The gastric precancerous cascade

Infection with CagA-positive Helicobacter pylori strain containing three EPIYA C phosphorylation sites is associated with more severe gastric lesions in experimentally infected Mongolian gerbils (Meriones unguiculatus)

Infection with Helicobacter pylori strains containing high number of EPIYA-C phosphorylation sites in the CagA is associated with significant gastritis and increased risk of developing pre-malignant gastric lesions and gastric carcinoma. However, these findings have not been reproduced in animal models yet. Therefore, we investigated the effect on the gastric mucosa of Mongolian gerbil (Meriones unguiculatus) infected with CagA-positive H. pylori strains exhibiting one or three EPIYA-C phosphorilation sites. Mongolian gerbils were inoculated with H. pylori clonal isolates containing one or three EPIYA-C phosphorylation sites. Control group was composed by uninfected animals challenged with Brucella broth alone. Gastric fragments were evaluated by the modified Sydney System and digital morphometry. Clonal relatedness between the isolates was considered by the identical RAPD-PCR profiles and sequencing of five housekeeping genes, vacA i/d region and of oipA. The other virulence markers were present in both isolates (vacA s1i1d1m1, iceA2, and intact dupA). CagA of both isolates was translocated and phosphorylated in AGS cells. After 45 days of infection, there was a significant increase in the number of inflammatory cells and in the area of the lamina propria in the infected animals, notably in those infected by the CagA-positive strain with three EPIYA-C phosphorylation sites. After six months of infection, a high number of EPIYA-C phosphorylation sites was associated with progressive increase in the intensity of gastritis and in the area of the lamina propria. Atrophy, intestinal metaplasia, and dysplasia were also observed more frequently in animals infected with the CagA-positive isolate with three EPIYA-C sites.  We conclude that infection with H. pylori strain carrying a high number of CagA EPIYA-C phosphorylation sites is associated with more severe gastric lesions in an animal model of H. pylori infection.

Influence of prostate stem cell antigen gene polymorphisms on susceptibility to Helicobacter pylori-associated diseases: a case-control study

BACKGROUND

Patients with duodenal ulcer have a reduced risk of developing gastric cancer compared to those without. Recently, the prostate stem cell antigen (PSCA) rs2294008 C>T polymorphism was found to be associated with different pathogenesis of duodenal ulcer and gastric cancer developments. However, whether PSCA rs2294008 C>T polymorphism is associated with severity of gastric mucosal atrophy is unclear. We examined the influence of the PSCA rs2294008 C>T polymorphism on susceptibility to H. pylori-related diseases and the relationships between PSCA polymorphism and gastric mucosal atrophy.

METHODS

PSCA rs2294008 C>T polymorphism was assessed in H. pylori-positive Japanese patients (n = 488) with noncardia gastric cancer (n = 193), gastric ulcer (n = 84), duodenal ulcer (n = 61), and atrophic gastritis (n = 150), as well as in H. pylori-negatives (n = 266).

RESULTS

Frequency of PSCA rs2294008 C/C genotype in duodenal ulcer was 36.1%, which was significantly higher than those with gastric cancer (12.4%), gastric ulcer (19.0%), gastritis (10.7%), and H. pylori-negatives (19.5%) (p < .001). Compared with duodenal ulcer, having the T allele significantly increased the risk of gastric cancer (OR: 3.97, 95% CI: 2.02-7.80; p < .001), gastric ulcer (2.40, 1.13-5.10; p = .023), and gastritis (4.72, 2.26-9.86; p < .001). Mean pepsinogen (PG) I/PG II ratio in T allele carriers (2.17 ± 0.75) was significantly lower than that in C/C genotype (3.39 ± 1.27, p < .001).

CONCLUSIONS

The PSCA rs2294008 C>T polymorphism is associated with differing susceptibilities to H. pylori-associated diseases. The PSCA rs2294008 C>T polymorphism may be acting through induction of gastric mucosal atrophy, finally leading to development of gastric ulcer and gastric cancer in PSCA rs2294008 T allele carriers, but not duodenal ulcer.

Genomic single nucleotide polymorphisms in the offspring of gastric cancer patients predispose to spasmolytic polypeptide-expressing metaplasia after H. pylori infection

Background

Gastric cancer exhibits familial clustering, and gastric cancer familial relatives (GCF) tend to present with corpus-predominant gastritis and precancerous lesions as SPEM or IM after H. pylori infection. The study determined whether the children of gastric cancer patients (GCA) had genomic single nucleotide polymorphisms (SNPs) predisposed to the gastric precancerous lesions as spasmolytic polypeptide-expressing metaplasia (SPEM) or intestinal metaplasia (IM).

Results

There were 389 family relatives of 193 non-cardiac GCA and 173 duodenal ulcer patients (DU), received blood sampling for DNA collection. The differences of the risk alleles of SNPs in the ITGA5, ITGB1, IL-10, COX-2, RUNX3, and TFF2 genes were compared between 195 children of GCA and 143 DU. The children of GCA had higher allele frequencies of ITGA5-1160 T-carrier (P = 0.006, OR[95% CI] = 2.2[1.2-4]), ITGB1-1949 A-carrier (P = 0.047; OR[95% CI] = 2.8[1.4-5.3]), ITGB1 + 31804 C-carrier (P = 0.013; OR[95% CI] = 4.7[1.7-13.0]), IL-10-592 AA (P = 0.014; OR[95% CI] = 2.3[1.4-4.0]) and COX-2-1195 G-carrier (P = 0.019; OR[95% CI] = 1.7[0.9-3.2]) than DU. The combined genotype with ITGA5-1160/ITGB1-1949/ITGB1 + 31804 as T/A/C carriers and COX-2-1195/IL-10-592 as G-carrier/AA was more prevalent in the children of GCA than in DU (P < 1×10⁻⁴), and predisposed with a 5.3-fold risk of getting SPEM in the H. pylori-infected children of GCA (P = 0.016). Such risk of getting SPEM increased to 112 folds, if combined with RUNX3 + 492/TFF2-308 as A-carrier/CC in this limited study scale (P = 1×10⁻⁴).

Conclusions

The SNPs of ITGA5-1160/ITGB1-1949/ ITGB1 + 31804 as T/A/C carriers and COX-2-1195/IL-10-592 as G-carrier/AA, or more specific to combine RUNX3 + 492/TFF2-308 as A-carrier/CC shall be host factor predisposing to gastric cancer during H. pylori infection, and serve as marker to identify high-risk subjects for H. pylori eradication.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-015-0121-7) contains supplementary material, which is available to authorized users.

Differential expression of microRNAs in preneoplastic gastric mucosa

Gastric carcinogenesis is a multifactorial H.pylori-triggered dynamic process that goes through a cascade of preneoplastic conditions. The expression of miRNAs in the stomach with regard to preneoplastic precursor conditions and H.pylori infection has not been investigated systematically. In this prospective proof-of-principle study, we evaluated the miRNA expression in gastric antrum and corpus mucosa from patients with chronic non-atrophic gastritis (CNAG), atrophic gastritis (AG), and GC compared to controls. Gastric normal mucosa shows a unique expression pattern for miR-21, miR-155 and miR-223, which is specific for different regions. In correlation with progression of Correa's cascade and H.pylori infection, we observed a gradual increase in miR-155 and miR-223 both in corpus and antrum and miR-21 only in the antrum mucosa. Using miRNA expression we calculated a score that allowed us to discriminate patients with AG from subjects with normal mucosa with high diagnostic accuracy in testing and validation cohorts reproducibly. In summary, the expression pattern of miRNAs in the gastric mucosa is gradually increased with progression of Correa's cascade and H.pylori infection, suggesting miRNAs as potential biomarkers for preneoplastic precursor conditions. However, differences of miRNA expression between the gastric antrum and the corpus need to be considered in future studies.

