: indications, preoperative diagnosis, techniques, evaluation of curability, complications, long-term postoperative surveillance, and histology.

NKCC1 promotes proliferation, invasion and migration in human gastric cancer cells via activation of the MAPK-JNK/EMT signaling pathway

Aims: This study aimed to explore the function of NKCC1 in the proliferation, migration and invasion of Gastric cancer (GC) cells. Materials and Methods: GC data extracted from the database was analyzed using molecular bioinformatics. The expression levels of NKCC1 in tissue samples from GC patients and GC cell lines were determined by Western blotting, qRT-PCR, and immunohistochemistry. Immunofluorescence was used to detect protein localization. The GC cell lines were transfected with NKCC1-shRNA or expression plasmid, and in vitro proliferation, invasion and migration were analyzed by the CCK8, wound healing and transwell tests. Results: The NKCC1 mRNA level was significantly increased in GC tissues than that in normal gastric tissues (P = 0.0195). This phenomenon was further confirmed by the analysis of the TCGA-GTEx database that includes 408 gastric cancer tissues and 211 normal gastric tissues (P < 0.01). Furthermore, the increased level of NKCC1 was significantly correlated with Tumor size (P = 0.039), lymphatic node metastasis (P = 0.035) and tumor stage (P = 0.034). In vitro experiments confirmed that NKCC1 expression was higher in GC cells compared to that in GES-1 cells, and was mainly localized to the cytoplasm and membrane. NKCC1 silencing inhibited GC cell proliferation, invasion, migration and EMT, whereas its overexpression had the opposite effects. Furthermore, NKCC1 overexpression upregulated and activated JNK, and the targeted inhibition of JNK by SP600125 abrogated the pro-metastatic effects of NKCC1. Conclusions: NKCC1 promotes migration and invasion of GC cells by MAPK-JNK/EMT pathway and can be a potential therapeutic target.

Narrative review of the role of gastroenterologist in the diagnosis, treatment and palliation in gastric and gastroesophageal cancer

Esophageal cancer (EC) and gastric cancer (GC) carry a high mortality rate. Unfortunately, a majority of patients are asymptomatic and at the time of diagnosis, the disease may invariably be in its advanced stages with limited curative options. Thus, it is imperative to recognize certain risk factors including gastroesophageal reflux disease (GERD), male gender, pre-existing Barrett’s esophagus, smoking history, obesity, Helicobacter pylori infection, atrophic gastritis among others for both EC and GC, intervene on time with screening and surveillance modalities if indicated and optimize treatment plans. With advances in endoscopic techniques, early neoplastic lesions are increasingly managed by gastroenterologists, offering an alternative to surgery. The gold standard for diagnosis of EC and GC is high definition endoscopy with adequate targeted biopsies. Endoscopic ultrasound (EUS) is a key in the staging of early cancers dictating the pathway for treatment options. We also play a key role in palliation cases with the aim to reduce the symptoms like nausea, vomiting and even when possible, restore oral intake and improve nutrition in both advanced GC and EC. This review article discusses the risk factors, diagnostic and endoscopic treatment modalities of early EC and GC and palliation of advanced cancer where gastroenterologists play a key role.

Artificial Intelligence for the Prediction of Helicobacter Pylori Infection in Endoscopic Images: Systematic Review and Meta-Analysis Of Diagnostic Test Accuracy

BACKGROUND

Helicobacter pylori plays a central role in the development of gastric cancer, and prediction of H pylori infection by visual inspection of the gastric mucosa is an important function of endoscopy. However, there are currently no established methods of optical diagnosis of H pylori infection using endoscopic images. Definitive diagnosis requires endoscopic biopsy. Artificial intelligence (AI) has been increasingly adopted in clinical practice, especially for image recognition and classification.

OBJECTIVE

This study aimed to evaluate the diagnostic test accuracy of AI for the prediction of H pylori infection using endoscopic images.

METHODS

Two independent evaluators searched core databases. The inclusion criteria included studies with endoscopic images of H pylori infection and with application of AI for the prediction of H pylori infection presenting diagnostic performance. Systematic review and diagnostic test accuracy meta-analysis were performed.

