Effectiveness of Helicobacter pylori eradication in the prevention of primary gastric cancer in healthy asymptomatic people: A systematic review and meta-analysis comparing risk ratio with risk difference

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.

Analysis of Characteristics and Risk Factors of Patients with Single Gastric Cancer and Synchronous Multiple Gastric Cancer among 14,603 Patients

Background/Aims

Synchronous multiple gastric cancer (SMGC) accounts for approximately 6% to 14% of gastric cancer (GC) cases. This study aimed to identify risk factors for SMGC.

Methods

A total of 14,603 patients diagnosed with GC were prospectively enrolled. Data including age, sex, body mass index, smoking, alcohol consumption, family history, p53 expression, microsatellite instability, cancer classification, lymph node metastasis, and treatment were collected. Risk factors were analyzed using logistic regression analysis between a single GC and SMGC.

Results

The incidence of SMGC was 4.04%, and that of early GC (EGC) and advanced GC (AGC) was 5.43% and 3.11%, respectively. Patients with SMGC were older (65.33 years vs 61.75 years, p<0.001) and more likely to be male. Lymph node metastasis was found in 27% of patients with SMGC and 32% of patients with single GC. Multivariate analysis showed that SMGC was associated with sex (male odds ratio [OR], 1.669; 95% confidence interval [CI], 1.223 to 2.278; p=0.001), age (≥65 years OR, 1.532; 95% CI, 1.169 to 2.008; p=0.002), and EGC (OR, 1.929; 95% CI, 1.432 to 2.600; p<0.001). Survival rates were affected by Lauren classification, sex, tumor size, cancer type, distant metastasis, and venous invasion but were not related to the number of GCs. However, the survival rate of AGC with SMGC was very high.

Conclusions

SMGC had unique characteristics such as male sex, older age, and EGC, and the survival rate of AGC, in which the intestinal type was much more frequent, was very good (Trial registration number: NCT04973631).

Endoscopic surveillance for familial intestinal gastric cancer in low-incidence areas: An effective strategy

While clinical practice guidelines for hereditary diffuse gastric cancer are well established, there is no consensus on the approach for familial intestinal gastric cancer (FIGC). In low-incidence gastric cancer (GC) areas such as the United States or most European countries, there are no evidence-based recommendations on endoscopic assessment in FIGC families. We aim to describe the yield of GC surveillance in these families, and to identify epidemiological risk factors for the development of GC and its precursor lesions. This is a multicenter observational study involving nine tertiary Spanish hospitals, in which all individuals fulfilling FIGC criteria who underwent endoscopic surveillance were included between 1991 and 2020. Forty-one healthy individuals of 31 families were recruited. The median number of upper gastrointestinal endoscopies per individual was 3 (interquartile range, IQR, 1-4). The median interval time between tests was 2 years (IQR 1.5-2.5), and the median follow-up was 9 years (IQR 3-14.5). In 18 (43.9%) subjects, a precursor lesion of GC was found during follow-up, and in 2 (4.9%), an early GC was identified, in which curative treatment was offered. Helicobacter pylori (Hp) infection proved to be independently associated with an increased risk of developing precursor lesions or GC, adjusted by age, gender and follow-up, with an Odds Ratio of 6.443 (1.36-30.6, P value .019). We present the first outcomes that support endoscopic surveillance with biopsies and detection of Hp in FIGC families, although the periodicity has yet to be defined.

Epidemiology of Gastric Cancer: Global Trends, Risk Factors and Premalignant Conditions

This review article aims to provide a comprehensive overview of recent epidemiology, pathogenesis, risk factors, and premalignant conditions of gastric cancer. Worldwide, gastric cancer is one of the most common and most fatal cancers. The incidence and mortality remain high in regions such as East Asia and Eastern Europe. Although there is a lower incidence in the United States, it remains a deadly disease. Age, gender, and race are non-modifiable demographic risk factors for developing gastric cancer. There have been several dietary and lifestyle risk factors such as salt preserved foods, N-nitroso compounds containing foods, tobacco smoke, alcohol use, and obesity that have been shown to contribute to the development of gastric cancer. Infections have additionally been shown to have a clear role in the pathogenesis of gastric cancer as Helicobacter pylori eradication has shown a significant reduction in the incidence of gastric cancer as well as other pathogens such as Epstein-Barr virus. There are certain premalignant lesions that increase the risk of developing gastric cancer. These include atrophic gastritis, and intestinal metaplasia amongst others.

Efficacy of antimicrobial therapy in patients with uncomplicated acute colonic diverticulitis: an updated systematic review and meta-analysis

The need for antimicrobial therapy for uncomplicated acute diverticulitis of the colon remains controversial. We conducted a systematic review of the efficacy of antimicrobial agents against this disease, including new randomized controlled trials (RCTs) reported in recent years, and evaluated their efficacy using a meta-analytic approach. RCTs were searched using PubMed, EMBASE, Google Scholar, Cochrane Library, Ichushi-Web, and eight registries. Keywords were 'colonic diverticulitis', 'diverticulitis', 'antimicrobial agents', ''antibiotics, 'complication', 'abscess', 'gastrointestinal perforation', 'gastrointestinal obstruction', 'diverticular hemorrhage', and 'fistula'. Studies with antimicrobial treatment in the intervention group and placebo or no treatment in the control group were selected by multiple reviewers using uniform inclusion criteria, and data were extracted. Prevention of any complication was assessed as the primary outcome, and efficacy was expressed as risk ratio (RR) and risk difference (RD). A meta-analysis was performed using 5 RCTs of the 21 studies that were eligible for scrutiny in the initial search and which qualified for final inclusion. Three of these studies were not included in the previous meta-analysis. Subjects included 1039 in the intervention group and 1040 in the control group. Pooled RR = 0.86 (95% confidence interval, 0.58-1.28) and pooled RD = -0.01 (-0.03 to 0.01) for the effect of antimicrobial agents in reducing any complications. Recurrences, readmissions, and surgical interventions did not significantly show the efficacies of using antimicrobial agents. A meta-analysis of recently reported RCTs did not provide evidence that antimicrobial therapy improves clinical outcomes in uncomplicated acute diverticulitis of the colon.

