Association between infection with Helicobacter pylori and risk of gastric cancer: evidence from a prospective investigation

Helicobacter pylori Eradication Reverses DNA Damage Response Pathway but Not Senescence in Human Gastric Epithelium

Helicobacter pylori (H. pylori) infection induces DNA Double-Strand Breaks (DSBs) and consequently activates the DNA Damage Response pathway (DDR) and senescence in gastric epithelium. We studied DDR activation and senescence before and after the eradication of the pathogen. Gastric antral and corpus biopsies of 61 patients with H. pylori infection, prior to and after eradication treatment, were analyzed by means of immunohistochemistry/immunofluorescence for DDR marker (γH2AΧ, phosporylated ataxia telangiectasia-mutated (pATM), p53-binding protein (53BP1) and p53) expression. Samples were also evaluated for Ki67 (proliferation index), cleaved caspase-3 (apoptotic index) and GL13 staining (cellular senescence). Ten H. pylori (-) dyspeptic patients served as controls. All patients were re-endoscoped in 72-1361 days (mean value 434 days), and tissue samples were processed in the same manner. The eradication of the microorganism, in human gastric mucosa, downregulates γH2AΧ expression in both the antrum and corpus (p = 0.00019 and p = 0.00081 respectively). The expression of pATM, p53 and 53BP1 is also reduced after eradication. Proliferation and apoptotic indices were reduced, albeit not significantly, after pathogen clearance. Moreover, cellular senescence is increased in H. pylori-infected mucosa and remains unaffected after eradication. Interestingly, senescence was statistically increased in areas of intestinal metaplasia (IM) compared with adjacent non-metaplastic mucosa (p < 0.001). In conclusion, H. pylori infection triggers DSBs, DDR and senescence in the gastric epithelium. Pathogen eradication reverses the DDR activation but not senescence. Increased senescent cells may favor IM persistence, thus potentially contributing to gastric carcinogenesis.

Efficacy and tolerability of Helicobacter pylori eradication regimes in South Kivu, Eastern of the Democratic Republic of Congo: A single center observational study

Background and Aims

Treating Helicobacter pylori infections has become a major challenge due to increased antibiotic resistance. The aim of this study was to investigate the efficacy and tolerability of the main standard regimens recommended for H. pylori eradication in Bukavu, Eastern of the Democratic Republic of Congo.

Methods

The study enrolled patients with evidence of H. pylori infection in histological examination or serology testing combined with a positive fecal antigen test. As first-line treatment, patients were randomized to either a 10-days (OAC-10) or a 14-days (OAC-14) regimen, employing a combination of omeprazole 20 mg, amoxicillin 1 g, and clarithromycin 500 mg twice daily. In case of failure, a second line regimen was evaluated and included two others protocols: OAC-10 regimen + levofloxacin 500 mg (OAC-10+) and the bismuth-based therapy (pantoprazole + bismuth salt + metronidazole + tetracycline) during 10 days. Our primary endpoint was H. pylori eradication and secondarily, the compliance and adverse effects were also evaluated.

Results

A total of 179 patients were enrolled. The eradication rate was 79.2% and 80.5% with the OAC-10 and OAC-14 regimen, respectively (p = 0.796). Adverse effects were significant higher in the OAC-14 group than in the OAC-10 group (36.5% vs. 57.8%; p < 0.001). On the other hand, the compliance rate was slightly higher in the OAC-10 group (97.9% vs. 91.6%, p = 0.052) while clinical improvement was almost similar in both groups. Regarding the second line regimen, the bismuth-based therapy (n = 18) seemed to show a better response with 100% of eradication rate and 100% of clinical improvement.

Conclusion

The classic 10-days triple therapy seems to be as effective as the 14-days regimen while having in addition a good tolerance. Apart from cost issues, the bismuth-based therapy seems to be a very good alternative in case of first-line treatment failure.

Helicobacter pylori CagA-mediated ether lipid biosynthesis promotes ferroptosis susceptibility in gastric cancer

Helicobacter pylori, particularly cytotoxin-associated gene A (CagA)-positive strains, plays a key role in the progression of gastric cancer (GC). Ferroptosis, associated with lethal lipid peroxidation, has emerged to play an important role in malignant and infectious diseases, but the role of CagA in ferroptosis in cancer cells has not been determined. Here, we report that CagA confers GC cells sensitivity to ferroptosis both in vitro and in vivo. Mechanistically, CagA promotes the synthesis of polyunsaturated ether phospholipids (PUFA-ePLs), which is mediated by increased expression of alkylglycerone phosphate synthase (AGPS) and 1-acylglycerol-3-phosphate O-acyltransferase 3 (AGPAT3), leading to susceptibility to ferroptosis. This susceptibility is mediated by activation of the MEK/ERK/SRF pathway. SRF is a crucial transcription factor that increases AGPS transcription by binding to the AGPS promoter region. Moreover, the results demonstrated that CagA-positive cells are more sensitive to apatinib than are CagA-negative cells, suggesting that detecting the H. pylori CagA status may aid patient stratification for treatment with apatinib.

Utilization of an Automated Latex Agglutination Turbidity Assay for Assessing Gastric Mucosal Alteration during Helicobacter pylori Infection

Background/Aims

: A latex agglutination turbidity (LA) assay to test for serum antibodies has been approved in Japan and Korea for mass screening of Helicobacter pylori infection. In this study, we evaluated the LA assay for diagnosing H. pylori infection and predicting gastric mucosal changes in a Mongolian population.

Methods

: In total, 484 individuals were classified into H. pylori-positive (n=356) and H. pylori-negative (n=128) groups, as determined by histology and H. pylori culture.

Results

: The best cutoff, sensitivity, and specificity values for the LA assay were 18.35 U/mL, 74.2%, and 65.6%, respectively. The LA values in the atrophic gastritis group were statistically higher than those in the other groups (healthy, chronic gastritis, intestinal metaplasia, and gastric cancer, p<0.0001). The cutoff value to distinguish the atrophic gastritis group from the other four groups was 32.0 U/mL, and its area under the curve was 0.673, which was the highest among the E-plate, pepsinogen (PG) I, PG II, and PG I/II ratio tests in our data. The odds ratios for atrophic gastritis determined by the LA assay and PG I test in multiple logistic regression were 2.5 and 1.9, respectively, which were significantly higher than for the other tests.

Conclusions

: The LA assay can determine the risk of atrophic gastritis, which in turn is a considerable risk factor for gastric cancer. We propose using this assay in combination with the PG I/II ratio to avoid missing gastric cancer patients who have a low LA value (less than 32.0 U/mL).

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

Biennial Endoscopic Surveillance of Gastrointestinal Metaplasia and Its Subtypes Reduces Gastric Cancer Mortality and Is Cost-Effective in a Markov State Transition Model

OBJECTIVES

Gastric cancer in the United States has a low survival rate mainly because of the late stage of diagnosis. Furthermore, there are no well-established guidelines concerning screening and surveillance even for higher risk patients such as those with nondysplastic noncardia gastrointestinal metaplasia (GIM), and thus they are not routinely performed. This study was designed to provide new evidence-based data that can be used to support the implementation of biennial surveillance guidelines in individuals with nondysplastic noncardia GIM. This practice can help detect early malignant lesions, thereby decreasing morbidity and mortality. We evaluated the cost-effectiveness of surveillance endoscopies for noncardia gastric cancer in populations with two different pathological diagnoses: mixed GIM and incomplete GIM (iGIM).

