Association of Helicobacter pylori infection with gastric carcinoma: a meta-analysis

Folate intake and the risk of upper gastrointestinal cancers: a systematic review and meta-analysis

BACKGROUND AND AIM

There is conflicting evidence on the association between folate intake and the risk of upper gastrointestinal tract cancers. In order to further elucidate this relationship, we performed a systematic review and quantitative meta-analysis of folate intake and the risk of esophageal, gastric, and pancreatic cancer.

METHODS

Four electronic databases (Medline, PubMed, Embase, and Current Contents Connect) were searched to July 26, 2013, with no language restrictions for observational studies that measured folate intake and the risk of esophageal cancer, gastric cancer, or pancreatic cancer. Pooled odds ratios and 95% confidence intervals were calculated using a random effects model.

RESULTS

The meta-analysis of dietary folate and esophageal cancer risk comprising of nine retrospective studies showed a decreased risk of esophageal cancer (odds ratio [OR] 0.59; 95% confidence interval [95% CI] 0.51-0.69). The meta-analysis of dietary folate and gastric cancer risk comprising of 16 studies showed no association (OR 0.94; 95% CI 0.78-1.14). The meta-analysis of dietary folate and pancreatic cancer risk comprising of eight studies showed a decreased risk of pancreatic cancer (OR 0.66; 95% CI 0.49-0.89).

CONCLUSION

Dietary folate intake is associated with a decreased risk of esophageal and pancreatic cancer, but not gastric cancer. Interpretation of these relationships is complicated by significant heterogeneity between studies when pooled, and by small numbers of studies available to analyze when stratification is performed to reduce heterogeneity.

Helicobacter pylori infection in obesity and its clinical outcome after bariatric surgery

The present review summarizes the prevalence and active clinical problems in obese patients with Helicobacter pylori (H. pylori) infection, as well as the outcomes after bariatric surgery in this patient population. The involvement of H. pylori in the pathophysiology of obesity is still debated. It may be that the infection is protective against obesity, because of the gastritis-induced decrease in production and secretion of the orexigenic hormone ghrelin. However, recent epidemiological studies have failed to show an association between H. pylori infection and reduced body mass index. H. pylori infection might represent a limiting factor in the access to bariatric bypass surgery, even if high-quality evidence indicating the advantages of preoperative H. pylori screening and eradication is lacking. The clinical management of infection is complicated by the lower eradication rates with standard therapeutic regimens reported in obese patients than in the normal-weight population. Prospective clinical studies to ameliorate both H. pylori eradication rates and control the clinical outcomes of H. pylori infection after different bariatric procedures are warranted.

Effect of Helicobacter pylori eradication on metachronous recurrence after endoscopic resection of gastric neoplasm

OBJECTIVES

Although many epidemiologic studies have shown that Helicobacter pylori (H. pylori) eradication has prophylactic effects on gastric cancer, their results are less clear in high-risk populations. We conducted this study to examine whether H. pylori eradication would affect the occurrence of metachronous gastric cancer after endoscopic resection in patients with early gastric cancer.

METHODS

We retrospectively analyzed 2,089 adults who underwent endoscopic resection of gastric low-grade neoplasia, high-grade neoplasia, or differentiated invasive neoplasia from 2004 to 2008 at Asan Medical Center. Of these, a total of 1,007 patients with early gastric cancer were enrolled in this study. We evaluated the demographic data, the pathology, and the incidence of metachronous recurrence by dividing them into three groups: those without active H. pylori infection (Hp negative group, n=340), those who successfully underwent H. pylori eradication (eradicated group, n=485), and those who failed or did not undergo H. pylori eradication (noneradicated group, n=182).

RESULTS

Metachronous recurrence was diagnosed in 75 patients, including 17 in the Hp, 34 in the eradicated, and 24 in the noneradicated groups. Median time to metachronous recurrence was 18 months (range, 7-75 months). The incidence of metachronous gastric cancer was 10.9 cases per 1,000 person-years in the Hp negative group, 14.7 cases per 1,000 person-years in the eradicated group, and 29.7 cases per 1,000 person-years in the noneradicated group. The hazard ratios in the noneradicated group compared with the Hp negative and eradicated groups were 2.5 (P<0.01) and 1.9 (P=0.02), respectively. H. pylori eradication reduced metachronous recurrence of gastric neoplasm, which was also shown in the secondary analysis of 1,487 patients with low-grade neoplasia and early gastric cancer.

CONCLUSIONS

Successful H. pylori eradication may reduce the occurrence of metachronous gastric cancer after endoscopic resection in patients with early gastric cancer.

Helicobacter pylori CagA and VacA genotypes and gastric phenotype: a meta-analysis

BACKGROUND

CagA+ and vacuolizing cytotoxin (VacA)-specific strains of Helicobacter pylori have been associated with different risks for developing gastric lesions. We aim to summarize a possible association between these genotypes and the risk for developing different gastric phenotypes.

MATERIALS AND METHODS

A MEDLINE database (PubMed) search was performed and a meta-analysis conducted.