Novel Mutations Conferring Amoxicillin Resistance in Helicobacter pylori in South Korea

Helicobacter pylori is the primary causative agent of gastritis, gastric ulcers, duodenal ulcers, gastric cancer, and peripheral B-cell lymphoma. H. pylori eradication often fails due to elevated antibiotic resistance. However, no previous studies have thoroughly examined amoxicillin resistance. Here, the objective was to identify clinical strains of H. pylori with amoxicillin resistance and to analyze single-nucleotide polymorphisms (SNPs) associated with amoxicillin resistance. From March 2015 to June 2019, genotypic and phenotypic amoxicillin resistance was analyzed using an E-test and whole-genome sequencing (WGS). Analysis of 368 clinical strains confirmed amoxicillin resistance in 31 strains (resistance rate of 8.7%). The genomes were extracted from nine resistant (<0.125 mg/L) strains, and WGS was performed for genetic analysis. WGS analysis identified SNPs present in pbp1a, pbp2, nhaC, hofH, hofC, and hefC in all nine isolates. Some of these genes may be related to amoxicillin resistance. A total of six SNPs (A69V, V374L, S414R, T503I, A592D, and R435Q) were identified in PBP2 of H-8, the most resistant strain. We predict that these six SNPs are associated with high amoxicillin resistance. Amoxicillin resistance should be considered in the clinical setting for the treatment failure of H. pylori eradication.

Network meta-analysis of different dosages of esomeprazole and rabeprazole for the treatment of Helicobacter pylori

BACKGROUND

The optimal dosage of new generation proton pump inhibitors (PPIs) in increasing cure rate of Helicobacter pylori (H. pylori) infection remains unclear. This network meta-analysis aimed to comprehensively evaluate the comparative efficacy and safety of different dosages of esomeprazole and rabeprazole in treating H. pylori infection.

MATERIALS AND METHODS

We searched PubMed, Cochrane Central Registry for Controlled Trials (CENTRAL), and EMBASE for randomized controlled trials (RCTs) involving esomeprazole and rabeprazole with different dosages from their inception through 31 March, 2022. After data extraction and risk of bias assessment, network meta-analyses were conducted using STATA 14.0. We calculated the surface under the cumulative ranking (SUCRA) to rank all regimens.

RESULTS

Thirteen studies including 14 reports were included. Six dosages including rabeprazole 10 mg (R10bid), 20 mg (R20bid), and 40 mg (R40bid) twice daily and esomeprazole 20 mg (E20bid) and 40 mg (E40bid) twice daily as well as 40 mg once daily (E40qd) were identified. Network meta-analysis suggested that R40bid ranked highest in the cure rate (83.8%), followed by E40bid (82.6%), E20bid (54.5%), R20bid (34.2%), R10bid (22.8%), and E40qd (22.0%); however, E40qd ranked highest in adverse events (91.1%), followed by R20bid (57.8), R10bid (57.6%), E20bid (38.9%), E40bid (34.2%), and R40bid (20.4%). Sensitivity analyses confirmed the robustness of these results.

CONCLUSIONS

Based on the available evidence, R40bid and E40bid might be the optimum dosage to increase the cure rate; however, E40qd was superior for adverse events. Nevertheless, future studies should validate the results from this network meta-analysis.

Diagnostic and Therapeutic Management of Helicobacter pylori Infection in Primary Care: Perspective of Application in France and Narrative Review of the Literature

BACKGROUND

Helicobacter pylori (Hp) infection affects 30% to 40% of people in industrialized countries.

AIM

This study aimed to synthesize knowledge on the diagnostic and therapeutic management of Hp infection in general practice in people under 40 years of age.

METHOD

A narrative review of the literature with an inductive content analysis of the articles was performed.

RESULTS

The extracted data (22 articles out of 106 included after screening of 965 articles) determined three areas of analysis: indications for screening, methods of screening and diagnosis by non-invasive tests, and treatment modalities.

DISCUSSION

Targeted, easily performed screening with noninvasive tests is recommended for patients younger than 45 years of age with no family history of gastric cancer and symptoms of dyspepsia without warning signs. Given their proximity to the general population and their coverage of the territory, general practitioners are ideally positioned. Treatment modalities are well-codified and feasible in primary care. Simplifying the recommendations available to them would optimize the identification of patients at risk and the management of Hp infection. Informing, educating, involving, supporting, and promoting the control of Hp infection in primary care will be future goals. Further research is needed in primary care to evaluate the impact of new procedures on Hp control.

Effect of Helicobacter pylori infection and its eradication on the expression of tight junction proteins in the gastric epithelium in relation to gastric carcinogenesis

BACKGROUND

Tight junction proteins (TJPs) play a role in epithelial defense mechanisms. However, the effect of Helicobacter pylori (Hp) on TJPs remains unclear. This study aimed to evaluate the expression of TJPs in relation to Hp infection and eradication in gastric carcinogenesis.

