Helicobacter pylori infection: independent risk indicator of gastric adenocarcinoma

Exploring the Link between Helicobacter pylori, Gastric Microbiota and Gastric Cancer

Gastric cancer (GC) still represents one of the leading causes of cancer-related mortality and is a major public health issue worldwide. Understanding the etiopathogenetic mechanisms behind GC development holds immense potential to revolutionize patients' treatment and prognosis. Within the complex web of genetic predispositions and environmental factors, the connection between Helicobacter pylori (H. pylori) and gastric microbiota emerges as a focus of intense research investigation. According to the most recent hypotheses, H. pylori triggers inflammatory responses and molecular alterations in gastric mucosa, while non-Helicobacter microbiota modulates disease progression. In this review, we analyze the current state of the literature on the relationship between H. pylori and non-Helicobacter gastric microbiota in gastric carcinogenesis, highlighting the mechanisms by which microecological dysbiosis can contribute to the malignant transformation of the mucosa.

Cost-effectiveness modelling of use of urea breath test for the management of Helicobacter pylori-related dyspepsia and peptic ulcer in the UK

OBJECTIVE

Clinical data comparing diagnostic strategies in the management of Helicobacter pylori-associated diseases are limited. Invasive and noninvasive diagnostic tests for detecting H. pylori infection are used in the clinical care of patients with dyspeptic symptoms. Modelling studies might help to identify the most cost-effective strategies. The objective of the study is to assess the cost-effectiveness of a 'test-and-treat' strategy with the urea breath test (UBT) compared with other strategies, in managing patients with H. pylori-associated dyspepsia and preventing peptic ulcer in the UK.

DESIGN

Cost-effectiveness models compared four strategies: 'test-and-treat' with either UBT or faecal antigen test (FAT), 'endoscopy-based strategy' and 'symptomatic treatment'. A probabilistic cost-effectiveness analysis was performed using a simulation model in order to identify probabilities and costs associated with relief of dyspepsia symptoms (over a 4-week time horizon) and with prevention of peptic ulcers (over a 10-year time horizon). Clinical and cost inputs to the model were derived from routine medical practice in the UK.

RESULTS

For relief of dyspepsia symptoms, 'test-and-treat' strategies with either UBT (€526/success) and FAT (€518/success) were the most cost-effective strategies compared with 'endoscopy-based strategy' (€1317/success) and 'symptomatic treatment' (€1 029/success). For the prevention of peptic ulcers, 'test-and-treat' strategies with either UBT (€208/ulcer avoided/year) or FAT (€191/ulcer avoided/year) were the most cost-effective strategies compared with 'endoscopy-based strategy' (€717/ulcer avoided/year) and 'symptomatic treatment' (€651/ulcer avoided/year) (1 EUR=0,871487 GBP at the time of the study).

CONCLUSION

'Test-and-treat' strategies with either UBT or FAT are the most cost-effective medical approaches for the management of H. pylori-associated dyspepsia and the prevention of peptic ulcer in the UK. A 'test-and-treat' strategy with UBT has comparable cost-effectiveness outcomes to the current standard of care using FAT in the UK.

Bismuth Concentrations in Patients Treated in Real-Life Practice with a Bismuth Subcitrate-Metronidazole-Tetracycline Preparation: The SAPHARY Study

INTRODUCTION

A fixed-dose association of bismuth subcitrate, metronidazole and tetracycline (BMT) (Pylera^®, Allergan, NJ, USA) was made available in France in 2013 for the eradication of Helicobacter pylori. Due to a historical issue of bismuth encephalopathy, the French Health Authorities requested a study of blood and plasma bismuth concentrations with BMT in daily practice.

AIMS

The aim of the study was to measure eventual bismuth accumulation and neurological toxicity in patients prescribed BMT.

METHODS

Patients initiating BMT for H. pylori between March 2014 and December 2015 were included. A blood sample was taken before first BMT intake and 24 h after the last intake, for assay of bismuth. A concentration > 50 μg/L was considered abnormal. Neurological complaints were assessed at inclusion, at the end of the 10-day treatment course, and 28 days later.

RESULTS

202 patients were included, of whom 190 took at least one dose of BMT, and 167 provided both required blood samples. Mean blood bismuth concentrations after the BMT course were 16.9 μg/L (95% confidence interval 15.6-18.3). Concentrations were > 50 μg/L (56.0 μg/L and 50.9 μg/L) in two elderly patients, one of whom presented mild, transient memory impairment during treatment. Non-serious neurological symptoms occurred in 20% of all patients and treatment failure was documented in 5% of patients.

CONCLUSIONS

In this study measuring blood bismuth concentrations in real-life practice, in < 1% of patients the BMT course resulted in blood bismuth concentrations > 50 μg/L. No serious neurological adverse events were observed.

STUDY REGISTRATION

EU-PAS register EUPAS3142 at www.encepp.eu ; ENCePP study seal.

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.

Alcohol drinking and gastric cancer risk: a meta-analysis of observational studies

BACKGROUND

Many studies investigated the association between alcohol drinking and gastric cancer risk, but the results were controversial. We performed a meta-analysis of observational studies to explore the association.

MATERIALS AND METHODS

We searched PubMed to identify the relevant studies that reported the association between alcohol drinking and gastric cancer risk up to December 31, 2016. We pooled relative risks (RRs) in random effects model and performed dose-response analysis to quantify the association. Cochran Q test and I2 analyses were used to evaluate the heterogeneity. Meta-regression, subgroup, sensitivity and publication bias analyses were also performed.

RESULTS

75 studies were included in our study. The pooled RR of high vs low total alcohol drinking was 1.25 (95% CI, 1.15-1.37, P < 0.001), and a nonlinear association was further observed. Subgroup analysis showed that alcohol drinking significantly associated with the risk of gastric noncardia cancer (RR, 1.19; 95% CI, 1.01-1.40, P = 0.033), but not with the risk of gastric cardia cancer (RR, 1.16; 95% CI, 0.98-1.39, P = 0.087). Notably, the pooled RRs of high vs low analyses were 1.13 (95% CI, 1.03-1.24, P = 0.012) for beer drinking, 1.22 (95% CI, 1.06-1.40, P = 0.005) for liquor drinking, and 0.99 (95% CI, 0.84-1.16, P = 0.857) for wine drinking.

CONCLUSIONS

Our meta-analysis found a nonlinear association between alcohol drinking and gastric cancer risk, and heavy drinking level was strongly related to gastric cancer risk. Beer and liquor had significant positive associations with gastric cancer risk, while wine drinking would not increase gastric cancer risk. These results need to be verified in future research.

Can Diet Modulate Helicobacter pylori-associated Gastric Pathogenesis? An Evidence-Based Analysis

Helicobacter pylori is involved in the pathogenesis of gastritis, peptic ulcer, and gastric cancer. The infection is prevalent in more than half of the world's population. Although the infection may lead to detrimental consequences, still the majority of the infected individuals only develop mild gastritis. Several factors are behind this paradoxical outcome including virulence of the infecting H. pylori strains, genetic background of the host, and factors related to lifestyle such as dietary habits. Among these, lifestyle including dietary factors was not in the limelight, until recently, as one of the important factors that could modulate H. pylori-linked gastric diseases. This review is directed to gather and elucidate the role of dietary components in augmenting or attenuating pathological processes initiated by H. pylori. Available evidence strongly supports the notion that the diet may play a critical role in defining the final outcome of H. pylori infection particularly if certain dietary components are taken on a regular basis for a long time. Despite a recent surge in research related to the role of dietary ingredients, further studies involving large-scale clinical trials are required to gain a better understanding of the precise role played by the dietary ingredients in H. pylori-associated pathogenesis.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

A novel fluorescent DNA sensor for ultrasensitive detection of Helicobacter pylori

In this work, a novel fluorescent DNA sensor for ultrasensitive detection of Helicobacter pylori (H. pylori) DNA was developed. This strategy took advantage of DNA hybridization between single-stranded DNA (ssDNA, which had been designed as an aptamer specific for H. pylori DNA) and the complementary target H. pylori DNA, and the feature that ssDNA bound to graphene oxide (GO) with significantly higher affinity than double-stranded DNA (dsDNA). ssDNA were firstly covalent conjugated with CuInS₂ quantum dots (QDs) by reaction between the carboxy group of QDs and amino group modified ssDNA, forming ssDNA-QDs genosensor. In the absence of the complementary target H. pylori DNA, GO could adsorb ssDNA-QDs DNA sensor and efficiently quench the fluorescence of ssDNA-QDs. While the complementary target H. pylori DNA was introduced, the ssDNA-QDs preferentially bound with the H. pylori DNA. The formation of dsDNA would alter the conformation of ssDNA and disturb the interaction between ssDNA and GO. Thus, the dsDNA-QDs/GO system exhibited a stronger fluorescence emission than that of the ssDNA-QDs/GO system. Under the optimized conditions, a linear correlation was established between the fluorescence intensity ratio I/I₀ and the concentration of H. pylori DNA in the range of 1.25-875pmolL^-1 with a detection limit of 0.46pmolL^-1. The proposed method was applied to the determination of H. pylori DNA sequence in milk samples with satisfactory results.