Addition of all-trans-retinoic acid to omeprazole and sucralfate therapy improves the prognosis of gastric dysplasia

OBJECTIVE

To investigate the efficacy of all-trans retinoic acid (ATRA) in human gastric dysplasia.

METHODS

In this double-blind study, patients with precancerous gastric dysplasia with or without intestinal metaplasia (IM) received either conventional treatment consisting of omeprazole and sucralfate (control group) or conventional treatment plus ATRA. Gastric mucosal biopsies were performed before and after drug treatment and were analysed histologically; expression of retinoblastoma (Rb) protein and HER2 protein in gastric mucosa were measured using immunohistochemistry.

RESULTS

A total of 122 patients were included in the study, 63 in the ATRA group and 59 in the control group. In the ATRA group, dysplasia was attenuated in 43 out of 63 patients (68%) compared with 22 out of 59 patients (37%) in the control group; however, IM was not affected by treatment in either group. ATRA treatment was associated with significantly increased Rb expression and decreased HER2 expression in gastric mucosa.

CONCLUSIONS

The use of conventional therapy plus ATRA for gastric dysplasia was associated with improved efficacy compared with conventional therapy alone. It was also accompanied by increased Rb expression and decreased HER2 expression in gastric mucosa. The addition of ATRA to conventional therapy for gastritis may improve the prognosis of gastric dysplasia.

H. pylori infection, inflammation and gastric cancer

INTRODUCTION

A strong association between chronic infection, inflammation, and cancer has been suggested.

DISCUSSION

Helicobacter pylori, a microaerophilic gram negative bacterium, infects about half the world's population. It has been defined as a definitive carcinogen in the pathogenesis of gastric cancer. H. pylori evades the host immune responses and persists in the stomach leading to gastritis gastric atrophy and sometimes gastric cancer.

CONCLUSION

Chronic H. pylori infection causes gastric cancer via two mechanisms: the presence of virulence factors and the induction of chronic inflammation which ultimately leads to neoplastic transformation.

Gastric cancer review

Gastric cancer is an aggressive disease that continues to have a daunting impact on global health. Despite an overall decline in incidence over the last several decades, gastric cancer remains the fourth most common type of cancer and is the second leading cause of cancer-related death worldwide. This review aims to discuss the global distribution of the disease and the trend of decreasing incidence of disease, delineate the different pathologic subtypes and their immunohistochemical (IHC) staining patterns and molecular signatures and mutations, explore the role of the pathogen H. pylori in tumorgenesis, discuss the increasing incidence of the disease in the young, western populations and define the role of biologic agents in the treatment of the disease.

Human viruses and cancer

The first human tumor virus was discovered in the middle of the last century by Anthony Epstein, Bert Achong and Yvonne Barr in African pediatric patients with Burkitt's lymphoma. To date, seven viruses -EBV, KSHV, high-risk HPV, MCPV, HBV, HCV and HTLV1- have been consistently linked to different types of human cancer, and infections are estimated to account for up to 20% of all cancer cases worldwide. Viral oncogenic mechanisms generally include: generation of genomic instability, increase in the rate of cell proliferation, resistance to apoptosis, alterations in DNA repair mechanisms and cell polarity changes, which often coexist with evasion mechanisms of the antiviral immune response. Viral agents also indirectly contribute to the development of cancer mainly through immunosuppression or chronic inflammation, but also through chronic antigenic stimulation. There is also evidence that viruses can modulate the malignant properties of an established tumor. In the present work, causation criteria for viruses and cancer will be described, as well as the viral agents that comply with these criteria in human tumors, their epidemiological and biological characteristics, the molecular mechanisms by which they induce cellular transformation and their associated cancers.

Risk factors of atrophic gastritis and intestinal metaplasia in first-degree relatives of gastric cancer patients compared with age-sex matched controls

Background:

To identify whether first-degree relatives (FDRs) of gastric cancer (GC) patients have increased risk for atrophic gastritis (AG) and intestinal metaplasia (IM) in relation to other risk factors of GC.

Methods:

The study cohort consisted of 224 pairs of age-sex matched controls and FDRs. AG and IM in the gastric mucosa were scored histologically using the updated Sydney classification. Risk of having AG and IM was studied by comparing FDRs to controls. Impacts of age, H. pylori infection, smoking, dietary and socioeconomic factors on the presence of AG and IM were studied.

Results:

In multivariate regression analysis, FDRs had adjusted OR of 2.69 (95% CI 1.06–6.80, P=0.037) for antral IM in male population. Adjusted OR for antral AG and IM were 9.28 (95% CI 4.73–18.18, P<0.001) and 7.81 (95% CI 3.72–16.40, P<0.001) for the H. pylori infected subjects in total population. Getting old by 5 years increased the ORs of having AG and IM by approximately 1.25 fold (P<0.001). Spicy food increased the OR of antral IM by 2.28 fold (95% CI 1.36–3.84, P=0.002).

Conclusions:

Family history of GC was an independent risk factor for antral IM in male in our study, which could be one reason for the increase of gastric cancer in the family member of gastric cancer. It could be an evidence for the necessity of frequent endoscopy in the presence of family history of GC compared to general population in male.

Prediction of gastric cancer development by serum pepsinogen test and Helicobacter pylori seropositivity in Eastern Asians: a systematic review and meta-analysis

BACKGROUND

To identify high-risk groups for gastric cancer in presumptively healthy populations, several studies have investigated the predictive ability of the pepsinogen test, H. Pylori antibodies, and a risk-prediction model based on these two tests. To investigate whether these tests accurately predict gastric cancer development, we conducted a systematic review and meta-analysis.

METHODS

PubMed and other electronic databases were searched for cohort studies published in English or Japanese from January 1985 through December 2013. Six reviewers identified eligible studies, and at least two investigators extracted data on population and study-design characteristics, quality items, and outcomes of interest. Meta-analyses were performed on non-overlapping studies.

RESULTS

Nine prospective cohorts from Eastern Asia reported in 12 publications, including 33,741 asymptomatic middle-aged participants of gastric cancer screening, were eligible. For discriminating between asymptomatic adults at high and low risk of gastric cancer, the pepsinogen test (summary hazard ratio [HR], 3.5; 95% confidence interval [CI], 2.7-4.7; I2 = 0%) and H. pylori antibodies (summary HR, 3.2; 95% CI, 2.0-5.2; I2 = 0%) were statistically significant predictors as standalone tests. Although the risk-prediction model was in general moderately accurate in separating asymptomatic adults into four risk groups (summary c-statistic, 0.71; 95% CI: 0.68-0.73; I2 = 7%), calibration seemed to be poor. The study validity was generally limited.

CONCLUSIONS

The serum pepsinogen test, H. pylori antibodies, and the four-risk-group model for predicting gastric cancer development seem to have the potential to stratify middle-aged presumptively healthy adults. Future research needs to focus on comparative studies to evaluate the impact of screening programs adopting these tests. Also, validation, preferably with model updating, is necessary to see whether the current model performance is transferable to different populations.