METHODS

In total, 510 subjects (284 controls and 226 gastric cancer [GC] patients) were prospectively enrolled in the study. The expression of claudin-1 and -2 (CLDN-1, -2), occludin (OCLN), and tight junction protein 1 (TJP1) was measured based on their Hp infection status in normal corpus mucosa and evaluated following Hp eradication using quantitative real-time polymerase chain reaction (qPCR) and immunohistochemistry (IHC).

RESULTS

The expression of TJP1 in Hp⁺ controls was significantly lower than that in Hp^- controls (p = 0.006), whereas it was higher in Hp⁺ than in Hp^- GC patients (p = 0.001). Moreover, the increased expression of TJP1 in Hp⁺ GC patients was reduced to levels in Hp^- within a year after Hp eradication and was maintained for more than 5 years. Furthermore, IHC results for TJP1 were similar to qPCR results. In particular, the higher IHC staining intensity of TJP1 in the cytosol of GC patients (p = 0.019) decreased after Hp eradication (p = 0.040).

CONCLUSION

Hp infection affects TJP expression. The high expression of TJP1 in Hp⁺ GC patients was restored to control levels after Hp eradication, suggesting that TJP1 plays a role in gastric carcinogenesis.

Lower Incidence of Hepatobiliary Cancer in Helicobacter pylori-Infected Persons: A Cohort Study of 53.633 Persons

BACKGROUND AND AIMS

Helicobacter pylori (HP) is known to be involved in intestinal carcinogenesis. As regards hepatobiliary cancers, there are few and inconsistent reports. We investigated HP infection and its association with the incidence of hepatobiliary cancers in a large cohort study. The cohort's appropriateness for the purpose was gauged by its ability to identify the established risk relation to gastric cancer.

METHODS

This historical study was performed in the Central Denmark Region. Patients were included from primary healthcare after being tested for HP infection with a urea breath test. Patients' diagnoses, age, gender, and country of birth were obtained from Danish national administrative registries. Cox regression was used to compare incidences of hepatobiliary and gastric cancer between HP-positive and HP-negative persons, adjusting for confounding variables.

RESULTS

A total of 53,633 persons were included and 10,553 were tested HP-positive. They were followed for a median of 4.6 years (total 250,515 person-years). We found 64 hepatobiliary cancers, with a markedly lower incidence in HP-positive persons; HR = 0.27 (95% CI 0.11-0.68). A higher incidence of gastric cancer in HP-positive persons was confirmed (HR = 1.99 (95% CI 1.35-2.94)).

CONCLUSION

The incidence of hepatobiliary cancers was remarkably lower in HP-infected persons after adjusting for age, gender, cirrhosis, alcohol-related diagnoses, chronic viral hepatitis, and country of origin. We found no methodological cause for this unexpected finding, and the pathogenic links between the infection and cancer remain to be identified. Our results must be confirmed in a similar cohort.

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.

Endoscopy Is Cost-Effective for Gastric Cancer Screening After Successful Helicobacter pylori Eradication

BACKGROUND

After successful Helicobacter pylori eradication, patients with gastric mucosal atrophy are at high risk of gastric cancer. Endoscopy can detect early gastric cancer with high sensitivity.

AIMS

This study aimed to assess the cost-effectiveness of annual endoscopy versus biennial endoscopy versus no screening for gastric cancer screening in patients after successful Helicobacter pylori eradication.

METHODS

We developed decision trees with Markov models for a hypothetical cohort of patients aged 50 years after successful Helicobacter pylori eradication over a lifetime horizon from a healthcare payer perspective. Main outcomes were costs, quality-adjusted life-years (QALYs), life expectancy life-years (LYs) with discounting at a fixed annual rate of 3%, and incremental cost-effectiveness ratios (ICERs).

RESULTS

In a base-case analysis, biennial endoscopy (US$4305, 19.785QALYs, 19.938LYs) was more cost-effective than annual endoscopy (US$7516, 19.808QALYs, 19.958LYs, ICER; US$135,566/QALY gained) and no screening (US$14,326, 19.704QALYs, 19.873LYs). In scenario analyses, biennial endoscopy for patients with mild-to-moderate gastric mucosal atrophy and annual endoscopy for patients with severe gastric mucosal atrophy were the most cost-effective. Cost-effectiveness was sensitive to incidence of gastric cancer and the proportion of stage I. Probabilistic sensitivity analyses using Monte Carlo simulation demonstrated that at a willingness-to-pay level of US$100,000/QALY gained, biennial endoscopy was optimal 99.9% for patients with mild-to-moderate gastric mucosal atrophy, and that annual endoscopy was optimal 98.4% for patients with severe gastric mucosal atrophy.

CONCLUSIONS

Based on cancer risk assessment of gastric mucosal atrophy and cost-effectiveness results, annual or biennial endoscopic surveillance could be established for patients after successful Helicobacter pylori eradication.

Sharing With Patients the Uncertainties Regarding the Management of Dyspepsia

Background: The management of patients with dyspepsia is uncertain. Some authors advocate endoscopy for all; others restrict endoscopy only to patients at high risk of gastric cancer, namely to those above an age threshold, or with a family history, dysphagia, loss of weight, anemia, or a childhood in Asian countries. Still others recommend various combinations between test-and-treat for Helicobacter pylori, anti-secretory treatment, and/or endoscopy.

Objective: To highlight the uncertainties in the choice between the various strategies and argue that these uncertainties should be shared with the patient.

Method: An overview of reported life expectancy, patient satisfaction, gastric cancer detection rates, symptom relief, and cost effectiveness of the management strategies for dyspepsia.

