Host-Environment Interactions: Their Impact on Progression from Gastric Inflammation to Carcinogenesis and on Development of New Approaches to Prevent and Treat Gastric Cancer

Predicting response to immunotherapy in gastric cancer via assessing perineural invasion-mediated inflammation in tumor microenvironment

BACKGROUND

The perineural invasion (PNI)-mediated inflammation of the tumor microenvironment (TME) varies among gastric cancer (GC) patients and exhibits a close relationship with prognosis and immunotherapy. Assessing the neuroinflammation of TME is important in predicting the response to immunotherapy in GC patients.

METHODS

Fifteen independent cohorts were enrolled in this study. An inflammatory score was developed and validated in GC. Based on PNI-related prognostic inflammatory signatures, patients were divided into Clusters A and B using unsupervised clustering. The characteristics of clusters and the potential regulatory mechanism of key genes were verified by RT-PCR, western-blot, immunohistochemistry and immunofluorescence in cell and tumor tissue samples.The neuroinflammation infiltration (NII) scoring system was developed based on principal component analysis (PCA) and visualized in a nomogram together with other clinical characteristics.

RESULTS

Inflammatory scores were higher in GC patients with PNI compared with those without PNI (P < 0.001). NII.clusterB patients with PNI had abundant immune cell infiltration in the TME but worse prognosis compared with patients in the NII.clusterA patients with PNI and non-PNI subgroups. Higher immune checkpoint expression was noted in NII.clusterB-PNI. VCAM1 is a specific signature of NII.clusterB-PNI, which regulates PD-L1 expression by affecting the phosphorylation of STAT3 in GC cells. Patients with PNI and high NII scores may benefit from immunotherapy. Patients with low nomogram scores had a better prognosis than those with high nomogram scores.

CONCLUSIONS

Inflammation mediated by PNI is one of the results of tumor-nerve crosstalk, but its impact on the tumor immune microenvironment is complex. Assessing the inflammation features of PNI is a potential method in predicting the response of immunotherapy effectively.

Involvement of Helicobacter pylori in Preoperative Gastric Findings on a Bariatric Population

The prevalence of Helicobacter pylori (Hp) in bariatric patients is common and related to gastric pathology. With preoperative upper gastrointestinal endoscopy (UGE), these pathologies and the presence of Hp are diagnosed. The histopathological study of the UGE biopsies is classified based on the Sydney System, a scoring system that stages chronic gastritis (CG) and precancerous gastric lesions. The objective is to assess the histological findings of gastric biopsies during routine UGE and to determine the involvement of Hp in gastric disorders in patients undergoing bariatric surgery. A multicenter retrospective review of prospectively collected databases was performed. The presence of CG, gastric atrophy (GA), and gastric intestinal metaplasia (GIM) in the study of the biopsies was assessed and correlated with Hp infection. The incidence of Hp among our bariatric population was 36.1%, and it increases with age. The percentage of patients with severe Hp infection is higher in patients with GA or GIM. The Hp eradication rate is also reduced when GA and GIM are present. A histological examination of all the biopsies did not show features of malignancy in any of the cases. Hp is not the only factor involved in the development of gastric pathology in bariatric patients.

Polymorphisms of an oncogenic gene, mesothelin, predict the risk and prognosis of gastric cancer in a Chinese Han population

Mesothelin (MSLN) is a cell surface protein associated with tumor invasion and metastasis. This study aims to explore the biological function of MSLN in gastric cancer and to evaluate the association of MSLN polymorphism (rs3764247, rs3764246, rs12597489, rs1057147, rs3765319) with the risk and prognosis of gastric cancer. Small interfering RNA (siRNA) transfection and MSLN overexpression were performed in human gastric cancer cell lines, respectively. The proliferation of tumor cells was evaluated by Cell counting kit 8(CCK-8) and colony formation assay. Wound healing assay and transwell assay were used to elucidate gastric cancer cell migration and invasion rates. We conducted a case-control study involving 860 patients with gastric cancer and 870 controls. All mutation sites were genotyped by PCR-LDR sequencing. First, our study revealed the cancer-promoting role of MSLN in gastric cancer. Second, we also demonstrated that rs3764247 and rs3764246 were associated with a reduced risk of gastric cancer (OR = 0.83, p = 0.010; OR = 0.84, p = 0.011; respectively). The clinicopathological analysis further showed that rs3764247 was closely related to T stage, vascular infiltration, and HER2 expression. In addition, in the survival analysis of 392 patients with gastric cancer, patients with rs3764247 CC genotype had poorer survival than patients with AA + AC genotype after adjusting for age, sex, TNM stage, and Lauren classification (HR = 2.07, p = 0.029). Our findings indicated that MSLN could be an oncogene whose polymorphisms were closely related to the risk and prognosis of gastric cancer.

Diagnosis and Treatment of Helicobacter pylori Infection

The last 5 years have seen major shifts in defining whom to test and how to treat Helicobacter pylori infection. Peptic ulcer has changed from a chronic disease to a one-off condition, and countries with a high incidence of gastric cancer have begun implementing population-wide screening and treatment. A proactive approach to testing and treatment of H. pylori is now recommended, including outreach to family members of individuals diagnosed with active infection as well as high-risk local populations such as immigrants from high-risk countries. Increasing antimicrobial resistance has resulted in an overall decline in treatment success, causing a rethinking of the approach to development of treatment guidelines as well as the need to adopt the principles of antibiotic usage and antimicrobial stewardship. Required changes include abandoning empiric use of clarithromycin, metronidazole, and levofloxacin triple therapies. Here, we discuss these transformations and give guidance regarding testing and use of therapies that are effective when given empirically.

Genetic polymorphisms of Cathepsin B are associated with gastric cancer risk and prognosis in a Chinese population

BACKGROUND

Genetic polymorphisms are believed to represent a key aspect of predisposition to gastric cancer (GC). Therefore, considering the important role of Cathepsin B (CTSB) in promoting cancer onset and development, it could be very worthful to explore the function of CTSB-related genetic polymorphisms in GC.

OBJECTIVE

In this study, we investigated the correlation of CTSB-related polymorphisms (rs9009A>T, rs6731T>C, rs1293303G>C, rs1874547C>T, rs3779659C>T, rs17814426C>T and rs148669985C>T) with GC risk and prognosis in a case-control study of 994 cases and 1000 controls.

METHODS

All tag single nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction-ligase detection reaction (PCR-LDR) sequencing technology.

RESULTS

The results indicated rs9009, rs6731 and rs17814426 correlated with decreased risks of GC (HR = 0.97, p< 0.001; HR = 0.86, P= 0.019; HR = 0.85, P= 0.017; respectively). Stratification analysis further showed rs17814426 variant genotypes correlated with earlier T stage (p= 0.044). In addition, GC patients carrying the C allele of rs6371 had better overall prognosis (HR = 0.62, 95%CI = 0.44-0.88).

CONCLUSION

Our results firstly suggested the importance of CTSB-related polymorphisms on GC which could predict GC risk and prognosis.

NOD1 rs2075820 (p.E266K) polymorphism is associated with gastric cancer among individuals infected with cagPAI-positive H. pylori

Background

Helicobacter pylori is detected by pathogen recognition receptors including toll-like receptors (TLR) and nucleotide-binding oligomerization domain (NOD)-like receptors, eliciting an innate immune response against this bacteria. The aim of this study was to assess if polymorphisms of TLR2, TLR4, TLR5, NOD1 and NOD2 genes are associated with gastric cancer, in particular in individuals infected with H. pylori.

Results

A case-control study of 297 gastric cancer patients and 300 controls was performed to assess the association of 17 polymorphisms. Analyses performed under the allele model did not find association with gastric cancer. However, NOD1 rs2075820 (p.E266K) showed association with intestinal-type gastric cancer among H. pylori infected subjects (OR = 2.69, 95% CI 1.41–5.13, p = 0.0026). The association was not statistically significant in diffuse-type gastric cancer cases (OR = 1.26, 95% CI 0.63–2.52, p = 0.51). When the analyses were performed in patients carrying H. pylori strains harboring the cag pathogenicity island (cagPAI), we noticed significant association with NOD1 rs2075820 (OR = 4.90, 95% CI 1.80–3.36, p = 0.0019), in particular for intestinal-type gastric cancer cases (OR = 7.16, 95% CI 2.40–21.33, p = 4.1 × 10^− 4) but not among diffuse-type gastric cancer cases (OR = 3.39, 95% CI 1.13–0.10, p = 0.03).