RESULTS

Ultimately, 8 studies were identified. Pooled sensitivity, specificity, diagnostic odds ratio, and area under the curve of AI for the prediction of H pylori infection were 0.87 (95% CI 0.72-0.94), 0.86 (95% CI 0.77-0.92), 40 (95% CI 15-112), and 0.92 (95% CI 0.90-0.94), respectively, in the 1719 patients (385 patients with H pylori infection vs 1334 controls). Meta-regression showed methodological quality and included the number of patients in each study for the purpose of heterogeneity. There was no evidence of publication bias. The accuracy of the AI algorithm reached 82% for discrimination between noninfected images and posteradication images.

CONCLUSIONS

An AI algorithm is a reliable tool for endoscopic diagnosis of H pylori infection. The limitations of lacking external validation performance and being conducted only in Asia should be overcome.

TRIAL REGISTRATION

PROSPERO CRD42020175957; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=175957.

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.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by <i>en bloc</i> fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Clinicopathologic Characteristics of Patients with Gastric Superficial Neoplasia and Risk Factors for Multiple Lesions after Endoscopic Submucosal Dissection in a Western Country

BACKGROUND

Endoscopic submucosal dissection (ESD) is a treatment for early gastric neoplasms that preserves the stomach. However, the risk of multiple lesions persists.

OBJECTIVES

To assess clinicopathologic characteristics of patients with early gastric neoplasms in a Western country and evaluate risk factors for multiple gastric lesions, synchronous, or metachronous.

METHODS

A retrospective cohort of 230 consecutive patients who underwent ESD for primary neoplasms from 2012 to 2017 (median follow-up: 33 months) was assessed to determine the clinicopathologic characteristics and risk factors for multiple lesions.

RESULTS

The mean age was 68 years, and 53.9% were male. Current/former smoking status was present in 40.4%, and 29.5% had family history of gastric cancer. A third of the patients had only focal gastric atrophy/metaplasia (operative link on gastritis assessment/operative link on gastric intestinal metaplasia assessment [OLGA/OLGIM] I/II; endoscopic grading of gastric intestinal metaplasia [EGGIM] 1-4). Synchronous and me-tachronous lesions occurred in 14.3 and 8.6% of patients, respectively. There was a trend for higher risk of multiple lesions in smokers and patients with extensive metaplasia (EGGIM >4), but only older age was an independent risk factor (OR 3.30; 95% CI 1.05-10.34). Age >60 years (OR 10.10, 95% CI 1.40-88.04), current/former smoking status (OR 3.64, 95% CI 1.07-12.40), and OLGIM III/IV (OR 3.07, 95% CI 1.01-9.36) were independent risk factors for synchronous lesions. No risk factors for metachronous lesions were found.

CONCLUSIONS

Surveillance limited to patients with advanced stages of gastritis may miss some primary superficial neoplasms. Although older age increases the risk of multiple lesions, no risk factors were found for metachronous lesions. Therefore, endoscopic surveillance after ESD should be done equally in all patients.

LINC00511 accelerated the process of gastric cancer by targeting miR-625-5p/NFIX axis

Background

Gastric cancer (GC) is a common-sighted cancer which is hard to cure over the world. Substantial researches revealed that long non-coding RNAs (lncRNAs) were fundamental regulators in the process of cancers. Nevertheless, the biological function of LINC00511 and how LINC00511 was involved in the regulatory system in GC remained unclear.

Methods

RIP assays and luciferase reporter assays were performed to illustrate combination between LINC00511 and miR-625-5p. Loss-of-function assays were applied for identifying LINC00511 function in GC.

Results

In our study, LINC00511 was discovered significantly high in expression in GC tissues and cell lines. Moreover, LINC00511 showed a strong expression in I/II and III/IV stage. Knockdown of LINC00511 could inhibit the cell proliferation while enhanced cell apoptosis rate in GC. We used nuclear–cytoplasmic fractionation to judge the subcellular localization of LINC00511. Furthermore, miR-625-5p was found to have binding sites for LINC00511 and negatively regulated by LINC00511. Overexpression of miR-625-5p repressed the course of GC. And knockdown of miR-625-5p could recover the effects of LINC00511 silence. Besides, NFIX was discovered as a downstream target of miR-625-5p and overexpression of NFIX could offset the influence of LINC00511 silence. The results of vivo studies manifested that down-regulation of LINC00511 could reduce the Ki67 expression and NFIX while lifted the expression of miR-625-5p.

