Helicobacter Pylori associated global gastric cancer burden

Epidemiology, pathogenicity, risk factors, and management of Helicobacter pylori infection in Saudi Arabia

Helicobacter pylori (H. pylori) is a gastric microbial pathogen that infects approximately half of the global population. This bacterium significantly contributes to various gastroduodenal diseases, including chronic active gastritis, peptic ulcerations, and malignant transformations. This review focuses on epidemiology, pathogenicity, virulence genes, risk factors, and management of H. pylori infection, specifically within the context of Saudi Arabia. The results presented here are grounded in studies conducted in Saudi Arabia, contrasting with mere bibliographic reviews of findings from other countries. H. pylori infection has been observed in Saudi Arabia, with substantial differences in the prevalence, ranging between 10-96% among various studied populations. Several risk factors for H. pylori infection have been identified, encompassing socioeconomic status, medical history, personal hygiene, and behavioral practices. Among the virulence genes harbored by H. pylori, cytotoxin-associated gene A (cagA) and vacuolating cytotoxin (vacA) are most common, with their presence correlating with the pathogenicity and clinical manifestations of the associated diseases. A range of invasive and non-invasive diagnostic assays have been utilized to identify H. pylori infection, with their employment being influenced by factors like availability, cost, patient age, gastric symptoms, and the specifics of clinical information sought. While detection methods like the H. pylori stool antigen test and the urea breath test offer more accuracy and speed, culturing remains indispensable for determining the antimicrobial susceptibility profile. The emergence of resistant strains across varying regional settings poses a significant challenge to treatment endeavors, necessitating an assessment of local antimicrobial resistance rates prior to formulating treatment strategies. The findings of this review highlight the importance of continuous implementation of screening, control, and prevention of H. pylori infection to combat the spreading infection and other related complications.

Updated epidemiology of gastrointestinal cancers in East Asia

Globally, gastrointestinal cancers represent more than one-fourth of all cancer incidence and one-third of cancer-related mortality. Although there has been much progress in screening colorectal cancer, the prognosis of other gastrointestinal cancers tends to be poor. The highest burden of gastrointestinal cancers, including stomach, liver, oesophageal and gallbladder cancers, was observed in regions in East Asia. The increasing burden of gastrointestinal cancers in East Asian regions is related to population growth, ageing and the westernization of lifestyle habits in this region. Furthermore, the rising incidence of young-onset colorectal cancer is an emerging trend in East Asia. This Review provides a comprehensive and updated summary of the epidemiology of gastrointestinal cancers in East Asia, with emphasis on comparing their epidemiology in East Asia with that in Western regions, and highlights the major risk factors and implications for prevention. Overall, to optimally reduce the disease burden incurred by gastrointestinal cancers in East Asian regions, a concerted effort will be needed to modify unhealthy lifestyles, promote vaccination against the hepatitis virus, control Helicobacter pylori, liver fluke and hepatitis virus infections, increase the uptake rate of colorectal cancer screening, enhance detection of early cancers and their precursors, and improve cancer survivorship through an organized rehabilitation programme.

The effect of cranberry supplementation on Helicobacter pylori eradication in H. pylori positive subjects: a systematic review and meta-analysis of randomised controlled trials

Helicobacter pylori infection is one of the most common chronic bacterial infections. Cranberry has been suggested for H. pylori eradication. We aimed to conduct the first meta-analysis to summarise current evidence on effects of cranberry supplementation on H. pylori eradication in H. pylori positive subjects. We searched the online databases up to December 2020. Four randomised clinical trials (RCT) were included with human subjects, investigating the effect of cranberry on H. pylori eradication. The pooled results were expressed as the OR with 95 % CI. Based on five effect sizes with a total sample size of 1935 individuals, we found that according to the OR, there was a positive effect of cranberry supplementation on H. pylori eradication, increasing the chance of H. pylori eradication by 1·27 times, but this relationship was not statistically significant (overall OR: 1·27; 95 % CI 0·63, 2·58). The results also indicated the moderate between-study heterogeneity (I² = 63·40 %; P = 0·03) of the studies. However, there were no significant differences in some subgroup analyses in the duration of treatment, the duration of follow-up and the Jadad score. Our findings revealed that although cranberry had a positive effect on H. pylori eradication in adults, this effect was not statistically significant. Due to the small number of included studies and moderate heterogeneities, the potential of cranberry supplementation on H. pylori eradication should be validated in large, multicentre and well-designed RCT in the future.

An Immunohistochemical Assessment of Ki-67 and P53 Over-expression in Helicobacter pylori-positive Gastritis

AIM: Helicobacter pylori infection of the stomach is a common disease and the resulting changes from it are many and deserve to be in the focus of researchers’ attention, to assess the expression of mutant P53 protein and Ki-67 markers in patients with gastritis secondary to H. pylori. METHODS: Thirty samples with positive H. pylori gastritis were included in a retrospective study in Mosul/Iraq. The histological parameters were assessed using the Sydney system, then, the expression of Ki-67 and P53 expression was studied by immunohistochemical methods. The significance level was appointed at (0.05). RESULTS: Ki-67 and P53 expression were found in 83.3% of the total cases. The study results show that 92% of positive Ki-67 and P53 cases had chronic inflammatory cell infiltration, polymorph nuclear cells infiltration, and atrophy. Whereas 96% of positive Ki-67 cases had no metaplasia, 92% of the positive P53 cases had no metaplasia. The results also showed that only 16% of the positive Ki-67 cases had dysplastic changes, and 24% of the positive cases of P53 cases were showed dysplasia. whenever P53 was negative; there is neither metaplasia nor dysplasia in the tissue, this does not apply to Ki-67 negative cases. CONCLUSIONS: Ki-67 and P53 expressions increase with chronicity of Helicobacter pylori-positive gastritis. P53 expression is amplified when atrophy is present in these samples.

Eastern European and Asian-born populations are prone to gastric cancer: an epidemiologic analysis of foreign-born populations and gastric cancer

BACKGROUND

The highest incidence of gastric cancer is in East Asia, corresponding to a high prevalence of Helicobacter pylori (H. pylori), yet other regions with a similarly high prevalence of H. pylori have lower cancer rates. Foreign-born persons who immigrate to the United States are thought to remain at high-risk for gastric cancer, but this has not been confirmed by large population-based studies.

METHODS

We evaluated total and foreign-born populations in metropolitan statistical areas (MSAs). Cardia and non-cardia gastric adenocarcinomas diagnosed between 2006 and 2016 were identified using the Surveillance, Epidemiology, and End Results Program. Generalized linear regression models determined whether the incidence of gastric cancer in each MSA was associated with specific foreign-born populations.

RESULTS

Among 32 MSAs, we identified 55,937 patients with gastric adenocarcinoma. A greater percentage of Eastern European-born individuals in an MSA was associated with a higher incidence of cardia cancers (coefficient 1.32, P=0.02). Evaluating Asian-born populations alone, a greater percentage of Japanese-born individuals was associated with a higher incidence of non-cardia cancers (coefficient 2.48, P=0.03), whereas Korean or Chinese origin was not associated with a significantly higher risk.

CONCLUSIONS

On a population level, a greater percentage of Eastern European-born individuals is associated with a higher incidence of cardia gastric adenocarcinomas. Among Asian-born individuals, Korean or Chinese origin was not associated with a significantly higher risk, but a greater percent of persons born in other Asian countries, including Japan, was associated with a higher incidence of non-cardia gastric adenocarcinomas in an MSA.

Global Incidence and Mortality of Gastric Cancer, 1980-2018

IMPORTANCE

Gastric cancer is one of the most common cancers, with a high mortality-to-incidence ratio. It is uncertain whether developed nations may encounter an increasing burden of gastric cancer in young adults, as occurs for other cancers.

