Meta-analysis: can Helicobacter pylori eradication treatment reduce the risk for gastric cancer?

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.

The second Irish Helicobacter pylori Working Group consensus for the diagnosis and treatment of Helicobacter pylori infection in adult patients in Ireland

BACKGROUND

There has been an increase in resistance to many of the antimicrobials used to treat Helicobacter pylori ( H. pylori ) nationally and internationally. Primary clarithromycin resistance and dual clarithromycin and metronidazole resistance are high in Ireland. These trends call for an evaluation of best-practice management strategies.

OBJECTIVE

The objective of this study was to revise the recommendations for the management of H. pylori infection in adult patients in the Irish healthcare setting.

METHODS

The Irish H. pylori working group (IHPWG) was established in 2016 and reconvened in 2023 to evaluate the most up-to-date literature on H. pylori diagnosis, eradication rates and antimicrobial resistance. The 'GRADE' approach was then used to rate the quality of available evidence and grade the resulting recommendations.

RESULTS

The Irish H. pylori working group agreed on 14 consensus statements. Key recommendations include (1) routine antimicrobial susceptibility testing to guide therapy is no longer recommended other than for clarithromycin susceptibility testing for first-line treatment (statements 6 and 9), (2) clarithromycin triple therapy should only be prescribed as first-line therapy in cases where clarithromycin susceptibility has been confirmed (statement 9), (3) bismuth quadruple therapy (proton pump inhibitor, bismuth, metronidazole, tetracycline) is the recommended first-line therapy if clarithromycin resistance is unknown or confirmed (statement 10), (4) bismuth quadruple therapy with a proton pump inhibitor, levofloxacin and amoxicillin is the recommended second-line treatment (statement 11) and (5) rifabutin amoxicillin triple therapy is the recommend rescue therapy (statement 12).

CONCLUSION

These recommendations are intended to provide the most relevant current best-practice guidelines for the management of H. pylori infection in adults in Ireland.

Helicobacter pylori Secondary Antibiotic Resistance after One or More Eradication Failure: A Genotypic Stool Analysis Study

Helicobacter pylori (H. pylori) antibiotic resistance is the leading cause for unsuccessful eradication therapy. After one or more failures, the chance of encountering secondary antibiotic resistance increases. The aim of this study was to characterize genotypic secondary resistance in a cohort of southern Italian H. pylori patients with at least one previous failure. Such patients collected stool samples using a dedicated kit (THD fecal testTM), and bacterial DNA was extracted and amplified using RT-PCR. Resistance to clarithromycin, amoxicillin, metronidazole, levofloxacin, and tetracycline was assessed using a high-resolution melting curve. We enrolled 50 patients. A total of 72% of patients failed one previous antibiotic course, 16% failed two, 10% failed three, and 2% failed four. The rate of secondary antibiotic resistance was 16% for clarithromycin, 18% for metronidazole, 14% for amoxicillin, 14% for levofloxacin, and 2% for tetracycline. Among the eight clarithromycin-resistant patients, five (62.5%) previously received a clarithromycin-based regimen. The same rate was 33.3% (3/9) for metronidazole. The only tetracycline-resistant patient had received Pylera. In conclusion, our data seem to show that, even though secondary resistance is not very high, resistance to clarithromycin could be very likely related to previous exposure to this antibiotic.

Type 2 Diabetes Mellitus and Helicobacter pylori Eradication in a Clinical Population

OBJECTIVES

Eradication of Helicobacter pylori reduces the risk of gastric cancer (GC). Individuals with type 2 diabetes mellitus (T2DM) are known to be at increased risk for GC. In a cohort of H. pylori-positive individuals, we assessed whether those with T2DM were at risk of persistent infection following H. pylori treatment compared with individuals without T2DM.

METHODS

A random subset of all individuals diagnosed as having H. pylori without intestinal metaplasia at endoscopy from 2015 to 2019 were stratified evenly by race (Black and White). After excluding those with T1DM and those without eradication testing after H. pylori treatment, logistic regression analysis was used to determine the association of T2DM with the risk of persistent H. pylori infection following treatment.

RESULTS

In 138 patients, H. pylori eradication rates did not differ between the 27% of individuals with T2DM compared to those without (81.1% vs 81.2%). After adjusting for age, race, and insurance status, we found no significant increased risk of persistent H. pylori infection for individuals with T2DM (odds ratio 1.40; 95% confidence interval 0.49-3.99).

CONCLUSIONS

H. pylori eradication rates do not differ by T2DM status, providing support for clinical trials of H. pylori eradication to reduce GC incidence among high-risk populations in the United States, such as individuals with T2DM.

Role of Helicobacter pylori virulence factors and alteration of the Tumor Immune Microenvironment: challenges and opportunities for Cancer Immunotherapy

Various forms of malignancies have been linked to Helicobacter pylori. Despite advancements in chemotherapeutic and surgical approaches, the management of cancer, particularly at advanced stages, increasingly relies on the integration of immunotherapy. As a novel, safe therapeutic modality, immunotherapy harnesses the immune system of the patient to treat cancer, thereby broadening treatment options. However, there is evidence that H. pylori infection may influence the effectiveness of immunotherapy in various types of cancer. This association is related to H. pylori virulence factors and the tumor microenvironment. This review discusses the influence of H. pylori infection on immunotherapy in non-gastrointestinal and gastrointestinal tumors, the mechanisms underlying this relationship, and directions for the development of improved immunotherapy strategies.

Gastric Cancer Risk Factors in a Veteran Population

INTRODUCTION

Risk factors for gastric cancer in the United States are not well understood, especially in populations with a low proportion of immigrants. We conducted a matched case-control study in a Veteran Affairs Medical Center to identify risk factors for gastric cancer.