Conclusion

Overall, the results from our study demonstrated that LINC00511 could function as a tumor promoter by targeting miR-625-5p NFIX axis, suggesting LINC00511 could be considered as a target for GC treatment.

Helicobacter pylori Infection following Endoscopic Resection of Early Gastric Cancer

The role of Helicobacter pylori (H. pylori) infection in patients following endoscopic resection of early gastric cancer (EGC) remains unclear. This article presents a review of literature published in the past 15 years. H. pylori-mediated persistent methylation levels are associated with the development of metachronous gastric cancer. The methylation of certain specific genes can be used to identify patients with a high risk of metachronous gastric cancer even after H. pylori eradication. H. pylori eradication after endoscopic resection should be performed as early as possible for eradication success and prevention of metachronous precancerous lesions. Although whether the eradication of H. pylori could prevent the development of metachronous cancer after endoscopic resection is controversial, several meta-analyses concluded that H. pylori eradication could reduce the incidence of metachronous gastric cancer significantly. In addition, H. pylori eradication in gastric cancer survivors after endoscopic resection could reduce healthcare cost and save lives in a cost-effective way. Taken together, H. pylori eradication after endoscopic resection of EGC is recommended as prevention for metachronous precancerous lesions and metachronous gastric cancer.

An Updated Approach to Evaluation and Treatment of Helicobacter pylori Infection

Helicobacter pylori is a chronic bacterial infection that can lead to peptic ulcer disease, chronic gastritis, and gastric cancer. Its prevalence in the United States is lower than in most of the world, although specific populations are at particular risk for disease-related complications, including those with lower socioeconomic status and older adults. Since its discovery, there have been advances in H. pylori diagnosis and treatment, which are the focus of this review for general practice. Practice guidelines have expanded the role for treatment, despite traditional management algorithms resulting in diminished effectiveness as a result of increasing antibiotic resistance. In this context, new approaches warrant discussion. As such, this review aims to provide a clinical context and framework for the testing and rational treatment of H. pylori infection consistent with the available evidence.

[Helicobacter pylori Eradication Therapy and Gastric Cancer Prevention]

Gastric cancer is the most common cancer in Korea and the fifth most common cancer globally. Helicobacter pylori (H. pylori) infection is considered the main etiologic agent for gastric cancer development. Most regional guidelines for H. pylori treatment recommend treating the organism to prevent gastric cancer in the high-risk group. However, evidence that such a strategy can also be applied to the general population, especially in terms of the preventive effect and safety, has not been adequately presented yet. Although a meta-analysis in the general population suggested effectiveness in decreasing gastric cancer incidence, individual studies should be critically reviewed to evaluate the soundness of the evidence. Recently published, long-term, Korean studies on metachronous gastric cancer prevention ended the controversies from previous short-term studies and confirmed the effectiveness. Currently, further prospective, large, randomized studies are ongoing in the general population and will provide more definitive, high-level evidence on this gastric cancer prevention strategy in the next decade.

Effect of Helicobacter pylori eradication on the incidence of gastric cancer: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori) is considered to be the most important risk factor for gastric cancer (GC). The International Agency for Research on Cancer reported that H. pylori eradication could reduce the risk of developing GC. Several clinical studies have investigated this relationship as well; however, their results are inconsistent owing to the varied inclusion criteria. To address the effect of H. pylori eradication on GC incidence, we conducted a comprehensive meta-analysis with several subgroup analyses to resolve these inconsistencies.

METHODS

We searched MEDLINE and Ichushi-Web to identify randomized control trial and cohort study articles (English or Japanese) through December 2016. Manual searches were also conducted to identify unlisted references in these databases. Eligible studies reported GC incidence as an outcome, with comparisons between H. pylori eradication and control groups. Subgroup analyses were conducted by country, conditions at baseline, and follow-up periods.