RESULTS

Forty-four studies were retrieved, all with either a case-control (n=13) or cross-sectional (n=31) design, including 17 374 patients. CagA positivity was associated with an increased risk for gastric cancer [odds ratio (OR) 2.09 (95% confidence interval (CI), 1.48-2.94)] compared with that in individuals without gastric lesions [OR 2.44 (95% CI 1.27-4.70)] and in those with previously identified gastritis. In addition, there was an increased risk for peptic ulcer disease [OR 1.69 (95% CI 1.12-2.55)]. Individuals harboring the H. pylori strains VacA s1 (vs. s2), m1 (vs. m2), s1m1 (vs. s1m2), and s1m1 (vs. s2m2) had an increased risk for development of cancer [OR of 5.32 (95% CI 2.76-10.26), 2.50 (95% CI 1.67-3.750), 2.58 (95% CI 1.24-5.38), and 4.36 (95% CI 2.08-9.10), respectively]. s1m1 strains (vs. s2m2) were also associated with peptic ulcer disease [OR 2.04 (1.01-4.13)].

CONCLUSION

Our results indicate that individuals infected with CagA+ H. pylori strains and those infected with VacA s1 and m1 strains have an increased risk for gastric cancer. Cohort studies are welcome to integrate this information in the management of at-risk individuals such as those with precancerous cancer conditions and/or a family history of gastric cancer.

Exploring bacterial flora in oral squamous cell carcinoma: a microbiological study

The oral cavity contains a unique and diverse microflora. While most of these organisms exhibit commensalism, shifts in bacterial community dynamics cause pathological changes within the oral cavity and at distant sites. We assessed the microbial flora using cultured saliva and oral swabs from subjects with oral squamous cell carcinoma (OSCC) and healthy controls. Microbial samples were collected from the carcinoma site, contralateral healthy mucosa, and saliva of the study group and samples were collected from healthy mucosa and saliva of controls. Samples were stored on ice and transported to the laboratory for culture. The median number of colony forming units (CFU)/ml at carcinoma sites was significantly greater than at the contralateral healthy mucosa. Similarly, in saliva of carcinoma subjects, the median number of CFU/ml was significantly greater than in saliva of control subjects.

ITGA1 polymorphisms and haplotypes are associated with gastric cancer risk in a Korean population

AIM: To evaluate the association between the genetic polymorphisms and haplotypes of the ITGA1 gene and the risk of gastric cancer.

METHODS: The study subjects were 477 age- and sex-matched case-control pairs. Genotyping was performed for 15 single nucleotide polymorphisms (SNPs) in ITGA1. The associations between gastric cancer and these SNPs and haplotypes were analyzed with multivariate conditional logistic regression models. Multiple testing corrections were carried out following methodology for controlling the false discovery rate. Gene-based association tests were performed using the versatile gene-based association study (VEGAS) method.

RESULTS: In the codominant model, the ORs for SNPs rs2432143 (1.517; 95%CI: 1.144-2.011) and rs2447867 (1.258; 95%CI: 1.051-1.505) were statistically significant. In the dominant model, polymorphisms of rs1862610 and rs2447867 were found to be significant risk factors, with ORs of 1.337 (95%CI: 1.029-1.737) and 1.412 (95%CI: 1.061-1.881), respectively. In the recessive model, only the rs2432143 polymorphism was significant (OR = 1.559, 95%CI: 1.150-2.114). The C-C type of ITGA1 haplotype block 2 was a significant protective factor against gastric cancer in the both codominant model (OR = 0.602, 95%CI: 0.212-0.709, P = 0.021) and the dominant model (OR = 0.653, 95%CI: 0.483-0.884). The ITGA1 gene showed a significant gene-based association with gastric cancer in the VEGAS test. In the dominant model, the A-T type of ITGA1 haplotype block 2 was a significant risk factor (OR = 1.341, 95%CI: 1.034-1.741). SNP rs2447867 might be related to the severity of gastric epithelial injury due to inflammation and, thus, to the risk of developing gastric cancer.

CONCLUSION: ITGA1 gene SNPs rs1862610, rs24321

43, and rs2447867 and the ITGA1 haplotype block that includes SNPs rs1862610 and rs2432143 were significantly associated with gastric cancer.