OBJECTIVES

To evaluate the incidence and mortality of gastric cancer and compare the global incidence trends between younger (<40 years) and older (≥40 years) populations.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study analyzed data from global and national cancer registries, including data from 1980 to 2018, with at least 15 calendar years of incidence and mortality data. Data on age-standardized incidence and mortality rates of gastric cancer among 48 countries were retrieved from the Surveillance, Epidemiology, and End Results Program, the National Cancer Institute, the Nordic Cancer Registries, and the World Health Organization Mortality Database. The 10-year incidence trend of gastric cancer was assessed by age and sex. The 2018 GLOBOCAN database was used for reporting the global incidence and mortality of gastric cancer, the most recent data available at the time of analysis. Analyses were performed between January 10, 2020, and March 20, 2020.

MAIN OUTCOMES AND MEASURES

The average annual percent change (AAPC) of the incidence and mortality trends as evaluated by joinpoint regression analysis.

RESULTS

A total of 1 033 701 new cases of gastric cancer and 782 685 related deaths were reported in 2018. Overall, the incidence of gastric cancer decreased in 29 countries, and mortality decreased in 41 countries. The age-standardized incidence of gastric cancer decreased from a range of 2.6 to 59.1 in 1980 to a range of 2.5 to 56.8 in 2018 per 100 000 persons. The overall age-standardized mortality rate changed from a range of 1.3 to 25.8 in 1980 to a range of 1.5 to 18.5 in 2018 per 100 000 persons, but increasing mortality was observed in Thailand (female: AAPC, 5.30; 95% CI, 4.38-6.23; P < .001; male: AAPC, 3.92; 95% CI, 2.14-5.74; P < .001). The incidence of gastric cancer decreased in most regions among individuals 40 years or older and increased in populations younger than 40 years in several countries, including Sweden (male: AAPC, 13.92; 95% CI, 7.16-21.11; P = .001), Ecuador (female: AAPC, 6.05; 95% CI, 1.40-10.92; P = .02), and the UK (male: AAPC, 4.27; 95% CI, 0.15-8.55; P = .04; female: AAPC, 3.60; 95% CI, 3.59-3.61; P < .001).

CONCLUSIONS AND RELEVANCE

In this population-based cohort study, an increasing incidence of gastric cancer was observed in younger individuals in some countries, highlighting the need for more preventive strategies in younger populations. Future research should explore the reasons for these epidemiologic trends.

Cancer Mortality Disparities among Asian American and Native Hawaiian/Pacific Islander Populations in California

BACKGROUND

Asian American and Native Hawaiian/Pacific Islanders (AANHPI) are the fastest growing minority in the United States. Cancer is the leading cause of death for AANHPIs, despite relatively lower cancer morbidity and mortality. Their recent demographic growth facilitates a detailed identification of AANHPI populations with higher cancer risk.

METHODS

Age-adjusted, sex-stratified, site-specific cancer mortality rates from California for 2012 to 2017 were computed for AANHPI groups: Chinese, Filipino, South Asian, Vietnamese, Korean, Japanese, Southeast Asian (i.e., Cambodian, Hmong, Laotian, Thai), and Native Hawaiian and Other Pacific Islander (NHOPI). Regression-derived mortality rate ratios (MRR) were used to compare each AANHPI group to non-Hispanic whites (NHW).

RESULTS

AANHPI men and women (total 40,740 deaths) had lower all-sites-combined cancer mortality rates (128.3 and 92.4 per 100,000, respectively) than NHWs (185.3 and 140.6) but higher mortality for nasopharynx, stomach, and liver cancers. Among AANHPIs, both NHOPIs and Southeast Asians had the highest overall rates including for colorectal, lung (men only), and cervical cancers; South Asians had the lowest. NHOPI women had 41% higher overall mortality than NHWs (MRR = 1.41; 95% CI, 1.25-1.58), including for breast (MRR = 1.33; 95% CI, 1.08-1.65) and markedly higher for endometrial cancer (MRR = 3.34; 95% CI, 2.53-4.42).

CONCLUSIONS

AANHPI populations present with considerable heterogeneous cancer mortality patterns. Heightened mortality for infection, obesity, and tobacco-related cancers in Southeast Asians and NHOPI populations highlight the need for differentiated priorities and public health interventions among specific AANHPI populations.

IMPACT

Not all AANHPIs have favorable cancer profiles. It is imperative to expand the focus on the currently understudied populations that bear a disproportionate cancer burden.

The influence of P-glycoprotein expression in the standard treatment of Helicobacter pylori infection in Sprague Dawley rats

BACKGROUND

P-glycoprotein (P-gp) is an Adenosine triphosphate (ATP) dependent drug-efflux pump which is located abundantly in the stomach and protects the gut mucosa from xenobiotic.

OBJECTIVE

The purpose of this study was to investigate the influence of P-gp modulation on the efficacy of treatment regimen.

METHOD

P-gp modulation in rats was performed by using P-gp inducer (150 mg/kg rifampicin) and P-gp inhibitor (10 mg/kg cyclosporine A) for 14 days prior to be infected with Helicobacter pylori (H. pylori). The rats were further divided into groups, which were normal control, vehicle control, antibiotics and omeprazole, antibiotics only and omeprazole only for another 2 weeks of treatment. The ulcer formation and P-gp expression were determined by using macroscopic evaluation and western blot analysis, respectively.

RESULTS

The highest P-gp expression was shown in the induced P-gp rats (2.00 ± 0.68) while the lowest P-gp expression was shown in the inhibited P-gp rats (0.45 ± 0.36) compared to the normal P-gp rats. In all groups, the rats which were infected with H. pylori, had a significant increase (p < 0.05) in P-gp expression level and a more severe ulcer formation compared to the healthy rats. The ulcer developed at different levels in the rats with inhibited, induced, or normal P-gp expression. After receiving the standard therapy for H. pylori, it was observed that the healing rate for ulcer was increased to 91% (rats with inhibited P-gp expression), 82% (rats with induced P-gp expression) and 75% in rats with normal P-gp. The use of rifampicin to induce P-gp level was also shown to be effective in eradicating the H. pylori infection.

CONCLUSION

The synergism in the standard therapy by using two antibiotics (clarithromycin and amoxicillin) and proton pump inhibitor (omeprazole) have shown to effectively eradicate the H. pylori infection. Thus, P-gp expression influenced the effectiveness of the treatment.

A Nomogram Based on Aspartate Aminotransferase/Alanine Aminotransferase (AST/ALT) Ratio to Predict Prognosis After Surgery in Gastric Cancer Patients

INTRODUCTION

Using the TMN classification alone to predict survival in patients with gastric cancer has certain limitations, we conducted this study was to develop an effective nomogram based on aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio to predict overall survival (OS) in surgically treated gastric cancer.

METHODS

we retrospectively analyzed 190 cases of gastric cancer and used Cox regression analysis to identify the significant prognostic factors for OS in patients with resectable gastric cancer. The predictive accuracy of nomogram was assessed using a calibration plot, concordance index (C-index) and decision curve. This was then compared with a traditional TNM staging system. Based on the total points (TPS) by nomogram, we further divided patients into different risk groups.

RESULTS

multivariate analysis of the entire cohort revealed that independent risk factors for survival were age, clinical stage and AST/ALT ratio, which were entered then into the nomogram. The calibration curve for the probability of OS showed that the nomogram-based predictions were in good agreement with actual observations. Additionally, the C-index of the established nomogram for predicting OS had a superior discrimination power compared to the TNM staging system [0.794 (95% CI: 0.749-0.839) vs 0.730 (95% CI: 0.688-0.772), p < 0.05]. Decision curve also demonstrated that the nomogram was better than the TNM staging system. Based on TPS of the nomogram, we further subdivided the study cohort into 3 groups including low risk (TPS ≤ 158), middle risk (158 < TPS ≤ 188) and high risk (TPS > 188) categories. The differences in OS rate were significant among the groups.

CONCLUSION

the established nomogram is associated with a more accurate prognostic prediction for individual patients with resectable gastric cancer.