MATERIALS AND METHODS

Gastric cancer patients and age- and sex-matched controls were identified in a 1:4 ratio from January 1, 1997 to October 31, 2018. Demographic, medical, endoscopic, and histologic data were extracted. We performed conditional logistic regression to estimate odds ratios and 95% CIs for associations between potential risk factors and gastric cancer.

RESULTS

Most gastric cancer cases were diagnosed on initial endoscopy (71.4%). Of these, the most common presenting stage was stage IV (40.8%). Risk factors for gastric cancer included Black and Asian race and never or current (compared to former) drinkers, although Helicobacter pylori eradication and pernicious anemia were associated with decreased risk.

CONCLUSIONS

The high proportion of late-stage gastric cancer diagnoses highlights the need for improved risk stratification as well as screening and surveillance protocols in the U.S. population. Racial disparities among veterans in an equal-access system necessitate further investigation into the etiology of these disparities.

Cross-talk between Helicobacter pylori and gastric cancer: a scientometric analysis

Background

Helicobacter pylori (HP) is considered a leading risk factor for gastric cancer (GC). The aim of this article is to conduct bibliometric and visual analysis to assess scientific output, identify highly cited papers, summarize current knowledge, and explore recent hotspots and trends in HP/GC research.

Methods

A bibliographic search was conducted on October 24, 2023, to retrieve relevant studies on HP/GC research between 2003 and 2022. The search terms were attached to HP and GC. The main data were from the Web of Science Core Collection (WoSCC). Data visualization was performed using Biblioshiny, VOSviewer, and Microsoft Excel.

Results

In HP/GC research, 1970 papers were retrieved. The total number of papers (Np) in HP/GC was growing from 2003 to 2022. China and Japan were in the leading position and made the most contributions to HP/GC. Vanderbilt University and the US Department of Veterans Affairs had the highest Np. The most productive authors were Peek Jr Richard M. and Piazuelo M Blanca. Helicobacter received the most Np, while Gastroenterology had the most total citations (TC). High-cited publications and keyword clustering were used to identify the current status and trends in HP/GC research, while historical citation analysis provided insight into the evolution of HP/GC research. The hot topics included the effect of HP on gastric tumorigenesis and progression, the pathogenesis of HP-induced GC (HP factors), and the mechanisms by which HP affects GC (host factors). Research in the coming years could focus on topics such as autophagy, gut microbiota, immunotherapy, exosomes, epithelial-mesenchymal transition (EMT), and gamma-glutamyl transpeptidase (GGT).

Conclusion

This study evaluated the global scientific output in HP/GC research and its quantitative characteristics, identified the essential works, and collected information on the current status, main focuses and emerging trends in HP/GC research to provide academics with guidance for future paths.

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.

Advancements in Understanding Gastric Cancer: A Comprehensive Review

As a complex and difficult condition, gastric cancer (GC) continues to have a big impact on the world's health. The goal of this review article is to give a thorough summary of the most recent developments and research discoveries in the field of stomach cancer. The review discusses a wide range of topics, such as the epidemiology and risk factors for GC, molecular insights into its pathogenesis, the use of biomarkers in diagnosis and prognosis, current and novel therapeutic approaches, and the intriguing potential of immunotherapy. In addition, procedures for surgery, therapy strategies, and imaging modalities for diagnosis and staging are examined. The paper emphasizes how crucial it is to comprehend the tumor microenvironment and how it affects the course of the disease. Overall, this review provides a comprehensive assessment of the current body of knowledge, highlights research gaps, and suggests future lines of inquiry to enhance the treatment of GC.

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.

Association between Age at Helicobacter pylori Eradication and the Risk of Gastric Cancer Stratified by Family History of Gastric Cancer: A Nationwide Population-Based Study

INTRODUCTION

This study compares the risk of GC according to age at H. pylori eradication, stratified based on the presence of family history of GC using a population-based large cohort.

METHOD

We analyzed individuals who underwent GC screening between 2013 and 2014 and received H. pylori eradication therapy before screening.

RESULTS

Among 1,888,815 H. pylori-treated patients, 2610/294,706 and 9332/1,594,109 patients with and without a family history of GC, respectively, developed GC. After adjusting for confounders, including age at screening, the adjusted hazard ratios (95% confidence intervals) for GC comparison, 70-74, 65-69, 60-64, 55-59, 50-54, 45-49, and <45 years with ≥75 years at H. pylori eradication were 0.98 (0.79-1.21), 0.88 (0.74-1.05), 0.76 (0.59-0.99), 0.62 (0.44-0.88), 0.57 (0.36-0.90), 0.38 (0.22-0.66), and 0.34 (0.17-0.67), respectively, among patients with a family history of GC (p < 0.001) and 1.01 (0.91-1.13), 0.95 (0.86-1.04), 0.86 (0.75-0.98), 0.67 (0.56-0.81), 0.56 (0.44-0.71), 0.51 (0.38-0.68), and 0.33 (0.23-0.47), respectively, among patients without a family history of GC (p < 0.001).

CONCLUSION

In patients with and without a family history of GC, young age at H. pylori eradication was significantly associated with a reduced risk of GC, suggesting that the early treatment of H. pylori infection can maximize GC prevention.

Concentration of circulating tumour DNA in patients with metastatic gastric cancer and its prognostic significance

Gastric cancer is one of the most common cancers worldwide. The amount of cell-free DNA (cfDNA) in the blood of patients with gastric cancer was found to be higher than that of healthy controls (69.1 ng/μL vs. 34.8 ng/μL). Patients with cfDNA ≤ 50 ng/μL were found to have an increased overall survival (OS) and progression free survival (PFS) than in patients with cfDNA > 50 ng/μL.