RESULTS

We selected 28 studies among 1583 references in the databases and 4 studies by manual searches. The H. pylori eradication group showed significantly lower risk of GC [odds ratio (OR) 0.46; 95% confidence interval 0.39-0.55]. The subgroup analyses indicated that the beneficial effect of eradication was greater in Japan (OR 0.39; 95% CI 0.31-0.49), particularly among those with benign conditions (OR 0.32; 95% CI 0.19-0.54), although none of them was statistically significant. However, reduction of gastric cancer after eradication was significantly greater (p = 0.01) in the groups with long-term (5 years or longer) follow-up (OR 0.32; 95% CI 0.24-0.43) as compared to those with shorter follow-up (less than 5 years) (OR 0.55; 95% CI 0.41-0.72).

CONCLUSION

Real world data showed that large-scale eradication therapy has been performed mostly for benign conditions in Japan. Since eradication effects in preventing gastric cancer are conceivably greater there, GC incidence may decline faster in Japan than expected from the previous meta-analyses data which were based on multi-national, mixed populations with differing screening quality and disease progression.

Helicobacter pylori status and risks of metachronous recurrence after endoscopic resection of early gastric cancer: a systematic review and meta-analysis

The impact of different Helicobacter pylori (H. pylori) status (H. pylori negative, H. pylori eradication and H. pylori persistence) on the development of metachronous gastric lesions after endoscopic resection of early gastric cancer is not well defined. Thus, a systematic review and meta-analysis was performed to investigate this relationship. Two authors independently searched the electronic databases (Pubmed, Embase, the Cochrane Library and Web of Science) through March 2018, without language restriction. Pooled risk ratio for metachronous gastric lesions with regard to H. pylori status was calculated using fixed- or random-effects models, and heterogeneity and publication bias were also measured. 20 eligible studies were finally identified in systematic review, and 17 out of 20 studies were further included in meta-analysis. H. pylori eradication was associated with overall 50% lower odds of metachronous events (RR = 0.50; 95 % CI 0.41-0.61). Pooled risk ratios for metachronous gastric neoplasm were 0.85 (95 % CI 0.43-1.68) between H. pylori-eradicated and -negative patients, and 0.63 (95 % CI 0.35-1.12) between H. pylori-negative and -persistent patients, respectively. In conclusion, based on the best available evidence, eradication of H. pylori can provide protection against secondary gastric neoplasm, and this quantitative benefit seemed greater than among asymptomatic individuals. Metachronous risk seems comparable between H. pylori-eradicated and -negative population, or between H. pylori-negative and -persistent patients.

Modified quadruple therapy versus bismuth-containing quadruple therapy in first-line treatment of Helicobacter pylori infection in Korea; rationale and design of an open-label, multicenter, randomized controlled trial

BACKGROUND

Clarithromycin-containing triple regimen for eradication of Helicobacter pylori is no longer acceptable in Korea due to high clarithromycin resistance. Concomitant therapy or bismuth-containing quadruple therapy is recommended as an alternative regimen. A recent study in Korea has shown that modified quadruple therapy has comparable efficacy and safety to concomitant therapy as a first-line regimen. However, there has been no comparative study of modified quadruple therapy with bismuth-containing quadruple therapy. The aim of this study is to compare the efficacy and safety of modified quadruple therapy with those of bismuth-containing quadruple therapy as a first-line regimen and to present the phenotypic and genotypic antibiotic resistance profile of H pylori.

METHODS

This study is an open-label, multicenter, randomized controlled trial. We are recruiting subjects endoscopically diagnosed with H pylori infection from 2 hospitals in Korea. Subjects will be randomly allocated either to modified quadruple therapy (proton-pump inhibitor bid, amoxicillin 1 g bid, metronidazole 500 mg tid, bismuth subcitrate 300 mg qid daily) or bismuth-containing quadruple therapy (proton-pump inhibitor bid, tetracycline 500 mg qid, metronidazole 500 mg tid, bismuth subcitrate 300 mg qid daily) for 14 days. The rate of eradication success and adverse events will be checked at least 4 weeks after the treatment. Antibiotic resistance will be established using both a bacterial culture with agar dilutions and DNA sequencing of the clarithromycin resistance point mutations in the 23S rRNA gene of H pylori.

CONCLUSION

The results of this study will provide solid evidence for determining the optimal treatment regimen for first-line H pylori eradication in Korea.

Gastric cancer: French intergroup clinical practice guidelines for diagnosis, treatments and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of gastric cancer published in October 2016, available on the website of the French Society of Gastroenterology (SNFGE) (www.tncd.org), updated in October 2017.