METHODS

Markov state transition models were developed using a cohort simulation of 1000 hypothetical patients. Analysis was conducted for both mixed and iGIM. Quality-adjusted life-years and transition probabilities were derived from the published medical literature. Costs associated with endoscopy, cancer care, and surgery were based on Medicare reimbursement. A willingness-to-pay threshold of $100,000 per quality-adjusted life-year was used to determine cost-effectiveness.

RESULTS

Our study determined that it is significantly cost-effective to perform biennial endoscopy surveillance in patients who have been incidentally found to have noncardia mixed GIM, with a cost savings of $5783.84 per person, and in those with iGIM, with a cost savings of $8093.08 per person.

CONCLUSIONS

Biennial endoscopy surveillance should be considered in all individuals found to have mixed or incomplete noncardia GIM on endoscopy. Furthermore, screening specifically for iGIM after differentiating between the two groups can lead to further cost savings. As such, we recommend that pathologists routinely differentiate between the two and recommend robust routine surveillance of iGIM.

The Microbiome in the Obesity-Breast Cancer Axis: Diagnostic and Therapeutic Potential

A growing body of evidence has demonstrated a relationship between the microbiome, adiposity, and cancer development. The microbiome is emerging as an important factor in metabolic disease and cancer pathogenesis. This review aimed to highlight the role of the microbiome in obesity and its association with cancer, with a particular focus on breast cancer. This review discusses how microbiota dysbiosis may contribute to obesity and obesity-related diseases, which are linked to breast cancer. It also explores the potential of the gut microbiome to influence systemic immunity, leading to carcinogenesis via the modulation of immune function. This review underscores the potential use of the microbiome profile as a diagnostic tool and treatment target, with strategies including probiotics, fecal microbiota transplantation, and dietary interventions. However, this emphasizes the need for more research to fully understand the complex relationship between the microbiome, metabolic disorders, and breast cancer. Future studies should focus on elucidating the mechanisms underlying the impact of the microbiome on breast cancer and exploring the potential of the microbiota profile as a biomarker and treatment target.

Controversies regarding management of Helicobacter pylori infections

PURPOSE OF REVIEW

The recognition that Helicobacter pylori should be considered and treated as an infectious disease has yet to fundamentally change diagnostic and treatment practices and has resulted in many controversies.

RECENT FINDINGS

We discuss the following controversies: whether the current 'per-patient' approach to H. pylori testing based on symptoms should be expanded to include achieving population-level H. pylori eradication, whether H. pylori should be approached as an infectious gastrointestinal disease similar to that of other infectious diseases of similar severity and outcome, whether treatment of H. pylori should be primarily empiric or based on antibiotic susceptibility and locally proven successful therapies as are other infectious diseases, whether it is necessary to obtain confirmation of treatment success in every patient treated for H. pylori , and whether potassium-competitive acid blockers should replace proton pump inhibitors in H. pylori therapy.

SUMMARY

Available guidelines and meta-analyses do not yet address H. pylori as an infectious disease. The diagnosis and management and treatment success of H. pylori infections trails behind that of other important infectious diseases. We provide new insights and propose changes in the traditional understanding required to modernize the management of H. pylori infections.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

PROSPERO REGISTRATION

CRD42021274120.

MAT Gain of Activity Mutation in Helicobacter pylori Is Associated with Resistance to MTAN Transition State Analogues

Helicobacter pylori is found in the gut lining of more than half of the world's population, causes gastric ulcers, and contributes to stomach cancers. Menaquinone synthesis in H. pylori relies on the rare futalosine pathway, where H. pylori 5'-methylthioadenosine nucleosidase (MTAN) is proposed to play an essential role. Transition state analogues of MTAN, including BuT-DADMe-ImmA (BTDIA) and MeT-DADMe-ImmA (MTDIA), exhibit bacteriostatic action against numerous diverse clinical isolates of H. pylori with minimum inhibitory concentrations (MIC's) of <2 ng/mL. Three H. pylori BTDIA-resistant clones were selected under increasing BTDIA pressure. Whole genome sequencing showed no mutations in MTAN. Instead, resistant clones had mutations in metK, methionine adenosyltransferase (MAT), feoA, a regulator of the iron transport system, and flhF, a flagellar synthesis regulator. The mutation in metK causes expression of a MAT with increased catalytic activity, leading to elevated cellular S-adenosylmethionine. Metabolite analysis and the mutations associated with resistance suggest multiple inputs associated with BTDIA resistance. Human gut microbiome exposed to MTDIA revealed no growth inhibition under aerobic or anaerobic conditions. Transition state analogues of H. pylori MTAN have potential as agents for treating H. pylori infection without disruption of the human gut microbiome or inducing resistance in the MTAN target.

Overlapping cytokines in H. pylori infection and gastric cancer: A tandem meta-analysis

Background

Previous evidence indicated that Helicobacter pylori-induced inflammation is the first step towards gastric carcinogenesis. However, investigations of the immunological factors driving this process have shown inconsistencies. We aimed to present a thorough summary of all researched cytokines in relation to H. pylori infection and GC and relate these to global GC risk.

Methods

We performed a systematic review and tandem meta-analysis identifying all published studies reporting on serum cytokine levels in H. pylori-infected cases vs. non-infected controls and gastric cancer cases vs. non-gastric cancer controls, with sub-analyses performed to identify global regional differences in cytokine induction and their correlation with GC incidence.

Results

Only levels of systemic IL-6 (standardized mean difference [SMD]:0.95, 95%CI [0.45;1.45]) and TNF-α (SMD:0.88, 95%CI [0.46; 1.29]) were significantly increased upon H. pylori infection. Sub-analysis showed that of IL-6 levels were increased upon H. pylori infection in East Asian, Middle Eastern and Southeast Asian cohorts, but not in North America, Europe, Russia and Africa. Serum levels of IL-6, IL-7, IL-10, IL-12, and TNF-α were significantly raised in GC. Exploration of the relationship between serum cytokines changes upon H. pylori infection and regional differences in risk of GC development indicated that the SMD of IL-6 serum levels presents a significant correlation with the relative incidence of GC (r=0.81, p=0.00014).

Conclusion

This study shows that H. pylori infection and GC are associated with increased IL-6 and TNF-α levels. Particularly, IL-6 shows region-specific increases that correlate with GC incidence, making it a key contender for the cause of this disease.

Indoor Solid Fuel Use and Non-Neoplastic Digestive System Diseases: A Population-Based Cohort Study Among Chinese Middle-Aged and Older Population

Objectives: We tended to explore the association of indoor air pollution (IAP) and non-neoplastic digestive system diseases (NNDSD) among the Chinese middle-aged and older population. Methods: From 2011 to 2018, we included 7884 NNDSD-free adults from the China Health and Retirement Longitudinal Study (CHARLS). Physician-diagnosed NNDSD was obtained by self-reported information at baseline and updated across follow-up surveys. We investigated the associations between baseline exposure of solid fuel use for cooking and/or heating and NNDSD diagnosed during follow-up through Cox proportional hazard models. Furthermore, we examined the relationship between cooking fuel switching and NNDSD diagnosed during follow-up. Results: Solid fuel use for cooking and/or heating was positively associated with NNDSD after adjusting for potential confounders. The risk of NNDSD among subjects who always use solid fuel for cooking (adjusted hazard ratio [aHR]: 1.42; 95% confidence interval [CI]: 1.09, 1.84) was higher than those with always clean fuels. Moreover, we found a lower NNDSD risk among participants who switched from solid to clean cooking fuel (aHR: 0.65; 95% CI: 0.49, 0.87) than those with always solid fuels. Conclusion: Our present study shows that indoor solid fuel use is a dependent risk factor for NNDSD. Moreover, switching to clean fuel may contribute to the prevention of digestive system illnesses.