At the bedside: Helicobacter pylori, dysregulated host responses, DNA damage, and gastric cancer

Clinical trials performed in populations at high GC risk have demonstrated that eradication of Helicobacter pylori from the stomach with a course of combination antimicrobials helps prevent gastric carcinogenesis when they are administered before precancerous lesions have yet developed. In this review, we consider the insights into H. pylori-associated gastric carcinogenesis that have been gained from these and many other clinical studies in the field to highlight priority areas for basic research and clinical investigation. Among these are defining the magnitude of the risk reduction that may be achieved in clinical practice and at a population level by H. pylori eradication and investigating when, during the slow multistep progression to GC, intervention will be of the most benefit. Additional strategies to prevent GC induced by H. pylori, including chemoprevention, dietary modification, and close endoscopic surveillance, may also have value in augmenting the risk reduction. Why only a small subpopulation of those infected by H. pylori go on to develop GC may be partially explained by genetic susceptibility related to SNPs in several genes regulating the intensity of the gastric inflammatory response to H. pylori. Investigation of the basic mechanisms underlying the promotion of GC by H. pylori and the associated inflammatory response will likely continue to improve clinical strategies for the prevention of one of the most common causes of cancer death globally. See related review, At the Bench: H. pylori, dysregulated host responses, DNA damage, and gastric cancer.

Effect of the -2081G/A polymorphism of the TLR4 gene and its interaction with Helicobacter pylori infection on the risk of gastric cancer in Chinese individuals

AIMS

Toll-like receptor 4 (TLR4) plays an important role in gastric carcinoma. Using a case-control study, we analyzed the genotypic distribution of TLR4 rs10983755 (-2081G/A) and rs11536878 in a Chinese population and investigated the effect of their interactions with Helicobacter pylori infection on susceptibility to gastric cancer (GC) and atrophic gastritis (AG).

METHODS

In this study, 409 and 581 cases of GC and AG, respectively, were selected for analyses along with an equal number of matched controls. The TLR4 polymorphisms were genotyped using Sequenom MassARRAY. Serum levels of anti-H. pylori IgG were determined by enzyme-linked immunosorbent assay.

RESULTS

The TLR4-2081G/A polymorphism was negatively associated with GC (AG+AA vs. GG: odds ratio [OR]=0.70, 95% confidence interval [CI]=0.53-0.93, p=0.012). A decreased risk of GC was observed in H. pylori negative and TLR4-2081(AG+AA) genotype subjects [H. pylori(-)/AG+AA vs. H. pylori(+)/GG: OR=0.16, 95% CI=0.09-0.27, p<0.001]. The rs11536878 polymorphism was not associated with GC or AG.

CONCLUSIONS

The TLR4-2081G/A polymorphism seems to affect the risk of gastric carcinogenesis and may to some degree play a protective role against H. pylori infection.

Temporal changes in serum biomarkers and risk for progression of gastric precancerous lesions: a longitudinal study

Effectively managing precancerous lesions is crucial to reducing the gastric cancer (GC) burden. We evaluated associations of temporal changes in multiple serological markers (pepsinogen I [PGI], PGII, PGI/II ratio, gastrin-17 and anti-Helicobacter pylori IgG) with risk for progression of gastric precancerous lesions. From 1997 to 2011, repeated esophagogastroduodenoscopies with gastric mucosal biopsies and blood sample collections were conducted on 2,039 participants (5,070 person-visits) in the Zhuanghe Gastric Diseases Screening Program, Liaoning, China. Serum biomarkers were measured using ELISA, and gastric biopsies were evaluated using standardized histologic criteria. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using generalized estimating equations for correlated binary outcomes. The ORs for progression of gastric conditions comparing those whose serum PGI, PGII, and anti-H. pylori IgG levels increased ≥ 50% relative to those whose decreased ≥ 50% were, respectively 1.67 (CI, 1.22-2.28), 1.80 (CI, 1.40-2.33) and 1.93 (CI, 1.48-2.52). The OR for those whose PGI/II ratio decreased ≥ 50% relative to those whose increased ≥ 50% was 1.40 (CI, 1.08-1.81), and for those whose PGII and anti-H. pylori IgG levels both increased ≥ 50% relative to those whose levels both decreased ≥ 50% the OR was 3.18 (CI, 2.05-4.93). Changes in gastrin-17 were not statistically significantly associated with progression. These findings suggest that temporal changes in serum PGI, PGII, PGI/II ratio, and anti-H. pylori IgG levels (especially PGII and anti-H. pylori IgG combined) may be useful for assessing and managing risk for progression of gastric precancerous lesions.

Helicobacter pylori infection: New pathogenetic and clinical aspects

Helicobacter pylori (H. pylori) infects more than half of the world’s human population, but only 1% to 3% of infected people consequently develop gastric adenocarcinomas. The clinical outcome of the infection is determined by host genetic predisposition, bacterial virulence factors, and environmental factors. The association between H. pylori infection and chronic active gastritis, peptic ulcer disease, gastric cell carcinoma, and B cell mucosa-associated lymphoid tissue lymphoma has been well established. With the exception of unexplained iron deficiency anemia and idiopathic thrombocytopenic purpura, H. pylori infection has no proven role in extraintestinal diseases. On the other hand, there is data showing that H. pylori infection could be beneficial for some human diseases. The unpredictability of the long-term consequences of H. pylori infection and the economic challenge in eradicating it is why identification of high-risk individuals is crucial.

Diagnostic capabilities of high-definition white light endoscopy for the diagnosis of gastric intestinal metaplasia and correlation with histologic and clinical data

OBJECTIVE

The aim of this study was the evaluation of the diagnostic accuracy of a specific high-definition white light endoscopy (HD-WLE) system for the optical recognition of intestinal metaplasia (IM) and the assessment of its correlation with histologic and clinical data.

METHODS

A total of 234 patients undergoing upper gastrointestinal endoscopy in an outpatient endoscopy suite for various indications were prospectively enrolled in this cross-sectional study. Gastric IM was diagnosed on the basis of three mucosal patterns identified using HD-WLE in a per-patient analysis. Histological evaluation was used as the gold standard, and special staining was conducted for subtyping of IM. Main outcome measurements were sensitivity, specificity, and likelihood ratio of HD-WLE and secondary associations with histologic and clinical data.

RESULTS

IM was found in 63/234 (27%) patients and low-grade dysplasia in 6/63 patients (9.5%). Sensitivity, specificity, accuracy, and likelihood ratio of all mucosal patterns were 74.6, 94, 88% and 13, respectively. All clinically significant type III IM and dysplasia lesions were endoscopically detected. All nonvisible lesions were of types I and II with mild grade and no dysplasia. Ten patients were considered false positives and the lesions were associated with severe inflammation and antralization.

CONCLUSION

The specific HD-WLE system showed satisfactory accuracy and high specificity during real-time, routine endoscopy practice. Specific mucosal patterns were correlated with level and grade of lesions. The sensitivity of the system is even higher when only clinically significant IM lesions are considered.