METHODS

This collaborative work was realized under the auspices of several French medical societies involved in management of gastric cancer. Recommendations are graded in three categories (A-C), according to the amount of evidence found in the literature until July 2017.

RESULTS

There are several known risk factors for gastric cancer, including Helicobacter pylori and genetic predispositions, both requiring a specific screening for patients and their relatives. The diagnosis and staging evaluation are essentially based on gastroscopy plus biopsies and computed tomography scan. The endoscopic ultrasonography can be used for superficial tumors in case of discussion for endoscopic resection (T1N0). For local disease (N+ and/or T > T1), the strategic therapy is based on surgery associated with perioperative chemotherapy. In the absence of preoperative treatment (for any raison), the postoperative chemoradiotherapy (or chemotherapy) should be discussed for patients with stage II or III tumor. For metastatic disease, the treatment is based on "palliative" chemotherapy consisting in a doublet or triplet regimens depending of age, performance status and HER2 tumor status. For patients with limited metastatic disease, surgical resection could be discussed in multidisciplinary meeting in case of stable disease after chemotherapy.

CONCLUSION

These guidelines in gastric cancer are done to help decision for daily clinical practice. These recommendations are permanently being reviewed. Each individual case must be discussed within a multidisciplinary team.

Occurrence of metachronous or synchronous lesions after endoscopic treatment of gastric epithelia dysplasia- impact of histologic features of background mucosa

AIMS

Endoscopic resection is a safe and effective method to treat gastric epithelia dysplasia (GED). However, the development of metachronous and synchronous lesions after treatment has become a major concern. In this study, we investigated clinicopathologic features of 105 GED lesions from endoscopic resections between January 2008 and December 2009. Our goal is to find histologic factors that predict synchronous and metachronous lesions after ESD treatment. We assessed the degree of intestinal metaplasia (IM) and atrophy, type of IM, presence of gastritis cystica profunda, and crypt dysplasia in the adjacent mucosa.

METHODS AND RESULTS

We divided 105 GED lesions into three groups: a single group without metachronous or synchronous GED or adenocarcinoma (n=35); a multiple synchronous group (n=30, group with synchronous occurrence of GED or adenocarcinoma after treatment); and a multiple metachronous group (n=40, group with metachronous occurrence of GED or adenocarcinoma after treatment). The multiple metachronous and synchronous groups showed larger sizes (p=0.003) and higher grades (p=0.021) as compared with the single group. Furthermore, marked IM and atrophy in adjacent mucosa were more easily seen in the multiple metachronous and synchronous groups as compared with the single group (p<0.0001). Interestingly, the presence of incomplete type of IM (p=0.025) and crypt dysplasia (p<0.0001) in background mucosa was associated with occurrence of metachronous and synchronous lesions following endoscopic resection of GED.

CONCLUSIONS

The histological features of background mucosa, such as intestinal metaplasia, atrophy, and crypt dysplasia could be used as indicators of occurrence of metachronous and synchronous lesions after endoscopic treatment of GED.

Potential lncRNA diagnostic biomarkers for early gastric cancer

Long noncoding RNAs (lncRNAs) serve important functions in many crucial biological processes; however, the effects of lncRNAs in early gastric cancer (EGC) are not entirely clear. The present study aimed to demonstrate the potential of lncRNAs to be used as biomarkers in EGC. Reverse transcription‑quantitative polymerase chain reaction was used to measure the expression levels of lncRNAs, including X inactive‑specific transcript (XIST), Yiya, brain cytoplasmic RNA 1 (BCYRN1), ribosomal RNA processing 1B (RRP1B), KCNQ1 opposite transcript 1 (KCNQ1OT1) and testes development related 1 (TDRG1), in EGC tissues compared with normal adjacent tissues (NATs). XIST, BCYRN1, RRP1B and TDRG1 were identified as differentially expressed in EGC tissues compared with NATs. The specificity and sensitivity of XIST, BCYRN1, RRP1B and TDRG1 were determined by receiver operating characteristic curve analysis. In addition, RRP1B expression was revealed to be significantly correlated with distal metastasis (P=0.020) and tumor‑node‑metastasis staging (P=0.018), and TDRG1 expression was significantly correlated with lymph node metastasis (P=0.001). Furthermore, BCYRN1, RRP1B and TDRG1 expression levels were compared between EGC tissues and plasma, and the results indicated that there were significant positive correlations of XIST, BCYRN1, RRP1B and TDRG1 expression levels between the EGC tissues and plasma. Therefore, the present study suggested that XIST, BCYRN1, RRP1B and TDRG1 may be served as potential diagnostic biomarkers for EGC.