Relationship of the Difficulty of Helicobacter pylori Eradication with Drinking Habits and Allergic Disease

Eradication of Helicobacter pylori (H. pylori) is crucial to reduce the risk of developing gastric ulcers and gastric cancer. Although immunoglobulin E (IgE) levels and alcohol consumption have been shown to influence the failure of H. pylori eradication, the relationship between these factors and the mechanism of failure has not been clarified. Because high IgE levels are associated with eradication failure, the purpose of this study was to clarify the factors leading to high IgE levels. Completed questionnaires and blood test data were collected from patients who visited a university hospital for H. pylori eradication. Logistic regression analysis was per-formed to examine the relationship between high IgE levels and allergic diseases. We also examined the relationship between alcohol intake and high IgE levels. Linear regression analysis was performed on the relationship between the amount of alcohol consumed and IgE measurements. The results showed that patients with allergic diseases and those with high alcohol intake had significantly higher IgE levels. High IgE levels are a risk factor for failure of H. pylori eradication that is associated with drinking habits and alcohol consumption, and our results suggest that daily alcohol consumption should be avoided even in non-allergic patients.

Role of New Anatomy, Biliopancreatic Reflux, and Helicobacter Pylori Status in Postgastrectomy Stump Cancer

Distal gastrectomy for benign gastroduodenal peptic disease has become rare, but it still represents a widely adopted procedure for advanced and, in some countries, even for early distal gastric cancer. Survival rates following surgery for gastric malignancy are constantly improving, hence the residual mucosa of the gastric stump is exposed for a prolonged period to biliopancreatic reflux and, possibly, to Helicobacter pylori (HP) infection. Biliopancreatic reflux and HP infection are considered responsible for gastritis and metachronous carcinoma in the gastric stump after oncologic surgery. For gastrectomy patients, in addition to eradication treatment for cases that are already HP positive, endoscopic surveillance should also be recommended, for prompt surveillance and detection in the residual mucosa of any metaplastic-atrophic-dysplastic features following surgery.

Relative risk of gastric cancer between those with and without Helicobacter pylori infection history in Japan

Background and Aim

The causal relationship between Helicobacter pylori (H. pylori) infection and gastric cancer has been established. Although the magnitude of the carcinogenic effect of H. pylori is the next concern, it has not been sufficiently evaluated in Japan. Spontaneous disappearance of H. pylori infection may have provoked underestimation of the carcinogenic effect of the infection. To reduce the influence, a comparison should be carried out between subjects with and without the infection history. Cutoff values of H. pylori antibody lower than the manufacturer's recommendation are known to be more appropriate to diagnose history of H. pylori infection. The aim was to evaluate the carcinogenic effect of H. pylori.

Methods

A case–control study consisting of 275 gastric cancer patients and 275 age‐ and sex‐matched controls was performed. Serum H. pylori antibody was measured using the “JHM‐Cap” kit with a domestic antigen (cut value of the manufacturer's recommendation was 2.3 EV: ELISA value). Using a conditional logistic model, the odds ratios (ORs) for five cutoff values adjusted for smoking and drinking doses were calculated.

Results

For cutoff values of 1.25, 1.5, 1.75, 2.0, and 2.3 EV, the ORs (95% confidence intervals) were 67.7 (9.1, 502), 37.2 (8.8, 157), 21.3 (9.0, 60.2), 25.5 (9.0, 72.7), and 25.9 (9.2, 73.2), respectively.

Conclusions

These results suggest that the risk ratio of gastric cancer between subjects with and without history of H. pylori infection in Japan may exceed 20.

Identification of B-Cell Epitopes of HspA from Helicobacter pylori and Detection of Epitope Antibody Profiles in Naturally Infected Persons

Helicobacter pylori (H. pylori), heat-shock protein A (HspA), is a bacterial heat-shock chaperone that serves as a nickel ion scavenging protein. Ni²⁺ is an important co-factor required for the maturation and enzymatic activity of H. pylori urease and [NiFe] hydrogenase, both of which are key virulence factors for pathogen survival and colonization. HspA is an important target molecule for the diagnosis, treatment, and immune prevention of H. pylori. In this work, HspA was truncated into five fragments to determine the location of an antigen immunodominant peptide. A series of overlapping, truncated 11-amino-acid peptides in immunodominant peptide fragments were synthesized chemically and screened by ELISA. The immunogenicity and antigenicity of the screened epitope peptides were verified by ELISA, Western blot, and lymphocyte proliferation tests. Two novel B-cell epitopes were identified, covering amino acids 2–31 of HspA, which are HP11 (2–12; KFQPLGERVLV) and HP19 (18–28; ENKTSSGIIIP). The antiserum obtained from HP11-KLH and HP19-KLH immunized mice can bind to naive HspA in H. pylori SS2000, rHspA expressed in E. coli, and the corresponding GST fusion peptide. Among HspA seropositive persons, the seropositive rates of HP11 and HP19 were 21.4% and 33.3%, respectively. Both of the B-cell epitopes of HspA are highly conserved epitopes with good antigenicity and immunogenicity.

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.

In vitro and in vivo inhibition of Helicobacter pylori by Lactobacillus plantarum pH3A, monolaurin, and grapefruit seed extract

Helicobacter pylori infection is the most common cause of gastritis and gastric ulcers. Considering the severe side effects of current antibiotic therapies, it is crucial to find an alternate treatment for H. pylori infection. In this study, we investigated the anti-H. pylori effects of a newly isolated strain of Lactobacillus plantarum (pH3A), monolaurin, grapefruit seed extract (GSE), and their synergies in vitro and in vivo. Monolaurin and GSE suppressed H. pylori growth and urease activity at a minimal inhibitory concentration (MIC) of 62.5 ppm. Live cells and cell-free culture supernatant (CFCS) of L. plantarum pH3A with or without pH adjustment also significantly inhibited H. pylori growth. Although synergy was not observed between monolaurin and GSE, the addition of CFCS significantly enhanced their anti-H. pylori activities. Moreover, L. plantarum pH3A significantly decreased the ability of H. pylori to adhere to AGS cells and interleukin (IL)-8 production in the H. pylori-stimulated AGS cell line. The addition of GSE or monolaurin strengthened these effects. In the in vivo study, H. pylori colonization of the mouse stomach and total serum IgG production were significantly reduced by L. plantarum pH3A treatment, but the addition of monolaurin or GSE did not contribute to these anti-H. pylori activities. Therefore, the L. plantarum pH3A strain can potentially be applied as an alternative anti-H. pylori therapy, but evidence of its synergy with monolaurin or GSE in vivo is still lacking.

From microbiota toward gastro-enteropancreatic neuroendocrine neoplasms: Are we on the highway to hell?

Gut microbiota is represented by different microorganisms that colonize the intestinal tract, mostly the large intestine, such as bacteria, fungi, archaea and viruses. The gut microbial balance has a key role in several functions. It modulates the host's metabolism, maintains the gut barrier integrity, participates in the xenobiotics and drug metabolism, and acts as protection against gastro-intestinal pathogens through the host's immune system modulation. The impaired gut microbiota, called dysbiosis, may be the result of an imbalance in this equilibrium and is linked with different diseases, including cancer. While most of the studies have focused on the association between microbiota and gastrointestinal adenocarcinomas, very little is known about gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs). In this review, we provide an overview concerning the complex interplay between gut microbiota and GEP NENs, focusing on the potential role in tumorigenesis and progression in these tumors.