Upper gastrointestinal physiology and diseases

Nordic research on physiology and pathophysiology of the upper gastrointestinal tract has flourished during the last 50 years. Swedish surgeons and physiologists were in the frontline of research on the regulation of gastric acid secretion. This research finally led to the development of omeprazole, the first proton pump inhibitor. When Swedish physiologists developed methods allowing the assessment of acid secretion in isolated oxyntic glands and isolated parietal cells, the understanding of mechanisms by which gastric acid secretion is regulated took a great step forward. Similarly, in Trondheim, Norway, the acid producing isolated rat stomach model combined with a sensitive and specific method for determination of histamine made it possible to evaluate this regulation qualitatively as well as quantitatively. In Lund, Sweden, the identification of the enterochromaffin-like cell as the cell taking part in the regulation of acid secretion by producing and releasing histamine was of fundamental importance both physiologically and clinically. Jorpes and Mutt established a center at Karolinska Institutet in Stockholm for the purification of gastrointestinal hormones in the 1960s, and Danes followed up this work by excelling in the field of determination and assessment of biological role of gastrointestinal hormones. A Finnish group was for a long period in the forefront of research on gastritis, and the authors' own studies on the classification of gastric cancer and the role of gastrin in the development of gastric neoplasia are of importance. It can, accordingly, be concluded that Nordic researchers have been central in the research on area of the upper gastrointestinal physiology and diseases.

Impact of bacterial infections on aging and cancer: impairment of DNA repair and mitochondrial function of host cells

The commensal floras that inhabit the gastrointestinal tract play critical roles in immune responses, energy metabolism, and even cancer prevention. Pathogenic and out of place commensal bacteria, can however have detrimental effects on the host, by introducing genomic instability and mitochondrial dysfunction, which are hallmarks of both aging and cancer. Helicobacter pylori and Enterococcus faecalis are bacteria of the gastrointestinal tract that have been demonstrated to affect these two hallmarks. These, and other bacteria, have been shown to decrease the transcription and translation of essential DNA repair subunits of major DNA repair pathways and increase production of reactive oxygen species (ROS). Defects in DNA repair cause mutations and genomic instability and are found in several cancers as well as in progeroid syndromes. This review describes our contemporary view on how bacterial infections impact DNA repair and damage, and the consequence on the mitochondrial and nuclear genomes. We argue that in the gastrointestinal tract, these mechanisms can contribute to tumorigenesis as well as cellular aging of the digestive system.

Epidemiology of gastric cancer in the gangetic areas of west bengal

There is marked geographical variation in the distribution and incidence of stomach cancer. We tried here to describe the pattern of relationships of age, sex, religion distribution, symptom profile, histological subtypes and Helicobacter pylori (H. pylori) infection with gastric cancer in Gangetic West Bengal. This study was done over a period of five years (2006–2010). The patients residing in the Gangetic areas of West Bengal presenting with upper gastrointestinal symptoms underwent UGI endoscopy. Among gastric cancer patients, demographic characteristics, symptomatology, macroscopic and histologic lesions and H. pylori status were analyzed. At confidence level 95%, “Z” and “P” value were calculated to find significance. Among 23851 patients underwent UGI endoscopy, 14106 were males, 9745 females, 17889 Hindus and 5962 Muslims. Among 462 gastric cancer patients, Male : Female 2.7 : 1, Hindus : Muslim 3 : 1, abdominal pain, indigestion, and weight-loss were commonest presentations. Antrum was the commonest site whereas ulceroproliferative type was commonest type. H. pylori positivity was 80.89% in adenocarcinoma with statistically significant relation with intestinal type. In future, our target will be to modify risk factors; it will need further demographic studies and analysis, so that we can detect it earliest.

Socio-demographic and geographical factors in esophageal and gastric cancer mortality in Sweden

Background

Socio-demographic factors and area of residence might influence the development of esophageal and gastric cancer. Large-scale population-based research can determine the role of such factors.

Methods

This population-based cohort study included all Swedish residents aged 30–84 years in 1990–2007. Educational level, marital status, place of birth, and place of residence were evaluated with regard to mortality from esophageal or gastric cancer. Cox regression yielded hazard ratios (HR) with 95% confidence intervals (CI), adjusted for potential confounding.

Results

Among 84 920 565 person-years, 5125 and 12 230 deaths occurred from esophageal cancer and gastric cancer, respectively. Higher educational level decreased the HR of esophageal cancer (HR = 0.61, 95%CI 0.42–0.90 in women, HR = 0.71, 95%CI 0.60–0.84 in men) and gastric cancer (HR = 0.80, 95%CI 0.63–1.03 in women, HR = 0.73, 95%CI 0.64–0.83 in men). Being unmarried increased HR of esophageal cancer (HR = 1.64, 95%CI 1.35–1.99 in women, HR = 1.64, 95%CI 1.50–1.80 in men), but not of gastric cancer. Being born in low density populated areas increased HR of gastric cancer (HR = 1.23, 95%CI 1.10–1.38 in women, HR = 1.37, 95%CI 1.25–1.50 in men), while no strong association was found with esophageal cancer. Living in densely populated areas increased HR of esophageal cancer (HR = 1.31, 95%CI 1.14–1.50 in women, HR = 1.40, 95%CI 1.29–1.51 in men), but not of gastric cancer.

Conclusion

These socio-demographic inequalities in cancer mortality warrant efforts to investigate possible preventable mechanisms and to promote and support healthier lifestyles among deprived groups.

Association between Helicobacter pylori infection and pancreatic cancer development: a meta-analysis

BACKGROUND

Pancreatic cancer is one of the most troublesome malignancies with dismal prognosis. H. pylori has been recognized as a type I carcinogen. Several studies have evaluated the association between H. pylori infection and pancreatic cancer development, however, the conclusions are inconsistent.

METHODS

Literature search was carried out in PubMed, EMBASE, Cochrane Library and CNKI databases to identify eligible researches. We performed overall meta-analysis of all studies included and subgroup analysis based on regional distribution. Quality of the studies (assessed by Newcastle-Ottawa quality assessment scale for case-control studies) and CagA+ strains of H. pylori were taken into consideration, and we conducted additional analyses including high-quality researches and those concerning CagA+ H. pylori respectively.

RESULTS

9 studies involving 3033 subjects (1083 pancreatic cancer cases, 1950 controls) were included. Summary OR and 95%CI of the overall meta-analysis of all included studies were 1.47 and 1.22-1.77, pooled data of the 4 high-quality studies were OR 1.28, 95%CI 1.01-1.63. OR of the 5 studies examined CagA+ strains was 1.42, corresponding 95%CI was 0.79 to 2.57. Summary estimates of subgroup analysis based on regional distribution are as follows, Europe group: OR 1.56, 95%CI 1.15-2.10; East Asia group: OR 2.01, 95%CI 1.33-3.02; North America group: OR 1.17, 95%CI 0.87-1.58. There was not obvious heterogeneity across the 9 studies. No publication bias was detected.

CONCLUSION

H. pylori infection is significantly, albeit weakly, associated with pancreatic cancer development. The association is prominent in Europe and East Asia, but not in North America. CagA+ H. pylori strains appear not to be associated with pancreatic cancer. However, more studies, especially prospective studies, are needed to validate our results.