Epidemiology of stomach cancer

Despite a decline in incidence and mortality during the last decades, stomach cancer is one of the main health challenges worldwide. According to the GLOBOCAN 2020 estimates, stomach cancer caused approximately 800000 deaths (accounting for 7.7% of all cancer deaths), and ranks as the fourth leading cause of cancer deaths in both genders combined. About 1.1 million new cases of stomach cancer were diagnosed in 2020 (accounting for 5.6% of all cancer cases). About 75% of all new cases and all deaths from stomach cancer are reported in Asia. Stomach cancer is one of the most lethal malignant tumors, with a five-year survival rate of around 20%. There are some well-established risk factors for stomach cancer: Helicobacter pylori infection, dietary factors, tobacco, obesity, and radiation. To date, the most important way of preventing stomach cancer is reduced exposure to risk factors, as well as screening and early detection. Further research on risk factors can help identify various opportunities for more effective prevention. Screening programs for stomach cancer have been implemented in a few countries, either as a national or opportunistic screening of high-risk individuals only. Generally, due to its high aggressiveness and heterogeneity, stomach cancer still remains a severe global health problem.

Socioeconomic Disparities in Gastric Cancer and Identification of a Single SES Variable for Predicting Risk

INTRODUCTION

Socioeconomic status (SES) is a known risk factor for gastric cancer (GC). This study seeks to examine education, income, and occupation variables separately to identify the single variable that can be best used to assess SES risk for GC.

METHODS

Data from a case-control survey study were used. Logistic regression models were created for education, income, and occupation adjusted for age, sex, and race. Models were compared using AIC, c-statistics, and pseudo-R square to determine the model that had the highest risk predictive ability.

RESULTS

GC cases had lower education levels and more commonly held jobs in unskilled labor. Annual household income was lower in cases compared to controls. Age, gender, race, education, and occupation were associated with increased risk of GC. The education model adjusted for age, gender, and race found < high school (HS) education to have an OR of 3.18 (95% CI 1.09-9.25) for GC compared to > HS education. The occupation model demonstrated that employment in unskilled labor had OR of 4.32 (95% CI 1.05-17.76) for GC compared to professional occupation. Model fit was best for the education model (AIC: 113.583, lower AIC is better) compared to income (117.562) or occupation (117.032). Education contributed the most to model variability (% delta pseudo-R square (4.7%)) compared to occupation (4.0%) or income (3.8%).

CONCLUSION

Education level was the single most reliable measure of GC risk among 3 SES variables and can be employed as an ideal single indicator of SES-related GC risk when multiple SES factors cannot be obtained.

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.

The role of the occupational physician in controlling gastric cancer attributable to Helicobacter pylori infection: A review

This review aimed to describe the potential role of occupational physician in the implementation of a screening program for Helicobacter pylori (Hp) infection for gastric cancer prevention. We reviewed the epidemiological background of gastric cancer and its association with Hp, exploring the hypothesis of a "test-and-treat" protocol among working population. Clinical trials and model-based studies were collected to provided empirical evidence of the feasibility of eradication on large scale. In particular, previous studies conducted in occupational settings were discussed. Hp prevalence ranges between about 20 and 90%, with higher rates in Asia and Latin America and lower rates in Europe and North America. Large-scale trials on screening and treatment of infection have been conducted especially in East Asia, lacking elsewhere. Only few studies investigated Hp prevalence among workers. The benefit of eradication at occupational level has not yet been adequately studied. The design of a workplace-based Hp screening program appears to be innovative and could contribute to controlling gastric cancer. The benefit would involve not only high-risk subjects, but also their families, since the route of transmission is principally within the household. An occupational setting for a Hp screening would have positive consequences in terms of individual and public health.

Current Advances and Outlook in Gastric Cancer Chemoresistance: A Review

BACKGROUND

Surgical resection of the lesion is the standard primary treatment of gastric cancer. Unfortunately, most patients are already in the advanced stage of the disease when they are diagnosed with gastric cancer. Alternative therapies, such as radiation therapy and chemotherapy, can achieve only very limited benefits. The emergence of cancer drug resistance has always been the major obstacle to the cure of tumors. The main goal of modern cancer pharmacology is to determine the underlying mechanism of anticancer drugs.

OBJECTIVE

Here, we mainly review the latest research results related to the mechanism of chemotherapy resistance in gastric cancer, the application of natural products in overcoming the chemotherapy resistance of gastric cancer, and the new strategies currently being developed to treat tumors based on immunotherapy and gene therapy.

CONCLUSION

The emergence of cancer drug resistance is the main obstacle in achieving alleviation and final cure for gastric cancer. Mixed therapies are considered to be a possible way to overcome chemoresistance. Natural products are the main resource for discovering new drugs specific for treating chemoresistance, and further research is needed to clarify the mechanism of natural product activity in patients. .

Clarithromycin versus furazolidone for naïve Helicobacter pylori infected patients in a high clarithromycin resistance area

BACKGROUND AND AIM

The increase in antibiotic resistance makes the eradication of Helicobacter pylori more difficult. Considering the limitations of the application of susceptibility-guided therapy, it is important to find an effective empirical regimen. The aim of the study is to compare the efficacy, safety, and cost-effectiveness of clarithromycin-based bismuth-containing quadruple therapy (C-BQT) and furazolidone-based bismuth-containing quadruple therapy (F-BQT) in naïve H. pylori positive patients.

METHODS

This was an open-label, randomized controlled, crossover trial. The trial comprised two phases. In C-F group, patients received C-BQT in the first phase; those who were still positive for H. pylori infection after the first phase entered the second phase to receive F-BQT as rescue treatment. In F-C group, patients were treated with F-BQT firstly and rescued with C-BQT.