Molecular Characterization of the Human Stomach Microbiota in Gastric Cancer Patients

Helicobacter pylori (Hp) is the primary cause of gastric cancer but we know little of its relative abundance and other microbes in the stomach, especially at the time of gastric cancer diagnosis. Here we characterized the taxonomic and derived functional profiles of gastric microbiota in two different sets of gastric cancer patients, and compared them with microbial profiles in other body sites. Paired non-malignant and tumor tissues were sampled from 160 gastric cancer patients with 80 from China and 80 from Mexico. The 16S rRNA gene V3-V4 region was sequenced using MiSeq platform for taxonomic profiles. PICRUSt was used to predict functional profiles. Human Microbiome Project was used for comparison. We showed that Hp is the most abundant member of gastric microbiota in both Chinese and Mexican samples (51 and 24%, respectively), followed by oral-associated bacteria. Taxonomic (phylum-level) profiles of stomach microbiota resembled oral microbiota, especially when the Helicobacter reads were removed. The functional profiles of stomach microbiota, however, were distinct from those found in other body sites and had higher inter-subject dissimilarity. Gastric microbiota composition did not differ by Hp colonization status or stomach anatomic sites, but did differ between paired non-malignant and tumor tissues in either Chinese or Mexican samples. Our study showed that Hp is the dominant member of the non-malignant gastric tissue microbiota in many gastric cancer patients. Our results provide insights on the gastric microbiota composition and function in gastric cancer patients, which may have important clinical implications.

Risk factors for metachronous gastric carcinoma development after endoscopic resection of gastric dysplasia: Retrospective, single-center study

AIM

To determine the gastric adenocarcinoma (GAC) occurrence rate and related factors, we evaluated the follow-up results of patients confirmed to have gastric dysplasia after endoscopic resection (ER).

METHODS

We retrospectively analyzed the medical records, endoscopic examination records, endoscopic procedure records, and histological records of 667 cases from 641 patients who were followed-up for at least 12 mo, from among 1273 patients who were conformed to have gastric dysplasia after Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) of gastric mucosal lesions between January 2007 and August 2013 at the Chungnam National University Hospital.

RESULTS

The mean follow-up period was 33.8 mo, and the median follow-up period was 29 mo (range: 12-87). During the follow-up period, the occurrence of metachronous GAC was 4.0% (27/667). The mean and median interval periods between the occurrence of metachronous GAC and endoscopic treatment of gastric dysplasia were 36.3 and 34 mo, respectively (range: 16-71). The factors related to metachronous GAC occurrence after ER for gastric dysplasia were male sex (5.3% vs 1.0%), open-type atrophic gastritis (9.5% vs 3.4%), intestinal metaplasia (6.8% vs 2.4%), and high-grade dysplasia (HGD; 8.4% vs 3.2%). Among them, male sex [OR: 5.05 (1.18-21.68), P = 0.029], intestinal metaplasia [OR: 2.78 (1.24-6.23), P = 0.013], and HGD [OR: 2.70 (1.16-6.26), P = 0.021] were independent related factors in multivariate analysis. Furthermore, 24 of 27 GAC cases (88.9%) occurred at sites other than the previous resection sites, and 3 (11.1%) occurred at the same site as the previous resection site.

CONCLUSION

Male sex, intestinal metaplasia, and HGD were significantly related to the occurrence of metachronous GAC after ER of gastric dysplasia, and most GACs occurred at sites other than the previous resection sites.