VEZT, a novel putative tumor suppressor, suppresses the growth and tumorigenicity of gastric cancer

Vezatin (VEZT), an adherens junctions transmembrane protein, was identified as a putative tumor suppressor in our previous study. However, the role of VEZT in tumorigenesis remains elusive. We aimed to clarify its epigenetic regulation and biological functions in gastric cancer. In this study, we show that the expression level of VEZT is involved in lymphatic metastasis, depth of cancer invasion and TNM stage in 104 gastric cancer patients. Bisulfate sequencing polymerase chain reaction (BSP) methods showed that VEZT was hypermethylated in tissues and corresponding blood of gastric cancer patients compared with healthy controls. Helicobacter pylori (H. pylori) infection induces the methylation and silencing of VEZT in GES-1 cells. Restoring VEZT expression in MKN-45 and NCI-N87 gastric cancer cells inhibited growth, invasion and tumorigenesis in vitro and in vivo. Global microarray analysis was applied to analyze the molecular basis of the biological functions of VEZT after VEZT transfection combined with real-time PCR and chromatin immunoprecipitation assay. G protein-coupled receptor 56(GPR56), cell growth, cell division cycle 42(CDC42), migration/invasion and transcription factor 19(TCF19), cell cycle progression, were identified as direct VEZT target genes. TCF19, a novel target of VEZT, was functionally validated. Overexpression of TCF19 in MKN-45 cells increased cell cycle progress and growth ability. This study provides novel insight into the regulation of the VEZT gene, which could represent a potential target for therapeutic anti-cancer strategies.

Effect of Helicobacter pylori eradication on gastric atrophy and intestinal metaplasia in patients with atrophic gastritis

AIM: To investigate the effect of Helicobacter pylori (H. pylori) eradication on gastric atrophy and intestinal metaplasia in patients with atrophic gastritis.

METHODS: Three hundred and ninety-two patients with atrophic gastritis and intestinal metaplasia who were treated from August 2009 to December 2009 at Shanghai 7^th People's Hospital were enrolled, of whom 300 were followed for 1 and 3 years by narrow band imaging-magnifying endoscopy (NBI-ME) and histopathological analysis after H. pylori eradication.

RESULTS: In patients with successful eradication, grades of disease activity and chronic inflammation significantly decreased at 1 year (in the antrum: 1.41 ± 0.64 vs 1.21 ± 0.65, 1.83 ± 0.59 vs 1.43 ± 0.50; in the corpus: 1.36 ± 0.67 vs 1.18 ± 0.67, 1.71 ± 0.46 vs 1.35 ± 0.48, all P < 0.005) and 3 years (in the antrum: 1.51 ± 0.62 vs 1.31 ± 0.69, 1.97 ± 0.60 vs 1.46 ± 0.50; in the corpus: 1.48 ± 0.65 vs 1.26 ± 0.69, 1.90 ± 0.56 vs 1.46 ± 0.50, all P < 0.005). The grade of corpus atrophy also significantly decreased at 1 year (1.54 ± 0.65 vs 1.36 ± 0.68, P < 0.005) and 3 years (1.68 ± 0.65 vs 1.50 ± 0.69, P < 0.005) after successful eradication. However, there was no significant change in intestinal metaplasia in both the antrum and corpus.

CONCLUSION: Eradication of H. pylori results in the alleviation of the severity of gastritis and the reversion of gastric atrophy in the corpus.

Genetic polymorphism of glutathione S-transferases M1 and T1, tobacco habits and risk of stomach cancer in Mizoram, India

AIM

The incidence of stomach cancer in Mizoram is highest in India. We have conducted a population based matched case-control study to identify environmental and genetic risk factors in this geographical area.

METHODS

A total of 102 histologically confirmed stomach cancer cases and 204 matched healthy population controls were recruited. GSTM1 and GSTT1 genotypes were determined by PCR and H. pylori infections were determined by ELISA.

RESULTS

Tobacco-smoking was found to be an important risk factor for high incidence of stomach cancer in Mizoram. Meiziol (local cigarette) smoking was a more important risk factor than other tobacco related habits. Cigarette, tuibur (tobacco smoke infused water) and betel nut consumption synergistically increased the risk of stomach cancer. Polymorphisms of GSTM1 and GSTT1 genes were not found to be directly associated with stomach cancer in Mizoram. However, they appeared to be effect modifiers. Persons habituated with tobacco smoking and/or tuibur habit had increased risk of stomach cancer if they carried the GSTM1 null genotype and GSTT1 non-null genotype.

CONCLUSION

Tobacco smoking, especially meiziol is the important risk factor for stomach cancer in Mizoram. GSTM1 and GSTT1 genes modify the effect of tobacco habits. This study is a first step in understanding the epidemiology of stomach cancer in Mizoram, India.

Association between genetic polymorphisms of NOD 1 and Helicobacter pylori-induced gastric mucosal inflammation in healthy Korean population

BACKGROUND

Gastric cancer is supposed to be a result of inflammation induced by Helicobacter pylori (H. pylori) infection. Nucleotide-binding oligomerization domain 1 (NOD 1) is required for the innate immune response to H. pylori. We aim to investigate whether single nucleotide polymorphism (SNP) in NOD 1 gene is associated with H. pylori-induced gastric mucosal inflammation in a healthy Korean population.

METHODS

The study was conducted on 412 adults who visited two different healthcare centers for health examinations. The G796A (E266K) NOD 1 SNP was detected by using polymerase chain reaction/restriction fragment length polymorphism. A gastritis score was calculated by the summed values of the grade and the activity of gastritis scored according to the updated Sydney system. The expression of IL-8 and COX-2 mRNA was assessed by quantitative reverse transcription polymerase chain reaction. In the group with H. pylori infection, the complete screening of the genes comprising the cag PAI was performed.