The relationship between Helicobacter pylori infection and the effects of chemotherapy in patients with advanced or metastatic gastric cancer

PURPOSE

Several reports have shown a better prognosis in gastric cancer patients who are positive for Helicobacter pylori (HP) infection compared with negative cases. However, there are currently no studies that investigate the relationship between HP infection and the effects of chemotherapy in gastric cancer patients. In this study, we report the relationship between HP infection and chemotherapy effects in patients with advanced or metastatic gastric cancer.

METHODS

Sixty-one patients with advanced or metastatic gastric cancer were enrolled in this study. Biopsies were conducted around the tumor site to determine HP status. Patients were then treated with combination 5-FU and cisplatin-based chemotherapy. And we compared chemotherapy response rate and overall survival rate between HP infection group and without HP infection group.

RESULTS

Twelve of 18 patients with HP infection (66.7 %) and 9 of 42 patients without HP infection (21.4 %) showed a partial response to chemotherapy (Chi square P = 0.001). Patients with HP infection had a median survival time of 13 months (95 % CI, 6.9-19.1 months), which was significantly longer than that of patients without HP infection (9 months; P = 0.027, log-rank test).

CONCLUSIONS

Patients with advanced or metastatic gastric cancer with concomitant HP infection had a better response to chemotherapy and had an improved overall prognosis compared with patients without HP infection. Further studies are warranted to confirm these findings.

Putative tumor metastasis-associated genes in human gastric cancer

Gastric cancer is one of the leading causes of cancer mortality and its malignancy, resulting from disseminated cancer cells of diffuse type, is clinically manifested as metastases to the liver and peritoneum. The aim of the present study was to identify putative tumor metastasis-associated genes in human gastric cancer cells of diffuse type. An MKN45 cell line constitutively expressing green fluorescent protein (MKN45-GFP) was established and selected using the Transwell® system for invasive sublines MKN45-GFP-4, MKN45-GFP-10 and MKN45-GFP-12. MKN45-GFP-10 and MKN45-GFP-12 are highly invasive compared to the others. The mRNA levels were measured with cDNA microarrays and correlated with their invasion abilities in these sublines. Many of the genes identified with a positive or negative correlation are associated with angiogenesis, cell cycle, cytoskeleton and cell motility, protease and cell adhesion, as well as cellular signal transduction. In particular, novel genes without known functions were also noted. RT-PCR and western blot analyses were applied to verify the expression of selective genes. Following orthotopical intraperitoneal implantation, MKN45-GFP-12 demonstrated significantly higher in vivo tumor malignancies than parental MKN45-GFP in ascites induction and liver -invasion in mice. We have identified putative gastric tumor metastasis-associated, as well as novel genes. These genes and their protein products are to be further explored for their functional roles associated with tumor metastasis. The molecular profiles of these identified genes, gene transcripts and proteins in the patient specimens are likely to be useful biomarkers for diagnostic, therapeutic and/or prognostics. Most importantly, they may be used as molecular targets for the discovery of antitumor drugs against human gastric cancer metastasis.

Spatial autocorrelation calculations of the nine malignant neoplasms in Taiwan in 2005-2009: a gender comparison study

Spatial analytical techniques and models are often used in epidemiology to identify spatial anomalies (hotspots) in disease regions. These analytical approaches can be used to identify not only the location of such hotspots, but also their spatial patterns. We used spatial autocorrelation methodologies, including Global Moran's I and Local Getis-Ord statistics, to describe and map spatial clusters and areas in which nine malignant neoplasms are situated in Taiwan. In addition, we used a logistic regression model to test the characteristics of similarity and dissimilarity between males and females and to formulate the common spatial risk. The mean found by local spatial autocorrelation analysis was used to identify spatial cluster patterns. We found a significant relationship between the leading malignant neoplasms and well-documented spatial risk factors. For instance, in Taiwan, the geographic distribution of clusters where oral cavity cancer in males is prevalent was closely correspond to the locations in central Taiwan with serious metal pollution. In females, clusters of oral cavity cancer were closely related with aboriginal townships in eastern Taiwan, where cigarette smoking, alcohol drinking, and betel nut chewing are commonplace. The difference between males and females in the spatial distributions was stark. Furthermore, areas with a high morbidity of gastric cancer were clustered in aboriginal townships where the occurrence of Helicobacter pylori is frequent. Our results revealed a similarity between both males and females in spatial pattern. Cluster mapping clarified the spatial aspects of both internal and external correlations for the nine malignant neoplasms. In addition, using a method of logistic regression also enabled us to find differentiation between gender-specific spatial patterns.

The effect of age and Helicobacter pylori infection on gastric epithelial cell kinetics

BACKGROUND

Helicobacter pylori infection is a known risk factor for gastric cancer. The aim of the study was to determine the effect of H. pylori and age on gastric epithelial cell kinetics.

METHODS

One hundred and fifty-seven patients (92 men, median age: 58.5 years, range: 18-85) who had undergone upper gastrointestinal endoscopy due to dyspeptic symptoms were enrolled into the study. Six antral biopsy samples were obtained for flow cytometric DNA analysis (expressed as proliferative index [PI], S+G2/M phase), presence of H. pylori (CLO-test, culture and histology), and histopathologic examination.

RESULTS

Eighty-four (53.5%) patients were H. pylori positive and 93.3% of patients had diploid pattern and 6.7% expressed aneuploid pattern. The mean PI was 4.8 ± 0.2 for the whole group studied. PI were 5.14 ± 0.33 and 4.26 ± 0.36 for H. pylori (+) and H. pylori (-) patients respectively (P = 0.017). When age groups were taken into account, PI was found higher in patients over 75 years of age (n = 14, PI = 6.66 ± 1.3) compared to patients under 35 years of age (n = 25, PI = 3.83 ± 0.41, P = 0.014). There was no correlation between histological changes and PI. H. pylori (P = 0.045) and age (P = 0.082) were independent factors for PI.

CONCLUSION

PI of gastric antral mucosa increases in patients with H. pylori infection. Although PI increases by age, H. pylori is the only factor that significantly and independently influences the rate of epithelial cell proliferation.

The Human Gastric Pathogen Helicobacter pylori and Its Association with Gastric Cancer and Ulcer Disease

With the momentous discovery in the 1980's that a bacterium, Helicobacter pylori, can cause peptic ulcer disease and gastric cancer, antibiotic therapies and prophylactic measures have been successful, only in part, in reducing the global burden of these diseases. To date, ~700,000 deaths worldwide are still attributable annually to gastric cancer alone. Here, we review H. pylori's contribution to the epidemiology and histopathology of both gastric cancer and peptic ulcer disease. Furthermore, we examine the host-pathogen relationship and H. pylori biology in context of these diseases, focusing on strain differences, virulence factors (CagA and VacA), immune activation and the challenges posed by resistance to existing therapies. We consider also the important role of host-genetic variants, for example, in inflammatory response genes, in determining infection outcome and the role of H. pylori in other pathologies—some accepted, for example, MALT lymphoma, and others more controversial, for example, idiopathic thrombocytic purpura. More recently, intriguing suggestions that H. pylori has protective effects in GERD and autoimmune diseases, such as asthma, have gained momentum. Therefore, we consider the basis for these suggestions and discuss the potential impact for future therapeutic rationales.

Prevention of Gastric Cancer: When is Treatment of Helicobacter Pylori Warranted?

Chronic gastritis induced by Helicobacter pylori (H. pylori) is the strongest known risk factor for adenocarcinoma of the distal stomach, yet the effects of bacterial eradication on carcinogenesis remain unclear. H. pylori isolates possess substantial genotypic diversity, which engenders differential host inflammatory responses that influence clinical outcome. H. pylori strains that possess the cag pathogenicity island and secrete a functional cytotoxin induce more severe gastric injury and further augment the risk for developing distal gastric cancer. Carcinogenesis is also influenced by host genetic diversity, particularly involving immune response genes such as interleukin-1ß and tumor necrosis factor-α. Human trials and anima studies have indicated that eradication of H. pylori prior to the development of atrophic gastritis offers the best chance for prevention of gastric cancer. However, although the timing of intervention influences the magnitude of suppression of premalignant and neoplastic lesions, bacterial eradication, even in longstanding infections, is of clear benefit to the host. It is important to gain insight into the pathogenesis of H. pylori-induced gastritis and adenocarcinoma not only to develop more effective treatments for gastric cancer, but also because it might serve as a paradigm for the role of chronic inflammation in the genesis of other malignancies that arise within the gastrointestinal tract.