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

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

Association Between Patients' Immunoglobulin E Levels and Difficulty Eradicating Helicobacter pylori

Background

Helicobacter pylori is a cause of gastric cancer, and thus the eradication of this bacterium is very important. The success rate of primary eradication has been dramatically increased by the introduction of potassium-competitive acid blockers. However, H. pylori cannot be eradicated in all patients, and the contributing factors need to be clarified.

Aim

Because allergy status may be a factor and considering research linking hay fever with eradication failure, the purpose of this study was to examine blood immunoglobulin E levels as a contributing factor in patients who were unable to eradicate H. pylori in a single eradication treatment and who underwent multiple eradication attempts.

Methods

Questionnaire data were collected from 250 patients who visited the Department of Gastroenterology, Hamamatsu University School of Medicine, for H. pylori eradication. In addition, non-specific IgE levels in the blood were measured and analyzed with one-way analysis of variance. Multinomial logistic regression analysis was performed to examine the association between the number of eradication attempts and the IgE level (< 500 vs ≥ 500 IU/mL).

Results

The mean IgE values were 188.4, 211.9, and 744.0 IU/mL in patients with one, two, and three or more eradication attempts, respectively (P < 0.05). The results of multinomial logistic regression analysis showed that attempting eradication three or more times was significantly associated with high levels of IgE, even after consideration of antibiotic sensitivity.

Conclusion

H. pylori eradication was less likely in patients with high IgE. It is thus necessary to study the appropriate regimen for patients with high IgE levels.

Chemoprevention Against Gastric Cancer

Gastric cancer is the fifth most common cause of cancer and the third leading cause of cancer-related deaths globally. The number of gastric cancer-related deaths is only projected to increase, attributable primarily to the expanding aging population. Prevention is a mainstay of gastric cancer control programs, particularly in the absence of accurate, noninvasive modalities for screening and early detection, and the absence of an infrastructure for this purpose in the majority of countries worldwide. Herein, we discuss the evidence for several chemopreventive agents, along with putative mechanisms. There remains a clear, unmet need for primary chemoprevention trials for gastric cancer.

Gastric Cancer Stem Cells: A Glimpse on Metabolic Reprogramming

Gastric cancer (GC) is one of the most widespread causes of cancer-related death worldwide. Recently, emerging implied that gastric cancer stem cells (GCSCs) play an important role in the initiation and progression of GC. This subpopulation comprises cells with several features, such as self-renewal capability, high proliferating rate, and ability to modify their metabolic program, which allow them to resist current anticancer therapies. Metabolic pathway intermediates play a pivotal role in regulating cell differentiation both in tumorigenesis and during normal development. Thus, the dysregulation of both anabolic and catabolic pathways constitutes a significant opportunity to target GCSCs in order to eradicate the tumor progression. In this review, we discuss the current knowledge about metabolic phenotype that supports GCSC proliferation and we overview the compounds that selectively target metabolic intermediates of CSCs that can be used as a strategy in cancer therapy.

Aminofutalosine Deaminase in the Menaquinone Pathway of Helicobacter pylori

Helicobacter pylori is a Gram-negative bacterium that is responsible for gastric and duodenal ulcers. H. pylori uses the unusual mqn pathway with aminofutalosine (AFL) as an intermediate for menaquinone biosynthesis. Previous reports indicate that hydrolysis of AFL by 5'-methylthioadenosine nucleosidase (HpMTAN) is the direct path for producing downstream metabolites in the mqn pathway. However, genomic analysis indicates jhp0252 is a candidate for encoding AFL deaminase (AFLDA), an activity for deaminating aminofutolasine. The product, futalosine, is not a known substrate for bacterial MTANs. Recombinant jhp0252 was expressed and characterized as an AFL deaminase (HpAFLDA). Its catalytic specificity includes AFL, 5'-methylthioadenosine, 5'-deoxyadenosine, adenosine, and S-adenosylhomocysteine. The k_cat/K_m value for AFL is 6.8 × 10⁴ M^-1 s^-1, 26-fold greater than that for adenosine. 5'-Methylthiocoformycin (MTCF) is a slow-onset inhibitor for HpAFLDA and demonstrated inhibitory effects on H. pylori growth. Supplementation with futalosine partially restored H. pylori growth under MTCF treatment, suggesting AFL deamination is significant for cell growth. The crystal structures of apo-HpAFLDA and with MTCF at the catalytic sites show a catalytic site Zn²⁺ or Fe²⁺ as the water-activating group. With bound MTCF, the metal ion is 2.0 Å from the sp³ hydroxyl group of the transition state analogue. Metabolomics analysis revealed that HpAFLDA has intracellular activity and is inhibited by MTCF. The mqn pathway in H. pylori bifurcates at aminofutalosine with HpMTAN producing adenine and depurinated futalosine and HpAFLDA producing futalosine. Inhibition of cellular HpMTAN or HpAFLDA decreased the cellular content of menaquinone-6, supporting roles for both enzymes in the pathway.

Microbiota and cancer: In vitro and in vivo models to evaluate nanomedicines

Nanomedicine implication in cancer treatment and diagnosis studies witness huge attention, especially with the promising results obtained in preclinical studies. Despite this, only few nanomedicines succeeded to pass clinical phase. The human microbiota plays obvious roles in cancer development. Nanoparticles have been successfully used to modulate human microbiota and notably tumor associated microbiota. Taking the microbiota involvement under consideration when testing nanomedicines for cancer treatment might be a way to improve the poor translation from preclinical to clinical trials. Co-culture models of bacteria and cancer cells, as well as animal cancer-microbiota models offer a better representation for the tumor microenvironment and so potentially better platforms to test nanomedicine efficacy in cancer treatment. These models would allow closer representation of human cancer and might smoothen the passage from preclinical to clinical cancer studies for nanomedicine efficacy.

Exhaled breath analysis in disease detection

Investigating the use of exhaled breath analysis to diagnose and monitor different diseases has attracted much interest in recent years. This review introduces conventionally used methods and some emerging technologies aimed at breath analysis and their relevance to lung disease, airway inflammation, gastrointestinal disorders, metabolic disorders and kidney diseases. One section correlates breath components and specific diseases, whereas the other discusses some unique ideas, strategies, and devices to analyze exhaled breath for the diagnosis of some common diseases. This review aims to briefly introduce the potential application of exhaled breath analysis for the diagnosis and screening of various diseases, thereby providing a new avenue for the detection of non-invasive diseases.

Impact of Helicobacter pylori Infection and Its Major Virulence Factor CagA on DNA Damage Repair

Helicobacter pylori infection induces a plethora of DNA damages. Gastric epithelial cells, in order to maintain genomic integrity, require an integrous DNA damage repair (DDR) machinery, which, however, is reported to be modulated by the infection. CagA is a major H. pylori virulence factor, associated with increased risk for gastric carcinogenesis. Its pathogenic activity is partly regulated by phosphorylation on EPIYA motifs. Our aim was to identify effects of H. pylori infection and CagA on DDR, investigating the transcriptome of AGS cells, infected with wild-type, ΔCagA and EPIYA-phosphorylation-defective strains. Upon RNA-Seq-based transcriptomic analysis, we observed that a notable number of DDR genes were found deregulated during the infection, potentially resulting to base excision repair and mismatch repair compromise and an intricate deregulation of nucleotide excision repair, homologous recombination and non-homologous end-joining. Transcriptome observations were further investigated on the protein expression level, utilizing infections of AGS and GES-1 cells. We observed that CagA contributed to the downregulation of Nth Like DNA Glycosylase 1 (NTHL1), MutY DNA Glycosylase (MUTYH), Flap Structure-Specific Endonuclease 1 (FEN1), RAD51 Recombinase, DNA Polymerase Delta Catalytic Subunit (POLD1), and DNA Ligase 1 (LIG1) and, contrary to transcriptome results, Apurinic/Apyrimidinic Endodeoxyribonuclease 1 (APE1) upregulation. Our study accentuates the role of CagA as a significant contributor of H. pylori infection-mediated DDR modulation, potentially disrupting the balance between DNA damage and repair, thus favoring genomic instability and carcinogenesis.