RESULTS

The genotype frequencies were 26.7% (AA type), 58.3% (GA), and 15.0% (GG). In H. pylori-positive patients, gastritis score of the AA genotype was significantly higher than those of the others (p = .04). Also, the IL-8 and COX-2 mRNA levels increased in the AA genotype. In the group with H. pylori infection, 31.9% were found to carry the complete cag PAI. When the subjects were infected with intact cag PAI, the IL-8 and COX-2 mRNA levels were significantly high in AA genotype.

CONCLUSION

G796A (E266K) NOD 1 polymorphism is closely correlated with H. pylori-associated gastric mucosal inflammation in the Korean population.

Overview of methodological quality of systematic reviews about gastric cancer risk and protective factors

BACKGROUND AND OBJECTIVE

A comprehensive overall review of gastric cancer (GC) risk and protective factors is a high priority, so we conducted the present study.

METHODS

Systematic searches in common medical electronic databases along with reference tracking were conducted to include all kinds of systematic reviews (SRs) about GC risk and protective factors. Two authors independently selected studies, extracted data, and evaluated the methodological qualities and the quality of evidence using R-AMSTAR and GRADE approaches.

RESULTS

Beta- carotene below 20 mg/day, fruit, vegetables, non-fermented soy-foods, whole-grain, and dairy product were GC protective factors, while beta-carotene 20 mg/day or above, pickled vegetables, fermented soy-foods, processed meat 30 g/d or above, or salty foods, exposure to alcohol or smoking, occupational exposure to Pb, overweight and obesity, helicobacter pylori infection were GC risk factors. So we suggested screening and treating H. pylori infection, limiting the amount of food containing risk factors (processed meat consumption, beta-carotene, pickled vegetables, fermented soy-foods, salty foods, alcohol), stopping smoking, avoiding excessive weight gain, avoidance of Pb, and increasing the quantity of food containing protective components (fresh fruit and vegetables, non-fermented soy-foods, whole-grain, dairy products).

CONCLUSIONS

The conclusions and recommendations of our study were limited by including SRs with poor methodological bases and low quality of evidence, so that more research applying checklists about assessing the methodological qualities and reporting are needed for the future.

IgG2 response and low IgG titre specific to Helicobacter pylori CagA as serological markers for gastric cancer

Infection with Helicobacter pylori cytotoxin-associated gene A (CagA)-positive strains is associated with the development of gastric cancer (GC). However, some reports have failed to demonstrate an increased frequency of CagA antibodies in GC patients. This study evaluated the response of IgG antibody and subclasses IgG1 and IgG2 against both CagA and H. pylori membrane antigens in patients with pre-cancerous lesions and cases with GC. A total of 137 patients with a positive serum IgG response to H. pylori were selected: 46 with intestinal metaplasia, 41 with gastric adenocarcinoma and 50 with non-atrophic gastritis (NAG) considered as controls. The response of total IgG, IgG1 and IgG2 was investigated by immunoblot and ELISA using an in-house recombinant CagA and membrane antigens from a local strain, and possible associations were estimated using a logistic regression model. Compared with NAG patients, GC patients showed a higher frequency of IgG2 CagA antibodies (55.2 vs 15.4 %, P = 0.001), but a lower frequency (80.5 vs 96.0 %, P = 0.021) and diminished levels of IgG2 H. pylori antibodies [12.5 vs 21.9 ELISA units (EU), P = 0.007]. GC patients also presented lower levels of CagA (32.6 vs 42.4 EU, P = 0.004) and H. pylori total IgG (33.7 vs 38.7 EU, P = 0.029). GC was associated with a positive IgG2 CagA response [odds ratio (OR) = 3.74, 95 % confidence interval (CI) 1.81-5.37; P = 0.002] and with a low titre of total IgG CagA antibodies (OR = 2.18, 95 % CI 1.35-2.69; P = 0.006). These results suggest that the IgG2 response to CagA could be used as a novel serological marker to identify patients with H. pylori-associated GC.

Irregular Meal Timing Is Associated with Helicobacter pylori Infection and Gastritis

Helicobacter pylori (HP) is associated with chronic gastritis and gastric cancer, and more than half of the world's population is chronically infected. The aim of this retrospective study was to investigate whether an irregular meal pattern is associated with increased risk of gastritis and HP infection. The study involved 323 subjects, divided into three groups as follows: subjects with HP infection and gastritis, subjects with gastritis, and a control group. Subjects were interviewed on eating habits and meal timing. Multivariate logistic regression was used to compare groups. Adjusted odds ratios (OR) were derived controlling for gender, age, stress, and probiotic consumption. Subjects who deviated from their regular meals by 2 hours or more had a significantly higher incidence of HP infection with gastritis (adjusted OR = 13.3; 95% CI 5.3–33.3; P < 0.001) and gastritis (adjusted OR = 6.1; 95% CI 2.5–15.0; P < 0.001). Subjects who deviated their meals by 2 hours or more, twice or more per week, had an adjusted OR of 6.3 and 3.5 of acquiring HP infection with gastritis (95% CI 2.6–15.2; P < 0.001) and gastritis (95% CI 1.5–8.5; P < 0.001), respectively. Frequent deviation in meal timing over a prolonged period appears associated with increased risk of developing HP infection and gastritis.