ACG Clinical Guideline: Treatment of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) infection is a common worldwide infection that is an important cause of peptic ulcer disease and gastric cancer. H. pylori may also have a role in uninvestigated and functional dyspepsia, ulcer risk in patients taking low-dose aspirin or starting therapy with a non-steroidal anti-inflammatory medication, unexplained iron deficiency anemia, and idiopathic thrombocytopenic purpura. While choosing a treatment regimen for H. pylori, patients should be asked about previous antibiotic exposure and this information should be incorporated into the decision-making process. For first-line treatment, clarithromycin triple therapy should be confined to patients with no previous history of macrolide exposure who reside in areas where clarithromycin resistance amongst H. pylori isolates is known to be low. Most patients will be better served by first-line treatment with bismuth quadruple therapy or concomitant therapy consisting of a PPI, clarithromycin, amoxicillin, and metronidazole. When first-line therapy fails, a salvage regimen should avoid antibiotics that were previously used. If a patient received a first-line treatment containing clarithromycin, bismuth quadruple therapy or levofloxacin salvage regimens are the preferred treatment options. If a patient received first-line bismuth quadruple therapy, clarithromycin or levofloxacin-containing salvage regimens are the preferred treatment options. Details regarding the drugs, doses and durations of the recommended and suggested first-line and salvage regimens can be found in the guideline.

Effect of World Health Organization (WHO) Histological Classification on Predicting Lymph Node Metastasis and Recurrence in Early Gastric Cancer

Background

The World Health Organization (WHO) histological classification for gastric cancer is widely accepted and used. However, its impact on predicting lymph node metastasis and recurrence in early gastric cancer (EGC) is not well studied.

Material/Methods

From 1987 to 2005, 2873 EGC patients with known WHO histological type who had undergone curative resection were enrolled in this study. In all, 637 well-differentiated adenocarcinomas (WD), 802 moderately-differentiated adenocarcinomas (MD), 689 poorly-differentiated adenocarcinomas (PD), and 745 signet-ring cell adenocarcinomas (SRC) were identified.

Results

The distribution of demographic and clinical features in early gastric cancer among WD, MD, PD, and SRC were significantly different. Lymph node metastasis was observed in 317 patients (11.0%), with the lymph node metastasis rate being 5.3%, 14.8%, 17.0%, and 6.3% in WD, MD, PD, and SRC, respectively. Univariate and multivariate analyses indicated that gender, tumor size, gross appearance, depth of invasion, and WHO classification were significantly associated with lymph node metastasis. Recurrence was observed in 83 patients (2.9%), with the recurrence rate being 2.2%, 4.5%, 3.0%, and 1.6% in WD, MD, PD, and SRC, respectively. Multivariate analysis confirmed that MD, elevated gross type, and lymph node metastasis were independent risk factors for recurrence in EGC. MD patients showed worse disease-free survival than non-MD patients (P=0.001).

Conclusions

WHO classification is useful and necessary to evaluate during the perioperative management of EGC. Treatment strategies for EGC should be made prudently according to WHO classification, especially for MD patients.

Clinicopathologic Similarities of the Main and Minor Lesions of Synchronous Multiple Early Gastric Cancer

The detection rate of early gastric cancer (EGC) is increasing due to improvements in diagnostic methods, but synchronous multiple EGC (SMEGC) remains a major problem. Therefore, we investigated the characteristics of and the correlation between the main and minor lesions of SMEGC. We retrospectively reviewed the medical records of patients with EGC between April 2008 and May 2013. The main lesion was defined as the one with the greatest invasion depth. If lesions had the same invasion depth, the tumor diameter was used to define the main lesion. Of 963 patients who had treatment for EGC, 37 patients with SMEGC were analyzed. The main and minor lesions showed a significant positive correlation of size (r = 0.533, P = 0.001). The main and minor lesions of SMEGC showed the same vertical and horizontal locations at 70.3% and 64.9%, respectively (P = 0.002 and P = 0.002). Macroscopic types were identical in 67.6% (P < 0.001), and 32.4% had identical macroscopic type and location. The main and minor lesions had identical characteristics of invasion depth, presence of lymphovascular invasion (LVI), and differentiation in 78.4%, 83.8%, and 83.8%, respectively. Differentiation, LVI, and invasion depth (microscopic characteristics) were simultaneously the same in 62.2%. The location, macroscopic type, and 3 microscopic characteristics were matched in 27%. The main and minor lesions of SMEGC have similar clinicopathologic characteristics. Therefore, the possibility of SMEGC should not be neglected in cases of EGC, considering an understanding of the characteristics and association of lesions.