Conclusions

NOD1 rs2075820 increases the risk of intestinal-type gastric cancer among individuals infected with H. pylori, particularly in those harboring the cagPAI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40659-021-00336-4.

SNP-SNP interactions of oncogenic long non-coding RNAs HOTAIR and HOTTIP on gastric cancer susceptibility

Genetic variants within oncogenic long non-coding RNAs HOTAIR and HOTTIP may affect their gene expression levels, thereby modifying genetic susceptibility to gastric cancer (GC). In a hospital-based study in Ardabil-a very high-risk area in North-West Iran, 600 blood samples from 300 GC patients and 300 healthy controls were recruited for genotyping. Seven HOTAIR (i.e., rs17720428, rs7958904, rs1899663, and rs4759314) and HOTTIP (i.e., rs3807598, rs17501292, and rs1859168) 'tag' single nucleotide polymorphisms (SNPs) were genotyped by the Infinium HTS platform. The rs17720428, rs7958904, and rs1899663 tagSNPs significantly increased GC risk under dominant models by 1.5-, 1.57-, and 1.5-fold, respectively. The G-C-T-A haplotype of HOTAIR tagSNPs increased the risk of GC by 1.31-fold. No significant association was found between HOTTIP SNPs and the risk of GC. HOTAIR and HOTTIP variants were also not associated with any clinicopathologic characteristics. The SNP-SNP interaction of HOTAIR rs17720428/rs7958904 with HOTTIP rs1859168 was associated with an increased risk of GC (rs17720428 TG-rs1859168 CC, OR = 1.76; rs7958904 GC-rs1859168 CC, OR = 1.85; rs7958904 CC-rs1859168 CC, OR = 1.86). Interestingly, the SNP-SNP interaction of HOTAIR rs1899663 with HOTTIP rs1859168 strongly increased the risk of GC (rs1899663 GT-rs1859168 CC, OR = 4.3; rs1899663 TT-rs1859168 CC, OR = 9.37; rs1899663 TT-rs1859168 CA, OR = 6.59). We showed that the HOTAIR rs17720428, rs7958904, and rs1899663 tagSNPs and their interactions with the HOTTIP rs1859168 polymorphism significantly increased the risk of GC. Specifically, novel SNP-SNP interactions between HOTAIR and HOTTIP tagSNPs have a larger impact than individual SNP effects on GC risk, thereby providing us with valuable information to reveal potential biological mechanisms for developing GC.

Impact of environmental factors on gastric cancer: A review of the scientific evidence, human prevention and adaptation

Globally, gastric cancer (GC) ranks fifth in prevalence and third in fatalities, and shows a distinct geographical distribution in morbidity and mortality. Such a spatial pattern indicates that environmental factors could be an important contributor to GC. We reviewed a total of 135 relevant peer-reviewed articles and other literature published 1936-2019 to investigate the scientific evidence concerning the effects of environmental factors on GC worldwide. Environmental factors affect GC from the aspects of water, soil, air, radiation, and geology. Risk factors identified include water type, water pollution, water hardness, soil type, soil pollution, soil element content, climate change, air pollution, radiation, altitude, latitude, topography, and lithology; and most of them have an adverse impact on GC. Furthermore, we found that their effects followed five common rules: (1) the leading environmental factors that affect GC incidence and mortality vary by region, (2) the same environmental factors may have different effects on GC in different regions, (3) some different environmental factors have similar effects on GC in essence, (4) different environmental factors often interact to have combined or synergistic effects on GC, and (5) environmental factors can affect human factors to have an impact on GC. Environmental factors have a great impact on GC. Human beings may prevent GC by controlling carcinogenic factors, screening high-risk populations and providing symptomatic and rehabilitative treatments. Furthermore, adaptation measures are recommended to reduce GC risk on private and public levels. Future studies should transcend existing empirical studies to develop causal relationship models and focus on vulnerable population analysis.

Nutritional neuropathies

Neuropathies associated with nutritional deficiencies are routinely encountered by the practicing neurologist. Although these neuropathies assume different patterns, most are length-dependent, sensory axonopathies. Cobalamin deficiency neuropathy is the exception, often presenting with a non-length-dependent sensory neuropathy. Patients with cobalamin and copper deficiency neuropathy characteristically have concomitant myelopathy, whereas vitamin E deficiency is uniquely associated with a spinocerebellar syndrome. In contrast to those nutrients for which deficiencies produce neuropathies, pyridoxine toxicity results in a non-length-dependent sensory neuronopathy. Deficiencies occur in the context of malnutrition, malabsorption, increased nutrient loss (such as with dialysis), autoimmune conditions such as pernicious anemia, and with certain drugs that inhibit nutrient absorption. When promptly identified, therapeutic nutrient supplementation may result in stabilization or improvement of these neuropathies.

Efficacy and Long-Term Safety of H. pylori Eradication for Gastric Cancer Prevention

Helicobacter pylori (H. pylori) has been shown to be a causal factor of gastric cancer in cohort studies and animal models. Meta-analysis of case-control studies nested within prospective cohorts showed that H. pylori infection was associated with a 5.9-fold increased risk of non-cardia gastric cancer. Prospective cohort studies showed that gastric cancer developed in 1–4% of H. pylori-infected subjects. Gastric cancer was successfully induced in Mongolian gerbils and insulin-gastrin (INS-GAS) transgenic mice after inoculation of H. pylori. Meta-analysis of randomized control trials also showed that eradication of H. pylori may reduce the risk of gastric cancer. However, there are several concerns regarding the widespread use of antibiotics to prevent gastric cancer, including the emergence of antibiotic resistance and the perturbation of gut microbiota after H. pylori eradication. Recent studies showed that eradication of H. pylori resulted in an increase in the bacterial diversity and restoration of the relative abundance of other bacteria to levels similar to H. pylori non-infected subjects in the gastric microbiota. The administration of antibiotics may also alter the composition of intestinal microbiota. The α-diversity and β-diversity of fecal microbiota are significantly altered immediately after H. pylori eradication but are gradually restored to levels similar to those before therapy. Yet, the rate of recovery varies with regimens. The diversity was restored at week 8 after triple therapy but was not yet fully recovered at 1 year after concomitant and quadruple therapies. Some studies showed that supplementation of probiotics may reduce the dysbiosis during H. pylori eradication therapy. Although some earlier studies showed high levels of macrolide resistance after triple therapy, recent studies showed that the increased antibiotic resistance rate may be restored 2–12 months after eradication therapy. These results collectively provide evidence of the long-term safety of H. pylori eradication. Yet, more prospective cohort studies and randomized trials are warranted to assess the efficacy and long-term safety of H. pylori eradication for gastric cancer prevention.

Vitamin B12 deficiency and clinical laboratory: Lessons revisited and clarified in seven questions

The objective of this review article is to address the most frequently asked questions that pathologists and primary care physicians might face when dealing with a patient with suspicion of vitamin B12 deficiency. More specifically, the article mainly discusses the importance and prevalence of the deficit, how to recognize it, and the important role of a prompt diagnosis confirmation based on laboratory biomarkers for efficient replacement therapy.

Association between the XPG gene rs2094258 polymorphism and risk of gastric cancer

BACKGROUND

Xeroderma pigmentosum group G (XPG) plays an important role in maintaining the stability and integrity of genomic DNA. Previous studies demonstrate some XPG gene polymorphisms are associated with susceptibility to gastric cancer (GC).

METHODS

The association between XPG rs2094258 polymorphism and GC risk was investigated first by a hospital-based case-control study involving 386 patients and 439 controls and then by a meta-analysis. The polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLR).

RESULTS

Xeroderma pigmentosum group G rs2094258 polymorphism was associated with an increased risk of GC in a Chinese population. The meta-analysis did not reveal any significant difference in the overall population. Subgroup analysis of geographic locations showed a significant association between the XPG gene rs2094258 polymorphism and GC risk in Southern China. Stratification analysis further indicated significant associations in hospital-based studies and studies using PCR-RFLR.

CONCLUSION

Xeroderma pigmentosum group G gene rs2094258 polymorphism may be associated with an increased risk of GC in Southern China. Nevertheless, the findings of this meta-analysis should be validated by well-designed large-scale case-control studies among other ethnicities.