Gastric cancer epidemiology and risk factors

Gastric cancer is a prevalent yet heterogeneous disease. From diet and lifestyle to genetics and ethnicity, our appreciation of the complexity of gastric cancer has evolved. This review will discuss the epidemiology of gastric cancer focusing on trends across various risk categories. We realize that gastric cancer is not merely a single disease, but rather individual diseases within a single organ-a distinction that will aid our understanding of disease heterogeneity and its significance.

Genetic polymorphisms in the osteopontin promoter increases the risk of distance metastasis and death in Chinese patients with gastric cancer

BACKGROUND

In vitro and in vivo studies have suggested that osteopontin (OPN) is associated with many types of cancers. However, no studies have reported the incidence of OPN polymorphisms and the risk of gastric cancer. The aim of this study was to investigate the association between OPN polymorphisms and gastric cancer in a Chinese patient population.

METHODS

Three genetic variants in the OPN promoter were genotyped using direct sequencing in 200 gastric cancer patients and 200 gender- and age-matched cancer-free controls. The 4-year survival curve was calculated using the Kaplan-Meier method and compared using the log-rank test for each single nucleotide polymorphism (SNP) site. We measured the promoter activity of the -443 T → C polymorphism using a dual luciferase reporter assay.

RESULT

For the variant at nt -443 (CC), there was a significant difference between the number of patients with stage IV and those with stage I gastric cancer (IA + IB; P = 0.014) and between those with stage IV and all other stages of gastric cancer (IA + IB + II + III; P = 0.02). For the variant at nt -443 (CT), there was a significant difference between the number of gastric cancer patients with stage IV and those with stage II (P = 0.013). The survival rates for patients with the C/C genotype were significantly lower than for patients with the other two genotypes (C/T, T/T). Moreover, significantly higher luciferase activities were observed in the pGL3-C construct compared to the pGL3-T construct.

CONCLUSIONS

This study provides the first evidence that variation at nt -443 in the OPN promoter increases the potential for gastric cancer metastasis and subsequent death in the Chinese population.

Prevalence of Helicobacter pylori infection in bariatric patients: a histologic assessment

BACKGROUND

Studies on rates of Helicobacter pylori (HP) infection in morbidly obese patients awaiting bariatric surgery are conflicting because of small sample size and variability in diagnostic testing. The objective of this study was to determine the rate of biopsy-proven active HP infection in morbidly obese patients undergoing bariatric surgery.

METHODS

Retrospective analysis was done on all morbidly obese patients who underwent bariatric surgery between 2001 and 2009. All patients underwent preoperative upper endoscopy with biopsy to evaluate HP status. All endoscopies and surgeries were performed by a single endoscopist and surgeon, respectively. Data were analyzed with Student t test, Pearson χ(2) test, and logistic regression for multivariate analysis.

RESULTS

The 611 patients included 79 males (12.9%) and 532 females (87.1%). Mean age was 39.9 ± 10.7 years, and mean body mass index (BMI) was 47.8 ± 6.4 kg/m(2). The overall HP infection rate was 23.7%. Rate of infection did not differ between gender (22.8% in males, 23.9% in females; P = .479) or BMI (48.6 ± 6.5 kg/m(2) in HP-positive patients, 47.5 ± 6.4 kg/m(2) in HP-negative patients; P = .087). Patients with HP were older compared with those without infection (41.2 versus 38.7 years; P =.016). Hispanics had a higher prevalence of HP (OR 2.35; P = .023).

CONCLUSION

Increasing BMI is not an independent risk factor for active HP infection within the morbidly obese patient population. Need for invasive testing to detect HP infection in these patients should be re-evaluated. Other methods of detecting active HP infection should be considered as an alternative to invasive or serologic testing.

Predictive factors for improvement of atrophic gastritis and intestinal metaplasia after Helicobacter pylori eradication: a three-year follow-up study in Korea

BACKGROUND AND AIMS

To date, data on the effects of anti-Helicobacter therapy on the improvement of atrophic gastritis (AG) and intestinal metaplasia (IM) have been conflicting. This study was performed to investigate whether eradication of H. pylori could lead to the improvement of AG and IM, and the prognostic factors associated with the improvement of AG and IM.

METHODS

Four hundred patients consisting of H. pylori-negative (n = 116) and H. pylori-positive (n = 284) groups were followed up 1 and 3 years after initial H. pylori tests. Serum levels of pepsinogen (PG), bacteria, environmental factors, and genetic polymorphisms were determined.