Helicobacter pylori associated chronic gastritis, clinical syndromes, precancerous lesions, and pathogenesis of gastric cancer development

Helicobacter pylori (H. pylori) infection is well known to be associated with the development of precancerous lesions such as chronic atrophic gastritis (AG), or gastric intestinal metaplasia (GIM), and cancer. Various molecular alterations are identified not only in gastric cancer (GC) but also in precancerous lesions. H. pylori treatment seems to improve AG and GIM, but still remains controversial. In contrast, many studies, including meta-analysis, show that H. pylori eradication reduces GC. Molecular markers detected by genetic and epigenetic alterations related to carcinogenesis reverse following H. pylori eradication. This indicates that these changes may be an important factor in the identification of high risk patients for cancer development. Patients who underwent endoscopic treatment of GC are at high risk for development of metachronous GC. A randomized controlled trial from Japan concluded that prophylactic eradication of H. pylori after endoscopic resection should be used to prevent the development of metachronous GC, but recent retrospective studies did not show the tendency. Patients with precancerous lesions (molecular alterations) that do not reverse after H. pylori treatment, represent the "point of no return" and may be at high risk for the development of GC. Therefore, earlier H. pylori eradication should be considered for preventing GC development prior to the appearance of precancerous lesions.

Helicobacter pylori eradication in the prevention of gastric cancer: are more trials needed?

The incidence of gastric cancer has decreased in much of the world, but gastric cancer remains the second leading cause of cancer death globally, and the burden is growing in many countries in East Asia and Latin America. Chronic infection with Helicobacter pylori is the dominant cause of gastric cancer, and two recent randomized trials showed that H. pylori eradication significantly decreased gastric cancer risk. Population screening and treating individuals for H. pylori also appears to be cost-effective. Nevertheless, current clinical guidelines differ as to whether asymptomatic adults should be screened and treated for H. pylori, and no countries have yet implemented eradication programs. Some of this inaction may reflect lingering doubts about the effectiveness of H. pylori eradication in preventing gastric cancer, but there is also uncertainty about possible risks of mass antibiotic treatment and its impact on gut flora. Appropriately designed studies will help address these issues and hasten the implementation of population-wide prevention programs.

Helminth co-infection in Helicobacter pylori infected INS-GAS mice attenuates gastric premalignant lesions of epithelial dysplasia and glandular atrophy and preserves colonization resistance of the stomach to lower bowel microbiota

Higher prevalence of helminth infections in Helicobacter pylori infected children was suggested to potentially lower the life-time risk for gastric adenocarcinoma. In rodent models, helminth co-infection does not reduce Helicobacter-induced inflammation but delays progression of pre-malignant gastric lesions. Because gastric cancer in INS-GAS mice is promoted by intestinal microflora, the impact of Heligmosomoides polygyrus co-infection on H. pylori-associated gastric lesions and microflora were evaluated. Male INS-GAS mice co-infected with H. pylori and H. polygyrus for 5 months were assessed for gastrointestinal lesions, inflammation-related mRNA expression, FoxP3(+) cells, epithelial proliferation, and gastric colonization with H. pylori and Altered Schaedler Flora. Despite similar gastric inflammation and high levels of proinflammatory mRNA, helminth co-infection increased FoxP3(+) cells in the corpus and reduced H. pylori-associated gastric atrophy (p < 0.04), dysplasia (p < 0.02) and prevented H. pylori-induced changes in the gastric flora (p < 0.05). This is the first evidence of helminth infection reducing H. pylori-induced gastric lesions while inhibiting changes in gastric flora, consistent with prior observations that gastric colonization with enteric microbiota accelerated gastric lesions in INS-GAS mice. Identifying how helminths reduce gastric premalignant lesions and impact bacterial colonization of the H. pylori infected stomach could lead to new treatment strategies to inhibit progression from chronic gastritis to cancer in humans.

Enhanced expression of activation-induced cytidine deaminase in human gastric mucosa infected by Helicobacter pylori and its decrease following eradication

BACKGROUND

Recent studies have shown important roles for activation-induced cytidine deaminase (AID), an intrinsic genome mutator, in H. pylori-associated gastric cancer development. Here, we evaluated the relationship between H. pylori-induced gastritis and AID expression from human biopsy specimens.

METHODS

In 109 patients with dyspeptic symptoms who had undergone endoscopy and received biopsy of the antrum, angulus, and corpus, H. pylori infection was diagnosed by serologic test, (13)C urea breath test, and histological examination. Histological scores of H. pylori, neutrophils, mononuclear cells, atrophy, and intestinal metaplasia (IM) were assessed using the updated Sydney system (USS). Immunohistochemical AID expression of the biopsy specimens was scored.

RESULTS

Sixty of 109 (55.0 %) patients were positive for H. pylori and eradication was successful in 48 patients. AID expression in H. pylori-infected mucosa was significantly higher (p < 0.01) than in non-infected mucosa. AID expression was highest in the antrum and was significantly (p < 0.01) reduced toward the proximal portion of the stomach. For USS, multivariate analysis using linear regression revealed that mononuclear cell infiltration (p < 0.01) and IM (p < 0.05) correlated independently with AID expression. After eradication of H. pylori, AID expression was significantly decreased (p < 0.01), but was still higher than that in H. pylori-negative patients in all sites of the stomach.

CONCLUSIONS

AID expression is elevated in H. pylori-positive patients and is reduced following H. pylori eradication. Moreover, AID expression is highest in the antrum and correlated with severity of chronic inflammation and IM, suggesting an important role for AID in gastric cancer development through gastritis.

Association between Helicobacter pylori and Barrett's esophagus: a case-control study

OBJECTIVES

The estimated association between Helicobacter pylori and Barrett's esophagus (BE) has been heterogenous across previous studies. In this study, we aimed to examine the association between H. pylori and BE and to identify factors that may explain or modify this association.

METHODS

We conducted a case-control study in which we used screening colonoscopy controls recruited from primary care clinics as our primary control group in order to minimize selection bias. All participants underwent an esophagogastroduodenoscopy with gastric mapping biopsies. We used logistic regression to obtain odds ratios (ORs) and 95% confidence intervals (CIs) to estimate the association between H. pylori and BE while controlling for confounders.

RESULTS

We identified 218 cases and 439 controls. The overall OR for the association between H. pylori and BE after controlling for age and white race was 0.55 (95% CI: 0.35-0.84). We observed an even stronger inverse association (OR: 0.28; 95% CI: 0.15, 0.50) among participants with corpus atrophy or antisecretory drug use ≥ 1 time per week (factors thought to lower gastric acidity), and no inverse association in patients without these factors (OR: 1.32; 95% CI: 0.66, 2.63).

CONCLUSIONS

The association between H. pylori and a decreased risk for BE appears to occur in patients with factors that would likely lower gastric acidity (corpus atrophy or taking antisecretory drugs at least once a week).

Gastric cancer: decreasing incidence but stable survival in the Netherlands

BACKGROUND

Gastric cardia and non-cardia cancer exhibit differences in biological and epidemiological features across the world. The aims of this study were to analyze trends in incidence, stage distribution, and survival over a 20-year period in the Netherlands, separately for both types of gastric cancer.

METHODS

Data on all patients with a diagnosis of gastric cancer in the period 1989-2008 were obtained from the nationwide Netherlands Cancer Registry. Time trends in incidence [analyzed as European Standard Rate per 100 000 (ESR)] and relative survival were separately analyzed for cardia and non-cardia gastric cancer.