Tag SNPs of long non-coding RNA TINCR affect the genetic susceptibility to gastric cancer in a Chinese population

Tissue differentiation-inducing non-protein coding RNA (TINCR) is required for normal epidermal differentiation. TINCR is also strongly overexpressed in human gastric cancer (GC) and contributes to carcinogenesis and tumor progression. However, the association between TINCR polymorphisms and the risk of any diseases, such as GC, remains unknown. In the present study, the tag single nucleotide polymorphisms rs8113645, rs2288947, rs8105637, and rs12610531 were analyzed in 602 patients with GC and 602 age- and sex-matched controls. Polymorphisms were genotyped using TaqMan technology. Carriers of variant rs8113645 and rs2288947 alleles indicated reduced risks of GC (p = 0.003 and 0.037, respectively). A allele genotypes of rs8113645 and G allele genotypes of rs2288947 (rs8113645 GA and AA; rs2288947 AG and GG) were also significantly associated with decreased GC risk (p < 0.05). Stratification analysis displayed that the correlations between GC risk and variant genotypes of both rs8113645 and rs2288947were more evident in younger individuals, men, nonsmokers, and individuals from rural areas. We also demonstrated that rs8113645 GA+AA genotype carriers had lower TINCR mRNA expression levels compared with common genotype in both normal and GC tissues (p < 0.05). These results suggest that long non-coding RNA TINCR polymorphisms may be implicated in GC development.

Autoimmune gastritis: relationships with anemia and Helicobacter pylori status

BACKGROUND

Autoimmune gastritis (AIG) is a gastric pathologic condition affecting the mucosa of the fundus and the body and eventually leading to hypo-achlorhydria.

AIMS

We report our clinical and pathological experience with AIG.

METHODS

Data from patients with a diagnosis of AIG seen in the period January 2002-December 2012 were retrieved. Only patients with complete sets of biopsies were analyzed.

RESULTS

Data from 138 patients were available for analysis. Pernicious anemia was present in 25% of patients, iron deficiency anemia was found in 29.7% of patients, hypothyroidism in 23% of patients, type 1 diabetes in 7.9% of patients, and vitiligo in 2.8% of patients. Parietal cell antibodies were positive in 65% of patients, and no patient had serology positive for celiac disease. All gastric biopsies showed glandular atrophy associated with enterochromaffin-like (ECL)-cells hyperplasia, features limited to the mucosa of the fundus and body, and focal glandular intestinal metaplasia. Helicobacter pylori was negative in all cases.

CONCLUSIONS

AIG was strongly associated with anemia; atrophy, intestinal metaplasia and ECL hyperplasia in the gastric fundus and body are hallmarks of this condition.

MUC1 rs4072037 polymorphism is associated with decreased risk of gastric cancer: a meta-analysis

BACKGROUND

Several studies have recently investigated the association between mucin 1 (MUC1) rs4072037 polymorphism and gastric cancer (GC) risk, but with conflicting results. The aim of this meta-analysis was to evaluate the association between MUC1 rs4072037 polymorphism and GC risk.

METHODS

A comprehensive database search of PubMed, Elsevier, Embase and China National Knowledge Infrastructure (CNKI) databases was performed to identify relevant studies. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of any association.

RESULTS

A total of 12 papers containing 18 studies were included in this meta-analysis, involving 12,373 cases and 15,008 controls. Our data suggested that rs4072037 polymorphism was associated with a decreased risk of GC. Stratification analyses of ethnicity indicated that rs4072037 decreased the risk of GC among white populations, but no significant relationship was observed among Asian populations. No significant associations were observed in subgroups of Lauren classification (intestinal or diffuse) and anatomical classification (cardia or non-cardia).

CONCLUSIONS

In conclusion, this meta-analysis suggested that rs4245739 polymorphism in the MUC1 gene may play a pivotal role in the pathogenesis of GC, especially for white populations.

Screening and treating Helicobacter pylori infection for gastric cancer prevention on the population level

Helicobacter pylori infection is the major cause of gastric cancer, and removal of H. pylori infection from a population could theoretically decrease the number of cases by about 89%. However, in real-life settings, few studies have reported the effect of screening and treating this pathogen in population-based programs. This is mainly because of the lack of an adequate infrastructure for delivery of systematic screening services to asymptomatic individuals, the lack of standardization to ensure that each subject receives the correct diagnostic testing and antibiotic treatment, and limited resources. We illustrate our method of implementing two population-based screen-and-treat programs in Taiwan, where the epidemiological characteristics of disease burden have changed from the traditionally Eastern pattern towards that of the Western countries. Our first example is a high-risk population that resides on an offshore island, in which a strategy of mass eradication of H. pylori was applied. The other example is an intermediate-risk population, which is representative of the general average-risk population, in which there is integration of the screen-and-treat method with the established framework of colorectal cancer screening using the fecal-occult blood test. The information provided here may be useful for integration of gastric cancer prevention measures into the healthcare priorities of populations with different gastric cancer risks, such as those with limited resources.

Clinicopathologic characteristics and prognostic of gastric cancer in young patients

OBJECTIVES

Gastric cancer (GC) in young patients is thought to exhibit a worse prognosis due to specific clinicopathologic characteristics and delayed diagnosis; however, the data are controversial. This study aimed to analyse the clinicopathologic characteristics and prognostic factors of GC in young patients and to determine whether GC is a different clinical entity in younger vs. older patients.

PATIENTS AND METHODS

Clinical data of 3930 gastric cancer patients who underwent radical gastrectomy were retrospectively analysed and divided into two age groups. The younger group consisted of 342 cases of patients aged 40 years or younger at the time of surgery, and the older group included 3588 cases of patients older than 40 years. Clinicopathologic characteristics were compared using Pearson's χ(2) or Fisher's exact tests, and survival curves were constructed using the Kaplan-Meier method.

RESULTS

Clinicopathologic characteristics of the younger group exhibited a predominance of females (p < 0.001), diffuse stomach lesions (p = 0.014), signet-ring cell type (p < 0.001), poorly differentiated histological tumours (p < 0.001), Borrmann type IV (p < 0.001), mixed Lauren's classification types (p = 0.004), and recurrence rate in the gastric remnant (p < 0.001). The overall 5-year survival rates in the younger group and older group were 60.8% and 53.7%, respectively (p = 0.017). When stratified by TNM stage, the younger group exhibited enhanced 5-year survival at stage IV compared with the older group (26.9% VS. 10.3%, p = 0.003).

CONCLUSION

Although younger patients with GC exhibit more aggressive cancer patterns and higher recurrence rate in the gastric remnant, the overall 5-year survival rate may be better than older patients.

Tag SNPs in long non-coding RNA H19 contribute to susceptibility to gastric cancer in the Chinese Han population

Long non-coding RNA (lncRNA) H19 is involved in tumor development, progression, and metastasis. This case-control study assessed the association between H19 genetic variants and susceptibility to gastric cancer (GC) in a Chinese Han population. We genotyped four lncRNA H19 single nucleotide polymorphisms (SNPs) (rs217727 C > T, rs2839698 C > T, rs3741216 A > T, rs3741219 T > C) in 500 GC patients and 500 healthy controls. Carriers of variant rs217727T and rs2839698T alleles showed increased GC risk (P = 0.008 and 0.011, respectively). Compared with the common genotype, CT + TT rs217727 and CT + TT rs2839698 genotypes were associated with significantly increased GC risk (P = 0.040, adjusted odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.01-1.71; P = 0.033, adjusted OR = 1.31, 95% CI = 1.02-1.69, respectively). Further stratified analyses revealed that the association between GC risk and variant genotypes of rs217727 was more profound in younger individuals (≤59 years) and non-smokers, while the association between risk and the rare rs2839698 genotype persisted in men and rural subjects. rs2839698 CT and TT genotypes were also associated with higher serum H19 mRNA levels compared with the CC genotype. These findings suggest that lncRNA H19 SNPs may contribute to susceptibility to GC.