RESULTS

The grade of corpus atrophy decreased at 1 and 3 years after successful eradication (p < .001 and p = .033, respectively). However, there was no significant change in the IM in the antrum and in the corpus. Prediction factors for the improvement of corpus AG by H. pylori eradication were baseline low PG I/II ratio (≤3), high salt intake, and corpus-predominant gastritis. IM improvement was also associated with spicy food intake and high baseline grade of IM, in addition to these factors. In addition, IL-1B-511 C/T and IL-6-572 C/G alleles were found to inhibit IM improvement. However, H. pylori-negative and noneradicated group did not show any significant change in AG or IM.

CONCLUSION

Corpus AG was reversed by H. pylori eradication, and improvement of IM by H. pylori eradiation was more definite in patients with severe IM, low PG I/II ratio, and corpus-predominant gastritis, suggesting that H. pylori eradication is valuable even in severe cases.

Helicobacter pylori eradication therapy in obese patients undergoing gastric bypass surgery--fourteen days superior to seven days?

BACKGROUND

The high prevalence of Helicobacter pylori (HP) in our obese population undergoing Roux-en-Y bypass gastric surgery (69.4%) and the concern that it may exacerbate postoperative foregut symptoms and increase gastric cancer risk led us to adopt a policy of HP systematic eradication in this group of patients. Our aim, in obese patients undergoing bypass gastric surgery, was to compare effectivity of 7- and 14-days clarithromycin-based triple therapy as the first-line treatment for HP eradication.

METHODS

Three hundred seventy-three patients [mean age 41.2 ± 10.3 years; 313 women (83.9%)] were HP positive determined by histology or urea breath test. In 2005, 94 patients (Group A) were treated with a 7-days triple therapy-proton pump inhibitor (PPI) b.i.d., clarithromycin (CL) 500 mg b.i.d., and amoxicillin (AMX) 1,000 mg b.i.d. Since 2006, 279 patients (Group B) were treated with a similar 14-days drug regimen-PPI b.i.d., CL 500 mg b.i.d., and AMX 1,000 mg b.i.d. Posttreatment HP status was assessed by C13 urea breath test 4-6 weeks after the end of therapy.

RESULTS

The eradication rates were 67.0% (Group A) and 79.9% (Group B). The eradication rate achieved with 14-days triple therapy was significantly higher than with 7-days triple therapy (OR = 1.96; 95% CI: 1.16-3.30; p = 0.016).

CONCLUSIONS

A 14-days triple therapy is more effective than 7-days triple therapy suggesting this regimen should be the first-line therapy for HP eradication in Portuguese obese patients undergoing bypass gastric surgery.

Association of IL-10-1082 promoter polymorphism with susceptibility to gastric cancer: evidence from 22 case-control studies

Evidence suggested that interleukin-10 (IL-10) may be involved in the etiology of gastric cancer (GC). However, epidemiological studies on the association between IL-10-1082 promoter polymorphism and GC risk are still ambiguous. To quantitatively summarize the evidence for such a relationship, we performed a meta-analysis. Systemic searches of the PubMed and Medline databases were performed, with the last report up to July 2011. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. 22 independent studies including 4,289 cases and 5,965 controls were involved in this meta-analysis. Obvious association was found when all studies were pooled into the meta-analysis (A vs. G: OR = 0.489, 95% CI = 0.335-0.713, P < 0.001). In the subgroup analysis by ethnicity, we observed significant associations in Asians (A vs. G: OR = 0.651, 95% CI = 0.506-0.838, P = 0.001; AA vs. GG: OR = 0.482, 95% CI = 0.328-0.709, P < 0.001; AA/AG vs. GG: OR = 0.711, 95% CI = 0.527-0.959, P = 0.025; AA vs.

AG/GG

OR = 0.701, 95% CI = 0.520-0.944, P = 0.019) and Caucasians (A vs. G: OR = 0.365, 95% CI = 0.140-0.949, P = 0.039), but not in Latino population. When stratified analysis by control sources, our results indicated that A allele decreased approximately 48% risk among population-based studies (A vs. G: OR = 0.524, 95% CI = 0.374-0.733, P < 0.001). Taken together, this meta-analysis suggests that IL-10-1082 polymorphism is associated with GC risk.

Efficacy of the Combination of Tetracycline, Amoxicillin, and Lansoprazole in the Eradication of Helicobacter pylori in Treatment-Naïve Patients and in Patients Who Are Not Responsive to Clarithromycin-Based Regimens: A Pilot Study

Background/Aims

The aim of this study was to evaluate the eradication rate of a triple therapy regimen that included a proton pump inhibitor, amoxicillin, and tetracycline instead of clarithromycin in treatment-Naïve patients and in patients who did not respond to standard triple therapy.

Methods

This study included 110 patients infected with Helicobacter pylori. Patients in groups A and B were treatment-Naïve, and those in group C were not responsive to previous standard triple therapy. Patients in group A (n=40) received lansoprazole 30 mg b.i.d., amoxicillin 1,000 mg b.i.d., and clarithromycin 500 mg b.i.d. for 14 days. Patients in groups B (n=40) and C (n=30) received lansoprazole 30 mg b.i.d., amoxicillin 1,000 mg b.i.d., and tetracycline 500 mg q.i.d. for 14 days.