Deep learning for sensitive detection of Helicobacter Pylori in gastric biopsies

Background

Helicobacter pylori, a 2 × 1 μm spiral-shaped bacterium, is the most common risk factor for gastric cancer worldwide. Clinically, patients presenting with symptoms of gastritis, routinely undergo gastric biopsies. The following histo-morphological evaluation dictates therapeutic decisions, where antibiotics are used for H. pylori eradication. There is a strong rational to accelerate the detection process of H. pylori on histological specimens, using novel technologies, such as deep learning.

Methods

We designed a deep-learning-based decision support algorithm that can be applied on regular whole slide images of gastric biopsies. In detail, we can detect H. pylori both on Giemsa- and regular H&E stained whole slide images.

Results

With the help of our decision support algorithm, we show an increased sensitivity in a subset of 87 cases that underwent additional PCR- and immunohistochemical testing to define a sensitive ground truth of HP presence. For Giemsa stained sections, the decision support algorithm achieved a sensitivity of 100% compared to 68.4% (microscopic diagnosis), with a tolerable specificity of 66.2% for the decision support algorithm compared to 92.6 (microscopic diagnosis).

Conclusion

Together, we provide the first evidence of a decision support algorithm proving as a sensitive screening option for H. pylori that can potentially aid pathologists to accurately diagnose H. pylori presence on gastric biopsies.

The Intersection between Oral Microbiota, Host Gene Methylation and Patient Outcomes in Head and Neck Squamous Cell Carcinoma

Simple Summary

Recently, there has been increased recognition of an association between the bacterial microbiome and cancer. In this study, we characterized the non-HPV head and neck squamous cell carcinoma (HNSCC) microbiome. We found a significant enrichment of Fusobacterium, depletion of Streptococcus, and the microbial signatures of twelve bacterial genera distinguishing HNSCC. With increased Fusobacterium—in particular, F. nucleatum—in our HNSCC cohort and its known association with prognosis in colorectal cancers (CRC), we sought to further characterize the association between clinical outcomes and F. nucleatum, and the host interaction with F. nucleatum. We identified a higher abundance of F. nucleatum in non-smokers and an improved survival, in contrast to CRC. An integrative analysis also identified that the enrichment of F. nucleatum was associated with host gene promoter methylation, suggesting that the bacterial mircobiome status may have a potential role as a prognostic biomarker and be involved in the pathogenesis of HNSCC.

Abstract

The role of oral microbiota in head and neck squamous cell carcinoma (HNSCC) is poorly understood. Here we sought to evaluate the association of the bacterial microbiome with host gene methylation and patient outcomes, and to explore its potential as a biomarker for early detection or intervention. Here we performed 16S rRNA gene amplicon sequencing in sixty-eight HNSCC patients across both tissue and oral rinse samples to identify oral bacteria with differential abundance between HNSCC and controls. A subset of thirty-one pairs of HNSCC tumor tissues and the adjacent normal tissues were characterized for host gene methylation profile using bisulfite capture sequencing. We observed significant enrichments of Fusobacterium and Peptostreptococcus in HNSCC tumor tissues when compared to the adjacent normal tissues, and in HNSCC oral rinses when compared to healthy subjects, while ten other bacterial genera were largely depleted. These HNSCC-related bacteria were discriminative for HNSCC and controls with area under the receiver operating curves (AUCs) of 0.84 and 0.86 in tissue and oral rinse samples, respectively. Moreover, Fusobacterium nucleatum abundance in HNSCC cases was strongly associated with non-smokers, lower tumor stage, lower rate of recurrence, and improved disease-specific survival. An integrative analysis identified that enrichment of F. nucleatum was associated with host gene promoter methylation, including hypermethylation of tumor suppressor genes LXN and SMARCA2, for which gene expressions were downregulated in the HNSCC cohort from The Cancer Genome Atlas. In conclusion, we identified a taxonomically defined microbial consortium associated with HNSCC that may have clinical potential regarding biomarkers for early detection or intervention. Host–microbe interactions between F. nucleatum enrichment and clinical outcomes or host gene methylation imply a potential role of F. nucleatum as a pro-inflammatory driver in initiating HNSCC without traditional risk factors, which warrants further investigation for the underlying mechanisms.

Salt Reduction to Prevent Hypertension and Cardiovascular Disease: JACC State-of-the-Art Review

There is strong evidence for a causal relationship between salt intake and blood pressure. Randomized trials demonstrate that salt reduction lowers blood pressure in both individuals who are hypertensive and those who are normotensive, additively to antihypertensive treatments. Methodologically robust studies with accurate salt intake assessment have shown that a lower salt intake is associated with a reduced risk of cardiovascular disease, all-cause mortality, and other conditions, such as kidney disease, stomach cancer, and osteoporosis. Multiple complex and interconnected physiological mechanisms are implicated, including fluid homeostasis, hormonal and inflammatory mechanisms, as well as more novel pathways such as the immune response and the gut microbiome. High salt intake is a top dietary risk factor. Salt reduction programs are cost-effective and should be implemented or accelerated in all countries. This review provides an update on the evidence relating salt to health, with a particular focus on blood pressure and cardiovascular disease, as well as the potential mechanisms.

The diverse roles of RIP kinases in host-pathogen interactions

Receptor Interacting Protein Kinases (RIPKs) are cellular signaling molecules that are critical for homeostatic signaling in both communicable and non-communicable disease processes. In particular, RIPK1, RIPK2, RIPK3 and RIPK7 have emerged as key mediators of intracellular signal transduction including inflammation, autophagy and programmed cell death, and are thus essential for the early control of many diverse pathogenic organisms. In this review, we discuss the role of each RIPK in host responses to bacterial and viral pathogens, with a focus on studies that have used pathogen infection models rather than artificial stimulation with purified pathogen associated molecular patterns. We also discuss the intricate mechanisms of host evasion by pathogens that specifically target RIPKs for inactivation, and finally, we will touch on the controversial issue of drug development for kinase inhibitors to treat chronic inflammatory and neurological disorders, and the implications this may have on the outcome of pathogen infections.

Emerging Evidence for Infectious Causes of Cancer in the United States

Worldwide, infectious agents currently contribute to an estimated 15% of new cancer cases. Most of these (92%, or 2 million new cancer cases) are attributable to 4 infectious agents: Helicobacter pylori, human papillomavirus, and hepatitis B and C viruses. A better understanding of how infectious agents relate to the US cancer burden may assist new diagnostic and treatment efforts. We review US-specific crude mortality rates from infection-associated cancers and describe temporal and spatial trends since 1999. We review the US-specific evidence for infection-cancer associations by reporting available estimates for attributable fractions for the infection-cancer associations. Death due to cancers with established infectious associations varies geographically, but estimates for the US attributable fraction are limited to a few observational studies. To describe the burden of infection-associated cancer in the United States, additional observational studies are necessary to estimate the prevalence of infection nationally and within subpopulations. As infectious associations emerge to explain cancer etiologies, new opportunities and challenges to reducing the burden arise. Improved estimates for the United States would help target interventions to higher-risk subpopulations.