Risk Factors and Incidence of Gastric Cancer After Detection of Helicobacter pylori Infection: A Large Cohort Study

BACKGROUND & AIMS

Nearly all studies of gastric adenocarcinoma in the United States have relied on national cancer databases, which do not include data on Helicobacter pylori infection, the most well-known risk factor for gastric cancer. We collected data from a large cohort of patients in the United States to calculate the incidence of and risk factors for nonproximal gastric adenocarcinomas after detection of H pylori. Secondary aims included identifying how treatment and eradication affect cancer risk.

METHODS

We performed a retrospective cohort study, collecting data from the Veterans Health Administration on 371,813 patients (median age 62 years; 92.3% male) who received a diagnosis of H pylori infection from January 1, 1994, through December 31, 2018. The primary outcome was a diagnosis of distal gastric adenocarcinoma 30 days or more after detection of H pylori infection. We performed a time to event with competing risk analysis (with death before cancer as a competing risk).

RESULTS

The cumulative incidence of cancer at 5, 10, and 20 years after detection of H pylori infection was 0.37%, 0.5%, and 0.65%, respectively. Factors associated with cancer included older age at time of detection of H pylori infection (subhazard ratio [SHR], 1.13; 95% confidence interval [CI], 1.11-1.15; P < .001), black/African American race (SHR, 2.00; 95% CI, 1.80-2.22), Asian race (SHR, 2.52; 95% CI, 1.64-3.89) (P < .001 for race), Hispanic or Latino ethnicity (SHR, 1.59; 95% CI, 1.34-1.87; P < .001), and history of smoking (SHR, 1.38; 95% CI, 1.25-1.52; P < .001). Women had decreased risk of gastric adenocarcinoma compared with men (SHR, 0.52; 95% CI, 0.40-0.68; P < .001); patients whose H pylori infection was detected based on serum antibody positivity also had a reduced risk of cancer (SHR 0.74; 95% CI, 0.54-1.04; P = .04). Patients who received treatment for their H pylori infection still had an increased risk of gastric cancer (SHR, 1.16; 95% CI, 0.74-1.83; P = .51) but confirmed H pylori eradication after treatment reduced risk of gastric cancer (SHR, 0.24; 95% CI, 0.15-0.41; P < .001).

CONCLUSIONS

In a study of 371,813 veterans with a diagnosis of H pylori infection, we found significantly higher risks of gastric cancer in racial and ethnic minorities and smokers. Treatment of H pylori infection decreased risk only if eradication was successful. Studies are needed on the effects of screening high-risk persons and to identify quality measures for diagnosis, resistance patterns, and treatment efficacy.

Helicobacter pylori is Associated with Less Fistulizing, Stricturing, and Active Colitis in Crohn's Disease Patients

Introduction A potential protective role of Helicobacter pylori (HP) infection against the development of Crohn's disease (CD) has been postulated. There is a lack of studies evaluating the association of HP with CD phenotypes. The aim of this study was to investigate the clinical features and disease activity of patients with CD who were diagnosed with HP infection. Methods The charts of 306 consecutive patients from the inflammatory bowel disease (IBD) database at the University of Florida College of Medicine, Jacksonville from January 2014 to July 2016 were reviewed. Ninety-one CD patients who were tested for HP were included, and the frequencies of strictures, fistulas, and colitis in surveillance biopsies in these patients were evaluated. Results Of the 91 CD patients tested for HP, 19 had HP infection. A total of 44 patients had fistulizing/stricturing disease, and 62 patients had active colitis. In the univariate analysis, patients with HP infection had less fistulizing/stricturing disease (21.1% vs. 55.6%, p = 0.009) and less active colitis (42.1% vs. 77.1%, p = 0.005). In the multivariate analysis, HP infection remained as a protective factor for fistulizing/stricturing disease phenotype (OR: 0.22; 95%CI: 0.06-0.97; p = 0.022) and active colitis (OR: 0.186; 95%CI: 0.05-0.65; p = 0.010). Conclusion HP infection was independently associated with less fistulizing/stricturing disease and less active colitis in CD patients. Our study suggests CD patients with a history of HP infection are less prone to complications.

Vaccine-induced gastric CD4+ tissue-resident memory T cells proliferate in situ to amplify immune response against Helicobacter pylori insult

BACKGROUND

Tissue-resident memory T cells accelerate the clearance of pathogens during recall response. However, whether CD4⁺ TRM cells themselves can provide gastric immunity is unclear.

MATERIALS AND METHODS

We established a parabiosis model between the enhanced green fluorescent protein and wild-type mice that the circulation system was shared, and the wild-type partner was vaccinated with H pylori vaccine composed of CCF and silk fibroin in gastric subserous layer to induce gastric EGFP⁺ CD4⁺ TRM cells. Antigen-specific EGFP⁺ CD4⁺ T cells and proliferous TRM cells were analyzed by flow cytometry. The colonization of H pylori was detected by quantitative real-time PCR. EGFP⁺ CD4⁺ TRM cells and the inflammation of the stomach were observed by histology.

RESULTS

A parabiosis animal model was employed to identify the cells that introduced by vaccination in GSL. Antigen-specific EGFP⁺ CD4⁺ T cells could be detected at day 7 post-vaccination. Thirty days later, EGFP⁺ CD4⁺ TRM cells were established with a phenotype of CD69⁺ CD103^- . Of note, we found that when circulating lymphocytes were depleted by FTY720 administration, these TRM cells could proliferate in situ and differentiate into effector Th1 cells after H pylori challenge. A decrease in H pylori colonization was observed in the vaccinated mice but not unvaccinated mice. Further, we found that although FTY720 was administrated, mounted pro-inflammatory myeloid cells still emerged in the stomach of the vaccinated mice, which might contribute to the reduction of H pylori colonization.

CONCLUSIONS

Our study reveals that H pylori vaccine-induced CD4⁺ TRM cells can proliferate and differentiate in situ to enhance gastric local immunity during recall response.

Effects of periodontal therapy on eradication and recurrence of Helicobacter pylori infection after successful treatment

OBJECTIVES

This study aimed to evaluate the effects of periodontal therapy on the efficacy of Helicobacter pylori eradication and on the recurrence of infection after eradication.

METHODS

We conducted a prospective randomized trial on 698 gastric H. pylori-infected patients, of whom 347 received gastric H. pylori treatment alone and 342 received gastric H. pylori treatment plus periodontal therapy. The presence of H. pylori and associated virulence genes were detected by real-time polymerase chain reaction.

RESULTS

After eradication of gastric H. pylori infection, the recurrence of gastric H. pylori was significantly lower in the gastric H. pylori treatment plus periodontal therapy group than in the group receiving gastric H. pylori treatment alone (OR 0.67; 95% CI 0.45 to 0.99), whereas the eradication rate was not significantly different (OR 0.87; 95% CI 0.68 to 0.98). There was a close relationship between the presence of H. pylori in saliva and its presence in the stomach.

CONCLUSIONS

The oral cavity is an important reservoir for gastric H. pylori infection. Adjunctive periodontal therapy could enhance the efficiency of H. pylori treatment and reduce the recurrence of gastric H. pylori infection.

Up-Regulation of MiR-1915 Inhibits Proliferation, Invasion, and Migration of Helicobacter pylori-Infected Gastric Cancer Cells via Targeting RAGE

PURPOSE

Helicobacter pylori (HP)-infected gastric cancer (GC) is known to be a fatal malignant tumor, but the molecular mechanisms underlying its proliferation, invasion, and migration remain far from being completely understood. Our aim in this study was to explore miR-1915 expression and its molecular mechanisms in regulating proliferation, invasion, and migration of HP-infected GC cells.

MATERIALS AND METHODS

Quantitative real-time PCR and western blot analysis were performed to determine miR-1915 and receptor for advanced glycation end product (RAGE) expression in HP-infected GC tissues and gastritis tissues, as well as human gastric mucosal cell line GES-1 and human GC cell lines SGC-7901 and MKN45. CCK8 assay and transwell assay were performed to detect the proliferation, invasion, and migration capabilities. MiR-1915 mimics and miR-1915 inhibitor were transfected into GC cells to determine the target relationship between miR-1915 and RAGE.