RESULTS

As first-line treatments, the eradication rates of C-BQT and F-BQT were 89.7% (157/175) and 92.0% (161/175) (P = 0.458) in intention-to-treat analysis and 93.4% (156/167) and 95.8% (161/168) (P = 0.327) in per-protocol analysis, respectively. The cumulative eradication rates of the C-F group and the F-C group were both 94.3% in intention-to-treat analysis (P = 1.000). Cost-effectiveness indexes of F-BQT and C-BQT were 0.54 and 1.24 in first-line treatments. Frequencies of adverse events in F-BQT and C-BQT had no differences (36.0% in C-BQT vs 32.6% in F-BQT, P = 0.499).

CONCLUSIONS

Furazolidone-based bismuth-containing quadruple therapy should be preferred for its excellent cost-effectiveness and acceptable safety.

Prognostic Role of RASSF1A, SOX17 and Wif-1 Promoter Methylation Status in Cell-Free DNA of Advanced Gastric Cancer Patients

Epigenetic modification of several genes is a key component in the development of gastric cancer. The methylation status of RASSF1A, SOX17 and Wif-1 genes was evaluated in the cell free circulating DNA of 70 patients with advanced gastric cancer, using methylation-specific PCR. Patients with higher cell-free DNA concentration seem to have lower PFS, than patients with lower cell-free DNA concentration (p = 0.001). RASSF1A was the tumor suppressor gene, most frequently methylated in metastatic gastric cancer patients, followed by SOX17 and Wif-1 (74.3%, 60.0% and 47.1%, respectively). Patients having the SOX17 promoter methylated, had lower progression free survival and overall survival, than unmethylated ones (p < 0.001). Patients having the Wif-1 promoter methylated, had lower progression free survival and overall survival, than unmethylated ones (p = 0.001). Patients having the RASSF1A promoter methylated, had lower progression free survival and overall survival, than unmethylated ones (p = 0.004). Promoter methylation of the examined genes was significantly associated with a decrease in progression free survival and overall survival, comparing to that of patients without methylation. Simultaneous methylation of the above genes was associated with even worse progression free survival and overall survival. The methylation of RASSF1A, SOX-17 and Wif-1 and genes, is a frequent epigenetic event in patients with advanced gastric cancer.

Exploration of endoscopic findings and risk factors of early gastric cancer after eradication of Helicobacter pylori

AIM

To explore the endoscopic features and risk factors of early gastric cancer (EGC) after eradication of Helicobacter pylori (H. pylori).

METHODS

A total of 1961 patients who underwent esophago-gastro-duodenoscopy (EGD) with a history of successful H. pylori eradication were enrolled in this multicenter research. Among them, 162 EGC lesions of 132 patients were detected. The endoscopic features and risk factors of post-eradication EGC were explored.

RESULTS

Severe atrophy (75.3% vs. 16.7%, p value <.01), intestinal metaplasia (96.3% vs. 77.1%, p value <.01), map-like redness (89.5% vs. 65.4%, p value <.01), distinct intermediate zone (IZ) (68.5% vs. 23.4%, p value <.01) and xanthoma (58.0% vs. 17.9%, p value <.01) were significantly more frequent in the CA group (patients with newly detected EGC after eradication of H. pylori) than in the NC group (patients without gastric cancer after eradication of H. pylori). In multivariate analysis, severe atrophy (odds ratio (OR) = 8.08; 95% confidence interval (CI), 3.43-20.0; p value<.01), map-like redness (OR = 1.75; 95% CI, 0.11-5.25; p value = .04), distinct IZ (OR = 2.87; 95% CI, 1.20-6.93; p value = .02) and xanthoma (OR = 2.84; 95% CI, 1.20-7.03; p value=.02) were proved to be risk factors for detection of EGC after eradication of H. pylori.

CONCLUSIONS

Severe atrophy and map-like redness and distinct IZ and xanthoma are risk factors of EGC after eradication of H. pylori.

Post-transplant malignancies in pediatric organ transplant recipients

The majority of cancer diagnoses in pediatric solid organ transplant recipients (SOTRs) are post-transplantation lymphoproliferative disorders (PTLD) or skin cancers. However, pediatric SOTRs are also at significantly elevated risk for multiple other solid and hematological cancers. The risks of specific cancers vary by transplanted organ, underlying disease, and immunosuppression factors. More than one-quarter of pediatric SOTRs develop cancer within 30 years of transplantation and their risk of solid cancer is 14 times greater than the general population. Pediatric SOTRs are at significantly higher risk of cancer-associated death. Improving patient survival among pediatric SOTRs puts them at risk of adult epithelial cancers associated with environmental carcinogenic exposures. Vaccination against oncogenic viruses and avoidance of excessive immunosuppression may reduce the risk of solid cancers following transplantation. Patient and family education regarding photoprotection is an essential component of skin cancer prevention. There is significant variability in cancer screening recommendations for SOTRs and general population approaches are typically not validated for transplant populations. An individualized approach to cancer screening should be developed based on estimated cancer risk, patient life expectancy, and screening test performance.

Gastric Cancer Incidence and Mortality in French Guiana: South American or French?

PURPOSE

Gastric cancer is a frequent cancer in the tropics. The objective was to review a decade of gastric cancer data, and to study its spatial and temporal trends.

METHODS

The cancer registry of French Guiana compiled exhaustive data on gastric cancer throughout French Guiana between 2005 and 2014. Age-standardized incidence and mortality rates were computed.

RESULTS

With 187 new cases recorded, gastric cancer ranked 6th (4.3%). It was more frequent in men than in women. The median age at diagnosis was 62 years for men and 65 years for women. The incidence rate standardized to the world population over the period 2005-2014 was 14.3 cases of gastric cancer per 100,000 man-years and 7.3 per 100,000 woman-years. The death rate from gastric cancer, standardized to the world population over the period 2005-2014, was 8.6 deaths from gastric cancer per 100,000 man-years and 3.4 per 100,000 women-years. These measures were lower than what is reported in Latin America, similar to Martinique and Guadeloupe-two tropical French territories-and higher than in France.