Main Findings: There are no randomized controlled trials of the effect of screening by endoscopy on mortality of patients with gastric cancer. Lower grades of evidence suggest that early diagnosis reduces this mortality. Analyses, which assume a survival benefit of early diagnosis, indicate that mass screening in countries of high incidence gastric cancer (> 10 cases per 100,000) and targeted screening of high-risk persons in countries of low-intermediate incidence (<10 cases per 100,000) is cost-effective at a willingness to pay of $20,000–50,000 per QALY. Prompt endoscopy appears to be best for patient satisfaction and gastric cancer detection, and test-and-treat for H pylori—for symptom relief and avoiding endoscopies.

Conclusions: The gain in life expectancy is the main source of uncertainty in the choice between management strategies. This choice should be shared with the patients after explaining uncertainties and eliciting their preferences.

Characteristics and Early Diagnosis of Gastric Cancer Discovered after Helicobacter pylori Eradication

The prevalence of gastric cancer after eradication (GCAE) is increasing dramatically in Japan. GCAE has characteristic features, and we must understand these features in endoscopic examinations. Differentiated cancer types were frequently found after eradication and included characteristic endoscopic features such as reddish depression (RD). However, benign RD can be difficult to distinguish from gastric cancer because of histological alterations in the surface structures (nonneoplastic epithelium or epithelium with low-grade atypia [ELA]) as well as multiple appearances of RD. Recently, we clarified similar alterations in genetic mutations between ELA and gastric cancer, suggesting that ELA is derived from gastric cancer. Clinically, submucosal invasive cancer was frequently found in patients after eradication therapy even if they received annual endoscopic surveillance. We can improve the diagnostic ability using image-enhanced endoscopy with magnified observation.

[Helicobacter pylori: When to look for an infection and treat it in adults?]

Helicobacter pylori infection is acquired during childhood mainly within the family. It causes active chronic gastritis associated with the development of many digestive and extra digestive diseases. Its expression results from interactions between the bacteria, the host and environmental factors modulating the evolution of gastritis and acid secretion. The French recommendations for research and treatment for curative or preventive purposes were updated in 2017. These are indications with a high level of evidence for association and efficacy of the eradication treatment: peptic ulcer, taking non-steroidal anti-inflammatory drugs or aspirin with an ulcer history, gastric MALT lymphoma, and localized resection of gastric cancer. The recommendations relate to other diseases with a lower level of evidence: functional dyspepsia, risk factors for gastric adenocarcinoma (family history of gastric cancer, Lynch syndrome, pre-neoplastic lesions: atrophy, intestinal metaplasia, dysplasia), unexplained iron deficiency anemia and vitamin B12 deficiency, immunological thrombocytopenic purpura, bariatric surgery isolating part of the stomach. The diagnosis is made by examining gastric biopsies or by non-invasive test depending on the clinical situation. The 10-day triple therapies guided by the study of antibiotic sensitivity (proton pump inhibitors (PPI), amoxicillin, clarithromycin or levofloxacin) are recommended as first-line treatment because of the increase in resistance, allowing the reduction of the duration of treatment, the number of antibiotics and side effects. By default, probabilistic quadruple therapies of 14 days are possible and interchangeable (PPI with amoxicillin, clarithromycin, metronidazole, or a combination of bismuth salt, tetracycline and metronidazole). Eradication control is necessary.

Helicobacter pylori healthy South Asians

We aimed to estimate the pooled prevalence of Helicobacter pylori among asymptomatic South Asians based on available literature and highlight the importance of screening asymptomatic individuals and implementing preventive strategies for eradicating H. pylori. Electronic databases such as PubMed and Embase, a regional database of WHO South Asian Region, and gray literature sites were searched for relevant studies from 1983 to 5 May 2020. In addition, references of the included studies were thoroughly searched. The random-effect model was used to calculate the pooled prevalence with a 95% confidence interval (CI) along with subgroup analysis. Analysis of 19 studies showed a pooled prevalence of 56.5%, ranging from 10.3 to 91.7%. In subgroup analysis by country, the highest prevalence rate was reported from Bangladesh (86.3%, 95% CI: 0.806-0.921), whereas the lowest prevalence was from Sri Lanka (10.3%, 95% CI: 0.072-0.135). No differences were found between males and females. Prevalence among children and adolescents was 65.3% (95% CI: 0.529-0.777), greater than adults, 56.9% (95% CI: 0.353-0.785). The prevalence rate showed a decreasing trend upon comparison of studies conducted before and after 2000. Our analysis reveals the high prevalence of H. pylori infection among asymptomatic healthy populations in South Asia, particularly in children and adolescents. Public health awareness and sanitation interventions, pure drinking water, and respective strategies on a policy level to eradicate H. pylori and additional extensive multicentric cohort studies are necessary.

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

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

Controversias en cirugía: Erradicación del Helicobacter pylori ¿Terapia a todos o según indicaciones usuales?