RESULTS

MiR-1915 was under-expressed, while RAGE was over-expressed in HP-infected GC tissues and GC cells. Over-expressed miR-1915 could attenuate cellular proliferation, invasion, and migration capacities. RAGE was confirmed to be the target gene of miR-1915 by bioinformatics analysis and luciferase reporter assay. Moreover, HP-infected GC cellular proliferation, invasion, and migration were inhibited after treatment with pcDNA-RAGE.

CONCLUSION

MiR-1915 exerted tumor-suppressive effects on cellular proliferation, invasion, and migration of HP-infected GC cells via targeting RAGE, which provided an innovative target candidate for treatment of HP-infected GC.

Aspects of Gut Microbiota and Immune System Interactions in Infectious Diseases, Immunopathology, and Cancer

The microbiota consists of a dynamic multispecies community of bacteria, fungi, archaea, and protozoans, bringing to the host organism a dowry of cells and genes more numerous than its own. Among the different non-sterile cavities, the human gut harbors the most complex microbiota, with a strong impact on host homeostasis and immunostasis, being thus essential for maintaining the health condition. In this review, we outline the roles of gut microbiota in immunity, starting with the background information supporting the further presentation of the implications of gut microbiota dysbiosis in host susceptibility to infections, hypersensitivity reactions, autoimmunity, chronic inflammation, and cancer. The role of diet and antibiotics in the occurrence of dysbiosis and its pathological consequences, as well as the potential of probiotics to restore eubiosis is also discussed.

In - Vitro activity of Desmostachya bipinnata (L.) Stapf successive extracts against Helicobacter pylori clinical isolates

Helicobacter pylori are well acknowledged as a major cause of gastrointestinal ailments and gastric cancers. Therefore, the present study aimed to investigate the potential in vitro activity of Desmostachya bipinnata against H. pylori, focusing on the determination of the most active extract responsible for the anti-helicobacter activity to produce new active drug from natural source. Desmostachya bipinnata total alcohol and successive extracts were in vitro tested against H. pylori. All extracts showed promising anti Helicobacter pylori activities. The most effective extract was diethyl ether extract, it showed 75% growth inhibition of the clinical Isolates bacterial Helicobacter pylori, in addition it showed high count reduction on the selected organisms in the different concentrations used (2xMIC, MIC & ½ MIC) compared with the untreated controls as well as the other extracts (chloroform, ethyl acetate and n-butanol). The oral median lethal dose (LD50) of the alcohol extract of the plant by doses up to 5000 mg/kg didn't showed any mortality or morbidity, in addition no side effects were recorded on both liver and kidney functions this means that the extract was safe for use.

The prevalence of Helicobacter pylori infection and other risk factors among Mongolian dyspeptic patients who have a high incidence and mortality rate of gastric cancer

BACKGROUND

Mongolia has not only the second highest incidence rate but also the highest mortality rate for gastric cancer globally. In addition to gastric cancer, ulcerative disease complications are also life threatening; thus, investigating Helicobacter pylori infection and other risk factors is essential.

RESULTS

H.pylori infection was high in tested dyspeptic patients from all parts of Mongolia, with an overall infection rate of 80.0%. Logistic regression analysis showed that H. pylori infection was associated with gastritis (odds ratio; 9.0 ([95% confidence interval 5.0-16.2]); p < 0.0001). H. pylori infection (3.3 [2.0-5.4]; p < 0.0001) and > 40 years old (1.5 [1.0-2.0]; p < 0.02) were both associated with atrophy. However, > 40 years old (3.8 [2.4-6.0]; p < 0.0001) and high salt intakes (1.6 [1.0-2.3]; p < 0.02), but not H. pylori infection, were associated with intestinal metaplasia. Excessive amount of salt usage was dramatically higher in northern and western parts of Mongolia, where precancerous diseases, such as erosive esophagitis (for cardia cancer), severe atrophy, and intestinal metaplasia (for non-cardia cancer), were highly prevalent.

CONCLUSIONS

H. pylori infection was the major gastric health problem among the Mongolian population. In addition, environmental factors such as high salt intake worsened the clinical outcome. Therefore, a nationwide screening and eradication of H. pylori infection as well as salt-reducing measures should be implemented.

Flagellin glycosylation with pseudaminic acid in Campylobacter and Helicobacter: prospects for development of novel therapeutics

Many pathogenic bacteria require flagella-mediated motility to colonise and persist in their hosts. Helicobacter pylori and Campylobacter jejuni are flagellated epsilonproteobacteria associated with several human pathologies, including gastritis, acute diarrhea, gastric carcinoma and neurological disorders. In both species, glycosylation of flagellin with an unusual sugar pseudaminic acid (Pse) plays a crucial role in the biosynthesis of functional flagella, and thereby in bacterial motility and pathogenesis. Pse is found only in pathogenic bacteria. Its biosynthesis via six consecutive enzymatic steps has been extensively studied in H. pylori and C. jejuni. This review highlights the importance of flagella glycosylation and details structural insights into the enzymes in the Pse pathway obtained via a combination of biochemical, crystallographic, and mutagenesis studies of the enzyme-substrate and -inhibitor complexes. It is anticipated that understanding the underlying structural and molecular basis of the catalytic mechanisms of the Pse-synthesising enzymes will pave the way for the development of novel antimicrobials.

Relationship of Helicobacter pylori seroprevalence with the occurrence and severity of psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory disease that affects the skin and joints and has a multifactorial etiology. Recently, it has been suggested that Helicobacter pylori infection may contribute as a trigger for the development of the disease.

OBJECTIVES

To determine the prevalence of H. pylori seropositivity in patients with psoriasis and to evaluate the relation between disease severity and H. pylori infection.

METHODS

H. pylori infection was assessed in psoriatic patients and controls by using H. pylori IgG quantitative enzyme immunoassay (ELISA test). The patients were classified according to the severity of the disease (PASI score).

RESULTS

One hundred and twenty six patients with psoriasis (73 females and 53 males); mean age 50.48 years; 65 patients (51.59%) had severe psoriasis, 40 (31.75%) moderate psoriasis and 21 (16.67%) mild psoriasis. Twenty one healthy volunteers included as a control group, mean age of 41.05 years, 13 females and 8 males. One hundred and eleven patients with psoriasis tested serologically, 80 (72.07%) were seropositive compared with 7 positive volunteers (33.33%; P=0.002). Forty-nine (75.38%) patients with severe psoriasis were positive, 25 (62.50%) with moderate psoriasis were positive and 6 (28.57%) with mild psoriasis were positive (P=0.045). Study limitations: none.

CONCLUSIONS

H. pylori infection influences the development of psoriasis and severity of the disease.

MicroRNA-200c regulates cisplatin resistance by targeting ZEB2 in human gastric cancer cells

This study was specifically designed to confirm the hypothesis that microRNA-200c (miR-200c) affects the development of cisplatin (DDP) resistance in human gastric cancer cells by targeting zinc finger E-box binding homeobox 2 (ZEB2). A total of 50 gastric cancer tissues and their corresponding normal adjacent tissue samples were collected. Then, the expression levels of miR-200c and ZEB2 in both gastric cancer specimens and cells were detected using the quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemical methods. A dual‑luciferase reporter gene assay was conducted to evaluate the effect of miR-200c on the 3'-untranslated region (3'UTR) luciferase activity of ZEB2. SGC7901/DDP cells were transfected with miR-200c mimics and ZEB2 siRNA, respectively. Subsequently, changes in cellular proliferation and apoptosis were detected through the methyl thiazolyl tetrazolium assay and flow cytometric analysis, respectively. We also carried out a western blot analysis assay in order to detect the expression of apoptosis-related genes and ZEB2. miR-200c was significantly downregulated and ZEB2 was significantly upregulated in both gastric cancer tissues and SGC7901/DDP cells when compared with those in normal tissues and SGC7901 cells (P<0.01). The dual luciferase reporter gene assay showed that miR-200c could specifically bind with the 3'UTR of ZEB2 and significantly suppress the luciferase activity by 42% (P<0.01). Upregulation of miR-200c or downregulation of ZEB2 enhanced the sensitivity of SGC7901/DDP cells to DDP. miR‑200c was significantly downregulated in both gastric cancer tissues and cells, while the expression of ZEB2 exhibited the opposite trend. Our study further demonstrated that miR-200c could enhance the sensitivity of SGC7901/DDP cells to DDP through targeted regulation of ZEB2 expression in gastric cancer tissues.