Results

In group A, eradication was achieved in 18 (45%) of the 40 patients included in the intention-to-treat (ITT) analysis and in 18 (47.4%) of the 38 patients included in the per-protocol (PP) analysis. In group B, eradication was achieved in 15 (37.5%) of the 40 patients included in the ITT analysis and in 15 (39.3%) of the 38 patients included in the PP analysis. In group C, eradication was achieved in 14 (46.6%) of the 30 patients included in the ITT analysis and in 14 (43.8%) of the 29 patients included in the PP analysis. There was no statistically significant difference among the 3 groups with regard to eradication rates (p>0.05).

Conclusions

Despite the low rate of resistance to tetracycline, the combination of lansoprazole, amoxicillin, and tetracycline instead of clarithromycin is not a good option for the eradication of H. pylori.

Gastric cancer risk according to the distribution of intestinal metaplasia and neutrophil infiltration

BACKGROUND AND AIM

Gastritis and intestinal metaplasia (IM) have long been known to be risk factors for and precursors of gastric cancer. We aimed to elucidate the association between gastric cancer risk and the distribution of precancerous lesions in the stomach by histological analyses.

METHODS

We analyzed patients from whom two biopsy specimens (one from the antrum and one from the corpus) were obtained by upper gastrointestinal endoscopy. Specimens were assessed for Helicobacter pylori, IM, and neutrophil infiltration (NI). Patients were classified into three groups based on the presence of IM. Patients were also classified into four groups based on the presence of NI. The prevalence of gastric cancer was compared between groups.

RESULTS

A total of 1395 patients were analyzed. Of these, 54 had gastric cancer (34 intestinal and 20 diffuse type). A multivariate analysis showed that male sex and the distribution of IM were independent risk factors for intestinal-type cancer. Compared with patients without IM (n = 1005), the odds ratio (OR) for patients with IM in the antrum only (n = 240) was 2.34 (95% confidence interval: 1.08-4.96), and that for patients with IM in the corpus (n = 150) was 5.84 (2.92-11.8). However, NI was related to diffuse-type cancer. Compared with patients without NI (n = 899), the OR for patients with NI in the corpus only (n = 122) was 3.66 (1.02-12.2).

CONCLUSIONS

The histological pattern and distribution of gastric mucosal change assessed by two biopsy specimens were related to gastric cancer.

Gastric carcinogenesis

INTRODUCTION

In most patients, gastric cancer is diagnosed in advanced stage. Curative treatment options are limited and the mortality is high. The process of gastric carcinogenesis is triggered by Helicobacter pylori-driven gastritis and is further characterized by its complexity of interaction with other risk factors. Health care systems are challenged for the improvement of prevention, early diagnosis, and effective treatments.

METHODS

An extensive literature research has been performed to elucidate the interplay between etiological factors involved in gastric carcinogenesis.

RESULTS

H. pylori is the most important carcinogen for gastric adenocarcinoma. Evidence is provided by experiments including animal studies as well as clinical observational and interventional studies in humans. Eradication has the potential to prevent gastric cancer and offers the greatest benefit if performed before premalignant changes of the gastric mucosa have occurred. Bacterial virulence factors are essential players in modulating the immune response involved in the initiation of the carcinogenesis in the stomach. Host genetic factors contribute to the regulation of the inflammatory response and in the aggravation of mucosal damage. The harmful role of environmental factors is restricted to salt intake and smoking of tobacco. The ingestion of fruit and vegetables has some protective effect.

CONCLUSION

Infection with H. pylori is the major risk factor for gastric cancer development, and thus, eradication of the Helicobacter offers a promising best option for prevention of the disease. Bacterial virulence, host genetic factors, and environmental influences are interacting in the multifactorial process of gastric carcinogenesis.

Supplementing vitamins C and E to standard triple therapy for the eradication of Helicobacter pylori

WHAT IS KNOWN AND OBJECTIVE

Helicobacter pylori eradication rates of currently accepted triple therapy regimens vary between geographic locations and do not exceed 70-80%. Eradication rates are much lower in locations where uncontrolled antibiotic use is common such as Turkey. In the present study, we aimed to test whether supplementing vitamins C and E to standard triple therapy, including a proton pump inhibitor plus amoxicillin plus clarithromycin, increased the H. pylori eradication rate.

METHODS

Two hundred patients infected with H. pylori were randomized into two groups in an open-label trial. In group A, patients (n = 160) were given standard triple therapy, including lansoprazole 30 mg BID plus amoxicillin 1000 mg BID plus clarithromycin 500 mg BID for 14 days, plus vitamin C 500 mg BID plus vitamin E 200 IU BID for 30 days. In group B, patients (n = 40) were given standard triple therapy for 14 days. The success of H. pylori eradication was defined as a negative ¹⁴C-urea breath test result, 4-6 weeks after the completion of therapy. Comaprisons were by both intention-to-treat (ITT) and per-protocol (PP) analysis.