La infección por Helicobacter pylori (H. pylori), es la infección bacteriana crónica más frecuente de la raza humana, afecta al 50 % de la población mundial y, por lo menos, al 80 % de la población colombiana. Esta bacteria es reconocida desde hace más de 15 años como un carcinógeno tipo I. De acuerdo con las indicaciones del Consenso de “Maastricht V” esta infección debe ser buscada y tratada en los pacientes con úlcera péptica activa, Linfoma MALT (por sus siglas en inglés, mucosa associated lymphoid tissue), cáncer gástrico temprano, púrpura que presenten síntomas dispépticos crónicos y usuarios crónicos de AINES. Debido al papel que tiene en la fisiopatología del cáncer gástrico, nace la iniciativa de realizar una búsqueda activa del H. pylori y erradicarlo en todas las personas, incluyendo aquellas asintomáticas en países con alta incidencia de esta neoplasia. Existen diversas publicaciones alrededor del mundo que así lo sugieren, mostrando resultados con impacto positivo en el curso y progresión de la enfermedad, sobre todo en las etapas más tempranas de la infección. Sin embargo, otros autores resaltan la creciente problemática de la resistencia bacteriana, y demuestran que el peso estadístico y los diferentes análisis de los estudios disponibles en la actualidad tienen poca validez para dar una recomendación extendida al paciente asintomático. Se cuestiona que tal vez, estamos utilizando las estrategias inadecuadas para manejar una situación de salud pública, ya que estamos enfocados en impactar a cada individuo con terapias antibióticas complejas, en vez de a la población en general con políticas de salud pública.

The Potential Benefits of Vonoprazan as Helicobacter pylori Infection Therapy

Helicobacter pylori infection is a severe global health problem that is closely associated with acid-related diseases and gastric malignancies. Eradicating H. pylori is strongly recommended for lowering peptic ulcer recurrence and preventing gastric cancer. The current approved H. pylori eradication regimen combines a proton pump inhibitor (PPI) with two antibiotics. Unfortunately, this regimen failed to meet expectations mostly due to antibiotic resistance and insufficient gastric acid suppression. Vonoprazan, a novel potassium-competitive acid blocker, showed promising results as a PPI replacement. Vonoprazan inhibits gastric acid secretion by acting as a reversible competitive inhibitor against potassium ions and forming disulfide bonds with the cysteine molecule of H⁺/K⁺-ATPase. Vonoprazan has superior pharmacological characteristics over PPI, such as no requirement for acid activation, stability in acidic conditions, shorter optimum acid suppression period, and resistance to cytochrome P (CYP)2C19 polymorphism. Several comparative randomized controlled trials and meta-analyses revealed the superiority of vonoprazan in eradicating H. pylori, notably the resistant strains. The adverse effect caused by vonoprazan is long-term acid suppression that may induce elevated gastrin serum, hypochlorhydria, and malabsorption. All vonoprazan studies have only been conducted in Japan. Further studies outside Japan are necessary for universally conclusive results.

Pathways of Gastric Carcinogenesis, Helicobacter pylori Virulence and Interactions with Antioxidant Systems, Vitamin C and Phytochemicals

Helicobacter pylori is a class one carcinogen which causes chronic atrophic gastritis, gastric intestinal metaplasia, dysplasia and adenocarcinoma. The mechanisms by which H. pylori interacts with other risk and protective factors, particularly vitamin C in gastric carcinogenesis are complex. Gastric carcinogenesis includes metabolic, environmental, epigenetic, genomic, infective, inflammatory and oncogenic pathways. The molecular classification of gastric cancer subtypes has revolutionized the understanding of gastric carcinogenesis. This includes the tumour microenvironment, germline mutations, and the role of Helicobacter pylori bacteria, Epstein Barr virus and epigenetics in somatic mutations. There is evidence that ascorbic acid, phytochemicals and endogenous antioxidant systems can modify the risk of gastric cancer. Gastric juice ascorbate levels depend on dietary intake of ascorbic acid but can also be decreased by H. pylori infection, H. pylori CagA secretion, tobacco smoking, achlorhydria and chronic atrophic gastritis. Ascorbic acid may be protective against gastric cancer by its antioxidant effect in gastric cytoprotection, regenerating active vitamin E and glutathione, inhibiting endogenous N-nitrosation, reducing toxic effects of ingested nitrosodimethylamines and heterocyclic amines, and preventing H. pylori infection. The effectiveness of such cytoprotection is related to H. pylori strain virulence, particularly CagA expression. The role of vitamin C in epigenetic reprogramming in gastric cancer is still evolving. Other factors in conjunction with vitamin C also play a role in gastric carcinogenesis. Eradication of H. pylori may lead to recovery of vitamin C secretion by gastric epithelium and enable regression of premalignant gastric lesions, thereby interrupting the Correa cascade of gastric carcinogenesis.

Helicobacter pylori antibiotic eradication coupled with a chemically defined diet in INS-GAS mice triggers dysbiosis and vitamin K deficiency resulting in gastric hemorrhage

Infection with Helicobacter pylori causes chronic inflammation and is a risk factor for gastric cancer. Antibiotic treatment or increased dietary folate prevents gastric carcinogenesis in male INS-GAS mice. To determine potential synergistic effects, H. pylori-infected male INS-GAS mice were fed an amino acid defined (AAD) diet with increased folate and were treated with antibiotics after 18 weeks of H. pylori infection. Antibiotic therapy decreased gastric pathology, but dietary folate had no effect. However, the combination of antibiotics and the AAD diet induced anemia, gastric hemorrhage, and mortality. Clinical presentation suggested hypovitaminosis K potentially caused by dietary deficiency and dysbiosis. Based on current dietary guidelines, the AAD diet was deficient in vitamin K. Phylloquinone administered subcutaneously and via a reformulated diet led to clinical improvement with no subsequent mortalities and increased hepatic vitamin K levels. We characterized the microbiome and menaquinone profiles of antibiotic-treated and antibiotic-free mice. Antibiotic treatment decreased the abundance of menaquinone producers within orders Bacteroidales and Verrucomicrobiales. PICRUSt predicted decreases in canonical menaquinone biosynthesis genes, menA and menD. Reduction of menA from Akkermansia muciniphila, Bacteroides uniformis, and Muribaculum intestinale were confirmed in antibiotic-treated mice. The fecal menaquinone profile of antibiotic-treated mice had reduced MK5 and MK6 and increased MK7 and MK11 compared to antibiotic-free mice. Loss of menaquinone-producing microbes due to antibiotics altered the enteric production of vitamin K. This study highlights the role of diet and the microbiome in maintaining vitamin K homeostasis.