Prevalence of Helicobacter pylori genotypes (vacA, cagA, cagE and virB11) in gastric cancer in Brazilian's patients: an association with histopathological parameters

PURPOSE

To investigate the frequency and the association of vacA alleles, cagA, cagE and virB11 genes of Helicobacter pylori from patients with gastric cancer, considering the clinic histopathological parameters.

METHODS

One hundred and one gastric adenocarcinoma tissues were assessed by PCR to detect H. pylori and vacA alleles, cagA, cagE and virB11.

RESULTS

The distribution of cases according to the presence of the genes studied showed that the group containing vacA s1m1, cagA, cagE and virB11 H. pylori genes was significantly more frequent, followed by the group with at least one marker on the right side and left of the island. They were also present in the early stages and were the most frequent in nearly all histopathological grades.

CONCLUSIONS

This study verified that vacAs1m1 and cag-PAI genes, cagA, cagE and virB11 are important H. pylori markers for gastric cancer development. Also, this study corroborates the importance of cagE and cagA together as cag-PAI marker.

Helicobacter pylori infection and gastric cardia cancer: systematic review and meta-analysis

OBJECTIVE

Helicobacter pylori infection is the most important risk factor for gastric cancer, but no association with cardia cancer has been recognized. However, a heterogeneous distribution of etiologically distinct types of cardia cancer may contribute to explain conflicting findings between studies in high- and low-risk settings. We aimed to quantify the association between H. pylori infection and gastric cardia cancer through meta-analysis, and to provide an explanation for the expected heterogeneity of results.

METHODS

We systematically reviewed published studies addressing the association between H. pylori infection and gastric cardia cancer (up to June 2009), and extracted relative risk (RR) estimates for the association with cardia and non-cardia cancers. Summary RR estimates and 95% confidence intervals (95% CI) were computed using random-effects models. Subgroup analyses were conducted, namely according to gastric cancer risk settings.

RESULTS

Thirty-four articles were considered for meta-analysis. For cardia cancer, summary RR was 1.08 (95% CI 0.83-1.40; I (2) = 52.8%), higher in high-risk (RR = 1.98; 95% CI 1.38-2.83; I (2) = 18.4%) than in low-risk settings (RR = 0.78; 95% CI 0.63-0.97; I (2) = 11.6%). For non-cardia cancer, RR estimates were similar in high- (RR = 3.02; 95% CI 1.92-4.74; I (2) = 90.7%) and low-risk settings (RR = 2.56; 95% CI 1.99-3.29; I (2) = 46.6%). These observations were consistent across different inclusion criteria and when accounting for the virulence of the infecting strains.

CONCLUSIONS

In high-risk settings, a positive association between H. pylori infection and gastric cancer was observed both for cardia and non-cardia cancers. The results support the hypothesis of a heterogeneous distribution of etiologically distinct types of cardia cancer.

The relationship between Helicobacter pylori genes cagE and virB11 and gastric cancer

BACKGROUND

The association between Helicobacter pylori gene diversity and gastric cancer has been poorly reported, although it is one of the important ways to explain the gastric pathogenesis. The aim of this study was to investigate the frequency of cagE and virB11 genes in H. pylori isolated from patients with gastric cancer and to analyze the histology profiles.

MATERIALS AND METHODS

The presence of H. pylori and subtypes (cagE and virB11) was detected by PCR from the genomic DNA of 101 patients who had been diagnosed with gastric cancer. The cases were grouped according to the presence/absence of the genes studied and were analyzed in relation to histopathological parameters.

RESULTS

H. pylori infection was detected in 94 out of 101 (93.1%) gastric carcinomas. The cases were categorized into the following groups: cagE+/virB11+, cagE+/virB11-, cagE-/virB11+, and cagE-/virB11-. Frequencies were: 50% (47/94) cagE+/virB11+, 3.2% (3/94) cagE+/virB11-, 10.6% (10/94) cagE-/virB11+, and 36.2% (34/94) cagE-/virB11-. Tumors in the gastric antrum were predominant. An exception was the cagE-/virB11- group, in which tumors had a tendency to be located in the gastric cardia; the majority of the cardia tumors (56% (14/25)) were in this group. Intestinal histology type was the most frequent, but the cagE+/virB11- group only had diffuse tumors. H. pyloricagE+/virB11+ occurred most frequently (except at stage III), and was present at all gastric cancer stages.

CONCLUSIONS

This study is the first to include a relevant number of gastric cancer cases with H. pylori infection, reporting the frequency and relationship of cagE and virB11 genes and the genesis of this tumor. The presence of these cag pathogenicity island genes shows that they are important factors for the pathogenesis and malignancy of gastric cancer related to H. pylori.

Characterization of the gastric cardia in volunteers from the general population. Type of mucosa, Helicobacter pylori infection, inflammation, mucosal proliferative activity, p53 and p21 expression, and relations to gastritis

The aim of this research was to characterize the mucosa of the gastric cardia in relation to infection with Helicobacter pylori and the occurrence of chronic gastritis in other parts of the stomach in a sample of the general population. In this study, 80 adult volunteers underwent esophagogastroscopy with biopsies from the gastric cardia, corpus, and antrum. Gastritis was classified according to the Sydney system. Chronic gastritis (cardia excepted) was diagnosed in 35 subjects, 30 with H. pylori infection. Epithelial proliferative activity (Ki-67), p53- and p21 expression were examined quantitatively with cell counting after immunohistochemical stainings. Esophagitis was diagnosed macroscopically. Fourty eight subjects had cardia-type and 32 corpus-type mucosa in the anatomical cardia. The prevalence of esophagitis (nine cases) did not differ between these groups. Carditis was more prevalent among subjects with cardia-type mucosa (73 vs. 28%, P < 0.0001). H. pylori was present in 48% of those with cardia-type and 25% of those with corpus-type mucosa (P = 0.06). Of the 44 subjects with carditis, 31 had H. pylori in this location. The group with H. pylori infection had significantly higher mucosal proliferative activity when compared to uninfected subjects. Among the subjects with H. pylori-associated carditis, more p53-positive epithelial cells were detected compared to both the non-infected group (P = 0.0004) and to subjects with non-H. pylori-associated carditis (P = 0.03). In subjects with cardia-type mucosa, and both carditis and gastritis, the degree of chronic inflammation was higher in the cardia compared to the corpus and antrum and the p53 expression was significantly higher in the cardia compared to the corpus, but similar to that in the antrum. The proliferative activity was significantly higher in the antrum compared to the cardia and corpus, respectively. In conclusion, H. pylori infection, carditis, and increased p53 expression are more common in subjects with cardia- than corpus-type mucosa in the gastric cardia. Carditis is mainly related to H. pylori infection. There are some differences regarding inflammation, proliferative activity, and p53 expression between the cardia and other regions of the stomach, yet the significance of these differences remains to be clarified.

A prospective study of Helicobacter pylori in relation to the risk for pancreatic cancer

BACKGROUND

The relationship between Helicobacter pylori infection and pancreatic cancer has been investigated in three previous studies with contradictory results. The aim of the present study was to investigate the association between H. pylori seropositivity and the risk for pancreatic cancer in a nested case-control study within a population based cohort.

METHODS

Selected birth-year cohorts (born 1921-1949) of residents in Malmö, Sweden, were invited to a health screening investigation. A total of 33 346 subjects participated. Cases with pancreatic cancer (n = 87) were matched to controls (n = 263) using age, sex and time for baseline investigation as matching variables. H. pylori serology was analysed in stored serum samples using an enzyme-linked immunosorbent assay. Odds ratios (OR) for pancreatic cancer were calculated with 95% confidence intervals (CI) using logistic regression.

RESULTS

H. pylori seropositivity was not associated with pancreatic cancer in the total cohort (adjusted OR 1.25 (0.75-2.09)). However, a statistically significant association was found in never smokers (OR 3.81 (1.06-13.63) adjusted for alcohol consumption) and a borderline statistically significant association was found in subjects with low alcohol consumption (OR 2.13 (0.97-4.69) adjusted for smoking).