Helicobacter pylori eradication for the prevention of gastric neoplasia

BACKGROUND

Gastric cancer is the third most common cause of cancer death worldwide. Individuals infected with Helicobacter pylori have a higher likelihood of developing gastric cancer than individuals who are not infected. Eradication of H. pylori in healthy asymptomatic individuals in the general population may reduce the incidence of gastric cancer, but the magnitude of this effect is unclear.

OBJECTIVES

To assess the effectiveness of eradication of H. pylori in healthy asymptomatic individuals in the general population in reducing the incidence of gastric cancer.

SEARCH METHODS

We identified trials by searching the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 1), MEDLINE (1946 to February 2020), and EMBASE (1974 to February 2020). We handsearched reference lists from trials selected by electronic searching to identify further relevant trials. We handsearched published abstracts from conference proceedings from the United European Gastroenterology Week (published in Gut) and Digestive Disease Week (published in Gastroenterology) between 2001 and 2019. We contacted members of the Cochrane Upper Gastrointestinal and Pancreatic Diseases Review Group and experts in the field and asked them to provide details of outstanding clinical trials and any relevant unpublished materials.

SELECTION CRITERIA

We analysed randomised controlled trials comparing at least one week of H. pylori therapy with placebo or no treatment in preventing subsequent development of gastric cancer in otherwise healthy and asymptomatic H. pylori-positive adults. Trials had to follow up participants for at least two years and needed to have at least two participants with gastric cancer as an outcome. We defined gastric cancer as any gastric adenocarcinoma, including intestinal (differentiated) or diffuse (undifferentiated) type, with or without specified histology.

DATA COLLECTION AND ANALYSIS

We collected data on incidence of gastric cancer, incidence of oesophageal cancer, deaths from gastric cancer, deaths from any cause, and adverse effects arising due to therapy.

MAIN RESULTS

Six trials met all our eligibility criteria and provided extractable data in the previous version. Following our updated search, one new RCT was identified, meaning that seven trials were included in this updated review. In addition, one previously included trial provided fully published data out to 10 years, and another previously included trial provided fully published data out to 22 years of follow-up. Four trials were at low risk of bias, one trial was at unclear risk, and two trials were at high risk of bias. Six trials were conducted in Asian populations. In preventing development of subsequent gastric cancer, H. pylori eradication therapy was superior to placebo or no treatment (RR 0.54, 95% confidence interval (CI) 0.40 to 0.72, 7 trials, 8323 participants, moderate certainty evidence). Only two trials reported the effect of eradication of H. pylori on the development of subsequent oesophageal cancer. Sixteen (0.8%) of 1947 participants assigned to eradication therapy subsequently developed oesophageal cancer compared with 13 (0.7%) of 1941 participants allocated to placebo (RR 1.22, 95% CI 0.59 to 2.54, moderate certainty evidence). H. pylori eradication reduced mortality from gastric cancer compared with placebo or no treatment (RR 0.61, 95% CI 0.40 to 0.92, 4 trials, 6301 participants, moderate certainty evidence). There was little or no evidence in all-cause mortality (RR 0.97, 95% CI 0.85 to 1.12, 5 trials, 7079 participants, moderate certainty evidence). Adverse events data were poorly reported.

AUTHORS' CONCLUSIONS

We found moderate certainty evidence that searching for and eradicating H. pylori reduces the incidence of gastric cancer and death from gastric cancer in healthy asymptomatic infected Asian individuals, but we cannot necessarily extrapolate this data to other populations.

Current Status of Helicobacter pylori Diagnosis and Eradication Therapy in Japan Using a Nationwide Database

BACKGROUND

Helicobacter pylori infection increases the risk of stomach cancer; therefore, eradication therapy is recommended for infected individuals. Although several methods are recommended for the diagnosis and therapy of H. pylori infection, their frequency and effectiveness have not been fully investigated in Japan.

METHODS

A nationwide claims database including >1.6 million patients (April 2008 - -October 2016) in Japan was utilized. We analyzed the distribution of methods for H. pylori diagnosis and therapy, waiting period between eradication and diagnostic test, and success rate of primary therapy.

RESULTS

Data for 481,041 patients were extracted. After primary eradication therapy, urea breath test was used for >80% of diagnoses, and antibody measurement for 0.7%. The success rate of primary eradication was >80% for most diagnostic methods and 69.0% for antibody measurement; inappropriately-timed antibody measurement may have contributed to this disparity. The overall success rate of eradication therapy decreased from 2011 to 2014, but increased from 2015, coinciding with launch of the potassium-competitive acid blocker vonoprazan, which showed a higher success rate of eradication than proton-pump inhibitors.

CONCLUSIONS

Diagnostic tests of H. pylori infection mostly followed Japanese Society for Helicobacter Research guidance, although some antibody measurements were timed inappropriately. Vonoprazan appears to increase the success rate of primary therapy.

Bacterial infection and non-Hodgkin's lymphoma

One quarter of all cancers are linked to infectious diseases. The link between viral infection and cancer has been widely studied, but few reports have focused on the carcinogenic role of bacterial infection. Nonetheless, Helicobacter pylori, Chlamydia psittaci, Coxiella burnetii, Borrelia burgdorferi and Campylobacter jejuni are bacteria that can be associated with non-Hodgkin's lymphoma (NHL), the most common haematologic malignancy. Here, we review the evidence in favour of a link between these bacterial infections and NHL. Sero-epidemiological observation makes it possible to identify a link between H. pylori, C. burnetii, B. burgdorferi infection and NHL. Helicobacter pylori, Chlamydia psittaci, Coxiella burnetii, Borrelia burgdorferi and Campylobacter jejuni could be identified in NHL tissue samples at the site of chronic inflammation, where B and T lymphocytes are attracted to participate in follicle formation. Lymphoma remissions have been observed under antimicrobial therapies supporting the carcinogenic contribution of bacteria. If the theory of causality is characterized by the lack of universal criteria for establishing a causal link between two diseases, infection and lymphoma, epidemiological, clinical, and histological evidences reported here, should lead clinicians to pay attention to these infectious agents, to detect early lymphoma transformation.

Recent Developments of Systemic Chemotherapy for Gastric Cancer

Gastric cancer (GC) is a molecularly heterogeneous disease. Its molecular background, epidemiology, and standard of care are quite different between Eastern and Western countries. Many efforts have been made in developing more effective surgeries and adjuvant chemotherapies for resectable GC in each region. Recently, an intensive combination of cytotoxic agents has been established as a new standard of adjuvant treatment. Meanwhile, palliative chemotherapy is a uniform standard treatment for unresectable GC worldwide. Recently, one of the most remarkable advances in therapy for unresectable GC has been the approval of immune checkpoint inhibitors (ICIs). The use of ICIs as frontline treatment is currently being investigated. In addition, novel combinations of ICIs and targeted drugs are being evaluated in clinical trials. Despite these advances, the complex biology of GC has resulted in the failure of targeted therapies, with the exceptions of HER2-targeted trastuzumab and VEGFR2-targeted ramucirumab. GC harbors many redundant oncogenic pathways, and small subsets of tumors are driven by different specific pathways. Therefore, a combination strategy simultaneously inhibiting several pathways and/or stricter patient selection for better response to targeted drugs are needed to improve clinical outcomes in this field.