The changing epidemiology of Asian digestive cancers: From etiologies and incidences to preventive strategies

Digestive cancers are a major health burden in Asia. Due to the presence of similar "infection-inflammation-cancer" pathways in the carcinogenesis process, eradicating infective pathogens or attenuating relevant inflammatory signaling pathways may reduce digestive cancer incidences and improve patient outcomes. The aim of this paper is to review the recent evidence regarding the epidemiology of three major digestive cancers in Asia: stomach cancer, liver cancer, and colorectal cancer. We focused on the incidence trends, the major etiologies, and especially the potential preventive strategies.

Helicobacter pylori: Effect of coexisting diseases and update on treatment regimens

The presence of concomitant diseases is an independent predictive factor for non-Helicobacter pylori (H. pylori) peptic ulcers. Patients contracting concomitant diseases have an increased risk of developing ulcer disease through pathogenic mechanisms distinct from those of H. pylori infections. Factors other than H. pylori seem critical in peptic ulcer recurrence in end stage renal disease (ESRD) and cirrhotic patients. However, early H. pylori eradication is associated with a reduced risk of recurrent complicated peptic ulcers in patients with ESRD and liver cirrhosis. Resistances to triple therapy are currently detected using culture-based and molecular methods. Culture susceptibility testing before first- or second-line therapy is unadvisable. Using highly effective empiric first-line and rescue regimens can yield acceptable results. Sequential therapy has been included in a recent consensus report as a valid first-line option for eradicating H. pylori in geographic regions with high clarithromycin resistance. Two novel eradication regimens, namely concomitant and hybrid therapy, have proven more effective in patients with dual- (clarithromycin- and metronidazole-) resistant H. pylori strains. We aim to review the prevalence of and eradication therapy for H. pylori infection in patients with ESRD and cirrhosis. Moreover, we summarized the updated H. pylori eradication regimens.

Genetic and epigenetic studies of FOXP3 in asthma and allergy

Multiple factors interact to trigger allergic diseases, including individual genetic background and factors related to the environment such as exposure to allergens, air pollution and respiratory infections. The FOXP3 transcription factor is constitutively expressed in CD4⁺CD25⁺FOXP3⁺ regulatory T cells (Tregs) and is critical for the maintenance of immune homeostasis. For example, FOXP3 is responsible for the suppression of the Th2 response following exposure to allergens. Studies have shown that expression of the FOXP3 gene is reduced in patients with asthma and allergies compared to healthy controls. Therefore, the impairment of FOXP3 function caused by genetic polymorphisms and/or epigenetic mechanisms may be involved in the etiology of asthma and other allergic diseases. This review discusses some aspects of the role of FOXP3 in the development of asthma and allergy, with a particular emphasis on genetic and epigenetic factors.

Association between LMP2 and LMP7 gene polymorphisms and the risk of gastric cancer: A case-control study

The integrality of low molecular weight protein (LMP)2/LMP7 function plays an important role in the processing of GC cell antigens. The purpose of the present hospital-based case-control study was to estimate the effect of polymorphisms in the LMP2 and LMP7 genes on the risk of GC. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to distinguish the Arg to His substitution at codon 60 of LMP2 (LMP2-60) and the Gln to Lys substitution at codon 145 of LMP7 (LMP7-145) in 502 gastric cancer patients and 502 age and gender-matched cancer-free control individuals. The Lys allele of the LMP7-145 variant was more frequent in GC patients compared with control individuals [P=0.004; adjusted odds ratio (OR), 1.39; 95% confidence interval (CI), 1.11-1.74]. The Gln/Lys and Lys/Lys genotypes increased the risk of GC compared with the Gln/Gln genotype (P=0.049 and P=0.041, respectively; adjusted OR, 1.32 and 2.13, respectively; 95% CI, 1.00-1.73 and 1.03-4.39, respectively). Compared with the Gln/Gln genotype, the LMP7-145 Gln/Lys and Lys/Lys variants of the LMP7 gene were also associated with increased susceptibility to GC (P=0.017; adjusted OR, 1.38; 95% CI, 1.06-1.80). Haplotype analysis revealed that the LMP2 (Arg)-LMP7 (Lys) haplotype was associated with increased risk of GC (P=0.013, adjusted OR=1.34, 95% CI=1.06-1.70). Stratified analysis revealed that the association between the risk of GC and the variant genotypes of LMP7-145 was stronger in older individuals (>59 years), males and non-smokers. However, no association between the LMP2-60 polymorphism and the risk of GC was observed. The present results suggest that the LMP7-145 genetic variant contributes to increased susceptibility to GC, and the Lys allele is an independent risk factor for GC.

[Proteomics analysis for Helicobacter pylori-infected gastric mucosa]

BACKGROUND/AIMS

Helicobacter pylori infection is linked to the development of gastric cancer. H. pylori-associated gastric inflammation is considered to be the first important step in the histogenesis of such neoplasia. However, studies that compare proteome of gastric mucosa infected with or without H. pylori are lacking.

METHODS

We employed proteomics analysis on the endoscopic biopsy specimens of gastric mucosa obtained from two groups (30 cases): healthy subjects without H. pylori infection (15 cases), and gastritis patients with H. pylori infection (15 cases). The pooled proteins obtained from gastric mucosa infected with or without H. pylori were separated by two-dimensional gel electrophoresis and analyzed by a computer-aided program. The altered protein expressions were then identified by mass spectrometry and validated by Western blotting and immunohistochemistry.

RESULTS

On mass spectrometry using MALDI TOF™ Analyzer, the up-regulation of Keratin 1, ezrin, adenosine triphosphate (ATP) synthase subunit alpha mitochondrial isoform c, Keratin type I cytoskeletal 19, and Keratin type I cytoskeletal 9 were identified; in contrast, 71 kd heat shock cognate protein, ATP synthase subunit alpha mitochondrial precursor, and annexin IV were down-regulated. Among them, membrane cytoskeleton linker ezrin was validated using Western blot and immunohistochemistry.

CONCLUSIONS

Expression of ezrin was significantly different between the gastric mucosa with and without H. pylori infection. Therefore, ezrin could be considered a promising potential molecular marker for detecting H. pylori infection in gastric mucosa.

MUC1 gene polymorphism rs4072037 and susceptibility to gastric cancer: a meta-analysis

The association between MUC1 polymorphism rs4072037 and the risk of gastric cancer has been described in several studies. However, these studies yielded inconsistent results, especially in different pathological type of gastric cancer. Therefore, we performed this meta-analysis to evaluate the relationship between MUC1 gene polymorphism and gastric cancer susceptibility. A comprehensive database search was performed to identify eligible studies. Odds ratios with 95% confidence intervals were calculated to assess the strength of the association between MUC1 rs4072037 and risk of gastric cancer. Subgroup analyses, publication bias, and sensitivity analyses were also conducted. PubMed, EMBASE, Web of Science and CNKI databases were systematically searched to identify relevant studies. A total of 9 studies (12 datasets) were included in the meta-analysis including 10,410 cases and 11,437 controls. Overall, the G allele at rs4072037 of MUC1 gene was associated with a significant decreased gastric cancer risk (OR=0.70, 95% CI: 0.64-0.76). The association was significant in both anatomic location and pathological subtype subgroup analyses. However, the association was detected in Asian rather than Caucasian. Our findings demonstrate that the presence of the G allele at rs4072037 of the MUC1 gene may contribute to protection against gastric cancer in Asian. Further large studies of multiethnic groups are needed to validate these findings.

Genetic polymorphisms and tissue expression of interleukin-22 associated with risk and therapeutic response of gastric mucosa-associated lymphoid tissue lymphoma

Chronic Helicobacter pylori-stimulated immune reactions determine the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. We aimed to explore the genetic predisposition to this lymphoma and its clinical implication. A total of 68 patients and 140 unrelated controls were genotyped for 84 single-nucleotide polymorphisms in genes encoding cytokines, chemokines and related receptors that play important roles in T cell-mediated gastrointestinal immunity. Five genotypes in IL-22, namely CC at rs1179246, CC at rs2227485, AA at rs4913428, AA at rs1026788 and TT at rs7314777, were associated with disease susceptibility. The former four genotypes resided in the same linkage disequilibrium block (r(2)=0.99) that conferred an approximately threefold higher risk. In vitro experiments demonstrated that co-culturing peripheral mononuclear cells or CD4(+) T cells with H. pylori stimulated the secretion of interleukin-22 (IL-22), and that IL-22 induced the expression of antimicrobial proteins, RegIIIα and lipocalin-2, in gastric epithelial cells. Furthermore, patients with gastric tissue expressing IL-22 were more likely to respond to H. pylori eradication (14/22 vs 4/19, P<0.006). We conclude that susceptibility of gastric MALT lymphoma is influenced by genetic polymorphisms in IL-22, the product of which is involved in mucosal immunity against H. pylori and associated with tumor response to H. pylori eradication.