CONCLUSION

We conclude that no association between H. pylori infection and the risk for pancreatic cancer was found in the total cohort. However, in never smokers and in subjects with low risk alcohol consumption, a positive H. pylori serology was associated with an increased risk for pancreatic cancer. These findings should be interpreted cautiously due to the limited number of cases in these subgroups.

p120 and Kaiso regulate Helicobacter pylori-induced expression of matrix metalloproteinase-7

Helicobacter pylori is the strongest known risk factor for gastric adenocarcinoma, yet only a fraction of infected persons develop cancer. One H. pylori constituent that augments disease risk is the cytotoxin-associated gene (cag) pathogenicity island, which encodes a secretion system that translocates bacterial effector molecules into host cells. Matrix metalloproteinase (MMP)-7, a member of a family of enzymes with tumor-initiating properties, is overexpressed in premalignant and malignant gastric lesions, and H. pylori cag(+) strains selectively increase MMP-7 protein levels in gastric epithelial cells in vitro and in vivo. We now report that H. pylori-mediated mmp-7 induction is transcriptionally regulated via aberrant activation of p120-catenin (p120), a component of adherens junctions. H. pylori increases mmp-7 mRNA levels in a cag- and p120-dependent manner and induces translocation of p120 to the nucleus in vitro and in a novel ex vivo gastric gland culture system. Nuclear translocation of p120 in response to H. pylori relieves Kaiso-mediated transcriptional repression of mmp-7, which is implicated in tumorigenesis. These results indicate that selective and coordinated induction of mmp-7 expression by H. pylori cag(+) isolates may explain in part the augmentation in gastric cancer risk associated with these strains.

H pylori (CagA) and Epstein-Barr virus infection in gastric carcinomas: Correlation with p53 mutation and c-Myc, Bcl-2 and Bax expression

AIM: To investigate the interrelationship between H pylori and Epstein-Barr virus (EBV) infection in the gastric carcinogenesis having in focus the p53 mutation and the c-Myc, Bcl-2 and Bax expression.

METHODS: seventy-one gastric carcinoma tissues were assessed by polymerase chain reaction (PCR) for H pylori and in situ hybridization for EBV. c-Myc, Bcl-2 and Bax expression were detected by immunohistochemistry and single-stranded conformational polymorphism (SSCP) for p53 mutation.

RESULTS: The positivity rates for H pylori and EBV were 94.4% and 8.45%, respectively. The majority of the cases displayed only the H pylori presence. All EBV positive cases were also H pylori positive. None infectious agent was observed in 5.55% of the cases. The intestinal type tumor was more frequent in the co-infected and non-infected groups. The female predominated in the non-infected group showing statistical significance (70.4% vs 29.6%, P = 0.039). The Bcl-2 was only detected in the group exclusively infected by H pylori. However, c-Myc and Bax were detected in the three groups but with a low frequency in the co-infected group. Mutation of p53 was present in all groups, with the highest frequencies in the H pylori positive groups.

CONCLUSION: The frequency of H pylori infection in gastric carcinomas was high. The presented data indicated that gastric carcinogenesis has different pathways depending of the presence of the two investigated infectious agents, suggesting a possible involvement of H pylori with apoptotic process. The low expression of c-Myc and Bax in the EBV-positive groups suggests that EBV may inhibit the expression of these proteins. Nevertheless, p53 mutation shows to be a relevant alteration, independent of both infectious agents.

Double-contrast upper gastrointestinal radiography: a pattern approach for diseases of the stomach

The double-contrast upper gastrointestinal series is a valuable diagnostic test for evaluating structural and functional abnormalities of the stomach. This article will review the normal radiographic anatomy of the stomach. The principles of analyzing double-contrast images will be discussed. A pattern approach for the diagnosis of gastric abnormalities will also be presented, focusing on abnormal mucosal patterns, depressed lesions, protruded lesions, thickened folds, and gastric narrowing.

Prevalence of Helicobacter pylori infection in advanced gastric carcinoma

BACKGROUND

[corrected] There is substantial evidence that infection with Helicobacter pylori plays a role in the development of gastric cancer and that it is rarely found in gastric biopsy of atrophic gastritis and gastric cancer. On advanced gastric tumors, the bacteria can be lost from the stomach.

AIMS

To analyze the hypothesis that the prevalence of H.pylori in operated advanced gastric carcinomas and adjacent non-tumor tissues is high, comparing intestinal and diffuse tumors according to Lauren's classification

METHODS

A prospective controlled study enrolled 56 patients from "Hospital Universitário", Federal University of Rio Grande do Norte, Natal, RN, Brazil, with advanced gastric cancer, treated from February 2000 to March 2003. Immediately after partial gastrectomy, the resected stomach was opened and several mucosal biopsy samples were taken from the gastric tumor and from the adjacent mucosa within 4 cm distance from the tumor margin. Tissue sections were stained with hematoxylin and eosin. Lauren's classification for gastric cancer was used, to analyse the prevalence of H. pylori in intestinal or diffuse carcinomas assessed by the urease rapid test, IgG by ELISA and Giemsa staining. H. pylori infected patients were treated with omeprazole, clarithromycin and amoxicillin for 7 days. Follow-up endoscopy and serology were performed 6 months after treatment to determine successful eradication of H. pylori in non-tumor tissue. Thereafter, follow-up endoscopies were scheduled annually. Chi-square and MacNemar tests with 0.05 significance were used.

RESULTS

Thirty-four tumors (60.7%) were intestinal-type and 22 (39.3%) diffuse type carcinomas. In adjacent non-tumor gastric mucosa, chronic gastritis were found in 53 cases (94.6%) and atrophic mucosa in 36 patients (64.3%). All the patients with atrophic mucosa were H. pylori positive. When examined by Giemsa and urease test, H. pylori positive rate in tumor tissue of intestinal type carcinomas was higher than that in diffuse carcinomas. In tumor tissues, 34 (60.7%) H. pylori-positive in gastric carcinomas were detected by Giemsa method. H. pylori was observed in 30 of 56 cases (53.5%) in tissues 4 cm adjacent to tumors. This difference was not significant. Eradication of H. pylori in non-tumor tissue of gastric remnant led to a complete negativity on the 12th postoperative month

CONCLUSIONS

The data confirmed the hypothesis of a high prevalence of H. pylori in tumor tissue of gastric advanced carcinomas and in adjacent non-tumor mucosa of operated stomachs. The presence of H. pylori was predominant in the intestinal-type carcinoma.

The decreasing burden of gastric cancer in Japan

Gastric cancer in Japan, previously the top killer cancer, has recently shown decreased incidence and mortality rates. Epidemiological studies have demonstrated that environmental factors are closely associated with stomach oncogenesis, as evident from the geographical differences seen throughout Japan in both incidence and mortality. Moreover, Japanese immigrant populations gradually exhibit the lower incidence and mortality rates of gastric cancer in their chosen country. Likewise, younger generations in Japan have lower mortality rates than older generations at the same age, which may be accounted by the dramatic lifestyle changes in Japan after World War II. In addition to exploring and learning from the impact of these environmental factors, deliberate strategies to further lower the incidence and mortality rates of gastric cancer must include aggressive eradication programs for Helicobacter pylori and dietary education in both school curricula and for the general adult population to lower the intake of causative agents such as salt and increase the intake of beneficial agents such as fruits, vegetables and seaweeds. The dietary education should be coupled with better motivation for the general population to undergo regular screening with improved techniques. In the future, changes in these environmental factors and progresses in the diagnosis of and therapeutic strategies for gastric cancer will lead to further decrease in the incidence and mortality rates of this disease in Japan.

Diet, H pylori infection and gastric cancer: evidence and controversies

Despite decreasing incidence and mortality rates, gastric cancer (GC) still remains the fourth most common cancer and the second most common cause of cancer-related deaths worldwide. Due to the limited treatment options, at present, prevention is likely to be the only effective means of controlling this disease. The success of a prevention strategy depends upon the understanding of etiological and pathogenic mechanisms underlying gastric carcinogenesis. The etiology of GC is multi-factorial, however, in the recent years, mounting evidence suggests that environmental factors play a key role. The most important environmental factors implicated in the pathogenesis of GC are diet and H pylori infection. Thus, modifications in lifestyle and dietary habit associated with eradication of H pylori infection could hypothetically represent the most promising potential targets for GC prevention. In this review we will address the evidence and the controversies on the role of these agents in non-cardia GC by focusing on retrospective and prospective observational studies and interventional trials.