Artificial Intelligence for Cataract Detection and Management

The rising popularity of artificial intelligence (AI) in ophthalmology is fuelled by the ever-increasing clinical "big data" that can be used for algorithm development. Cataract is one of the leading causes of visual impairment worldwide. However, compared with other major age-related eye diseases, such as diabetic retinopathy, age-related macular degeneration, and glaucoma, AI development in the domain of cataract is still relatively underexplored. In this regard, several previous studies explored algorithms for automated cataract assessment using either slit lamp of color fundus photographs. However, several other study groups proposed or derived new AI-based calculation for pre-cataract surgery intraocular lens power. Along with advancements in digitization of clinical data, data curation for future cataract-related AI developmental work is bound to undergo significant improvements in the foreseeable future. Even though most of these previous studies reported early promising performances, limitations such as lack of robust, high-quality training data, and lack of external validations remain. In the next phase of work, apart from algorithm's performance, it will also be pertinent to evaluate deployment angles, feasibility, efficiency, and cost-effectiveness of these new cataract-related AI systems.

Evaluation of cell-penetrating peptide-peptide nucleic acid effect in the inhibition of cagA in Helicobacter pylori

Helicobacter pylori is the most common cause of chronic infection in human and is associated with gastritis, peptic ulcer disease, and adenocarcinoma of mucosa-associated lymphoid tissue cells. Peptide nucleic acid (PNA) is a synthetic compound, which can inhibit the production of a particular gene. This study aimed to investigate the effect of PNA on inhibiting the expression of cagA. After confirmation of the desired gene by polymerase chain reaction (PCR), the antisense sequence was designed against cagA gene. The minimum inhibitory concentrations of conjugated PNA against H. pylori was determined. The effect of the compound on the expression level of the cagA was investigated in HT29 cell culture using real-time PCR. The results showed 2 and 3 log reduction in bacterial count after 8- and 24-h treatment with 4 and 8 μM of the compound, respectively. The lowest expression level of the cagA gene was observed at a concentration of 8 μM after 6 h. The results of this study showed that cell-penetrating peptide antisense can be employed as effective tools for inhibiting the target gene mRNA for various purposes. Moreover, further research is necessary to assess the potency, safety, and pharmacokinetics of CPP-PNAs for clinical prevention and treatment of infections due to H. pylori.

A current clinical overview of atrophic gastritis

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

High-definition optical magnification with digital chromoendoscopy detects gastric mucosal changes in dyspeptic-patients

BACKGROUND

Accurate detection of gastric infection by Helicobacter pylori (H. pylori) and premalignant lesions are important for effective provision of treatment, preventing the development of gastric neoplasia. Optical enhancement systems with optical magnification improved the identification of mucosal superficial and vascular patterns in patients with dyspepsia.

AIM

To evaluate an optical enhancement system with high-definition magnification, for diagnosis of normal gastric mucosa, H. pylori-associated gastritis, and gastric atrophy.

METHODS

A cross-sectional, nonrandomized study from November 2015 to April 2016 performed in a single-tertiary academic center from Ecuador. Seventy-two consecutive patients with functional dyspepsia according to the Rome III criteria, were tested for H. pylori using a stool antigen test and were assigned to an Hp⁺ group or an Hp⁻ control group. Esophagogastroduodenoscopy with high-definition optical magnification and digital chromoendoscopy was performed, and patients were classified into 4 groups, in accordance to the microvascular-architecture pattern of the mucosa. Interobserver and intraobserver agreement among operators were calculated.

RESULTS

Of the 72 participants, 35 were Hp⁺ and 37 were Hp⁻. Among 10 patients with normal mucosal histology in biopsy samples, 90% had a Type I pattern of microvascular architecture by endoscopy. Among participants with type IIa and type IIb patterns, significantly more were Hp⁺ than Hp⁻ (32 vs 8), and most (31 out of 40) had histological diagnoses of chronic active gastritis. Two of the three participants with a histological diagnosis of atrophy had a type III microvascular pattern. The type I pattern predicted normal mucosa, type IIa–IIb predicted H. pylori infection, and type III predicted atrophy with sensitivities of 90.0%, 91.4%, and 66.7%, respectively. The intraobserver and interobserver agreements had kappa values of 0.91 and 0.89, respectively.

CONCLUSION

High-definition optical magnification with digital chromoendoscopy is useful for diagnosis of normal gastric mucosa and H. pylori-associated gastritis with high accuracy, but further studies are needed to determine whether endoscopic diagnosis of gastric atrophy is feasible.

Molecular anatomy and pathogenic actions of Helicobacter pylori CagA that underpin gastric carcinogenesis

Chronic infection with Helicobacter pylori cagA-positive strains is the strongest risk factor for gastric cancer. The cagA gene product, CagA, is delivered into gastric epithelial cells via the bacterial type IV secretion system. Delivered CagA then undergoes tyrosine phosphorylation at the Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs in its C-terminal region and acts as an oncogenic scaffold protein that physically interacts with multiple host signaling proteins in both tyrosine phosphorylation-dependent and -independent manners. Analysis of CagA using in vitro cultured gastric epithelial cells has indicated that the nonphysiological scaffolding actions of CagA cell-autonomously promote the malignant transformation of the cells by endowing the cells with multiple phenotypic cancer hallmarks: sustained proliferation, evasion of growth suppressors, invasiveness, resistance to cell death, and genomic instability. Transgenic expression of CagA in mice leads to in vivo oncogenic action of CagA without any overt inflammation. The in vivo oncogenic activity of CagA is further potentiated in the presence of chronic inflammation. Since Helicobacter pylori infection triggers a proinflammatory response in host cells, a feedforward stimulation loop that augments the oncogenic actions of CagA and inflammation is created in CagA-injected gastric mucosa. Given that Helicobacter pylori is no longer colonized in established gastric cancer lesions, the multistep nature of gastric cancer development should include a “hit-and-run” process of CagA action. Thus, acquisition of genetic and epigenetic alterations that compensate for CagA-directed cancer hallmarks may be required for completion of the “hit-and-run” process of gastric carcinogenesis.

Relationship between African Biogeographical Ancestry and Helicobacter pylori infection in children of a large Latin American urban center

BACKGROUND AND AIM

The relationship between race/ethnicity and H pylori infection has been extensively reported, with a higher prevalence of infection observed in black individuals. Whether such differences are due to genetic factors underlying African ancestry remains to be clarified. In the present study, we evaluated the association between the proportion of individual African ancestry and H pylori infection in a sample of 1046 children living in a large Latin American urban center.

MATERIALS AND METHODS

Estimation of individual biogeographical ancestry was based on 370,539 SNPs and performed using the ADMIXTURE software. Multivariate logistic regression models and mediation analysis considering the influence of previously recognized socioenvironmental risk factors to H pylori infection were performed. All analyses were conducted using the statistical package STATA v.14.0.

RESULTS

Each 10% increase in the proportion of individual African ancestry was positively and independently associated with H pylori infection in our population (adjusted OR = 1.22, 95% CI = 1.10-1.36, P < .001). Mediation analysis demonstrated that only 9.23% of the effect of the individual African ancestry on H pylori infection was explained by factors such as household income, the absence of street paving and crowding.

CONCLUSIONS

The results suggest that genetic variants that covariate with African ancestry may explain an important part of the racial differences observed for the prevalence of H pylori infection.

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

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

NOD-like receptor signaling in inflammation-associated cancers: From functions to targeted therapies

BACKGROUND

Recently, many studies have reported that some botanicals and natural products were able to regulate NOD-like receptor signaling. NOD-like receptors (NLRs) have been established as crucial regulators in inflammation-associated tumorigenesis, angiogenesis, cancer cell stemness and chemoresistance. NLRs specifically sense pathogen-associated molecular patterns and respond by activating other signaling regulators, including Rip2 kinase, NF-κB, MAPK and ASC/caspase-1, leading to the secretion of various cytokines.