Dissolution enhancement and in vitro performance of clarithromycin nanocrystals produced by precipitation-lyophilization-homogenization method

The gastroduodenal diseases caused by Helicobacter pylori were commonly treated with antibiotic clarithromycin as a standard regimen. According to the poorly water-soluble of clarithromycin, the nanocrystal formulation was prepared. The aim of this study was to investigate an enhancement effect of clarithromycin nanocrystals produced by precipitation-lyophilization-homogenization (PLH) method on the saturation solubility, dissolution velocity, antibiotic activity, permeability through the gastric mucus and cellular permeability. Poloxamer 407 and sodium lauryl sulfate (SLS) were chosen as combined stabilizers in the nanocrystal system. The obtained clarithromycin nanocrystals were identified as cubic particles by SEM with a bulk population of approximately 400nm existed in crystalline and/or partial amorphous form as investigated by DSC and XRPD. The saturation solubility of the clarithromycin nanocrystals was increased by 1.5- and 6-folds higher than clarithromycin powder in buffer pH 5.0 and 6.8, respectively. The dissolution profiles of clarithromycin nanocrystals at pH 5.0 and 6.8 were significantly different from clarithromycin powder and the marketed product (f1 value >15 and f2 value <50). All dissolution parameters (relative dissolution rate, percent dissolution efficiency and mean dissolution time) showed that clarithromycin nanocrystals had higher dissolution rate when compared with the clarithromycin powder, the lyophilized coarse suspension and the marketed product. The bioassay study by diffusion agar method showed a maintained antibiotic activity of clarithromycin nanocrystals solubilized in buffer solution which was greater potency than the lyophilized coarse suspension and the clarithromycin powder. Additionally, the nanocrystals possessed higher permeability through gastric mucus and cellular monolayer of Caco-2 and NCI-N87 cells as compared to the lyophilized coarse suspension and the clarithromycin powder. The results indicated that, the developed clarithromycin nanocrystals were a potential delivery system that exerts more effectiveness in H. pylori eradication.

Promoter polymorphisms of miR-34b/c are associated with risk of gastric cancer in a Chinese population

More and more evidence reveals that noncoding RNA miR-34b/c and tumor suppressor gene TP-53 independently, and/or jointly, play crucial roles in carcinogenesis. The purpose of the present hospital-based case-control study was to investigate the association between the miR-34b/c rs4938723 and TP53 Arg72Pro polymorphisms and the risk of gastric cancer. Two polymorphisms were genotyped in 419 gastric cancer patients and 402 age- and sex-matched cancer-free controls using polymerase chain reaction-restriction fragment length polymorphism analysis. The CC genotype and C allele of the miR-34b/c rs4938723 were associated with a significantly decreased risk of gastric cancer compared with the TT genotype and T allele (CC vs. TT: P = 0.006, adjusted odds ratio (OR) = 0.53, 95 % confidence interval (95 % CI) = 0.34-0.83; C vs. T: P = 0.005, adjusted OR = 0.75, 95 % CI = 0.61-0.92). Compared with individuals with the wild-type TT genotype, subjects with the variant genotypes (CT + CC) had a significantly decreased risk of gastric cancer (P = 0.047, adjusted OR = 0.75, 95 % CI = 0.57-0.99). Stratified analysis showed that the association between the risk of gastric cancer and the variant genotypes of miR-34b/c was more profound among men. However, no overall association was found between the TP53 Arg72Pro polymorphism and gastric cancer risk. In the combined analysis, no effects of the interaction of miR-34b/c rs4938723 and TP53Arg72Pro on gastric cancer risk were observed. Our findings indicate that the miR-34b/c rs4938723 CT/CC genotypes may be associated with a decreased risk of gastric cancer and the C allele may be a protective factor in gastric cancer.

Approach to Helicobacter pylori infection in geriatric population

The prevalence of Helicobacter pylori (H. pylori) infection and its complications increase with age. The majority of infected individuals remain asymptomatic throughout the life but 10%-20% develops peptic ulcer disease and 1% gastric malignancies. The incidence of ulcers and their complications are more common in the older population resulting in higher hospitalization and mortality rates. The increased use of medications causing gastric mucosal damage and the decreased secretion of protective prostaglandins in elderly are major factors increasing gastric mucosal sensitivity to the destructive effects of H. pylori. Due to higher prevalence of gastrointestinal (GI) malignancies, upper GI endoscopy is mostly preferred in elderly for the diagnosis of infection. Therefore, “endoscopy and treat” strategy may be more appropriate instead of “test and treat” strategy for dyspeptic patients in older age. Urea breath test and stool antigen test can be used for control of eradication, except for special cases requiring follow-up with endoscopy. The indications for treatment and suggested eradication regimens are similar with other age groups; however, the eradication failure may be a more significant problem due to high antibiotic resistance and low compliance rate in elderly. Multidrug usage and drug interactions should always be considered before starting the treatment. This paper reviews briefly the epidemiology, diagnosis, disease manifestations, and treatment options of H. pylori in the geriatric population.

Pattern-recognition receptors and gastric cancer

Chronic inflammation has been associated with an increased risk of several human malignancies, a classic example being gastric adenocarcinoma (GC). Development of GC is known to result from infection of the gastric mucosa by Helicobacter pylori, which initially induces acute inflammation and, in a subset of patients, progresses over time to chronic inflammation, gastric atrophy, intestinal metaplasia, dysplasia, and finally intestinal-type GC. Germ-line encoded receptors known as pattern-recognition receptors (PRRs) are critical for generating mature pro-inflammatory cytokines that are crucial for both Th1 and Th2 responses. Given that H. pylori is initially targeted by PRRs, it is conceivable that dysfunction within genes of this arm of the immune system could modulate the host response against H. pylori infection, and subsequently influence the emergence of GC. Current evidence suggests that Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR5, and TLR9), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) (NOD1, NOD2, and NLRP3), a C-type lectin receptor (DC-SIGN), and retinoic acid-inducible gene (RIG)-I-like receptors (RIG-I and MDA-5), are involved in both the recognition of H. pylori and gastric carcinogenesis. In addition, polymorphisms in genes involved in the TLR (TLR1, TLR2, TLR4, TLR5, TLR9, and CD14) and NLR (NOD1, NOD2, NLRP3, NLRP12, NLRX1, CASP1, ASC, and CARD8) signaling pathways have been shown to modulate the risk of H. pylori infection, gastric precancerous lesions, and/or GC. Further, the modulation of PRRs has been suggested to suppress H. pylori-induced inflammation and enhance GC cell apoptosis, highlighting their potential relevance in GC therapeutics. In this review, we present current advances in our understanding of the role of the TLR and NLR signaling pathways in the pathogenesis of GC, address the involvement of other recently identified PRRs in GC, and discuss the potential implications of PRRs in GC immunotherapy.

Cytokines, cytokine gene polymorphisms and Helicobacter pylori infection: Friend or foe?

Helicobacter pylori (H. pylori) is a flagellated, spiral-shaped, microaerophilic Gram-negative bacillus that colonises the gastric mucosa of more than 50% of the human population. Infection is a risk factor for gastritis, ulcer disease and stomach cancer. Immunity against H. pylori is mainly related to Th1/Th17 skewing, and the activation of regulatory T cells is the main strategy used to limit inflammatory responses, which can result in the pathogen persistence and can lead to chronic gastrointestinal diseases, including cancer. Furthermore, host genetic factors that affect cytokines may determine differences in the susceptibility to many diseases. In this review, we present the cytokine profiles and the main cytokine gene polymorphisms associated with resistance/susceptibility to H. pylori and discuss how such polymorphisms may influence infection/disease outcomes.

Ecological study of gastric cancer in Brazil: Geographic and time trend analysis

AIM: To investigate the geographic distributions and time trends of gastric cancer (GC) incidence and mortality in Brazil.

METHODS: An ecological study of the DATASUS registry was conducted by identifying hospitalizations for GC between January 2005 and December 2010. The data included information on the gender, age, and town of residence at the time of hospital admission and death.