Incidence of esophageal and gastric cancers among Hispanics, non-Hispanic whites and non-Hispanic blacks in the United States: subsite and histology differences

OBJECTIVE

We examined subsite- and histology-specific esophageal and gastric cancer incidence patterns among Hispanics/Latinos and compared them with non-Hispanic whites and non-Hispanic blacks.

METHODS

Data on newly diagnosed esophageal and gastric cancers for 1998-2002 were obtained from 37 population-based central cancer registries, representing 66% of the Hispanic population in the United States. Age-adjusted incidence rates (2000 US) were computed by race/ethnicity, sex, anatomic subsite, and histology. The differences in incidence rates between Hispanics and non-Hispanics were examined using the two-tailed z-statistic.

RESULTS

Squamous cell carcinoma accounted for 50% and 57% of esophageal cancers among Hispanic men and women, respectively, while adenocarcinoma accounted for 43% among Hispanic men and 35% among Hispanic women. The incidence rate of squamous cell carcinoma was 48% higher among Hispanic men (2.94 per 100,000) than non-Hispanic white men (1.99 per 100,000) but about 70% lower among Hispanics than non-Hispanic blacks, for both men and women. In contrast, the incidence rates of esophageal adenocarcinoma were lower among Hispanics than non-Hispanic whites (58% lower for men and 33% for women) but higher than non-Hispanic blacks (70% higher for men and 64% for women). Cardia adenocarcinoma accounted for 10-15% of gastric cancers among Hispanics, and the incidence rate among Hispanic men (2.42 per 100,000) was 33% lower than the rate of non-Hispanic white men (3.62 per 100,000) but 37% higher than that of non-Hispanic black men. The rate among Hispanic women (0.86 per 100,000), however, was 20% higher than that of non-Hispanic white women (0.72 per 100,000) and 51% higher than for non-Hispanic black women. Gastric non-cardia cancer accounted for approximately 50% of gastric cancers among Hispanics (8.32 per 100,000 for men and 4.90 per 100,000 for women), and the rates were almost two times higher than for non-Hispanic whites (2.95 per 100,000 for men and 1.72 per 100,000 for women) but about the same as the non-Hispanic blacks.

CONCLUSION

Subsite- and histology-specific incidence rates of esophageal and gastric cancers among Hispanics/Latinos differ from non-Hispanics. The incidence rates of gastric non-cardia cancer are almost two times higher among Hispanics than non-Hispanic whites, both men and women. The rates of gastric cardia cancer are lower among Hispanics than non-Hispanic whites for men but higher for women. The rates of esophageal and gastric cardia adenocarcinomas are higher among Hispanics than non-Hispanic blacks.

Green Tea Polyphenols Reduce Gastric Epithelial Cell Proliferation and Apoptosis Stimulated by Helicobacter pylori Infection

Recently the finding of gastric cancer in Helicobacter pylori (H. pylori)-infected mouse models was reported. Studies of humans and animal models have shown that H. pylori infection stimulates gastric epithelial cell proliferation and apoptosis. Polyphenols contained in green tea and related compounds were reported to have a variety anti-tumor effects and bactericidal properties. We studied the effect of green tea polyphenols on gastric cell proliferation and apoptosis in an H. pylori-infected mouse model. This model was prepared by inoculating Balb/c mice with 10(8) cfu of H. pylori (NCTC 11637 strain) by gavage. Beginning 18 weeks after inoculation, 0.5% polyphenols were given in drinking water every day for 2 weeks. Mice were sacrificed 1 h after bromodeoxyuridine (BrdU) was given i.p. for preparation of paraffin-embedded specimens. Cell proliferation and apoptosis were examined by the avidin-biotin complex method using anti-BrdU antibody and the TUNEL method, respectively. H. pylori infection resulted in increased BrdU-labeled cells in both the antrum and the bodies. Administration of polyphenols suppressed this increased proliferation. H. pylori infection increased apoptotic cells in both the antrum and the corpus in comparison with controls. This increase was not seen in H. pylori-infected mice given polyphenols. We conclude the administration with polyphenols might suppress gastric carcinogenesis that is in part related to H. pylori infection.

Helicobacter pylori and oesophageal and gastric cancers in a prospective study in China

In a cohort of 29,584 residents of Linxian, China, followed from 1985 to 2001, we conducted a case-cohort study of the magnitude of the association of Helicobacter pylori seropositivity with cancer risk in a random sample of 300 oesophageal squamous cell carcinomas, 600 gastric cardia adenocarcinomas, all 363 diagnosed gastric non-cardia adenocarcinomas, and a random sample of the entire cohort (N=1050). Baseline serum was evaluated for IgG antibodies to whole-cell and CagA H. pylori antigens by enzyme-linked immunosorbent assay. Risks of both gastric cardia and non-cardia cancers were increased in individuals exposed to H. pylori (Hazard ratios (HRs) and 95% confidence intervals=1.64; 1.26-2.14, and 1.60; 1.15-2.21, respectively), whereas risk of oesophageal squamous cell cancer was not affected (1.17; 0.88-1.57). For both cardia and non-cardia cancers, HRs were higher in younger individuals. With longer time between serum collection to cancer diagnosis, associations became stronger for cardia cancers but weaker for non-cardia cancers. CagA positivity did not modify these associations. The associations between H. pylori exposure and gastric cardia and non-cardia adenocarcinoma development were equally strong, in contrast to Western countries, perhaps due to the absence of Barrett's oesophagus and oesophageal adenocarcinomas in Linxian, making all cardia tumours of gastric origin, rather than a mixture of gastric and oesophageal malignancies.

Inflammation, atrophy, and gastric cancer

The association between chronic inflammation and cancer is now well established. This association has recently received renewed interest with the recognition that microbial pathogens can be responsible for the chronic inflammation observed in many cancers, particularly those originating in the gastrointestinal system. A prime example is Helicobacter pylori, which infects 50% of the world's population and is now known to be responsible for inducing chronic gastric inflammation that progresses to atrophy, metaplasia, dysplasia, and gastric cancer. This Review provides an overview of recent progress in elucidating the bacterial properties responsible for colonization of the stomach, persistence in the stomach, and triggering of inflammation, as well as the host factors that have a role in determining whether gastritis progresses to gastric cancer. We also discuss how the increased understanding of the relationship between inflammation and gastric cancer still leaves many questions unanswered regarding recommendations for prevention and treatment.

Opposing Risks of Gastric Cardia and Noncardia Gastric Adenocarcinomas Associated With Helicobacter pylori Seropositivity

BACKGROUND

Colonization with Helicobacter pylori is a risk factor for gastric adenocarcinoma, but the magnitude of this association and its relationship to anatomic location of the cancer, duration of follow-up, age at diagnosis, histologic subtype, and H. pylori strain differences are less clear. We conducted a prospective nested case-control study of H. pylori serology to address these questions.

METHODS

Case and control subjects were selected from the 29,133 50- to 69-year-old males recruited into the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. At baseline, detailed demographic data and a serum sample were collected. From 1985 to 1999, 243 incident cases of gastric adenocarcinoma were diagnosed in cohort members. Serum samples from 234 case subjects (173 with noncardia gastric cancers and 61 with gastric cardia cancers) and 234 age-matched control subjects were assayed for antibodies against H. pylori whole-cell and CagA antigens. We fit conditional logistic regression models to estimate the unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association of H. pylori seropositivity, defined as seropositivity to either whole-cell or CagA antigens, with noncardia gastric and gastric cardia cancers. All statistical tests were two-sided.

RESULTS

H. pylori seropositivity was strongly associated with the risk of noncardia gastric cancer (adjusted OR = 7.9, 95% CI = 3.0 to 20.9) but was inversely associated with the risk of gastric cardia cancer (adjusted OR = 0.31, 95% CI = 0.11 to 0.89). H. pylori seropositivity rates did not vary statistically significantly by length of follow-up, age at diagnosis, or histologic subtype. A calculation of rates showed that the absolute risks of noncardia gastric and cardia gastric adenocarcinomas in the H. pylori-positive participants of this cohort would be 63 and 12 per 100,000 person-years, respectively, whereas corresponding rates in H. pylori-negative participants would be 8 and 37 per 100,000 person-years, respectively.