Helicobacter pylori in Dyspepsia: Phenotypic and Genotypic Methods of Diagnosis

Background:

Helicobacter pylori affects almost half of the world's population and therefore is one of the most frequent and persistent bacterial infections worldwide. H. pylori is associated with chronic gastritis, ulcer disease (gastric and duodenal), mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Several diagnostic methods exist to detect infection and the option of one method or another depends on various genes, such as availability, advantages and disadvantages of each method, monetary value, and the age of patients.

Materials and Methods:

Patients with complaints of abdominal pain, discomfort, acidity, and loss of appetite were chosen for endoscopy, detailed history was contained, and a physical examination was conducted before endoscopy. Biopsies (antrum + body) were received from each patient and subjected to rapid urease test (RUT), histopathological examination (HPE), polymerase chain reaction (PCR), and culture.

Results:

Of the total 223 biopsy specimens obtained from dyspeptic patients, 122 (54.7%) were positive for H. pylori for HPE, 109 (48.9%) by RUT, 65 (29.1%) by culture, and 117 (52.5%) by PCR. The specificity and sensitivity were as follows: RUT (99% and 88.5%), phosphoglucosamine mutase PCR assay (100% and 95.9%), and culture (100% and 53.3%), respectively.

Conclusion:

In this study, we compared the various diagnostic methods used to identify H. pylori infection indicating that, in comparison with histology as gold standard for detection of H. pylori infection, culture and PCR showed 100% specificity whereas RUT and PCR showed 99% and 100% sensitivity, respectively.

Diversification of the vacAs1m1 and vacAs2m2 Strains of Helicobacter pylori in Meriones unguiculatus

The bacterium Helicobacter pylori exhibits great genetic diversity, and the pathogenic roles of its virulence factors have been widely studied. However, the evolutionary dynamics of H. pylori strains during stomach colonization are not well-characterized. Here, we analyzed the microevolutionary dynamics of the toxigenic strain vacAs1m1, the non-toxigenic strain vacAs2m2, and a combination of both strains in an animal model over time. Meriones unguiculatus were inoculated with the following bacteria: group 1-toxigenic strain vacAs1m1/cagA+/cagE+/babA2+; ST181, group 2-non-toxigenic strain vacAs2m2/cagA+/cagE+/babA2+; ST2901, and group 3-both strains. The gerbils were euthanized at different time points (3, 6, 12, and 18 months). In group 1, genetic alterations were observed at 6 and 12 months. With the combination of both strains, group 3 also exhibited genetic alterations at 3 and 18 months; moreover, a chimera, vacA m1-m2, was detected. Additionally, four new sequence types (STs) were reported in the PubMLST database for H. pylori. Synonymous and non-synonymous mutations were analyzed and associated with alterations in amino acids. Microevolutionary analysis of the STs (PHYLOViZ) identified in each group revealed many mutational changes in the toxigenic (vacAs1m1) and non-toxigenic (vacAs2m2) strains. Phylogenetic assessments (eBURST) did not reveal clonal complexes. Our findings indicate that the toxigenic strain, vacAs1m1, and a combination of toxigenic and non-toxigenic strains acquired genetic material by recombination. The allelic combination, vacAs2m1, displayed the best adaptation in the animal model over time, and a chimera, m1-m2, was also identified, which confirmed previous reports.

Treatment of synchronous adenocarcinoma and lymphoma of the stomach: A case report

Gastric cancer is one of the leading causes of cancer-related mortality worldwide. The majority of gastric cancers are diagnosed at an advanced or metastatic stage, with a 5-year survival rate of ~5-20% and a median overall survival of <1 year. Synchronous occurrence of gastric adenocarcinoma and lymphoma is rare, and thus far there is no consensus regarding their management. We herein describe a case of synchronous gastric adenocarcinoma and diffuse large B-cell lymphoma in a patient with chronic hepatitis B and the treatment strategy. A literature review with the most up-to-date treatment options and their application in similar situations was also performed.

Sero-prevalence and associated factors of Helicobacter pylori infection among adult patients with dyspepsia attending the gastroenterology unit in a tertiary hospital in Mwanza, Tanzania

BACKGROUND

Prevalence of H.pylori infection varies greatly between populations in different countries. This study was conducted to determine the magnitude of H.pylori among adult patients with dyspepsia attending the gastroenterology unit at Bugando medical centre.

METHODS

A cross sectional study involving 202 dyspeptic patients was conducted between June and July 2014. A Standardized data collection tool was used to collect socio-demographic characteristics. H.pylori antibodies were detected using rapid immunochromatographic tests according to manufacturer's instructions.

RESULTS

The median age of study population was 42 (IQR: 33-54). Females 105 (51.9%) formed majority of the population studied. Of 202 participants; 119 (58.9%) were from rural areas. Seroprevalence of H.pylori infection was found to be 79/202 (39.1%, 95% CI: 32.3-45.7). As the age increased the risk of having H.pylori infection also increased (OR: 1.02 95% CI: 1-1.04, P=0.02). On multivariate logistic regression analysis untreated drinking water was found to predict H.pylori seropositivity (OR: 2.33, CI: 1.09-4.96, p=0.028).

CONCLUSION

The seroprevalence of H.pylori among dyspeptic patients is high in this setting. Therefore the community in Mwanza should be educated on the use of safe drinking water in order to minimize H. pylori infections.

Draft Genome Sequence of a Helicobacter pylori Strain Isolated from a Patient with Diffuse Gastritis from a Region of High Cancer Risk in Colombia

The draft genome sequence of one Colombian Helicobacter pylori strain is presented. This strain was isolated from a patient with diffuse gastritis from Tibaná, Boyacá, a region with high gastric cancer risk.

Elevated levels of adaption in Helicobacter pylori genomes from Japan; a link to higher incidences of gastric cancer?

Helicobacter pylori is a bacterium that lives in the human stomach and is a major risk factor for gastric cancer and ulcers. H.pylori is host dependent and has been carried with human populations around the world after their departure from Africa. We wished to investigate how H.pylori has coevolved with its host during that time, focusing on strains from Japanese and European populations, given that gastric cancer incidence is high in Japanese populations, while low in European. A positive selection analysis of eight H.pylori genomes was conducted, using maximum likelihood based pairwise comparisons in order to maximize the number of strain-specific genes included in the study. Using the genic Ka/Ks ratio, comparisons of four Japanese H.pylori genomes suggests 25–34 genes under positive selection, while four European H.pylori genomes suggests 16–21 genes; few of the genes identified were in common between lineages. Of the identified genes which were annotated, 38% possessed homologs associated with pathogenicity and / or host adaptation, consistent with their involvement in a coevolutionary ‘arms race’ with the host. Given the efficacy of identifying host interaction factors de novo, in the absence of functionally annotated homologs our evolutionary approach may have value in identifying novel genes which H.pylori employs to interact with the human gut environment. In addition, the larger number of genes inferred as being under positive selection in Japanese strains compared to European implies a stronger overall adaptive pressure, potentially resulting from an elevated immune response which may be linked to increased inflammation, an initial stage in the development of gastric cancer.

Comparison of gastric cancer survival between Caucasian and Asian patients treated in the United States: results from the Surveillance Epidemiology and End Results (SEER) database

BACKGROUND

The prognosis for gastric cancer is better for Asian than for Caucasian patients. The primary driver of this difference is unknown. This study determined whether the survival advantage of Asian ethnicity continued to hold after control was used for other well-known prognostic factors.