CONCLUSIONS

Gastric cancer affected more males and the median age was younger than in France. Standardized incidence and mortality rates for gastric cancer in French Guiana were between those of France and those of Latin America, and they were comparable to those of the French West Indies. The downward trend in a context of rapid economic growth suggests further gains that could be achieved by improving electricity, water, and sanitation coverage throughout the territory despite challenging geography, and better access to care and Helicobacter pylori eradication.

The updated JSPGHAN guidelines for the management of Helicobacter pylori infection in childhood

The Japan Pediatric Helicobacter pylori Study Group published the first guidelines on childhood H. pylori infection in 1997. They were later revised by the Japanese Society for Pediatric Gastroenterology, Hepatology and Nutrition (JSPGHAN). The H. pylori eradication rates, when employing triple therapy with amoxicillin and clarithromycin, currently recommended as the first-line therapy of H. pylori infection in Japan, have substantially decreased, creating an important clinical problem worldwide. In Japanese adults, the "test-and-treat" strategy for H. pylori infection is under consideration as an approach for gastric cancer prevention. However, the combined North American and European pediatric guidelines have rejected such a strategy for asymptomatic children. As risk for gastric cancer development is high in Japan, determining whether the "test-and-treat" strategy can be recommended in children has become an urgent matter. Accordingly, the JSPGHAN has produced a second revision of the H. pylori guidelines, which includes discussion about the issues mentioned above. They consist of 19 clinical questions and 34 statements. An H. pylori culture from gastric biopsies is recommended, not only as a diagnostic test for active infection but for antimicrobial susceptibility testing to optimize eradication therapy. Based upon antimicrobial susceptibility testing of H. pylori strains (especially involving clarithromycin), an eradication regimen including use of the antibiotics to which H. pylori is susceptible is recommended as the first-line therapy against H. pylori-associated diseases. The guidelines recommend against a "test-and-treat" strategy for H. pylori infection for asymptomatic children to protect against the development of gastric cancer because there has been no evidence supporting this strategy.

Gastric cancer prevention strategies: A global perspective

Gastric cancer (GC) is the fifth most common cancer worldwide, and mortality rates are still high. Primary preventive strategies, aimed to reduce risk factors and promote protective ones, will lead to a decrease in GC incidence. Helicobacter pylori infection is a well-established carcinogen for GC, and its eradication is recommended as the best strategy for the primary prevention. However, the role of other factors such as lifestyle, diet, and drug use is still under debate in GC carcinogenesis. Unfortunately, most patients with GC are diagnosed at late stages when treatment is often ineffective. Neoplastic transformation of the gastric mucosa is a multistep process, and appropriate diagnosis and management of preneoplastic conditions can reduce GC-related mortality. Several screening strategies in relation to GC incidence have been proposed in order to detect neoplastic lesions at early stages. The efficacy of screening strategies in reducing GC mortality needs to be confirmed. This review provides an overview of current international guidelines and recent literature on primary and secondary prevention strategies for GC.

Evaluation of the Epidemiologic Efficacy of Eradicating Helicobacter pylori on Development of Gastric Cancer

Eradication of Helicobacter pylori colonization has been reported to affect the progression of gastric cancer. A comprehensive literature search was performed from 1997 to 2017 using electronic databases. All randomized controlled trials (RCTs) and nonrandomized controlled trials (non-RCT) evaluated the effect of H. pylori eradication on development of gastric cancer. Four RCTs and 9 non-RCTs were included (n = 40,740 participants; 321,269 person-years). Overall, H. pylori eradication therapy was associated with a significantly reduced risk of gastric cancer (incidence rate ratio (IRR) = 0.52, 95% confidence interval (CI): 0.41, 0.65). Results of mixed-effect Poisson regression meta-analysis were similar to those of traditional meta-analyses. In stratified analyses, the IRRs were 0.59 (95% CI: 0.41, 0.86) in RCTs and 0.48 (95% CI: 0.36, 0.64) in non-RCTs. The IRRs were 0.45 (95% CI: 0.34, 0.61) in patients and 0.63 (95% CI: 0.44, 0.90) in the general population. Moreover, the relative risk reduction was approximately 77% on the development of noncardiac gastric cancer with H. pylori eradication therapy in China. Attributable risk percentage and population attributable risk percentage for Chinese patients were 77.08% and 75.33%, respectively, and for Japanese patients were 57.80% and 45.99%, respectively. H. pylori eradication therapy reduces the risk of noncardiac gastric cancer development. The findings indicate the importance of early intervention with H. pylori eradication therapy from the perspective of epidemiology.

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.

Effectiveness of Helicobacter pylori eradication in preventing metachronous gastric cancer and preneoplastic lesions. A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori is a significant risk factor for gastric cancer. Recent trials show eradication decreases the incidence of gastric cancer in patients with early-stage gastric cancer. However, data on gastric cancer prevention are inconsistent for patients with precancerous lesions such as atrophic gastritis and intestinal metaplasia.

AIM

The aim of the study is to assess the efficacy of H. pylori eradication in gastric cancer prevention in patients with varying risk factors for gastric cancer at baseline.

METHODS

A systematic review and meta-analysis were performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. PubMed, Medline, and Google Scholar were searched from inception through March 2019 for randomized controlled trials (RCTs) studying H. pylori eradication on gastric cancer prevention. We estimated the odds ratio (OR) with 95% confidence interval (CI) for each outcome using a random-effects model. P values of less than 0.05 were considered significant.