Mechanisms of the Epithelial-Mesenchymal Transition and Tumor Microenvironment in Helicobacter pylori-Induced Gastric Cancer

Helicobacter pylori (H. pylori) is one of the most common human pathogens, affecting half of the world’s population. Approximately 20% of the infected patients develop gastric ulcers or neoplastic changes in the gastric stroma. An infection also leads to the progression of epithelial–mesenchymal transition within gastric tissue, increasing the probability of gastric cancer development. This paper aims to review the role of H. pylori and its virulence factors in epithelial–mesenchymal transition associated with malignant transformation within the gastric stroma. The reviewed factors included: CagA (cytotoxin-associated gene A) along with induction of cancer stem-cell properties and interaction with YAP (Yes-associated protein pathway), tumor necrosis factor α-inducing protein, Lpp20 lipoprotein, Afadin protein, penicillin-binding protein 1A, microRNA-29a-3p, programmed cell death protein 4, lysosomal-associated protein transmembrane 4β, cancer-associated fibroblasts, heparin-binding epidermal growth factor (HB-EGF), matrix metalloproteinase-7 (MMP-7), and cancer stem cells (CSCs). The review summarizes the most recent findings, providing insight into potential molecular targets and new treatment strategies for gastric cancer.

Risk of stomach cancer incidence in a cohort of Mayak PA workers occupationally exposed to ionizing radiation

Stomach cancer is a widespread health condition associated with environmental and genetic factors. Contribution of ionizing radiation to stomach cancer etiology is not sufficiently studied. This study was aimed to assess an association of the stomach cancer incidence risk with doses from occupational radiation exposure in a cohort of workers hired at main Mayak production association facilities in 1948–1982 taking into account non-radiation factors including digestive disorders. The study cohort comprised 22,377 individuals and by 31.12.2013 343 stomach cancer diagnoses had been reported among the cohort members. Occupational stomach absorbed doses were provided by the Mayak Worker Dosimetry System– 2008 (MWDS–2008) for external gamma ray exposure and by the Mayak Worker Dosimetry System– 2013 (MWDS–2013) for internal exposure to plutonium. Excess relative risks (ERR) per Gy for stomach cancer were estimated using the Poisson’s regression. Analyses were run using the AMFIT module of the EPICURE software. The stomach cancer incidence risk in the study cohort was found to be significantly associated with the stomach absorbed dose of gamma rays: ERR/Gy = 0.19 (95% CI: 0.01, 0.44) with a 0 year lag, and ERR/Gy = 0.20 (95% CI: 0.01, 0.45) with a 5 year lag. To estimate the baseline risk, sex, attained age, smoking status and alcohol consumption, chronic diseases (peptic ulcer, gastritis and duodenitis) were taken into account. No modifications of the radiogenic risk by non-radiation factors were found in the study worker cohort. No association of the stomach cancer incidence risk with internal exposure to incorporated plutonium was observed.

Comparative Efficacy and Safety of Biosimilar Rituximab and Originator Rituximab in Rheumatoid Arthritis and Non-Hodgkin's Lymphoma: A Systematic Review and Meta-analysis

BACKGROUND

Rituximab is a biologic medicine widely used for the treatment of autoimmune diseases and lymphoma. Several biosimilars of rituximab have been developed and marketed with the expiration of the originator rituximab's patent; thus, systematic combination and analysis of the latest data on the efficacy and safety of biosimilars and the demonstration of the interchangeability of biosimilar agents are required.

OBJECTIVE

The objective of this study was to collate available data from head-to-head randomized controlled trials (RCTs) and evaluate the efficacy and safety of biosimilar rituximab compared with the reference drug in patients with rheumatoid arthritis (RA) and non-Hodgkin's lymphoma (NHL).

METHODS

The PubMed, EMBASE, Cochrane Library, and Google Scholar databases were searched to identify head-to-head RCTs that directly compare the efficacy and safety of biosimilar rituximab and its originator. The efficacy outcome for RA was the American College of Rheumatology (ACR) response rates and the outcome for NHL was the response rate. The occurrence of adverse events (AEs) and anti-drug antibodies (ADAs) were evaluated for the safety outcome. Data on the pharmacokinetic profile were also included as a secondary outcome.

RESULTS

Eleven head-to-head RCTs with 3163 patients were included (1744 patients with RA and 1419 patients with NHL). Biosimilars of rituximab showed similar efficacy in the clinical response in both RA and NHL. The pooled risk ratio (RR) of the ACR 20% response rate (ACR20) response in patients with RA at weeks 24 and 48 was 0.99 (p = 0.70, 95% confidence interval [CI] 0.92-1.06) and 1.04 (p = 0.73, 95% CI 0.83-1.31), respectively. The pooled RR of the overall response at week 24 in NHL patients was 1.02 (p = 0.31, 95% CI 0.98-1.07). No significant differences were found in the formation of ADAs (RR 0.86, p = 0.20, 95% CI 0.68-1.08) or AEs (RR 1.04, p = 0.30, 95% CI 0.97-1.12).