METHODS

In this study, 12,773 patients who underwent gastrectomy for treatment of adenocarcinoma of the stomach were identified from the Surveillance, Epidemiology, and End Results cancer registry. Patients with cardia tumor were excluded from the study. The independent prognostic effect of ethnicity was evaluated by adjusting for other known factors.

RESULTS

The Asian patients tended to have a diagnosis at an earlier age (66.8 vs. 68.5 years), more lymph nodes examined (16 vs. 13), and more positive lymph nodes (5.1 vs. 4.8). Survival was better for the Asian patients than for the Caucasian patients, with a 12 % 5-year survival difference. Among the patients with IB, IIA, and IIB disease, the Asian patients had 37, 72, and 13 months longer median survival time than the corresponding Caucasian patients. The multivariate Cox model showed persistence of this result after adjustment for imbalances of age, gender, tumor grade, and number of examined and positive lymph nodes. The largest risk reduction was observed for the stage IA patients (31 %) and the smallest for the stage IIIC patients (9 %).

CONCLUSION

After excluding proximal gastric cancers, controlling for the imbalance of known prognostic factors, and decreasing in the influence of D2 lymphadenectomy, stage migration, and chemo/radiation therapy by including only patients treated in the United States, this study found that the survival advantage of Asian ethnicity continued to be present.

The Relationship between Eating and Lifestyle Habits and Cancer in Van Lake Region: Another Endemic Region for Esophageal and Gastric Cancers

Purpose. To examine the relationship between esophageal and gastric cancers commonly seen in Van Lake region and the traditional eating habits of the geography. Materials and Methods. Esophageal and gastric cancer cases, who underwent surgery between January 1, 2012, and December 31, 2013, were examined. Pathology reports of the patients and presence of Helicobacter pylori (HP) were recorded. Surveys were filled by face to face meeting or telephone call. Control group was created with randomly selected individuals without any cancer diagnosis having age, gender, and socioeconomic characteristics similar to patient group. All data were analyzed using SAS.9.3 statistical programme. Results. Compared with the control group, herby cheese consumption (a component of eating habits) and smoking were significantly higher in the patient group (P < 0.001). Tandoor exposure is compared in terms of female gender, and significant difference was found between the groups (P = 0.0013). As a result of the analysis with logistic regression more than 150 gr of herby cheese consumption per day was found to increase the cancer risk (odds ratio 1.017; 95% CI: 1.012-1.022). Conclusion. A high consumption of herby cheese, cooking bread on tandoor, and heavy smoking were seen to be important risk factors for esophageal and gastric cancers.

Beyond the stomach: An updated view of Helicobacter pylori pathogenesis, diagnosis, and treatment

Helicobacter pylori (H. pylori) is an extremely common, yet underappreciated, pathogen that is able to alter host physiology and subvert the host immune response, allowing it to persist for the life of the host. H. pylori is the primary cause of peptic ulcers and gastric cancer. In the United States, the annual cost associated with peptic ulcer disease is estimated to be $6 billion and gastric cancer kills over 700000 people per year globally. The prevalence of H. pylori infection remains high (> 50%) in much of the world, although the infection rates are dropping in some developed nations. The drop in H. pylori prevalence could be a double-edged sword, reducing the incidence of gastric diseases while increasing the risk of allergies and esophageal diseases. The list of diseases potentially caused by H. pylori continues to grow; however, mechanistic explanations of how H. pylori could contribute to extragastric diseases lag far behind clinical studies. A number of host factors and H. pylori virulence factors act in concert to determine which individuals are at the highest risk of disease. These include bacterial cytotoxins and polymorphisms in host genes responsible for directing the immune response. This review discusses the latest advances in H. pylori pathogenesis, diagnosis, and treatment. Up-to-date information on correlations between H. pylori and extragastric diseases is also provided.

Helicobacter pylori identification: a diagnostic/confirmatory method for evaluation

The Helicobacter pylori extra gastric reservoir is probably the oral cavity. In order to evaluate the presence of this bacterium in patients with periodontitis and suspicious microbial cultures, saliva was collected from these and non-periodontitis subjects. PCRs targeting 16S rRNA gene and a 860 bp specific region were performed, and digested with the restriction enzyme DdeI. We observed that the PCR-RFLP approach augments the accuracy from 26.2 % (16/61), found in the PCR-based results, to 42.6 % (26/61), which is an excellent indicator for the establishment of this low-cost procedure as a diagnostic/confirmatory method for H. pylori evaluation.

Associations between the four toll-like receptor polymorphisms and the risk of gastric cancer: a meta-analysis

PURPOSE

The association between Toll-like receptor 2 (TLR2) -196 to -174del polymorphism and Toll-like receptor 4 (TLR4) polymorphisms (Asp299Gly, Thr399Ile, and 3725G>C) and gastric cancer risk are still conflicting. For better understanding of the effects of these four polymorphisms on gastric cancer risk, a meta-analysis was performed.

METHODS

An extensive search was performed to identify all case-control studies investigating such associations. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the relationship.

RESULTS

A total of 21 studies (3,436 cases and 4,239 controls) were found to be eligible for meta-analysis. In the overall analysis, a significantly increased risk was observed in TLR4 Asp299Gly polymorphism (G allele vs. A allele: OR=1.84, 95%CI: 1.41, 2.39; GA vs. AA: OR=1.89, 95%CI: 1.43, 2.48; Recessive model: OR=1.90, 95%CI: 1.44, 2.49) and TLR4 Thr399Ile polymorphism (T allele vs. C allele: OR=1.97, 95%CI: 1.22, 3.18; TC vs. CC: OR=1.94, 95%CI: 1.19, 3.15; Recessive model: OR=1.98, 95%CI: 1.21, 3.21), whereas no associations were found in any genetic models of TLR2 -196 to -174del and TLR4 3725G>C polymorphisms. Similar results were found in the subgroup analyses by ethnicity. However, we detected that A allele carriers of the TLR4 Asp299Gly polymorphism might have an increase risk of gastric cancer in the Helicobacter pylori-positive population (G allele vs. A allele: OR=2.01, 95%CI: 1.22, 3.31).

CONCLUSION

The results of this meta-analysis indicate that the TLR4 Asp299Gly and Thr399Ile polymorphisms are risk factors for gastric cancer development.

Genetic variation in PSCA and risk of gastric advanced preneoplastic lesions and cancer in relation to Helicobacter pylori infection

SNPs in the Prostate Stem Cell Antigen (PSCA) gene have been found associated with gastric cancer (GC) risk in a genome-wide association study. This association has been replicated in several populations. In this study we assessed the impact of PSCA genotype on the risk of advanced gastric precancerous lesions and GC. We used baseline gastric histopathology data and DNA from frozen gastric biopsies of 2045 subjects enrolled in a chemoprevention trial for gastric precancerous lesions in Venezuela, and 180 cases of GC from the same area. We analyzed 3 SNPs in the PSCA gene (rs2294008, rs9297976 and rs12155758) which were previously found to be associated with GC risk in Europeans. The T allele of rs2294008 was found to be associated with a higher prevalence of atrophic gastritis (OR = 1.44; 95% CI 1.03-2.01 for the dominant model) and intestinal metaplasia (OR = 1.50; 95% CI 1.13-1.98 for the dominant model). We also confirmed the association with higher risk of gastric cancer (OR = 2.34; 95% CI 1.36-4.01 for the allele carriers). SNP rs12155758 was not associated with risk of gastric preneoplastic lesions, but we confirmed its association with higher GC risk (OR 1.95; 95% CI 1.29-2.97 for dominant model). We tested the relevance of the presence of the Helicobacter pylori cagA gene, which is known to increase the risk of more severe gastric lesions, but we did not find any clearcut interaction with PSCA SNPs in defining risk of gastric precancerous lesions or cancer.