CONCLUSION

H. pylori is a strong risk factor for noncardia gastric cancer but is inversely associated with the risk of gastric cardia cancer. These findings bolster the hypothesis that decreasing H. pylori prevalence during the past century may have contributed to lower rates of noncardia cancer and higher rates of cardia cancer in Western countries.

Plasma and dietary carotenoid, retinol and tocopherol levels and the risk of gastric adenocarcinomas in the European prospective investigation into cancer and nutrition

Despite declining incidence rates, gastric cancer (GC) is a major cause of death worldwide. Its aetiology may involve dietary antioxidant micronutrients such as carotenoids and tocopherols. The objective of this study was to determine the association of plasma levels of seven common carotenoids, their total plasma concentration, retinol and α- and γ-tocopherol, with the risk of gastric adenocarcinoma in a case–control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC), a large cohort involving 10 countries. A secondary objective was to determine the association of total sum of carotenoids, retinol and α-tocopherol on GCs by anatomical subsite (cardia/noncardia) and histological subtype (diffuse/intestinal). Analytes were measured by high-performance liquid chromatography in prediagnostic plasma from 244 GC cases and 645 controls matched by age, gender, study centre and date of blood donation. Conditional logistic regression models adjusted by body mass index, total energy intake, smoking and Helicobacter pylori infection status were used to estimate relative cancer risks. After an average 3.2 years of follow-up, a negative association with GC risk was observed in the highest vs the lowest quartiles of plasma β-cryptoxanthin (odds ratio (OR)=0.53, 95% confidence intervals (CI)=0.30–0.94, P_trend=0.006), zeaxanthin (OR=0.39, 95% CI=0.22–0.69, P_trend=0.005), retinol (OR=0.55, 95% CI=0.33–0.93, P_trend=0.005) and lipid-unadjusted α-tocopherol (OR=0.59, 95% CI=0.37–0.94, P_trend=0.022). For all analytes, no heterogeneity of risk estimates or significant associations were observed by anatomical subsite. In the diffuse histological subtype, an inverse association was observed with the highest vs lowest quartile of lipid-unadjusted α-tocopherol (OR=0.26, 95% CI=0.11–0.65, P_trend=0.003). These results show that higher plasma concentrations of some carotenoids, retinol and α-tocopherol are associated with reduced risk of GC.

Adenocarcinoma of the ileoanal pouch for ulcerative colitis--a complication of severe chronic atrophic pouchitis?

BACKGROUND

The appearance of a carcinoma in the ileal pouch after restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative proctocolitis is rare. Most of these adenocarcinomas previously described in literature develop from residual viable rectal mucosa. We report a case of an adenocarcinoma arising in all probability from the ileal pouch after malignant transformation of the ileal pouch mucosa based on a chronic atrophic pouchitis.

PATIENT AND METHODS

A 34-year-old man developed an adenocarcinoma after a double-stapled ileorectal J-pouch for ulcerative colitis (UC) proceeded from malignant ileal transformation. Before surgery, he had a 20-year history of UC refractory to medical therapy, but no occurrence of backwash ileitis, dysplasia or colitis-associated illness. He experienced severe pouchitis after IPAA since the ileostomy closure. Carcinoma was ensured by endoscopy, and the patient underwent an abdominoperineal pouch extirpation combined with excision of perirectal tissues and anal canal. Histology after surgery showed a pT4,pN2(4/16)pM0,G3 adenocarcinoma with global severe chronic atrophic pouchitis (CAP), villous atrophy and malignant ileal transformation. No metaplasia of the rectal mucosa was found, not even malignant epithelial transformation of the anal canal.

CONCLUSION

This case suggests that a malignant transformation of the ileal pouch mucosa may occur as a pure complication of severe CAP, even in the absence of backwash ileitis or a previous history of cancer. The absence of metaplasia of the rectal mucosa revealed the passage from CAP to dysplastic epithelium and to cancer. A multifactorial development of carcinogenesis is supposed, but we emphasize the importance of severe CAP, and that careful surveillance is needed in patients after IPAA. We must submit that this is just a case report and cannot stand for general cancer development in ulcerative colitis, but it may point out the risk factor of chronic inflammation and leads the surgeon to skillful working when building the pouch.

Correlation of Epstein-Barr virus and its encoded proteins with Helicobacter pylori and expression of c-met and c-myc in gastric carcinoma

AIM

To investigate the interrelationship of Epstein-Barr virus (EBV) and EBV- encoded proteins with Helicobacter pylori (H pylori) infection and the expression of c-met and c-myc oncogene proteins in gastric carcinoma, and to explore their role in gastric carcinogenesis.

METHODS

One hundred and eighty-five gastric carcinoma tissues were detected by polymerase chain reaction (PCR)-Southern blot for EBV genome and in situ hybridization (ISH) for EBV-encoded small RNA 1 (EBER1). Gastric carcinoma with positive EBER1 signals was confirmed EBV-associated gastric carcinoma (EBVaGC). The status of H pylori infection in 185 gastric carcinomas was assessed by rapid urease test and PCR. The samples with positive PCR and urease test were defined as H pylori infection. The expression of c-met and c-myc oncogene proteins in tissues of EBVaGC and matched EBV-negative gastric carcinoma (EBVnGC) were examined by immunohistochemistry. RT-PCR and Southern hybridization were used to detect the expression of nuclear antigens (EBNAs) 1 and 2, latent membrane protein (LMP) 1, early genes BARF1 and BHRF1 in EBVaGC cases.

RESULTS

The positive rate of H pylori and EBV in 185 gastric carcinomas was 59.45% (110/185) and 7.03% (13/185) respectively. No difference was found in sex, age, pathological differentiation, clinical stages and lymph node metastasis between H pylori-positive and H pylori-negative gastric carcinomas. However, the positive rate of H pylori infection in the antrum gastric carcinomas was higher than that of cardia and body gastric carcinomas. In our series, age, pathological differentiation, clinical stages, lymph node metastasis and location of cancer were not different between EBVnGC and EBVaGC, while the positive rate of EBV in male patients was significantly higher than that of female patients. The positivity of H pylori in EBV-associated and EBV-negative gastric carcinomas was 46.15% (6/13) and 81.40%(104/172) respectively. There was no significant correlation between EBV and H pylori infection. The c-met overexpression was significantly higher in the EBVaGC group than in the EBVnGC group. However, c-met and c-myc expression did not show significant difference between the two groups. Transcripts of EBNA1 were detected in all 13 EBVaGCs, while both EBNA2 and LMP1 mRNA were not detected. Six of the 13 cases exhibited BARF1 transcripts and 2 exhibited BHRF1 transcripts.

CONCLUSION

The positivity of H pylori in EBVnGCs is higher than that of EBVaGCs, but no significant correlation is found between EBV infection and H pylori infection. H pylori-positive gastric carcinoma is predominant in antrum location, while EBVaGC has a tendency of predominance in cardia/body location. EBV infection is associated with c-met abnormal expression but not with c-myc protein in EBVaGC. c-met overexpression is not induced by LMP1. BARF1 and BHRF1 may play important roles in the tumorigenesis of EBVaGC through different pathways.

Hormone replacement therapy and risks of oesophageal and gastric adenocarcinomas

Oesophageal and gastric adenocarcinoma share an unexplained male predominance, which would be explained by the hypothesis that oestrogens are protective in this respect. We carried out a nested case–control study of hormone replacement therapy (HRT) among 299 women with oesophageal cancer, 313 with gastric cancer, and 3191 randomly selected control women, frequency matched by age and calendar year in the General Practitioners Research Database in the United Kingdom. Data were adjusted for age, calendar year, tobacco smoking, alcohol consumption, body mass index, hysterectomy, and upper gastrointestinal disorders. Among 1 619 563 person-years of follow-up, more than 50% reduced risk of gastric adenocarcinoma was found among users of HRT compared to nonusers (odds ratio (OR), 0.48, 95% confidence interval (CI) 0.29–0.79). This inverse association appeared to be stronger for gastric noncardia (OR 0.34, 95% CI 0.14–0.78) and weaker for gastric cardia tumours (OR 0.68, 95% CI 0.23–2.01). There was no association between HRT and oesophageal adenocarcinoma (OR 1.17, 95% CI 0.41–3.32).