RESULTS

A total of 47 295 patients were included. Incidence rates per 100 000 for cardia cancer declined from 5.7 to 4.3 for males and remained stable for females (1.2). For non-cardia cancer, the incidence in males declined from 25 to 14 and in females from 10 to 7. Proportional incidence in stage IV cardia and non-cardia cancer increased in 2004-2008 (cardia 32-42%, non-cardia 33-45%). Five-year survival rates for stage I-III and X (unknown) remained stable (cardia cancer: 20%, non-cardia gastric cancer: 31%). Five-year survival for stage IV disease was 1.9% and 1.0% for cardia and non-cardia gastric cancer.

CONCLUSION

The incidence of gastric cancer in the Netherlands markedly decreased over the past decades, in particular of non-cardia cancer. Survival remained dismal. Improvement of survival remains a challenge for the multidisciplinary team involved in gastric cancer treatment.

Study of risk factors for gastric cancer by populational databases analysis

AIM: To study the association between the incidence of gastric cancer and populational exposure to risk/protective factors through an analysis of international databases.

METHODS: Open-access global databases concerning the incidence of gastric cancer and its risk/protective factors were identified through an extensive search on the Web. As its distribution was neither normal nor symmetric, the cancer incidence of each country was categorized according to ranges of percentile distribution. The association of each risk/protective factor with exposure was measured between the extreme ranges of the incidence of gastric cancer (under the 25^th percentile and above the 75^th percentile) by the use of the Mann-Whitney test, considering a significance level of 0.05.

RESULTS: A variable amount of data omission was observed among all of the factors under study. A weak or nonexistent correlation between the incidence of gastric cancer and the study variables was shown by a visual analysis of scatterplot dispersion. In contrast, an analysis of categorized incidence revealed that the countries with the highest human development index (HDI) values had the highest rates of obesity in males and the highest consumption of alcohol, tobacco, fruits, vegetables and meat, which were associated with higher incidences of gastric cancer. There was no significant difference for the risk factors of obesity in females and fish consumption.

CONCLUSION: Higher HDI values, coupled with a higher prevalence of male obesity and a higher per capita consumption of alcohol, tobacco, fruits, vegetables and meat, are associated with a higher incidence of gastric cancer based on an analysis of populational global data.

Up-regulation of CLDN1 in gastric cancer is correlated with reduced survival

Background

The genetic changes in gastric adenocarcinoma are extremely complex and reliable tumor markers have not yet been identified. There are also remarkable geographical differences in the distribution of this disease. Our aim was to identify the most differentially regulated genes in 20 gastric adenocarcinomas from a Norwegian selection, compared to matched normal mucosa, and we have related our findings to prognosis, survival and chronic Helicobacter pylori infection.

Methods

Biopsies from gastric adenocarcinomas and adjacent normal gastric mucosa were obtained from 20 patients immediately following surgical resection of the tumor. Whole genome, cDNA microarray analysis was performed on the RNA isolated from the sample pairs to compare the gene expression profiles between the tumor against matched mucosa. The samples were microscopically examined to classify gastritis. The presence of H. pylori was examined using microscopy and immunohistochemistry.

Results

130 genes showed differential regulation above a predefined cut-off level. Interleukin-8 (IL-8) and Claudin-1 (CLDN1) were the most consistently up-regulated genes in the tumors. Very high CLDN1 expression in the tumor was identified as an independent and significant predictor gene of reduced post-operative survival. There were distinctly different expression profiles between the tumor group and the control mucosa group, and the histological subsets of mixed type, diffuse type and intestinal type cancer demonstrated further sub-clustering. Up-regulated genes were mapped to cell-adhesion, collagen-related processes and angiogenesis, whereas normal intestinal functions such as digestion and excretion were associated with down-regulated genes. We relate the current findings to our previous study on the gene response of gastric epithelial cells to H. pylori infection.

Conclusions

CLDN1 was highly up-regulated in gastric cancer, and CLDN1 expression was independently associated with a poor post-operative prognosis, and may have important prognostic value. IL-8 and CLDN1 may represent central links between the gene response seen in acute H. pylori infection of gastric epithelial cells, and ultimately gastric cancer.

Biomarkers of Helicobacter pylori-associated gastric cancer

Helicobacter pylori-associated gastric cancer is a major cause of morbidity and mortality worldwide, and is predicted to become even more common in developing countries as the population ages. Since gastric cancer develops slowly over years to decades, and typically progresses though a series of well-defined histologic stages, cancer biomarkers have potential to identify asymptomatic individuals in whom surgery might be curative, or even those for whom antibiotics to eradicate H. pylori could prevent neoplastic transformation. Here we describe some of the challenges of biomarker discovery, summarize current approaches to biomarkers of gastric cancer, and explore some recent novel strategies.

Echoes of a distant past: The cag pathogenicity island of Helicobacter pylori

This review discusses the multiple roles of the CagA protein encoded by the cag pathogenicity island of Helicobacter pylori and highlights the CagA degradation activities on p53. By subverting the p53 tumor suppressor pathway CagA induces a strong antiapoptotic effect. Helicobacter pylori infection has been always associated with an increased risk of gastric cancer. The pro-oncogenic functions of CagA also target the tumor suppressor ASPP2. In the absence of tumor suppressor genes, cells survive and proliferate at times and in places where their survival and proliferation are inappropriate.

Helicobacter pylori infection--a boon or a bane: lessons from studies in a low-prevalence population

Helicobacter pylori (H. pylori) infection is etiologically associated with gastric cancer and peptic ulcer diseases which are both important public health burdens which could be largely eliminated by H. pylori eradication. However, some investigators urge caution based on the hypothesis that eradication of H. pylori may result in an increase in the incidence of gastroesophageal reflux disease, esophageal adenocarcinoma, and childhood asthma. The ethnic Malays of northeastern Peninsular Malaysia have long had a low prevalence of H. pylori infection and, as expected, the incidence of gastric cancer and its precursor lesions is exceptionally low. The availability of a population with a low H. pylori prevalence and generally poor sanitation allows separation of H. pylori from the hygiene hypothesis and direct testing of whether absence of H. pylori is associated with untoward consequence. Contrary to predictions, in Malays, erosive esophagitis, Barrett's esophagus, distal esophageal cancers, and childhood asthma are all of low incidence. This suggests that H. pylori is not protective rather the presence of H. pylori infection is likely a surrogate for poor hygiene and not an important source of antigens involved in the hygiene hypothesis. Helicobacter pylori in Malays is related to transmission from H. pylori-infected non-Malay immigrants. The factors responsible for low H. pylori acquisition, transmission, and burden of H. pylori infection in Malays remain unclear and likely involves a combination of environmental, host (gene polymorphisms), and strain virulence factors. Based on evidence from this population, absence of H. pylori infection is more likely to be boon than a bane.

The Prevalence of Helicobacter pylori Infection Decreases with Older Age in Atrophic Gastritis

The clinical pathological characteristics of 3969 adult patients with chronic atrophic gastritis were retrospectively studied. The positivity of intestinal metaplasia and dysplasia in atrophic gastric specimens increased with age; however, H. pylori positivity and inflammatory activity decreased significantly with increased age. H. pylori infection was present in 21.01% of chronic atrophic gastritis patients, and 92.33% of the subjects with H. pylori infection were found to have simultaneous inflammatory activity. The intestinal metaplasia and dysplasia positivity markedly increased as the degree of gastric atrophy increased. In conclusion, the incidence of H. pylori infection decreased with age and correlated significantly with inflammatory activity in atrophic gastritis patients. The intestinal metaplasia and dysplasia positivity notably increased as the degree of gastric atrophy increased. Large population-based prospective studies are needed to better understand the progression of CAG.