RESULTS: The GC rates, adjusted according to available hospital beds, decreased from 13.8 per 100000 in 2005 to 12.7 per 100000 in 2010. The GC rates decreased more among the younger age groups, in which the male-to-female difference also decreased in comparison to the older age groups. Although the lethality rates tended to increase with age, young patients were proportionally more affected. The spatial GC distribution showed that the rates were higher in the south and southeast. However, while the rates decreased in the central-west and south, they increased in the northern regions. A geographic analysis showed higher rates of GC in more urbanized areas, with a coast-to-inland gradient. Geographically, GC lethality overlapped greatly with the hospital admission rates.

CONCLUSION: The results of this study support the hypothesis of a critical role for environmental factors in GC pathogenesis. The declining rates in young patients, particularly males, suggest a relatively recent decrease in the exposure to risk factors associated with GC. The spatial distribution of GC indicates an ongoing dynamic change within the Brazilian environment.

Gastric colonisation with a restricted commensal microbiota replicates the promotion of neoplastic lesions by diverse intestinal microbiota in the Helicobacter pylori INS-GAS mouse model of gastric carcinogenesis

OBJECTIVES

Gastric colonisation with intestinal flora (IF) has been shown to promote Helicobacter pylori (Hp)-associated gastric cancer. However, it is unknown if the mechanism involves colonisation with specific or diverse microbiota secondary to gastric atrophy.

DESIGN

Gastric colonisation with Altered Schaedler's flora (ASF) and Hp were correlated with pathology, immune responses and mRNA expression for proinflammatory and cancer-related genes in germ-free (GF), Hp monoassociated (mHp), restricted ASF (rASF; 3 species), and specific pathogen-free (complex IF), hypergastrinemic INS-GAS mice 7 months postinfection.

RESULTS

Male mice cocolonised with rASFHp or IFHp developed the most severe pathology. IFHp males had the highest inflammatory responses, and 40% developed invasive gastrointestinal intraepithelial neoplasia (GIN). Notably, rASFHp colonisation was highest in males and 23% developed invasive GIN with elevated expression of inflammatory biomarkers. Lesions were less severe in females and none developed GIN. Gastritis in male rASFHp mice was accompanied by decreased Clostridum species ASF356 and Bacteroides species ASF519 colonisation and an overgrowth of Lactobacillus murinus ASF361, supporting that inflammation-driven atrophy alters the gastric niche for GI commensals. Hp colonisation also elevated expression of IL-11 and cancer-related genes, Ptger4 and Tgf-β, further supporting that Hp infection accelerates gastric cancer development in INS-GAS mice.

CONCLUSIONS

rASFHp colonisation was sufficient for GIN development in males, and lower GIN incidence in females was associated with lower inflammatory responses and gastric commensal and Hp colonisation. Colonisation efficiency of commensals appears more important than microbial diversity and lessens the probability that specific gastrointestinal pathogens are contributing to cancer risk.

Helicobacter pylori infection synergizes with three inflammation-related genetic variants in the GWASs to increase risk of gastric cancer in a Chinese population

Background

Three recent genome-wide association studies (GWASs) have reported that three SNPs (rs4072037, rs13361707 and rs2274223) located on genes related to host inflammatory response are significantly associated with susceptibility to gastric cancer (GC) in Chinese populations. Helicobacter pylori infection is also an important risk factor for GC through causing inflammatory response in the gastric mucosa. However, no study has established whether there are potential gene-environment interactions between these genetic variants and H. pylori infection to the risk of GC.

Methods

We genotyped three polymorphisms (rs4072037 at 1q22, rs13361707 at 5p13, and rs2274223 at 10q23) in 335 Chinese gastric adenocarcinoma patients and 334 controls. H. pylori serology was examined by enzyme-linked immunosorbent assay. Multivariable logistic regression models were used to evaluate the association between the variables and GC risk.

Results

We confirmed that the three SNPs (rs4072037, rs13361707 and rs2274223) were significantly associated with GC susceptibility. H. pylori infection also significantly increased the risk of GC. Furthermore, there were joint effects between H. pylori infection and the three SNPs on the risk of GC. The most elevated risk of GC was found in subjects with H. pylori seropositivity and AA genotypes for rs4072037 [odds ratio (OR), 3.95; 95% confidence interval (CI), 2.29–6.79], H. pylori seropositivity and CT/CC genotypes for rs13361707 (OR, 2.68; 95% CI, 1.62–4.43), H. pylori seropositivity and AG/GG genotypes for rs2274223 (OR, 2.45; 95% CI, 1.55–3.88) compared with those with H. pylori seronegativity and other genotypes of each SNP. Significant interactions were observed between H. pylori seropositivity and the three SNPs (all P_{G× E} <0.05) to the risk of GC.

Conclusion

These findings indicate that the three SNPs (rs4072037, rs13361707 and rs2274223) identified in the GWASs may interact with H. pylori infection to increase the risk of GC.

TLR9 promoter polymorphism is associated with both an increased susceptibility to gastric carcinoma and poor prognosis

Objective

Genetic polymorphisms of Toll-like receptors (TLRs) may influence the effects of H. pylori infection and play important roles in gastric carcinogenesis. The aim of this study was to determine whether the polymorphisms of TLR4 and TLR9 are associated with susceptibility to gastric carcinoma and its prognosis.

Methods

This study consisted of 314 patients with gastric cancer and 314 healthy controls. The polymorphisms were assessed using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analysis. Survival was analyzed by Kaplan–Meier survival curves.

Results

No variant genotypes of TLR4+896A/G, TLR4+1196C/T, or TLR9 -1237T/C were detected. For TLR9 -1486 T/C, multiple logistic regression analyses revealed that compared with the TT homozygote, patients with both the TC variant (adjusted odds ratio (OR) = 1.47, 95% confidence interval (CI) = 1.04–2.10) and the CC variant (adjusted OR = 1.63, 95% CI = 1.01–2.64) had higher risks of gastric cancer. Further stratification analyses revealed that an increased risk of gastric cancer associated with C carriers was evident among females (adjusted OR = 1.84, 95%CI = 1.02–3.33), in younger subjects aged less than 60 years old (adjusted OR = 1.86, 95%CI = 1.15–3.00), and subjects with H. pylori infection (adjusted OR = 1.53, 95% CI = 1.03–2.27). We also observed a significant association between C carriers and noncardia gastric cancer (adjusted OR = 1.51, 95% CI = 1.03–2.20). In addition, we demonstrated that the C carrier genotype and H. pylori infection may have a synergistic effect and conferred an OR of 2.44 for developing gastric cancer. TLR9 -1486C was also identified as an independent marker of poor survival of carcinoma.

Conclusions

Our results suggest that TLR9 -1486C carriers are associated with an increased risk and poor prognosis of gastric carcinoma in the Chinese population.

Janus kinase 2 polymorphisms are associated with risk in patients with gastric cancer in a Chinese population

AIM

To evaluate the impact of the Janus kinase 2 single nucleotide polymorphisms (SNPs) on gastric cancer risk.

METHODS

In this hospital-based, case-control study, the genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism protocols in 661 individuals (359 gastric cancer patients and 302 age and sex matched cancer-free controls).

RESULTS

Both the frequency of A allele in rs2230724 and G allele in rs1887427 were more frequent in patients with gastric cancer (P = 0.013 and 0.001, respectively). Compared with the common genotype, subjects with the (AG+AA) genotypes of rs2230724 and the (AG+GG) genotypes of rs1887427 had a 59% and 98% increased risk of developing gastric cancer, respectively (P = 0.010, adjusted OR = 1.59, 95% CI = 1.12-2.27; P<0.001, adjusted OR = 1.98, 95% CI = 1.39-2.81, respectively). Further stratified analysis showed that the association between the risk of gastric cancer and the rare genotypes of rs2230724 were more profound in the subgroups of elder individuals (>56 years), males, nonsmokers and urban subjects, while the association between the risk and the rare genotypes of rs1887427 persisted in subgroups of younger individuals (≤56 years), males, nonsmokers and both of rural and urban subjects.

CONCLUSION

The JAK2 gene rs2230724 and rs1887427 polymorphisms are associated with an increased risk of gastric cancer in a Chinese Han population.