PURPOSE

The aim of this article is to review the molecular mechanisms of NOD-like receptor signaling in inflammation-associated cancers and the NLRs-targeted botanicals and synthetic small molecules in cancer intervention.

RESULTS

Aberrant activation of NLRs occurs in various cancers, orchestrating the tissue microenvironment and potentiating neoplastic risk. Blocking NLR inflammasome activation by botanicals or synthetic small molecules may be a valuable way to prevent cancer progression. Moreover, due to the roles of NLRs in regulating cytokine production, NLR signaling may be correlated with senescence-associated secretory phenotype.

CONCLUSION

In this review, we discuss how NLR signaling is involved in inflammation-associated cancers, and highlight the NLR-targeted botanicals and synthetic small molecules in cancer intervention.

Relationship between primary eradication of Helicobacter pylori and drinking habits in women: collaborative research between a pharmacy and a clinic

Helicobacter pylori is a cause of stomach cancer and peptic ulcer. For prevention, improving the eradication rate of H. pylori is crucial. However, the association between eradication and lifestyle of infected patients, including alcohol consumption, remains unclear. We explored associations between failed primary eradication therapy and drinking status by sex. This study involved 356 patients who visited a pharmacy with prescriptions for primary H. pylori eradication therapy. We assessed drinking habits using a questionnaire. Data on patients with failed primary eradication were provided by the nearby local clinic. We performed logistic regression analysis to examine the effect of drinking habit and frequency of drinking on failed primary eradication by sex. The odds ratio of primary eradication failure in female patients with a drinking habit was 3.75 (P = 0.001), but that in male patients was not significant. The odds ratio tended to increase in relation to drinking frequency in women. Frequent consumption of alcohol is not only likely to affect eradication, but also has a large impact on the bodies of women, who are more susceptible than men to the effects of alcohol. Thus, women should take greater care in alcohol consumption.

Effects of Anti-Helicobacter pylori Therapy on Incidence of Autoimmune Diseases, Including Inflammatory Bowel Diseases

BACKGROUND & AIMS

Helicobacter pylori induces immune tolerance and is associated with a lower risk for immune-mediated disorders, such as autoimmune and inflammatory bowel diseases (IBD). We aimed to determine the effects of treatment for H pylori infection on the incidence of autoimmune disease and IBD.

METHODS

We collected data from the National Health Insurance Research Database in Taiwan on patients younger than 18 years old without a prior diagnosis of autoimmune disease or IBD. Patients with peptic ulcer disease (PUD) with treatment of H pylori infection (PUD+HPRx), PUD without H pylori treatment (PUD-HPRx), a urinary tract infection (UTI) treated with cephalosporin, or without PUD (controls) were matched for age, sex, insurance, and Charlson's comorbidity index score.

RESULTS

Of the 1 million patients we collected data from in 2005, we included 79,181 patients in the study. We compared the effects of treatment for H pylori infection on the risk of autoimmunity or IBD and found that PUD+HPRx has the highest adjusted hazard risk (aHR) for autoimmunity or IBD (aHR, 2.36), compared to PUD-HPRx (aHR, 1.91) or UTI (aHRs, 1.71) (P < .001). The increased risk of autoimmune disease was not completely accounted for by antibiotic therapy alone, because PUD+HPRx had a higher aHR than UTI (P < .001). A small but significant increase in mortality was observed in the PUD+HPRx cohort (aHR, 1.11; P = .001).

CONCLUSION

In an analysis of data from the National Health Insurance Research Database in Taiwan, we found that treatment for H pylori infection is associated with a significant increase in the risk for autoimmune disease, including IBD.

The Epidemiology of Gastric Cancers in the Era of Helicobacter pylori Eradication: A Nationwide Cancer Registry-Based Study in Taiwan

BACKGROUND

Helicobacter pylori eradication has been shown to decrease gastric adenocarcinoma risk. The epidemiology of gastric lymphoma, which is also associated with H. pylori, and other rare subtypes of gastric cancer is less clear. This study comprehensively evaluated the incidence trend and the survival of gastric cancer in Taiwan by histologic subtype.

METHODS

The incidence trends of gastric cancer in Taiwan from 1996 and 2013 were evaluated using data from the Taiwan Cancer Registry. The life-table method and the Cox proportional hazards analysis were used to evaluate the survival of gastric cancer.

RESULTS

The incidence of all gastric cancers in Taiwan decreased from 15.97 per 100,000 in 1996 to 11.57 per 100,000 in 2013. The most frequent histologic subtype of gastric cancer in Taiwan was adenocarcinoma, followed by lymphoma and sarcoma (mainly gastrointestinal stromal tumor). The best survival was in patients with sarcoma, followed by lymphoma, neuroendocrine tumor, and adenocarcinoma. Generally, women had a better survival than men. The incidence of adenocarcinoma significantly decreased from 13.56 per 100,000 in 1996 to 9.82 per 100,000 in 2013 (P < 0.0001). In contrast, the incidences of mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma did not decrease.

CONCLUSIONS

The incidence of adenocarcinoma and lymphoma, both of which are associated with H. pylori, showed diverging trends. The survival of gastric cancer differed by histologic subtype and sex.

IMPACT

The disparity in the incidence trends between gastric lymphoma and adenocarcinoma, both associated with H. pylori, warranted the need to search for additional risk factors of gastric lymphoma.

Gastric Cancer - From Aetiology to Management: Differences Between the East and the West

Gastric cancers are highly prevalent in both the East and the West, although they differ in aetiology and prognostic outcome. Management of gastric cancer from screening to definitive treatment varies substantially between Eastern and Western countries and regions, owing to numerous factors, including government incentives to carry out population-wide screening programmes to detect early disease, differences in clinical and biological tumour behaviours and responsiveness to treatment, patient accessibility to effective treatment, etc. This review highlights and contrasts the differences in tumour aetiology and histology, as well as the management approaches between the East and the West, which gives important insights and inspirations on future international multicentre research collaboration to combat this dreadful malignancy.

Comparison of the detection of Helicobacter pylori infection by commercially available serological testing kits and the 13C-urea breath test

BACKGROUND

Serum Helicobacter pylori (H. pylori) antibody kits (LZ and LIA) using the latex agglutination immunoassay method are commercially available, but few studies have been performed to determine their diagnostic accuracy or to compare their results with those of enzyme-linked immunosorbent assay (ELISA) kits (EP and EIA).

METHODS

Sera were obtained from 213 hospital outpatients with dyspeptic symptoms. The serological results were compared with the result of the ¹³C-urea breath test (UBT) which seems to be reliable.

RESULTS

Of the 213 subjects, 154 were diagnosed as positive for H. pylori infection according to the UBT. The sensitivities and specificities of these tests were 97.4% and 76.3%, 98.1% and 78.0%, 99.4% and 74.6%, and 98.1% and 71.2% for the EP, LZ, EIA and LIA tests, respectively. When the 13 subjects whose seropositive results of the four kits were completely opposite to the negative results of the UBT were excluded, the specificities of evaluated kits were all higher than 90%. The concordance rate between the EP and EIA tests was 98.1% (Spearman's rank correlation coefficient = 0.83) and that between the LZ and LIA tests was 97.1% (correlation coefficient = 0.91). The LZ gave higher antibody titer value than EP (p < 0.0001, Z = 9.82; Wilcoxon signed-rank test), and EIA gave higher value than LIA (p < 0.0001, Z = 6.43; Wilcoxon signed-rank test).

CONCLUSIONS

The latex immunoassay method provided the same reliability to ELISA in terms of the diagnostic accuracy for current H. pylori infection, although we should take into account the titer value differences by each test method in practical use.