Multiple infections and cancer: implications in epidemiology

Approximately 18% of the global cancer burden has been attributed to infectious agents, with estimates ranging from 7% in developed countries to about 22% in developing countries. Chronic infections caused by the hepatitis B and C viruses, human papilloma viruses (HPV), and Helicobacter pylori (H. pylori) are reported to be responsible for approximately 15% of all human cancers. Interestingly, although many of the infectious agents that have been associated with cancer--such as HPV, Epstein-Barr virus (EBV), and H. pylori--are highly prevalent in the world, most infected individuals do not develop cancer but remain lifelong carriers. Malignancies associated with infectious agents may result from prolonged latency as a result of chronic infections. Pathogenic infections are necessary but are not sufficient for cancer initiation or progression. Cancer initiation may require additional cofactors, including secondary infections. Therefore, in patients with chronic infection with one agent, secondary co-infection with another agent may serve as an important co-factor that may cause cancer initiation and progression. Additionally, opportunistic co-infections could significantly inhibit response to cancer treatment and increase cancer mortality. Co-infections are relatively common in areas with a high prevalence of infectious agents, especially in developing countries. These co-infections can cause an imbalance in the host immune system by affecting persistence of and susceptibility to malignant infections. Several articles have been published that focus on infectious agents and cancer. In this article, we discuss the role of infectious agents in malignancies, highlight the role of multiple/co-infections in cancer etiology, and review implications for cancer epidemiology.

Relation of helicobacter pylori infection and multiple sclerosis in Iranian patients

Multiple sclerosis (MS) is the most prevalent central nervous system demyelinating disease. There are known risk factors for MS. However, there is uncertainty in its protective factors. Few studies have demonstrated that some chronic infections may have protective effects on this disease. We carried this study to investigate the relation between Helicobacter pylori (HP) infection and the prevalence and severity of MS. In this case-control study, 163 MS patients and 150 sex- and age- matched controls were included. Blood samples for IgG and IgM anti HP antibodies were collected from all individuals. Also, the Expanded Disability Status Scale (EDSS) was used to evaluate the MS patients. Suitable statistical analysis was applied. A Significant difference was observed in seropositivity between these two groups (P<0.001) but no significant difference was seen in seropositivity between conventional and opticospinal MS (P=0.522). No significant difference was observed in seropositivity among ages (P=0.075) and between genders (P=0.204). A significant difference was seen in EDSS value between seropositive and seronegative patients (P=0.017). We concluded that patients with HP infection had lower incidence of multiple sclerosis and MS patients with HP infection showed lower neurologic complications, which can demonstrate that HP infection may have a protective influence on MS pathogenesis.

PLCE1 polymorphism and upper gastrointestinal cancer risk: a meta-analysis

BACKGROUND

In recent years, the PLCE1 rs2274223 polymorphism has been extensively investigated as a potential risk factor for upper gastrointestinal cancers, including squamous cell carcinoma (ESCC) and gastric cancer. However, the results of these studies have been inconsistent.

METHODS

A meta-analysis of 13 case-control studies was performed including more than 11,000 subjects with genotyped PLCE1 rs2274223 polymorphisms. Odds ratios (OR) with 95% confidence intervals (CI) were employed to assess the association of the PLCE1 rs2274223 polymorphism with a susceptibility to ESCC or gastric cancer.

RESULTS

A statistically significant increase in the risk of ESCC was associated with the PLCE1 rs2274223 polymorphism. This included the homozygous genetic model (OR = 1.46), heterozygous genetic model (OR = 1.25) and allelic genetic model (OR = 1.23). Similar results were consistently found for gastric cancer. In a subgroup analysis, the PLCE1 rs2274223 polymorphism was found to be a very sensitive marker for gastric cardia cancer as shown by the homozygous genetic model (OR = 2.23), heterozygous genetic model(OR = 1.59) and allelic genetic model (OR = 1.47). The risk associations of all of the gastric cardia cancer models were statistically significant. In contrast, none of the genetic models for non-cardia gastric cancer were significant.

CONCLUSIONS

In this meta-analysis, the PLCE1 rs2274223 polymorphism was confirmed to have a statistically significant association with an increasing risk of ESCC and gastric cancer. The increase risk was especially observed for gastric cardia cancer.

Epidemiology of Helicobacter pylori infection in six Latin American countries (SWOG Trial S0701)

OBJECTIVE

To investigate the potential determinants of Helicobacter pylori infection between adults 21-65 years old.

METHODS

Data are from the initial screening visit of a randomized clinical trial of three antibiotic regimens to eradicate H. pylori, conducted in seven sites (Santiago-Chile, Túquerres-Colombia, Guanacaste-Costa Rica, Copán-Honduras, Obregón and Tapachula-México, León-Nicaragua). Thousand eight hundred and fifty-nine adults from the general population were screened for H. pylori infection using an urea breath test (UBT) and were interviewed to assess socioeconomic-, demographic-, and symptom-related characteristics. Logistic regression was used to assess the relationship between these characteristics and H. pylori positivity at enrollment.

RESULTS

Among the 1,852 eligible participants for whom a conclusive UBT result was obtained, H. pylori prevalence was 79.4 %, ranging from 70.1 to 84.7 % among the seven centers. Prevalence did not differ by sex (female: 78.4, male: 80.9; p = 0.20) or age (p = 0.08). H. pylori positivity increased with increasing number of siblings (p trend <0.0001). Participants with education beyond 12 years were less likely to be UBT-positive (OR 0.4: 0.3-0.6, compared to participants with 0-6 years of schooling) as were those employed outside the home (OR 0.7: 0.6-1.0). Odds of H. pylori infection increased with the presence of certain living conditions during childhood including having lived in a household with an earth floor (OR 1.8: 1.4-2.4), lack of indoor plumbing (OR 1.3: 1.0-1.8) and crowding (OR 1.4: 1.0-1.8, for having more than two persons per bedroom). Regarding current household conditions, living with more than 3 children in the household (OR 1.7: 1.2-2.5) and crowding (OR 1.8: 1.3-2.3) were associated with H. pylori infection.

CONCLUSIONS

The prevalence of H. pylori in adults was high and differed significantly among the six Latin American countries studied (p < 0.001). Our findings confirm the strong link between poor socioeconomic conditions and H. pylori infection.

Relatedness of Helicobacter pylori populations to gastric carcinogenesis

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that infects half of the human population. The infection is associated with chronic inflammation of the gastric mucosa and peptic ulcers. It is also a major risk factor for gastric cancer. Phylogenetic analysis of global strains reveals there are seven populations of H. pylori, including hpAfrica1, hpAfrica2, hpEastAsia, hpEurope, hpNEAfrica, hpAsia2 and hpSahul. These populations are consistent with their geographical origins, and possibly result from geographical separation of the bacterium leading to reduced bacterial recombination in some populations. For each population, H. pylori has evolved to possess genomic contents distinguishable from others. The hpEurope population is distinct in that it has the largest genome of 1.65 mbp on average, and the highest number of coding sequences. This confers its competitive advantage over other populations but at the cost of a lower infection rate. The large genomic size could be a cause of the frequent occurrence of the deletion of the cag pathogenicity island in H. pylori strains from hpEurope. The incidence of gastric cancer varies among different geographical regions. This can be attributed in part to different rates of infection of H. pylori. Recent studies found that different populations of H. pylori vary in their carcinogenic potential and contribute to the variation in incidence of gastric cancer among geographical regions. This could be related to the ancestral origin of H. pylori. Further studies are indicated to investigate the bacterial factors contributing to differential virulence and their influence on the clinical features in infected individuals.

Retracted: Increased risk of stomach and esophageal malignancies in people with AIDS

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief and Authors. The authors recently discovered two programming errors that affected the results in their article on the epidemiology of esophageal and stomach cancers in human immunodeficiency virus infected people. As a result of these errors, the standardized incidence ratios (SIRs) were too high. The corrected SIRs are all lower than the authors reported, and the corrected SIR for stomach cancer is no longer significantly elevated. These errors affect Tables 2-5 in the paper. Because the new findings alter the conclusions, the editors and authors have jointly made the decision to retract the paper. The authors would like to express their sincere regret at the errors in their initial report and any inconvenience or confusion that they created. The corrected results may be obtained by contacting the corresponding author, Dr. Eric A. Engels, by email at engelse@exchange.nih.gov.