The involvement of Helicobacter pylori thioredoxin-1 in gastric carcinogenesis

Helicobacter pylori infection is related to the development of gastric diseases. Various virulence factors are responsible for the pathogenic mechanisms of H. pylori infection. Our previous studies using two-dimensional gel electrophoresis showed that H. pylori thioredoxin-1 (Trx1) is overexpressed in gastric carcinomas. Here, we examined whether H. pylori Trx1 is a novel virulence factor associated with gastric tumorigenesis. We found that Trx1 expression in H. pylori isolated from gastric cancer tissues was significantly higher than that from tissues exhibiting gastritis. In the gastric epithelial cell line GES-1, infection of H. pylori with high Trx1 expression significantly induced cell apoptosis, decreased the expression of cyclin D1 and upregulated p21. However, in the gastric cancer cell line BGC823, high Trx1 expression in H. pylori significantly increased cell proliferation, and upregulated cyclin D1. The effects on cell lines were confirmed using the H. pylori Trx1-knockout mutant strain. Our observations indicate that high Trx1 expression in H. pylori is associated with gastric carcinogenesis. In H. pylori, Trx1 likely participates in the pathogenesis of gastric cancer and H. pylori expressing high levels of Trx1 would be expected to be highly pathogenic in gastric diseases in China.

Helicobacter pylori-Induced Chronic Gastritis and Assessing Risks for Gastric Cancer

Chronic gastritis is an inflammation of the gastric mucosa and has multiple etiologies. Here we discuss the pathological alterations induced by Helicobacter pylori (HP) leading to chronic gastritis and the epigenetic bases underlying these changes. We review the histology of the normal gastric mucosa and overview the role of HP in the multistep cascade of GC. We attempt to define the role of the Operative Link for Gastritis Assessment (OLGA) staging system in assessing the risk of GC. The epigenetic bases of chronic gastritis, mainly DNA methylation, are presented through examples such as (i) the methylation of the promoter region of E-cadherin in HP-induced chronic gastritis and its reversion after HP eradication and (ii) the association of methylation of the promoter region of Reprimo, a p53-mediated cell cycle arrest gene, with aggressive HP strains in high risk areas for GC. In addition, we discuss the finding of RPRM as a circulating cell-free DNA, offering the opportunity for noninvasive risk assessment of GC. Finally, the integration of OLGA and tissue biomarkers, by systems pathology approach, suggests that severe atrophy has a greater risk for GC development if, in addition, overexpressed p73. This trial is registered with ClinicalTrials.gov NCT01774266.

Gastric cáncer: Overview

Gastric cancer ranks fourth in incidence and second in mortality among all cancers worldwide. Despite the decrease in incidence in some regions of the world, gastric cancer continues to present a major clinical challenge due to most cases being diagnosed in advanced stages with poor prognosis and limited treatment options. The development of gastric cancer is a complex and multifactorial process involving a number of etiological factors and multiple genetic and epigenetic alterations. Among the predisposing factors are: Helicobacter pylori infection, high salt intake, smoking, and in a small percentage of patients, a familial genetic component. More than 95% of stomach cancer cases are adenocarcinomas, which are classified into two major histologic types: intestinal and diffuse. Intestinal type adenocarcinoma is preceded by a sequence of gastric lesions known as Correa´s cascade and is the histologic type associated with the global decrease in gastric cancer rates. Diffuse type adenocarcinomas have a more aggressive behavior and worse prognosis than those of the intestinal type. According to the anatomical location, adenocarcinomas are classified as proximal (originating in the cardia) and distal (originating in the body and antrum). This classification seems to recognize two different clinical entities. Surgical resection of the tumor at an early stage is the only effective treatment method. Therefore, the identification and surveillance of patients at risk may play a significant role in survival rates. Anti-Helicobacter pylori therapy has been shown to be an effective measure in the prevention of gastric cancer.

Gastric precancerous lesions are associated with gene variants in Helicobacter pylori-susceptible ethnic Malays

AIM: To identify genes associated with gastric precancerous lesions in Helicobacter pylori (H. pylori)-susceptible ethnic Malays.

METHODS: Twenty-three Malay subjects with H. pylori infection and gastric precancerous lesions identified during endoscopy were included as “cases”. Thirty-seven Malay subjects who were H. pylori negative and had no precancerous lesions were included as “controls”. Venous blood was collected for genotyping with Affymetrix 50K Xba1 kit. Genotypes with call rates < 90% for autosomal single nucleotide polymorphisms (SNPs) were excluded. For each precancerous lesion, associated SNPs were identified from Manhattan plots, and only SNPs with a χ²P value < 0.05 and Hardy Weinberg Equilibrium P value > 0.5 was considered as significant markers.

RESULTS: Of the 23 H. pylori-positive subjects recruited, one sample was excluded from further analysis due to a low genotyping call rate. Of the 22 H. pylori-positive samples, atrophic gastritis only was present in 50.0%, complete intestinal metaplasia was present in 18.25%, both incomplete intestinal metaplasia and dysplasia was present in 22.7%, and dysplasia only was present in 9.1%. SNPs rs9315542 (UFM1 gene), rs6878265 (THBS4 gene), rs1042194 (CYP2C19 gene) and rs10505799 (MGST1 gene) were significantly associated with atrophic gastritis, complete intestinal metaplasia, incomplete metaplasia with foci of dysplasia and dysplasia, respectively. Allele frequencies in “cases”vs“controls” for rs9315542, rs6878265, rs1042194 and rs10505799 were 0.4 vs 0.06, 0.6 vs 0.01, 0.6 vs 0.01 and 0.5 vs 0.02, respectively.

CONCLUSION: Genetic variants possibly related to gastric precancerous lesions in ethnic Malays susceptible to H. pylori infection were identified for testing in subsequent trials.

How long will it take to reduce gastric cancer incidence by eradicating Helicobacter pylori infection?

Helicobacter pylori (H. pylori) is the most important risk factor for the development of gastric cancer. The objective of this article is to estimate how the number of clinically diagnosed cases caused by H. pylori would reduce in the years after the eradication of the infection from a population. It is assumed that the eradication of H. pylori will prevent the start of some new gastric tumors, but those that have passed the "point of no return" will continue to develop until diagnosed clinically. The observed reduction in the number of clinically diagnosed cases of gastric cancer will depend on the form and parameters of the distribution of the time t taken for tumor to develop into a clinical case after passing the "point of no return." This analysis assumes that the time t follows normal and log-normal distributions with means 5, 10, and 15 years. If the mean value of time t were 5 years, H. pylori caused cases should be almost eliminated after 10 years, whereas if the mean were 10 years, the number of cases should be halved. If the mean were 15 years, the reduction would only be about 15% after 10 years. The eradication of H. pylori from a population will reduce the incidence of gastric cancer, but the follow-up time needed to show and evaluate the reduction may be longer than that that has been used in studies published so far.