Helicobacter pylori is not the predominant etiology for liver cirrhosis patients with peptic ulcer disease

OBJECTIVES

Patients with liver cirrhosis (LC) often develop peptic ulcers. The differentiation of Helicobacter pylori etiology in LC patients from that of peptic ulcers in non-LC patients is critical. This study aimed to determine whether H. pylori plays a central role in LC patients with peptic ulcers.

METHODS

LC was defined by International Classifications of Diseases, Revision 9, and Clinical Modification (ICD-9-CM) codes 571.2, 571.5, and 571.6. To be defined as non-LC, we did not identify patients in an inpatient setting or by one or more ambulatory care claims containing the International Classifications of Diseases, Revision 9, and Clinical Modification codes 571.2, 571.5, and 571.6. The sample included 9465 H. pylori-positive patients and 3418 H. pylori-negative patients. A logistic regression model was used to calculate the odds ratio (OR) and a 95% confidence interval was used to determine whether LC was an independent factor of lower H. pylori infection rates in peptic ulcer patients.

RESULTS

This study included 102 decompensated LC patients with peptic ulcers, 39 H. pylori-positive and 63 H. pylori-negative. There were 360 compensated LC patients with peptic ulcers, 193 H. pylori-positive and 167 H. pylori-negative. Among the non-LC patients with peptic ulcers, 9233 were H. pylori-positive and 3188 were H. pylori-negative. On the basis of logistic regression analysis, decompensated LC patients (OR=0.23, P<0.001) and compensated LC patients (OR=0.48, P<0.001) had lower H. pylori infection rates.

CONCLUSION

H. pylori is not the predominant etiology for LC, especially the decompensated type, either with peptic ulcer disease or with recurrent ulcer disease.

Association between IRS-2 G1057D polymorphism and risk of gastric cancer

AIM: To investigate the relationship between insulin receptor substrate-2 (IRS-2) G1057D polymorphism and the risk of gastric cancer (GC) in a Chinese population.

METHODS: A case-control study with 197 GC patients and 156 age- and sex- matched control subjects was conducted. The genotypes of polymorphism were assessed by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS: The genotype frequencies of IRS-2 G1057D polymorphism in cases were obviously different from those in the control group (P = 0.031). Compared with GG genotype carriers, the risk for GC was significantly higher (adjusted odds ratio = 2.32, 95% CI: 1.03-5.23, P = 0.042) in the individuals with the IRS-2 DD genotype. Furthermore, stratified analysis was performed based on age, sex, smoking status and residence, but no significant difference between the two groups was found. In addition, no significant association between genotypes and clinicopathological features was observed either.

CONCLUSION: This study demonstrates that IRS-2 G1057D is involved in susceptibility to GC, although further large-sample studies are still needed.

Effects of interleukin-10 polymorphisms, Helicobacter pylori infection, and smoking on the risk of noncardia gastric cancer

Objective

Both variations in the interleukin-10 (IL10) gene and environmental factors are thought to influence inflammation and gastric carcinogenesis. Therefore, we investigated the associations between IL10 polymorphisms, Helicobacter pylori (H. pylori) infection, and smoking in noncardia gastric carcinogenesis in Koreans.

Methods

We genotyped three promoter polymorphisms (-1082A>G, -819T>C, and -592 A>C) of IL10 in a case-control study of 495 noncardia gastric cancer patients and 495 sex- and age-matched healthy controls. Multiple logistic regression models were used to detect the effects of IL10 polymorphisms, H. pylori infection, and smoking on the risk of gastric cancer, which was stratified by the histological type of gastric cancer.

Results

The IL10-819C and -592C alleles were found to have complete linkage disequilibrium, and all three IL10 polymorphisms were associated with an increased risk of intestinal-type noncardia gastric cancer. These associations were observed only in H. pylori-positive subjects and current smokers. A statistically significant interaction between the IL10-592 genotype and H. pylori infection on the risk of intestinal-type gastric cancer was observed (P for interaction  = 0.047). In addition, H. pylori-positive smokers who were carriers of either the IL10-1082G (OR [95% CI]  = 17.76 [6.17−51.06]) or the -592C (OR [95% CI]  = 8.37 [2.79−25.16]) allele had an increased risk of intestinal-type gastric cancer compared to H. pylori-negative nonsmokers homozygous for IL10-1082A and -592A, respectively. The interaction between the IL10-1082 polymorphism and the combined effects of H. pylori infection and smoking tended towards significance (P for interaction  = 0.080).

Conclusions

Inflammation-related genetic variants may interact with H. pylori infection and smoking to increase the risk of noncardia gastric cancer, particularly the intestinal-type. These findings may be helpful in identifying individuals at an increased risk for developing noncardia gastric cancer.

Potentially functional variants of PLCE1 identified by GWASs contribute to gastric adenocarcinoma susceptibility in an eastern Chinese population

BACKGROUND

Recent genome-wide association studies (GWAS) have found a single nucleotide polymorphism (SNP, rs2274223 A>G) in PLCE1 to be associated with risk of gastric adenocarcinoma. In the present study, we validated this finding and also explored the risk associated with another unreported potentially functional SNP (rs11187870 G>C) of PLCE1 in a hospital-based case-control study of 1059 patients with pathologically confirmed gastric adenocarcinoma and 1240 frequency-matched healthy controls.

METHODOLOGY/PRINCIPAL FINDINGS

We determined genotypes of these two SNPs by the Taqman assay and used logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (95% CI). We found that a significant higher gastric adenocarcinoma risk was associated with rs2274223 variant G allele (adjusted OR = 1.35, 95% CI = 1.14-1.60 for AG+GG vs. AA) and rs11187870 variant C allele (adjusted OR = 1.26, 95% CI = 1.05-1.50 for CG+CC vs. GG). We also found that the number of combined risk alleles (i.e., rs2274223G and rs11187870C) was associated with risk of gastric adenocarcinoma in an allele-dose effect manner (P(trend) = 0.0002). Stratification analysis indicated that the combined effect of rs2274223G and rs11187870C variant alleles was more evident in subgroups of males, non-smokers, non-drinkers and patients with gastric cardia adenocarcinoma. Further real-time PCR results showed that expression levels of PLCE1 mRNA were significantly lower in tumors than in adjacent noncancerous tissues (0.019±0.002 vs. 0.008±0.001, P<0.05).

CONCLUSIONS/SIGNIFICANCES

Our results further confirmed that genetic variations in PLCE1 may contribute to gastric adenocarcinoma risk in an eastern Chinese population.

Diagnosis and management of pernicious anemia

Pernicious anemia is a macrocytic anemia due to cobalamin deficiency, which is the result of intrinsic factor deficiency. Pernicious anemia is associated with atrophic body gastritis, whose diagnostic criteria are based on the histologic evidence of gastric body atrophy associated with hypochlorhydria. Serological markers suggesting the presence of oxyntic mucosa damage are increased levels of fasting gastrin and decreased levels of Pepsinogen I. Without the now obsolete Schilling's test, intrinsic factor deficiency may not be proven, and gastric intrinsic factor output after pentagastric stimulation has been proposed. Intrinsic factor autoantibodies are useful surrogate markers of pernicious anemia. The management of patients with pernicious anemia should focus on the life-long replacement treatment with cobalamin and the monitoring to early diagnose an eventual onset of iron deficiency. Moreover, these patients should be advised about possible gastrointestinal long-term consequences, such as gastric cancer and carcinoids.

Association between ITGA2 C807T polymorphism and gastric cancer risk

AIM: To evaluate the impact of the ITGA2 gene polymorphism on gastric cancer risk.

METHODS: A hospital-based case-control study was conducted, including 307 gastric cancer patients and 307 age- and gender-matched control subjects. The genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism assay.

RESULTS: The frequencies of the wild and variant genotypes in cases were significantly different from those of controls (P = 0.019). Compared with individuals with the wild genotype CC, subjects with the variant genotypes (CT + TT) had a significantly higher risk of gastric cancer (adjusted odds ratio = 1.57, 95% CI = 1.13-2.17, P = 0.007). In stratified analyses, the elevated gastric cancer risk was especially evident in older individuals aged > 58 years, nonsmokers and rural subjects. Further analyses revealed that the variant genotypes were associated with poor tumor differentiation and adjacent organ invasion in the sub-analysis of gastric cancer patients.