HLA-DQB1 locus and gastric cancer in Helicobacter pylori infection

BACKGROUND AND AIMS

It has been suggested that the incidence of digestive diseases associated with Helicobacter pylori is influenced by the strain diversity of H. pylori, factors involving the host or environment, and the duration of infection. The authors have previously reported that human leukocyte antigen (HLA)-DQB1*0401 plays an important role in the development of atrophic gastritis in H. pylori infected patients. The aim of the present study was to investigate the relationship between HLA-DQB1 genotype and cancer development.

METHODS

HLA-DQB1 genotyping was performed by the PCR-RFLP method on 122 H. pylori-infected non-ulcer dyspepsia (NUD) patients, 53 gastric cancer patients and 28 uninfected controls. To reliably estimate the grade of atrophic gastritis, histological evaluation was performed.

RESULTS

The allele frequency of DQB1*0401 was significantly higher in intestinal type cancer patients compared with age- and sex-matched H. pylori-infected NUD patients. There was no significant difference in the mean atrophic scores of the biopsy samples from the lesser curvature of the mid-corpus between these groups.

CONCLUSIONS

HLA-DQB1*0401 is a useful marker for determining susceptibility to intestinal type gastric cancer.

The association between the interleukin-1 polymorphisms and gastric cancer risk depends on the family history of gastric carcinoma in the study population

OBJECTIVES

The association between interleukin-1 polymorphisms, H. pylori and increased gastric cancer risk remains controversial.

AIMS

To compare the prevalence of these polymorphisms in individuals with two mutually exclusive diseases connected with infection, gastric cancer, and duodenal ulcer.

METHODS

121 gastric cancer and 119 duodenal ulcer patients. Genomic DNA was typed for polymorphisms at position -511, -31 in the interleukin-1beta gene (IL-1 beta) using primer extension and mass-spectrometry. Analysis of the variable number of tandem repeats in intron 2, in its receptor antagonist gene (IL-1RN) was performed by PCR and agarose gel electrophoresis.

RESULTS

All subjects were successfully genotyped for the three gene loci. IL-1 beta-511 was found to be in reverse linkage disequilibrium with IL-1 beta-31. The differences between gastric cancer and duodenal ulcer patients concerned only heterozygous variant of IL-1beta and were related to family history of gastric cancer, tumor stage, histology, site. Thus, CT carriers were found to have a higher risk of sporadic [OR 2.21 (95% CI, 1.22-3.99)], early [OR 2.81 (95% CI, 1.14-6.93)], diffuse [OR 2.48, (95% CI 1.21-5.09)] or non-cardia gastric cancer [OR 1.88 (95% CI 1.06-3.33)]. Furthermore, CT genotype was significantly more prevalent in gastric cancer patients with negative than in those with a positive family history (p = 0.039).

CONCLUSIONS

The association between the interleukin-1 polymorphisms and gastric cancer risk depends on the family history of gastric carcinoma in the study population. This phenomenon may be in part responsible for differences in results of interleukin-1 studies performed on populations with low and high gastric cancer prevalence.

Epidemiology of gastric cancer

The incidence and mortality of gastric cancer have fallen dramatically in US and elsewhere over the past several decades. Nonetheless, gastric cancer remains a major public health issue as the fourth most common cancer and the second leading cause of cancer death worldwide. Demographic trends differ by tumor location and histology. While there has been a marked decline in distal, intestinal type gastric cancers, the incidence of proximal, diffuse type adenocarcinomas of the gastric cardia has been increasing, particularly in the Western countries. Incidence by tumor sub-site also varies widely based on geographic location, race, and socio-economic status. Distal gastric cancer predominates in developing countries, among blacks, and in lower socio-economic groups, whereas proximal tumors are more common in developed countries, among whites, and in higher socio-economic classes. Diverging trends in the incidence of gastric cancer by tumor location suggest that they may represent two diseases with different etiologies. The main risk factors for distal gastric cancer include Helicobacter pylori (H pylori) infection and dietary factors, whereas gastroesophageal reflux disease and obesity play important roles in the development of proximal stomach cancer. The purpose of this review is to examine the epidemiology and risk factors of gastric cancer, and to discuss strategies for primary prevention.

Gastritis from NSAIDS to Helicobacter pylori

Gastritis is a histologic diagnosis. To understand gastritis, the radiologist must have some working knowledge of gastric histology and pathology. Therefore, this article first describes normal histologic and radiologic anatomy. The pathology of gastritis is then presented to give the radiologist a basis for understanding the radiologic findings. Finally, gastritis is discussed from a clinical and radiologic perspective.

Helicobacter pylori-stimulated interleukin-8 (IL-8) promotes cell proliferation through transactivation of epidermal growth factor receptor (EGFR) by disintegrin and metalloproteinase (ADAM) activation

Helicobacter pylori infection increases the risk of hyperplastic polyps and gastric cancer, but the mechanisms remain to be elucidated. H. pylori was recently shown to transactivate epidermal growth factor receptor (EGFR) through metalloprotease stimulation. The present study was designed to investigate the effect of interleukin-8 (IL-8) induced by H. pylori infection on EGFR transactivation and epithelial cell growth. H. pylori Sydney strain 1 (SS1) having wild-type cag(+)A was used. Phospho-EGFR assay was performed by immunoprecipitation using anti-human EGFR and anti-phosphotyrosine antibodies. DNA synthesis was evaluated by [3H]thymidine uptake using the human gastric cancer cell line, KATO III. H. pylori induced EGFR phosphorylation, and a disintegrin and metalloproteinase (ADAM) inhibitor, KB-R7785, completely suppressed EGFR phosphorylation. IL-8 also induced EGFR phosphorylation, while anti-IL-8 and anti-IL-8 receptor (CXCR1) neutralizing antibodies suppressed EGFR phosphorylation. [(3)H]Thymidine uptake analysis demonstrated that H. pylori increased DNA synthesis in gastric epithelial cells, and tyrosine kinase inhibitor, MEK inhibitor, and ADAM inhibitor suppressed the DNA synthesis induced by H. pylori. H. pylori-stimulated IL-8 accelerates processing of EGFR ligands through ADAM activation, and cleaved EGFR ligands bind and stimulate EGFR in paracrine and autocrine manners to induce cell proliferation. This may be one of the mechanisms of hyperplastic polyp and gastric cancer development in H. pylori-infected gastric mucosa.

Prevalence of Helicobacter pylori infection, endoscopic gastric findings and dyspeptic symptoms among a young Japanese population born in the 1970s

BACKGROUND

With the prevalence of Helicobacter pylori (H. pylori) infection rapidly decreasing in Japan, endoscopic findings and dyspeptic symptoms need to be re-evaluated.

METHODS

In a health check-up program, endoscopy was performed on 530 young Japanese subjects (371 men and 159 women) born in the 1970s. Helicobacter pylori infection was evaluated using serology and a rapid urease test. Endoscopic gastritis was classified according to the Sydney classification system, in addition to nodular gastritis. Dyspeptic symptoms were also recorded before endoscopy.

RESULTS

Of the 530 subjects, 87 (16.4%) were H. pylori positive. Of the 443 H. pylori-negative subjects, 349 (78.8%) were considered to have endoscopically normal gastric mucosa. However, of the 87 H. pylori-positive subjects, only 19 (21.8%) tested normal (P < 0.001). The prevalence of several types of gastritis was significantly higher in H. pylori-positive subjects compared with H. pylori-negative subjects: atrophic gastritis (37.9% vs 1.1%, P < 0.001), flat erosive gastritis (29.9% vs 7.2%, P < 0.001), rugal hyperplastic gastritis (12.6% vs 0.0%, P < 0.001), and nodular gastritis (13.8% vs 0.0%, P < 0.001). Other types of gastritis were not related to H. pylori status. The prevalence of subjects with dyspeptic symptoms was significantly higher in H. pylori-positive subjects compared with H. pylori-negative ones (28.7% vs 6.5%, P < 0.001).

CONCLUSION

It is suggested that in consideration of its recent low prevalence and the slow increase in its infection, the prevalence of H. pylori-related gastritis will gradually decrease in Japan. Further studies will be required to ascertain if there is a need for H. pylori eradication in this young population.