RESULTS

Nine RCTs with total of 6967 patient were included in the analysis. There was significant reduction in gastric cancer incidence in the H. pylori group for patients with early gastric cancer status post endoscopic mucosal resection OR, 0.47; 95% CI, 0.33-0.67; P < 0.0001; I = 0%. There was no difference in gastric cancer incidence in patients with atrophic gastritis and intestinal metaplasia at baseline for H. pylori arm OR, 0.67; 95% CI, 0.42-1.07; P = 0.09; I = 0%). Atrophic gastritis and intestinal metaplasia improved from baseline in the H. pylori arm compared to placebo OR, 2.61; 95% CI, 1.41-4.81; P = 0.002; I = 88 and OR, 2.61; 95% CI, 1.66-4.11; P ≤ 0.0001; I = 0%, respectively.

CONCLUSIONS

H. pylori eradication is associated with reduced gastric cancer incidence in patients with early-stage gastric cancer and improvement in atrophic gastritis and intestinal metaplasia. There was no difference in gastric cancer incidence in patients with atrophic gastritis and intestinal metaplasia at baseline.

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.

Quality Indicators for the Detection of Helicobacter pylori-Negative Early Gastric Cancer: A Retrospective Observational Study

Background/Aims

While Helicobacter pylori (HP)-negative gastric cancer is frequently reported, little is known about the predictors for detecting HP-negative early gastric cancer (EGC). We aimed to evaluate the predictors for the detection of HP-negative EGC.

Methods

We retrospectively reviewed 13,477 consecutive asymptomatic cases where upper endoscopy was performed by nine physicians from April 2017 to March 2019 and analyzed the detection rate of high-risk lesions (HRLs), including EGC, tubular adenoma, and lymphoma, according to the status of HP infection. The observation time was corrected for multiple regression analyses.

Results

For all physicians, the average observation time for screening HP-eradicated and -naïve patients was shorter than that for screening HP-positive patients (p<0.05). Multiple regression analyses revealed that the observation time in the three groups was an independent predictor for detecting HRLs in HP-eradicated patients (p=0.03106, 0.01263, and 0.02485, respectively), while experience of endoscopy was an independent predictor for detecting HRLs in HP-naïve patients (p=0.02638).

Conclusions

While observation time during screening endoscopy was a quality indicator for detecting HRLs in HP-eradicated patients, experience of endoscopy was a quality indicator for detecting HRLs in HP-naïve patients.

Risk factors for gastric precancerous and cancers lesions in Latin American counties with difference gastric cancer risk

OBJECTIVE

To evaluate the risk factors associated with pre-neoplastic lesions and gastric cancer in countries with different cancer risk in Latin America.

METHODS

1222 questionnaires of risk factors related to pre-neoplastic lesions and gastric cancer were obtained from patients from Mexico (N = 559), Colombia (N = 461) and Paraguay (N = 202), who were treated at the gastroenterology or oncology service of participant hospitals. In addition, biopsies specimens to establish histological diagnosis and blood to detect IgG antibodies against Helicobacter-pylori (H. pylori) whole-cell antigens and CagA protein using an ELISA were collected. These consisted of 205 gastric cancer, 379 pre-neoplastic (intestinal metaplasia (IM) / atrophic gastritis) and 638 control (normal /non-atrophic gastritis) cases. The odds ratio (OR) and 95% confidence intervals (CI) associated with potential risk factors were estimated by polynomial logistic regression model.

RESULTS

Seropositivity to H. pylori was associated with risk of pre-neoplastic lesions, with OR = 1.9 (CI 95% 1.2-2.9; p = 0.006). Grain / cereal intake (OR = 1.6, 95% CI 1.0-2.5 ; p = 0.049) and egg intake (OR = 1.7 95% CI 1.1-2.6 ; p = 0.021) were related to gastric cancer. Among, people who did not developed gastric cancer, smoking more than five cigarette per day had the highest risk of being infected by H. pylori (OR = 1.9; CI 95% 1.1-3.3 ; p = 0.028).

CONCLUSION

The present study in Latin American countries confirmed that similar environmental factors such as smoking and grain/cereal consumption were associated with H. pylori infection and its induced gastric lesions as reported in other regions where dominant H. pylori strains differ.

The role of the gastric bacterial microbiome in gastric cancer: Helicobacter pylori and beyond

A link between chronic inflammation and carcinogenesis has been depicted in many organ systems. Helicobacter pylori is the most prevalent bacterial pathogen, induces chronic gastritis and is associated with more than 90% of cases of gastric cancer (GC). However, the introduction of nucleotide sequencing techniques and the development of biocomputional tools have surpassed traditional culturing techniques and opened a wide field for studying the mucosal and luminal composition of the bacterial gastric microbiota beyond H. pylori. In studies applying animal models, a potential role in gastric carcinogenesis for additional bacteria besides H. pylori has been demonstrated. At different steps of gastric carcinogenesis, changes in bacterial communities occur. Whether these microbial changes are a driver of malignant disease or a consequence of the histologic progression along the precancerous cascade, is not clear at present. It is hypothesized that atrophy, as a consequence of chronic gastric inflammation, alters the gastric niche for commensals that might further urge the development of H. pylori-induced GC. Here, we review the current state of knowledge on gastric bacteria other than H. pylori and on their synergism with H. pylori in gastric carcinogenesis.

Inpatient burden of gastric cancer in the United States

Background

Gastric cancer is associated with significant morbidity and mortality. Over one-half of patients have advanced disease at the time of presentation, leading to a significant burden on the healthcare system. Limited epidemiological data exists on national inpatient hospitalization trends. The aim of this study is to determine the inpatient burden of gastric cancer in the United States.