CONCLUSION: The ITGA2 gene C807T polymorphism may be associated with an increased risk of gastric cancer, differentiation and invasion of gastric cancer.

Ku80 gene G-1401T promoter polymorphism and risk of gastric cancer

AIM: To evaluate the possible relationship between the Ku80 gene polymorphism and the risk of gastric cancer in China.

METHODS: In this hospital-based case-control study of gastric cancer in Jiangsu Province, China, we investigated the association of the Ku80 G-1401T (rs828907) polymorphism with gastric cancer risk. A total of 241 patients with gastric cancer and 273 age- and sex-matched control subjects were genotyped and analyzed by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS: The frequencies of genotypes GG, GT and TT were 65.6%, 22.8% and 11.6% in gastric cancer cases, respectively, and 75.8%, 17.6% and 6.6% in controls, respectively. There were significant differences between gastric cancer and control groups in the distribution of their genotypes (P = 0.03) and allelic frequencies (P = 0.002) in the Ku80 promoter G-1401T polymorphism.

CONCLUSION: The T allele of Ku80 G-1401T may be associated with the development of gastric cancer.

Why is the coexistence of gastric cancer and duodenal ulcer rare? Examination of factors related to both gastric cancer and duodenal ulcer

The coexistence of gastric cancer with duodenal ulcer has been found empirically to be rare, but why it is rare is difficult to explain satisfactorily. To elucidate this question, we carried out a literature review of the subject. The frequency with which the two diseases coexist is 0.1-1.7%, and the main factor associated with both gastric cancer and duodenal ulcer is Helicobacter pylori infection. However, there are marked differences between the disorders of hyperchlorhydria in duodenal ulcer, and hypochlorhydria in gastric cancer. The most acceptable view of the reason for the difference may be that the acquisition of H. pylori infection occurs mainly in childhood, so that the time of acquisition of atrophic gastritis may be the most important, and if atrophic gastritis is not acquired early, high levels of gastric acid may occur, and consequently acute antral gastritis and duodenal ulcer may occur in youth, whereas, in elderly individuals, persistent H. pylori infections and the early appearance of atrophic gastritis may be the causes of low gastric acid, and consequently gastric cancer may occur. In patients with duodenal ulcer, factors such as nonsteroidal anti-inflammatory drugs (NSAIDs) and dupA-H. pylori strains may contribute to preventing the early acquisition of atrophic gastritis, while acid-suppressive therapy and vascular endothelial growth factor and other entities may inhibit atrophic gastritis. In contrast, in gastric cancer, factors such as excessive salt intake, acid-suppressive therapy, polymorphisms of inflammatory cytokines, and the homB-H. pylori strain may contribute to the early acquisition of atrophic gastritis, while factors such as NSAIDs; fruits and vegetables; vitamins A, C, and E; and good nutrition may inhibit it.

Retrospective analysis of prognostic outcome of gastric cancer in young patients

BACKGROUND

It has been suggested that gastric cancer in young patients has a worse prognosis than in older patients, but this is controversial. This retrospective investigation was undertaken to understand the clinicopathological features and identify the prognostic factors of gastric cancer in young patients.

METHODS

Patients included in this study were those treated and followed up for gastric cancer from 1989 to 2005. Operative records, clinical, pathological, and follow-up data were reviewed. The critical age cut-off value for obtaining distinctive prognoses was 34 years.

RESULTS

Of 1730 gastric cancer patients whose records were reviewed, 27 were less than 34 years old (YGC group). The YGC group contained significantly higher percentages of females, stage IV, macroscopic type 4 tumors, poorly differentiated histology, peritoneal dissemination, and epigastric pain symptoms than the gastric cancer group aged 34 years or more (OGC group). Survival in the YGC group was significantly worse than in the OGC group (p = 0.0363). Ten-year survival was 68.5% in the YGC group and 81.8% in the OGC group. Survival in the YGC group was poorer for the stage IV patients, compared with OGC patients, especially for the stage IV patients with peritoneal dissemination and without liver metastases (H0P1 patients) (p = 0.049).

CONCLUSIONS

Age in gastric cancer affects the prognosis, which in gastric cancer patients less than 34 years old was significantly poorer than for older patients, because of the high incidence of stage IV cancer with peritoneal dissemination in gastric cancer patients less than 34 years old.

Prevalence of parietal cell antibodies in a large cohort of patients with autoimmune thyroiditis

BACKGROUND

Autoimmune thyroiditis (AIT) may be associated with other organ-specific autoimmune disorders, including autoimmune gastritis, but the prevalence of this association is not entirely quantified. The aim of this study was to investigate the prevalence of parietal cell antibodies (PCA) in a large cohort of consecutive patients with AIT.

METHODS

We retrospectively studied 2016 consecutive women and 258 men with AIT seen at our referral center in the period from 2004 to 2008. All patients were screened for the presence of PCA in the serum.

RESULTS

The prevalence of serum PCA in female patients was 29.7% and progressively increased from 13% in the first-second decade of life to peak at 42% in the ninth decade. During follow up, 21.1% of the PCA-positive patients converted to PCA-negative status. Mean (±standard deviation) basal PCA levels in this group were significantly lower (32 ± 28 U/mL) compared with those remaining PCA positive (129 ± 200 U/mL). A similar prevalence (29.8%) with a similar age-dependency was found in male patients.

CONCLUSIONS

In conclusion, our study demonstrates a high, age-dependent prevalence of PCA in an unselected large population of patients with AIT.

Gastric Cancer Working Group report

EPIDEMIOLOGY

Gastric cancer is the second most common cancer in Asia, more than half of the world's gastric cancer cases arise in Eastern Asia, and the majority of Asia's cases still occur in the distal part of the stomach.

ETIOLOGY AND PREVENTION

The etiology of gastric cancer consists of genetic susceptibility, Helicobacter pylori infection and environmental risk factors. Helicobacter pylori eradication treatment, consumption of fresh vegetables and fruits and use of aspirin and non-steroidal anti-inflammatory drugs seem to reduce the risk of gastric cancer.

ENDOSCOPY AND DIAGNOSIS

Screening for gastric cancer is cost-effective in countries with high incidence. Risk stratification may increase the cost-effectiveness of screening in populations at moderate risk. Endoscopic resection is curative in a subset of patients with early cancer.

SURGERY AND ADJUVANT TREATMENT

R0 resection with D2 lymph node dissection has produced the best survival data. Some kind of post-operative adjuvant chemotherapy including S-1 is recommended after D2 surgery.

CHEMOTHERAPY FOR ADVANCED GASTRIC CANCER

As chemotherapy for gastric cancer, fluorouracils plus platinum are the most widely accepted first-line regimens, whereas taxanes or irinotecan are mostly used in second- and third-line settings. Differences in the approval and medical insurance systems may influence the status of these regimens. Trastuzumab in combination with fluorouracils/platinum will be a standard regimen for HER2-positive gastric cancer. Many new targeting agents are currently under investigation, and Asian countries are playing important roles in investigation and development of new and better treatments for this malignancy.

Grb2-associated binder 1 (Gab1) genetic polymorphism, Helicobacter pylori infection, and chronic atrophic gastritis among older adults from Germany

Grb2-associated binder 1 (Gab1) plays an important role in the regulation of cell growth and transformation. A single nucleotide polymorphism (SNP) (rs3805246) in the Gab1 gene has been suggested to be related to the risk of Helicobacter pylori infection and chronic atrophic gastritis (CAG) in a study from Japan. We aimed to assess the associations in a population-based study from Germany. In the baseline examination of ESTHER, a population-based study conducted in Saarland, serum pepsinogen I and II and H. pylori serostatus were measured by ELISA. The Gab1 SNP (rs3805246) was genotyped in 351 serologically defined CAG cases and 351 age- and sex-matched non-CAG controls. A nonsignificant association was observed between the Gab1 SNP and CAG, with an adjusted odds ratio of 1.15 (0.85-1.55) for AA/AG carriers compared to GG carriers. The magnitude of the association did not change when the analysis was restricted to H. pylori seropositive subjects. Furthermore, no significant relation was found between the SNP and H. pylori seropositivity among non-CAG controls. We could not confirm a major association between Gab1 SNP (rs3805246) and the predisposition to H. pylori infection and CAG in this study population from Germany. Further studies with larger sample size are needed to clarify a potential modest effect of Gab1 genetic polymorphisms.