The gastric fluid proteome as a potential source of gastric cancer biomarkers

Gastric cancer is a significant cause of death in many parts of the world. Although timely intervention is associated with better clinical outcome, early gastric cancer detection is frequently not possible given its asymptomatic nature. As such, sensitive and specific gastric cancer biomarkers are highly sought after as diagnostic surrogates that may replace invasive endoscopic and histological examinations. Unlike gastric cancer tissue and serum which are heterogeneous and overloaded with abundant proteins, the gastric fluid contains a concentrated molecular biopsy of the stomach that accurately reflects gastric oncology. This review attempts to (i) summarise the state of proteomics-based gastric cancer biomarker discovery from patient gastric fluids, (ii) outline key considerations in working with the body fluid, and (ii) discuss how the challenges in gastric cancer diagnosis may be overcome with new perspectives in gastric cancer screening.

The corpus-predominant gastritis index may serve as an early marker of Helicobacter pylori-infected patients at risk of gastric cancer

BACKGROUND

To eradicate Helicobacter pylori before the occurrence of precancerous changes is important to prevent gastric carcinogenesis.

AIM

To validate whether the corpus-predominant gastritis index (CGI) can serve as an early marker to identify the H. pylori-infected patients at risk of gastric carcinogenesis.

METHODS

This study enrolled 188 subjects, including 43 noncardiac gastric cancer patients, 63 of their first-degree relatives and 82 sex- and age-matched duodenal ulcer patients as controls. All received endoscopy to provide topographic gastric specimens to test for H. pylori infection and its related histological features, translated into the operative link on gastritis assessment (OLGA), operative link on gastric intestinal metaplasia assessment (OLGIM) stages, and the presence of CGI. Spasmolytic polypeptide-expressing metaplasia (SPEM) was assessed by immunohistochemistry staining of trefoil factor 2.

RESULTS

Gastric cancer patients had higher prevalence of CGI and OLGIM stage II-IV, but not OLGA stage II-IV, than the controls (P = 0.001, OR = 3.4[95% CI: 1.4-8.1] for CGI; OR = 5.0[95% CI: 2.0-12.8] for OLGIM). In patients with the combined presence of CGI and OLGIM stage II-IV, the risk of gastric cancer increased to 9.8 (P < 0.001). The first-degree relatives of the gastric cancer patients had a higher rate of the presence of CGI, but not OLGA or OLGIM stage II-IV than the duodenal ulcer controls (P = 0.001). Of the first-degree relatives, the presence of CGI increased the risk of SPEM (P = 0.003, OR = 5.5[95% CI: 1.8-17.0]).

CONCLUSION

The corpus-predominant gastritis index, which is highly correlated to SPEM, may serve as an early marker to identify the H. pylori-infected patients at a higher risk of gastric cancer.

Neutrophil-rich gastric carcinomas: light and electron microscopic study of 9 cases with particular reference to neutrophil apoptosis

The authors report 9 cases of gastric carcinomas characterized by a prominent neutrophilic infiltration of the stroma. These tumors (8 of intestinal type, 1 of diffuse type) showed a pushing growth pattern. Metastatic involvement of regional lymph nodes was seen in 5 cases. The metastatic foci were associated with heavy neutrophilia as well. There was no histologic evidence of Helicobacter pylori infection, whereas various degrees of multifocal intestinal metaplasia were present in the background mucosa. Based on histologic and histochemical results, there were no apparent causes due to other infectious agents responsible for the neutrophil-rich gastric carcinomas. Some of intraepithelial and stromal neutrophils exhibited apoptotic changes, such as chromatin condensation and cell shrinkage, and were TUNEL-positive. Electron microscopy disclosed apoptotic neutrophils in cytoplasmic vacuoles of tumor cells, a finding suggestive of neutrophil-tumor cell phagocytosis (cannibalism). Different stages of neutrophil apoptosis were also shown by electron microscopy and the ultrastructural findings were compared to those described in experimental models, both in vivo and in vitro.

[Gastric cancer risk estimate in patients with chronic gastritis associated with Helicobacter pylori infection in a clinical setting]

BACKGROUND/AIM

Severity of chronic gastritis associated with Helicobacter pylori infection (CGAHpI) could play a role in evaluating the potential risk to develop gastric cancer. Our aim was to estimate the risk for gastric cancer in a clinical setting, according to histopathologic criteria, by applying the gastric cancer risk index (GCRI) METHODS: Histopathologic study of the gastric biopsies (corpus-antrum) from consecutive adult patients that underwent gastroesophageal duodenoscopy was carried out, and the GCRI was applied in patients presenting with CGAHpI.

RESULTS

One hundred eleven patients (77% female) with a mean age of 38.6±13.1 years were included. Active Helicobacter pylori infection (aHpi) was diagnosed in 77 cases (69.40%). In 45% of the cases with aHpi, pangastritis (23%) or corpus-predominant gastritis (22%) was diagnosed. Nine cases were diagnosed with intestinal metaplasia (8%), 7 of which (77.70%) were in the aHpi group. Twenty one percent of the patients with aHpi had a GCRI of 2 (18.10%) or 3 (2.50%) points (high risk index), while 79.10% accumulated a GCRI of 0 or 1 points (low risk index). Of the patients with no aHpi, none of them had 3 points (p=0.001). Of the 18 patients that accumulated 2 or 3 points, 6 (33.30%) presented with intestinal metaplasia (all with pangastritis and corpus-predominant gastritis), of which 4 cases (66.60%) had aHpi.

CONCLUSIONS

The estimated gastric cancer risk in patients with CGAHpI in the clinical setting studied was relatively low and 5% of the patients had a histopathologic phenotype associated with an elevated risk for developing gastric cancer.

Undifferentiated early gastric cancer diagnosed as differentiated histology based on forceps biopsy

Histological diagnosis before endoscopic resection (ER) is important to determine whether ER should be performed; indeed, the use of ER for undifferentiated early gastric cancer (UD-EGC) remains controversial. The aim was to investigate the clinicopathological features of UD-EGC in ER specimens, diagnosed as differentiated histology based on biopsy. 289 patients with EGC were treated by ER. Among them, 13.1% were diagnosed as UD-EGC after ER, and 18.4% of them showed differentiated histology based on biopsy before ER. We analyzed UD-EGC with differentiated histology (D-group) compared to undifferentiated histology (UD-group) on biopsy. The D-group showed moderately differentiated adenocarcinoma on biopsy and poorly differentiated adenocarcinoma in ER specimens. The D-group was significantly associated with older age, intestinal metaplasia in the surrounding mucosa, and larger size than the UD-group. Gland portion of tumor, mixed-type Lauren classification, submucosal invasion, lymphovascular invasion, and perineural invasion were more common in the D-group than in the UD-group. The number of biopsies was not different between the groups. When comparing the histopathological mapping findings and endoscopic appearances of the D-group, the zone of transition from differentiated to undifferentiated histology was frequently found on one or two peripheral sides of the lesion. In conclusion, areas of EGC greater than 20mm with moderately differentiated histology on biopsy may contain an undifferentiated component. UD-EGC with differentiated histology on biopsy may show more aggressive behavior than UD-EGC, consistent with the biopsy pathology. Biopsy at several peripheral sides of the lesion may be helpful for diagnosis of UD histology before treatment.

Systematic review: gastric cancer incidence in pernicious anaemia

BACKGROUND

Pernicious anaemia (PA) has an increased risk for gastric cancer (GC). It is not established whether PA patients need to undergo endoscopic/histological follow-up.

AIM

To provide a systematic overview of the literature on PA and the development of gastric cancer, to estimate the gastric cancer incidence-rate.