Methods

We analyzed the Nationwide Inpatient Sample (NIS) database for all subjects with the diagnosis of malignant neoplasm of the stomach (ICD-9 code 151.x) as primary diagnosis during the period from 2001-2011. NIS is the largest all-payer inpatient care database in the U.S. Statistical significance of variation in the number of hospitalizations, patient demographics, and comorbidity measures was determined using Cochran-Armitage trend test.

Results

From 2001 to 2011, the number of hospitalizations with the diagnosis of malignant neoplasm of the stomach ranged between 22,430 and 25,371, however, the trend was not significant. Men were always more affected than women with no significant change in overall proportion (P<0.0001). Overall, in-hospital mortality decreased from 11.19% in 2001 to 6.47% in 2011 (P<0.0001). However, average cost of care per hospitalization increased from $21,710 in 2001 to $24,706 in 2011 (adjusted for inflation, P<0.0001).

Conclusions

The total number of hospitalizations remained relatively stable throughout the study period with higher proportion of men affected every year. Although in-hospital mortality in patients with the diagnosis of gastric cancer decreased over the study period, there was a significant rise in the cost of care.

What is the Relevance of Gastric Microbiota Beyond H. pylori?

PURPOSE

The role of Helicobacter pylori as key factor in gastric inflammation and the development of (pre-)cancerous lesions is undisputable. As an open system, the human upper gastrointestinal tract harbors a complex bacterial community which is highly impacted by the absence or presence of H. pylori. The interaction between other bacteria and H. pylori might impact on gastric carcinogenesis.

RECENT FINDINGS

Several studies demonstrated differences in the composition of the gastric bacterial community in different stages of gastritis and between samples from tumor and adjacent tissue. In addition, animal studies demonstrated an increased and accelerated development of precancerous lesions in mice colonized with intestinal flora and H. pylori compared with mice mono-infected with H. pylori.

CONCLUSION

Other bacteria beyond H. pylori enter the focus in research on gastric carcinogenesis. However, we are still far from a thorough understanding of the pathophysiology of host-microbiota interaction and its impact on the development of malignant and precancerous changes.

Efficacy of Low Dose Proton Pump Inhibitor-Based Therapy to Eradicate Helicobacter pylori in Patients with Subtotal Gastrectomy

Proton pump inhibitor (PPI)-based therapy is standard to eradicate Helicobacter pylori (H. pylori). Gastric acidity is lowered after gastrectomy because of bile reflux and impaired mechanism of acid secretion. Therefore, low-dose PPI may be effective for H. pylori eradication in the remnant stomach after gastrectomy. In this study, we compared the efficacy of low-dose PPI with standard double-dose PPI to eradicate H. pylori in patients who underwent subtotal gastrectomy. A total of 145 patients who were treated for eradication after gastrectomy was analyzed. They were treated with PPI-based triple regimen (PPI, clarithromycin and amoxicillin) for 14 days. We compared the eradication rate in the low-dose PPI group (lansoprazole 15 mg once daily) with that in the standard double-dose PPI group (lansoprazole 30 mg twice daily). The H. pylori eradication rate was 79.1% in the low-dose PPI group and 85.3% in the standard double-dose group; the difference was not significant statistically (p = 0.357). In the multivariate analysis, low-dose PPI (odds ratio (OR) = 1.79, 95% confidence interval (CI), 0.68–4.69) was not associated with eradication failure, while Billroth II anastomosis (OR = 4.45, 85% CI, 1.23–16.2) was significantly associated with eradication failure. Low-dose PPI-based triple regimen was as effective as standard double-dose PPI-based regimen for H. pylori eradication in patients with subtotal gastrectomy. Further study is needed to confirm the effect of low-dose PPI on H. pylori eradication in patients with gastrectomy.

Association of Helicobacter pylori with oral potentially malignant disorders and oral squamous cell carcinoma-a systematic review and meta-analysis

OBJECTIVE

To assess any potential association between Helicobacter pylori and oral squamous cell carcinoma/oral potentially malignant disorders.

MATERIALS AND METHODS

Data mining was done using PubMed, Cochrane Library, and SCOPUS databases. The search included articles published up to May 2019. Newcastle-Ottawa scale was used to score the quality of the included articles. Data including the type of study, the sample population, the type of oral lesion, and the resulting statistical data were extracted.

RESULTS

Out of 131 screened articles, only 15 articles fulfilled the eligibility criteria. Among the 15 studies, 9 focused on oral squamous cell carcinoma and 6 focused on oral potentially malignant disorders. Eight out of the 9 oral squamous cell carcinoma studies were included in the meta-analysis. Forest plot was generated using the odds ratio and confidence intervals calculated for each of the included studies. Due to the lack of sufficient studies, the meta-analysis was not performed for oral potentially malignant disorders.

CONCLUSION

Due to the contradictory results of the included studies, it was not possible to make any conclusive statement on the potential association of H. pylori with oral squamous cell carcinoma. The variations in the methodology, especially the differences in the sensitivity/specificity of the diagnostic modalities could be the cause for differential results.

CLINICAL RELEVANCE

Although the association of H. pylori with oral squamous cell carcinoma could not be confirmed, it is vital to reduce the excess oral microbial load, especially in patients exhibiting oral mucosal changes with no history of associated risk factors.

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.

International Cancer Microbiome Consortium consensus statement on the role of the human microbiome in carcinogenesis

OBJECTIVE

In this consensus statement, an international panel of experts deliver their opinions on key questions regarding the contribution of the human microbiome to carcinogenesis.

DESIGN

International experts in oncology and/or microbiome research were approached by personal communication to form a panel. A structured, iterative, methodology based around a 1-day roundtable discussion was employed to derive expert consensus on key questions in microbiome-oncology research.