CONCLUSION

This systematic review and conventional meta-analysis demonstrated the overall similarity of the long-term efficacy and safety of biosimilar rituximab to those of originator rituximab in RA and NHL patients by combining direct evidence from head-to-head trials. PROSPERO registration No. CRD42019125138.

Helicobacterpylori eradication treatment for gastric carcinoma prevention in asymptomatic or dyspeptic adults: systematic review and Bayesian meta-analysis of randomised controlled trials

OBJECTIVES

Recent meta-analyses of eradication therapy in Helicobacter pylori-infected adults reported significant reductions in gastric carcinoma risk. However, concerns about supporting unfocused screening and eradication programme in healthy, asymptomatic populations have arisen. We performed a systematic review and Bayesian meta-analysis to provide an accurate interpretation of randomised evidence on the preventive effectiveness of eradication therapy on gastric carcinoma risk.

METHODS

We searched databases including PubMed, Cochrane Central and Embase for reference and citation tracking without language restrictions, from inception through 31 July 2018. Paired investigators independently selected randomised controlled trials (RCTs) comparing eradication therapy with placebo or no treatment for asymptomatic or dyspeptic H. pylori-infected adults with no previous gastric carcinoma. The main outcome was gastric carcinoma incidence; secondary outcomes included gastric carcinoma-specific, non-gastric carcinoma and all-cause mortality.

RESULTS

A total of 5 population-based and 2 outpatient care-based RCTs involving 7303 adults were eligible. Eradication algorithms were heterogeneous, and unsuccessful eradication and reinfection were frequently observed. A Bayesian meta-analysis with competing risk outcomes found low-certainty evidence that eradication therapy might be more likely than control to reduce gastric carcinoma risk (HR=0.65; 95% credible interval (CrI) 0.41 to 1.0; I² =11%). The CrIs included the null effects across the subgroup and sensitivity analyses, apart from those based on particular models that excluded two RCTs that enrolled subjects with specific histological findings only (HR=0.55; CrI 0.30 to 0.89; I² =14%). The uncertainty of the average 41% risk reduction in gastric carcinoma-specific mortality included a clinically important mortality risk increase (HR=0.59 favouring eradication therapy; CrI 0.25 to 1.20; I² =13%; low certainty).

CONCLUSIONS

There is insufficient evidence to support or refute the effectiveness of eradication therapy in preventing gastric carcinoma in H. pylori-infected, high-risk populations. Rigorously conducted large RCTs of healthy infected adults only would provide evidence of the true efficacy of successful eradication. PROSPERO registration number: CRD42014009245.

Chemoprevention of gastric cancer by Helicobacter pylori eradication and its underlying mechanism

The cascade of gastric cancer, a leading cause of cancer incidence and mortality, is multifactorial. Helicobacter pylori (HP) infection plays a major role in gastric cancer (GC), and there has been an accumulation of data regarding the chemopreventive effect of HP eradication. However, it remains unclear how HP infection causes GC and how HP eradication prevents GC. To clarify this issue, the following approaches were performed in this review article. First, how HP-induced atrophic gastritis (AG) and intestinal metaplasia (IM) provoke the development of GC is shown, followed by how long HP eradication takes to induce a reversible change in AG and IM. Second, epigenetic studies of PTPN6, MOS, DCC, CRK, and VAV1 were performed in noncancerous gastric specimens in terms of HP status. Among these genes, MOS was found to be a possible surrogate marker for GC development. HP eradication decreased aberrant DNA methylation in a gene-specific manner, and MOS played a role in metachronous gastric neoplasms. Third, transforming growth factor-β1 (TGF-β1) and TGF-β1-induced epithelial-mesenchymal transition (EMT) markers were investigated in gastric mucosa. HP infection triggered the TGF-β1-induced EMT pathway and caused the emergence of GC stem cells, such as CD44v8-10. When HP was eradicated, these two pathways were inhibited. Finally, a 2222 cohort study showed that HP eradication significantly decreased the risk of noncardiac GC. Taken together, HP eradication is effective as a primary GC prevention method, and its underlying mechanism includes reversibility of AG and IM, methylation, EMT, and stem cells.

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.

Can Aminoglycosides Be Used as a New Treatment for Helicobacter pylori? In vitro Activity of Recently Isolated Helicobacter pylori

BACKGROUND

Smectite can serve as a drug delivery system and gentamicin-intercalated smectite hybrids are expected to supersede the standard therapy for Helicobacter pylori eradication. The aim of this study was to confirm whether the minimum inhibitory concentration (MIC) of aminoglycosides applied as smectite hybrids remained low against recently isolated H. pylori strains.

MATERIALS AND METHODS

A total of 140 strains were collected for a minimum period of 3 years. Antimicrobial susceptibility tests were performed, and the MICs of eight antibiotics (amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin, gentamicin, netilmicin, and tobramycin) were determined by using the Epsilometer test and following the European Committee on Antimicrobial Susceptibility Testing recommendations.

RESULTS

The resistance rate of clarithromycin was high, up to 30.7%, although it is a major antimicrobial agent used in standard therapy. The MIC₅₀ and MIC₉₀ of gentamicin (0.25 mg/L and 0.75 mg/L) and netilmicin (0.19 mg/L and 0.75 mg/L) were lower than other alternative therapies for H. pylori eradication. In clarithromycin-resistant strains, the MIC₅₀ was 0.25 mg/L and the MIC₉₀ was 1 mg/L for gentamicin; for netilmicin, the values were 0.25 mg/L and 0.75 mg/L, respectively.

CONCLUSION

Through the use of gentamicin and netilmicin, which have low MICs for H. pylori, aminoglycoside-intercalated smectite hybrids are expected to emerge as a new standard therapy for H. pylori eradication.