METHODS

According to PRISMA, we identified studies on PA patients reporting the incidence of gastric cancer. Quality of studies was evaluated using the Newcastle-Ottawa Quality Assessment Scale. Meta-analysis on annual gastric cancer incidence rates was performed.

RESULTS

Twenty-seven studies met eligibility criteria. 7 studies were of high, 6 of medium, 10 of low and 4 of very low quality. Gastric cancer incidence-rates ranged from 0% to 0.2% per person-years in 7 American, from 0% to 0.5% in 2 Asiatic, from 0% to 1.2% in 11 Northern European studies and from 0% to 0.9% in 7 studies from other European countries. The incidence-rates of gastric cancer ranged from 0% to 1.2% per person-years in studies which used gastroscopy, from 0.1% to 0.9% in those based on International Classification of Disease. Heterogeneity between studies was not statistically significant at the 5% level (Chi-squared test = 17.9, P = 0.08). The calculated pooled gastric cancer incidence-rate was 0.27% per person-years. Meta-analysis showed overall gastric cancer relative risk in PA as 6.8 (95% CI: 2.6-18.1).

CONCLUSIONS

This systematic review shows a pooled gastric cancer incidence-rate in pernicious anaemia of 0.27% per person-years and an estimated nearly sevenfold relative risk of gastric cancer in pernicious anaemia patients. Further high quality studies are needed to confirm this higher risk.

Atrophic gastritis: Helicobacter pylori versus duodenogastric reflux

OBJECTIVES

The objective of this study was to asses the prevalence of atrophic gastritis in children. We also wanted to compare the clinical manifestation, endoscopic appearance and the degree of the gastric atrophy in children and to identify the possible causes which determine gastric atrophy.

METHODS

We evaluated 247 children with chronic gastritis (153 female/94 male, mean age 12.32 years). Atrophy was defined as the loss of normal glandular components, including replacement with fibrosis and/or intestinal metaplasia.

RESULTS

The prevalence of the atrophic gastritis was 16.6% (41 cases), mean age 11.59+/-1.75 years, male-to-female ratio 16:25. The clinical manifestations were correlated with the patient age (infants and toddlers were evaluated mostly for weight loss - 4 cases, and older children for abdominal pain - 22 cases). The endoscopic appearance was described as either nodular (15 cases), or erythematous gastritis (10 cases), or normal (10 cases). According to the Sydney System, the degree of atrophy was found to be mild in 3 patients, moderate in 25, and severe in 13 patients; 14 cases were associated with duodenogastric reflux, 5 with Helicobacter pylori and 2 with Helicobacter heilmannii infection, but in 17 cases the etiology was unknown.

CONCLUSIONS

Atrophic gastritis is present in childhood, even at very young ages (infants, toddlers). The endoscopic appearance is not characteristic for the presence of atrophy. The degree of the atrophy is not correlated with the age of the children. Because of the relatively high number of duodenogastric reflux associated with gastric atrophy, further studies need to evaluate the potential causes and clinical course.

Can the incidence of gastric cancer be reduced in the new century?

Gastric cancer (GC) is one of the most common cancers in the world. The incidence and mortality rate of GC vary among different countries. It is suggested that GC is the result of the interaction between Helicobacter pylori (H. pylori) infection and the genetic and environmental factors in the host. H. pylori infection is the trigger of intestinal gastric adenocarcinoma. The incidence of GC is highest in East Asia and East Europe, but much lower in Africa; however, H. pylori infection is commonly seen in Africa, which is known as the African enigma. The 5-year survival of early GC is far better than that of advanced GC. A high detection rate of early GC could help us to conquer GC. A decreasing trend of GC incidence has been witnessed worldwide. With the improvement of living conditions and the achievements of scientific research, it seems possible that there will be a further reduction in the incidence of GC in the new century.

Prescribing optimal nutrition and physical activity as "first-line" interventions for best practice management of chronic low-grade inflammation associated with osteoarthritis: evidence synthesis

Low-grade inflammation and oxidative stress underlie chronic osteoarthritis. Although best-practice guidelines for osteoarthritis emphasize self-management including weight control and exercise, the role of lifestyle behavior change to address chronic low-grade inflammation has not been a focus of first-line management. This paper synthesizes the literature that supports the idea in which the Western diet and inactivity are proinflammatory, whereas a plant-based diet and activity are anti-inflammatory, and that low-grade inflammation and oxidative stress underlying osteoarthritis often coexist with lifestyle-related risk factors and conditions. We provide evidence-informed recommendations on how lifestyle behavior change can be integrated into "first-line" osteoarthritis management through teamwork and targeted evidence-based interventions. Healthy living can be exploited to reduce inflammation, oxidative stress, and related pain and disability and improve patients' overall health. This approach aligns with evidence-based best practice and holds the promise of eliminating or reducing chronic low-grade inflammation, attenuating disease progression, reducing weight, maximizing health by minimizing a patient's risk or manifestations of other lifestyle-related conditions hallmarked by chronic low-grade inflammation, and reducing the need for medications and surgery. This approach provides an informed cost effective basis for prevention, potential reversal, and management of signs and symptoms of chronic osteoarthritis and has implications for research paradigms in osteoarthritis.

Proteomic profiling of paraffin-embedded samples identifies metaplasia-specific and early-stage gastric cancer biomarkers

Early diagnosis and curative resection are the predominant factors associated with increased survival in patients with gastric cancer. However, most gastric cancer cases are still diagnosed at later stages. Since most pathologic specimens are archived as FFPE samples, the ability to use them to generate expression profiles can greatly improve cancer biomarker discovery. We sought to uncover new biomarkers for stomach preneoplastic metaplasias and neoplastic lesions by generating proteome profiles using FFPE samples. We combined peptide isoelectric focusing and liquid chromatography-tandem mass spectrometry analysis to generate proteomic profiles from FFPE samples of intestinal-type gastric cancer, metaplasia, and normal mucosa. The expression patterns of selected proteins were analyzed by immunostaining first in single tissue sections from normal stomach, metaplasia, and gastric cancer and later in larger tissue array cohorts. We detected 60 proteins up-regulated and 87 proteins down-regulated during the progression from normal mucosa to metaplasia to gastric cancer. Two of the up-regulated proteins, LTF and DMBT1, were validated as specific markers for spasmolytic polypeptide-expressing metaplasia and intestinal metaplasia, respectively. In cancers, significantly lower levels of DMBT1 or LTF correlated with more advanced disease and worse prognosis. Thus, proteomic profiling using FFPE samples has led to the identification of two novel markers for stomach metaplasias and gastric cancer prognosis.

Early gastric cancer: an update on endoscopic management

PURPOSE OF REVIEW

The review focuses on the latest endoscopic techniques that are emerging in the management of early gastric cancer.

RECENT FINDINGS

Improved sensitivity and specificity in the diagnosis of early gastric cancers has been demonstrated in a number of studies by narrow band imaging (92.7 and 94.5%), confocal laser endomicroscopy (90.2 and 98.5%), and magnification chromoendoscopy (88.6 and 93.2%), respectively. In early gastric cancer, endoscopic submucosal dissection (ESD) has been shown to be superior to endoscopic mucosal resection (EMR) with curative resection rate at 79.5% for ESD vs. 59% for EMR, and a lower local recurrence rate at 0.82% for ESD vs. 5.03% for EMR.

SUMMARY

Advanced diagnostic and therapeutic endoscopic techniques are changing the paradigm of care in patients with early gastric cancers.