RESULTS

Some 18 experts convened for the roundtable discussion and five key questions were identified regarding: (1) the relevance of dysbiosis/an altered gut microbiome to carcinogenesis; (2) potential mechanisms of microbiota-induced carcinogenesis; (3) conceptual frameworks describing how the human microbiome may drive carcinogenesis; (4) causation versus association; and (5) future directions for research in the field.The panel considered that, despite mechanistic and supporting evidence from animal and human studies, there is currently no direct evidence that the human commensal microbiome is a key determinant in the aetiopathogenesis of cancer. The panel cited the lack of large longitudinal, cohort studies as a principal deciding factor and agreed that this should be a future research priority. However, while acknowledging gaps in the evidence, expert opinion was that the microbiome, alongside environmental factors and an epigenetically/genetically vulnerable host, represents one apex of a tripartite, multidirectional interactome that drives carcinogenesis.

CONCLUSION

Data from longitudinal cohort studies are needed to confirm the role of the human microbiome as a key driver in the aetiopathogenesis of cancer.

Effect of Helicobacter pylori eradication and high-density lipoprotein on the risk of de novo gastric cancer development

BACKGROUND AND AIMS

The effect of Helicobacter pylori eradication on de novo gastric cancer is controversial, although meta-analyses suggest a reduction in gastric cancer after eradication. The effect of high-density lipoprotein (HDL) on gastric cancer has been rarely reported.

METHODS

In this large retrospective cohort study, participants underwent endoscopy and H pylori testing from 2003 to 2011 and underwent follow-up endoscopy and H pylori testing until 2013. H pylori infection was detected using a rapid urease test or histologic test. The H pylori eradication group was defined as successful eradication, whereas the H pylori persistent group was defined as noneradication or eradication failure. The risk of cancer was measured with hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Among 10,328 healthy subjects (5951 men; mean age, 48.7 years), 31 gastric cancers were detected during a median follow-up of 5.5 years. De novo gastric cancer developed in 21 of 3508 subjects (.6%) in the noneradication group, 4 of 2050 subjects (.2%) in the successful eradication group, and 6 of 4770 participants (.13%) in the absence of H pylori group. In the adjusted analysis, H pylori eradication decreased de novo gastric cancer risk (HR, .29; 95% CI, .10-.86) compared with the persistent group. The risk of de novo gastric cancer in absence of H pylori was also much lower compared with the persistent group (HR, .24; 95% CI, .09-.60). Low serum HDL increased the risk of de novo gastric cancer (HR, 2.67; 95% CI, 1.14-6.16).

CONCLUSIONS

Successful H pylori eradication reduced de novo gastric cancer, whereas low HDL increased its risk.

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.

DNA methylation silencing of microRNA gene methylator in the precancerous background mucosa with and without gastric cancer: Analysis of the effects of H. pylori eradication and long-term aspirin use

The risk of gastric cancer (GC) declines after Helicobacter pylori (H. pylori) eradication and long-term aspirin use. We evaluated the effects of H. pylori eradication (Cohort 1) and aspirin use (Cohort 2) on the methylation of microRNAs (miRNAs), such as miR-34c, miR-124a-3, miR-129-2, and miR-137, in the gastric mucosa with and without GC, i.e., in atrophic mucosal glands without intestinal metaplasia (non-IM) and intestinal metaplastic glands (IM). DNA was isolated from non-IM and IM separately using laser caption microdissection. In Cohort 1, H. pylori eradication was associated with a significant reduction of miR-124a-3 methylation only in non-IM, but not in IM. miR-129-2 methylation in non-IM may be a surrogate marker of GC in H. pylori-infected patients. In Cohort 2, aspirin did not reverse miRNA methylation in either non-IM or IM, irrespective of H. pylori infection. miR-129-2 methylation in non-IM was an independent predictive marker of GC in H. pylori-infected but not -eradicated patients. These results indicate that H. pylori eradication and aspirin use were less effective for improving methylation in IM than in non-IM; thus, these interventions are recommended at an early stage prior to the development of IM to prevent GC development. In addition, the effects of the interventions were not uniform for each miRNA gene.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

¹³C-Urea Breath Test Accuracy for <i>Helicobacter pylori</i> Infection in the Asian Population: A Meta-Analysis

Background:

Helicobacter pylori (H. pylori) infection is known to be associated with peptic ulcer and gastric cancer. Detection of H. pylori infection is a significant part of peptic ulcer and gastric cancer prevention and management. ¹³C-urea breath test (UBT) provides a good option for the pathogen detection due to its accuracy and safety.

Objective:

This review aims to evaluate the ¹³C-UBT diagnostic accuracy studies conducted among Asian population and validate its use for the Asian population.

Methods:

Original articles were systematically searched in PubMed, Scopus, and Google Scholar using the PICOS strategy by applying relevant keywords. Only studies published in English and conducted in Asia were included. Our search returned 276 articles. After assessment, 11 articles which answered our research question and met the criteria set for systematic review and meta-analysis were accepted. A total of 15 study protocols were extracted from the 11 accepted articles.

Findings:

Majority of the studies were conducted in Hong Kong (six), followed by Taiwan (five), Japan (two), and one each in Singapore and Israel. All studies had used histology as part of its gold standard of reference. All but one study was performed on adult populations. The summary estimate for sensitivity was 97% (95% CI: 96, 98%), and specificity was 96% (95% CI: 95, 97%), with significant heterogeneity between studies. Adjusting for the dose (50 mg) and breath sample collection time (20 minutes) had improved both accuracy estimates and significantly reduced heterogeneity.

Conclusion:

This review supports the test-and-treat strategy for H. pylori infection management. Prevalence and cost-effectiveness studies are mandatory for health authorities to adopt this strategy into national policy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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