Helicobacter pylori Infection: New Facts in Clinical Management

PURPOSE

The global prevalence of Helicobacter pylori remains high in spite of its significant downwards trajectory in many regions. The clinical management of H. pylori infection merits guidance to meet ongoing challenges on whom and how to test, prevent, and cure related diseases.

RECENT FINDINGS

Several international guidelines and consensus reports have updated the management strategies for cure of the H. pylori infection. The definition of H. pylori gastritis as an infectious disease independent of whether or not presenting with clinical manifestations and symptoms has broadened the use of the test and treat strategy. Patients on selected long-term medications, such as aspirin, other anti-platelet agents, NSAIDs, and PPIs should be considered for H. pylori test and treat. Important progress is made with initiatives in primary and secondary gastric cancer prevention. Uncertainties persist in the interpretation of the role of H. pylori in association with extragastric diseases. Selection of therapies needs to address individual antibiotic resistance and regional surveillance of resistance for the adoption of an effective treatment algorithm.

CONCLUSION

Clinical aspects of H. pylori infection have evolved over time and the therapeutic management requires continuous adaptation. A vaccine is still a non-fulfilled promise. The future will tell us more about the role of H. pylori in interactions with the gut microbiome.

Multi‑layered prevention and treatment of chronic inflammation, organ fibrosis and cancer associated with canonical WNT/β‑catenin signaling activation (Review)

β-catenin/CTNNB1 is an intracellular scaffold protein that interacts with adhesion molecules (E-cadherin/CDH1, N-cadherin/CDH2, VE-cadherin/CDH5 and α-catenins), transmembrane-type mucins (MUC1/CD227 and MUC16/CA125), signaling regulators (APC, AXIN1, AXIN2 and NHERF1/EBP50) and epigenetic or transcriptional regulators (BCL9, BCL9L, CREBBP/CBP, EP300/p300, FOXM1, MED12, SMARCA4/BRG1 and TCF/LEF). Gain-of-function CTTNB1 mutations are detected in bladder cancer, colorectal cancer, gastric cancer, liver cancer, lung cancer, pancreatic cancer, prostate cancer and uterine cancer, whereas loss-of-function CTNNB1 mutations are also detected in human cancer. ABCB1, ALDH1A1, ASCL2, ATF3, AXIN2, BAMBI, CCND1, CD44, CLDN1, CTLA4, DKK1, EDN1, EOMES, FGF18, FGF20, FZD7, IL10, JAG1, LEF1, LGR5, MITF, MSX1, MYC, NEUROD1, NKD1, NODAL, NOTCH2, NOTUM, NRCAM, OPN, PAX3, PPARD, PTGS2, RNF43, SNAI1, SP5, TCF7, TERT, TNFRSF19, VEGFA and ZNRF3 are representative β-catenin target genes. β-catenin signaling is involved in myofibroblast activation and subsequent pulmonary fibrosis, in addition to other types of fibrosis. β-catenin and NF-κB signaling activation are involved in field cancerization in the stomach associated with Helicobacter pylori (H. pylori) infection and in the liver associated with hepatitis C virus (HCV) infection and other etiologies. β-catenin-targeted therapeutics are functionally classified into β-catenin inhibitors targeting upstream regulators (AZ1366, ETC-159, G007-LK, GNF6231, ipafricept, NVP-TNKS656, rosmantuzumab, vantictumab, WNT-C59, WNT974 and XAV939), β-catenin inhibitors targeting protein-protein interactions (CGP049090, CWP232228, E7386, ICG-001, LF3 and PRI-724), β-catenin inhibitors targeting epigenetic regulators (PKF118-310), β-catenin inhibitors targeting mediator complexes (CCT251545 and cortistatin A) and β-catenin inhibitors targeting transmembrane-type transcriptional outputs, including CD44v6, FZD7 and LGR5. Eradicating H. pylori and HCV is the optimal approach for the first-line prevention of gastric cancer and hepatocellular carcinoma (HCC), respectively. However, β-catenin inhibitors may be applicable for the prevention of organ fibrosis, second-line HCC prevention and treating β-catenin-driven cancer. The multi-layered prevention and treatment strategy of β-catenin-related human diseases is necessary for the practice of personalized medicine and implementation of precision medicine.

Advanced gastrointestinal carcinoma with massive ascites and hydrothorax during pregnancy: A case report and review of the literature

RATIONALE

Gastrointestinal carcinoma is rare during pregnancy. It is usually diagnosed at an advanced stage because special gastrointestinal symptoms are generally overlooked during pregnancy, and there are many limitations and contraindications for using diagnostic tools during pregnancy.

PATIENT CONCERNS

We present a case of a 29-year-old patient with 27 weeks and 5 days of gestation due to massive ascites and hydrothorax.

DIAGNOSES

The patient was diagnosed with an advanced gastrointestinal cancer. Pathological report showed poorly differentiated tumor with the signet ring cell component.

INTERVENTIONS

Caesarean section was performed. At the same time, an abdominal exploration showed that the omentum was like biscuits . There were extensive and firm intestinal adhesions, and many tumor lesions were found on the surface of greater curvature of stomach, spleen, intestine, peritoneum, ascending colon and descending colon.

OUTCOMES

Gastrointestinal surgeon was invited during operation, and palliative gastrectomy was not performed because of extensive metastases. The patient died 30 days after caesarean section.

LESSONS

This study present a case with advanced gastrointestinal cancer during pregnancy. We suggest that endoscopic exam is recommended if the patient is highly suspicious.