Genetics and molecular pathology of gastric malignancy: Development of targeted therapies in the era of personalized medicine

Gastric malignancy constitutes a major cause of cancer deaths worldwide. Despite recent advances in surgical techniques combined with neoadjuvant chemotherapy and radiotherapy approaches, patients with advanced disease still have poor outcomes. An emerging understanding of the molecular pathways that characterize cell growth, cell cycle, apoptosis, angiogenesis, invasion and metastasis has provided novel targets in gastric cancer therapy. In this review, recent advances in the understanding of molecular tumorigenesis for common gastric malignancies are discussed. We also briefly review the current targeted therapies in the treatment of gastric malignancies. Practical insights are highlighted including HER2 testing and target therapy in gastric adenocarcinoma, morphologic features and molecular signatures of imatinib-resistance GISTs, and recent investigations aimed at tumor-specific therapy for neuroendocrine tumors.

Downregulation of tumor suppressor QKI in gastric cancer and its implication in cancer prognosis

Gastric cancer (GC) is the fourth most common cancer and second leading cause of cancer-related death worldwide. RNA-binding protein Quaking (QKI) is a newly identified tumor suppressor in multiple cancers, while its role in GC is largely unknown. Our study here aimed to clarify the relationship between QKI expression with the clinicopathologic characteristics and the prognosis of GC. In the 222 GC patients' specimens, QKI expression was found to be significantly decreased in most of the GC tissues, which was largely due to promoter hypermethylation. QKI overexpression reduced the proliferation ability of GC cell line in vitro study. In addition, the reduced QKI expression correlated well with poor differentiation status, depth of invasion, gastric lymph node metastasis, distant metastasis, advanced TNM stage, and poor survival. Multivariate analysis showed QKI expression was an independent prognostic factor for patient survival.

Prostate stem cell antigen polymorphisms and susceptibility to gastric cancer: a systematic review and meta-analysis

BACKGROUND

Many studies have reported that prostate stem cell antigen (PSCA) polymorphisms (rs2294008 and/or 2976392) are significantly associated with gastric cancer (GC) risk, although the published results are inconsistent. We conducted a systematic review and meta-analysis for relevant literatures to quantitatively evaluate the relationship between PSCA polymorphisms and GC susceptibility.

METHODS

Extensive searches were conducted in three databases up to November 1, 2011. ORs and 95% CIs were used to assess the strength of the associations. The data were further stratified by ethnicity, histopathology, subsite, and study design. All of the associations were evaluated with dominant model and recessive model, respectively. Heterogeneity and publication bias were also assessed by Q test, I(2), and funnel plot accordingly.

RESULTS

Nine articles including 11 case-control data sets were included, with 10,746 GC cases and 9,158 controls for rs2294008 and 6,060 cases and 4,824 controls for rs2976392. The results showed that risk allele carriers were significantly associated with GC risk compared with nonrisk allele homozygotes. In stratification analyses, these associations remained significant for majority of subgroups except for Caucasians and noncardia tumor in dominant model, and cardia tumor in both dominant and recessive model. Random model was used when heterogeneity among studies was detected. No publication bias was observed.

CONCLUSIONS

The two loci of PSCA (rs2294008 and rs2976392) were both significantly associated with GC susceptibility and in linkage disequilibrium.

IMPACT

More prospective studies on PSCA polymorphisms at multicenters with sufficient sample size and less heterogeneity will be needed for further validations.

Positive selection on a bacterial oncoprotein associated with gastric cancer

Background

Helicobacter pylori is a vertically inherited gut commensal that is carcinogenic if it possesses the cag pathogenicity island (cag PaI); infection with H.pylori is the major risk factor for gastric cancer, the second leading cause of death from cancer worldwide (WHO). The cag PaI locus encodes the cagA gene, whose protein product is injected into stomach epithelial cells via a Type IV secretion system, also encoded by the cag PaI. Once there, the cagA protein binds to various cellular proteins, resulting in dysregulation of cell division and carcinogenesis. For this reason, cagA may be described as an oncoprotein. A clear understanding of the mechanism of action of cagA and its benefit to the bacteria is lacking.

Association of polymorphisms in TLR genes and in genes of the Toll-like receptor signaling pathway with cancer risk

Toll-like receptors (TLRs) constitute a family of receptors directly recognizing a wide spectrum of exogenous and endogenous ligands playing the key role in realization of innate and adaptive immune response, and participating in the processes of cell proliferation, survival, apoptosis, angiogenesis, tissue remodeling and repair. Polymorphisms in TLR genes may shift balance between pro- and anti-inflammatory cytokines, modulating the risk of infection, chronic inflammation and cancer. The short list of TLR polymorphisms perspective for oncogenomic investigations can include rs10008492, rs4833103, rs5743815, rs11466657, rs7696175 (TLR1-TLR6-TLR10 gene cluster); rs3804100, rs4696480, -196 - -174 del (Delta22), GT-microsatellite polymorphism (TLR2); 829A/C (TLR3); rs5743836, rs352140 (TLR9). The extended list can additionally include rs4833095 rs5743551, rs5743618 (TLR1); rs5743704, rs62323857, rs1219178642 (TLR2); rs5743305, rs3775291, rs121434431, rs5743316 (TLR3); rs5744168 (TLR5); rs179008 (TLR7); rs3764880, rs2407992 (TLR8); rs352139, rs187084, rs41308230, rs5743844 (TLR9); rs4129009 (TLR10). General reasons for discrepancies between studies are insufficiency of sample size, age/gender/BMI/ethnic/racial differences, differences in prevalence of infectious agent in case and control groups, differences in immune response caused by specific ligand, differences in stratification, methods of diagnostics of cancer or chronic inflammatory conditions, genotyping methods, and chance. Future well-designed studies on large samples should shed light on the significance of TLR polymorphisms for cancer prevention.

Low serum pepsinogen I and pepsinogen I/II ratio and Helicobacter pylori infection are associated with increased risk of gastric cancer: 14-year follow up result in a rural Chinese community

The correlation between low serum PG level and H. pylori infection with the development of gastric cancer has caused considerable concerns all over the world. Some authors exclaimed that gastric cancer developed only in patients infected with H. pylori, whereas the other had different findings. In this study, 1,501 adult local residents with determined serum PG levels and anti H. pylori IgG status were followed for 14 years for the development of gastric cancer in a rural community with high risk of gastric cancer in Hebei Province, China. The results showed the accumulated gastric cancer incidence in the subjects with abnormal PG level and those with H. pylori infection were all significantly higher than that in the corresponding normal controls (53.9‰ vs. 12.7‰, p < 0.05 and 23.1‰ vs. 5.93‰, p < 0.05). The highest gastric cancer incidence was seen in the subjects with both abnormal serum PG and positive H. pylori (56.0‰), and followed by the subjects with abnormal PG and negative H. pylori (47.6‰) and those with normal serum PG and positive H. pylori (18.4‰). The abnormal serum PG level (OR 3.029) and H. pylori infection (OR 4.345) were all risk factors for the development of gastric cancer. The results suggested that the subjects with abnormal serum PG level and/or positive H. pylori infection in the rural area of China were all high risk population for gastric carcinoma and the subjects with both abnormal serum PG and positive H. pylori infection were at especially high risk for the development of gastric carcinoma.

The Helicobacter pylori Ferric Uptake Regulator (Fur) is essential for growth under sodium chloride stress

Epidemiological data and animal models indicate that Helicobacter pylori and dietary NaCl have a synergistic ill effect on gastric maladies. Here we show that the Ferric Uptake Regulator (Fur), which is a crucial regulatory factor required for H. pylori colonization, is essential for growth in the presence of high NaCl concentrations. Moreover, we demonstrate that the transcriptional response induced by sodium chloride stress exhibits similarities to that seen under iron depletion.