RESULTS AND DISCUSSION

Two hundred patients (137 women, 63 men) were analysed using ITT analysis and 195 patients completed the study. In group A, H. pylori eradication was achieved in 132 of the 160 patients (82·5%) included in ITT analysis and 132 of the 157 patients (84%) included in PP analysis. In group B, H. pylori eradication was achieved in 18 of the 40 patients (45%) included in ITT analysis and 18 of the 38 patients (47·4%) included in PP analysis. Eradication rates were significantly higher in group A than in group B (P < 0·005). Eradication rates were not statistically significant between men and women in both groups.

WHAT IS NEW AND CONCLUSION

Adding vitamins C and E to standard triple therapy increases the eradication rate of H. pylori. Vitamins C and E may increase the eradication rate via increasing the effectiveness of the antibiotics by decreasing oxidative stress in the gastric mucosa and strengthening the immune system.

Combined effect of miR-146a rs2910164 G/C polymorphism and Toll-like receptor 4 +3725 G/C polymorphism on the risk of severe gastric atrophy in Japanese

BACKGROUND

A G/C polymorphism in miRNA-146a (rs2910164) was shown to be associated with the risk of hepatocellular carcinoma.

OBJECTIVE

This study aimed to examine the associations of the miR-146a G/C (rs2910164) and TLR4 +3725 G/C (rs11536889) polymorphisms with the risk of Helicobacter pylori (H. pylori) infection, gastric atrophy, and gastric cancer in a Japanese population.

METHODS

Subjects for this study were 583 histologically diagnosed gastric cancer patients and age- and sex-frequency-matched 1,742 control outpatients (1,637 subjects were eligible for the analyses), who visited Aichi Cancer Center Hospital from the year 2001 to 2005. Serum pepsinogens were measured to evaluate gastric atrophy.

RESULTS

When H. pylori-seropositive subjects or subjects with gastric atrophy were defined as H. pylori-infected subjects, the age- and sex-adjusted odds ratio (aOR) of severe gastric atrophy among the H. pylori infected was 1.44 (95% confidence interval [95% CI]=0.89-2.34, p=0.133) in G/G genotype of miR-146a polymorphism. When combined with TLR4 G/C polymorphism, the OR in those with miR-146a G/G and TLR4 G/C+C/C genotypes was significantly increased relative to those with miR-146a C/C+G/C and TLR4 G/G among the H. pylori-infected subjects: aOR=2.04 (95% CI=1.10-3.82, p=0.025).

CONCLUSIONS

This study revealed the combined effect of miR-146a rs2910164 G/G and TLR4 +3725 C allele on the increased risk of severe gastric atrophy among the H. pylori-infected Japanese subjects.

H. pylori seropositivity before age 40 and subsequent risk of stomach cancer: a glimpse of the true relationship?

Stomach carcinogenesis involves mucosal and luminal changes that favor spontaneous disappearance of Helicobacter pylori. Therefore, the association between the infection and cancer risk might typically be underestimated. As acquisition of the infection almost invariably occurs before adulthood, the serostatus at age 16–40 should best reflect the lifetime occurrence of the infection. We therefore conducted a case-control study nested within a historic cohort of about 400,000 individuals who donated sera before age 40 to either of two large Swedish Biobanks between 1968 and 2006, and whose records were linked to complete nationwide registers. For each stomach adenocarcinoma case occurring at least 5 years after serum donation 2 controls were selected matched on age, sex and year of donation and biobank. Serum immunoglobulin G antibodies against H. pylori cell-surface antigens (Hp-CSAs) were measured with an enzyme–linked immunosorbent assay and antibodies against CagA with an immunoblot assay. Conditional logistic regression models were used to estimate odds ratios (ORs) for stomach adenocarcinoma among H. pylori infected relative to uninfected. We confirmed 59 incident cases of stomach adenocarcinoma (41 non-cardia tumors) during follow-up. ORs for non-cardia stomach adenocarcinoma among subjects with Hp-CSA antibodies (regardless of CagA serostatus), antibodies against CagA (regardless of Hp-CSA serostatus), and antibodies to both, relative to those who were seronegative to both, were 17.1 (95% confidence interval [CI] 4.0–72.9), 10.9 (95% CI 3.2–36.9), and 48.5 (95% CI 5.8–407.4), respectively. H. pylori infection is a much stronger risk factor for non-cardia stomach adenocarcinoma than initially realized. However, further studies are needed to answer whether it is a necessary cause, as the possibility of misclassification of H. pylori status could not be ruled out in our study.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

H. pylori infection is a key risk factor for proximal gastric cancer

BACKGROUND

Despite evidence for the association of distal gastric cancer (GC) with the H. pylori infection, relevance of the infection for proximal GC is uncertain.

AIMS

We analysed the prevalence of H.pylori in proximal and distal GC and its association with premalignant mucosal alterations in different gastric locations.

METHODS

We performed a retrospective analysis on 152 patients with GC, stratified according to the location of the main tumor mass into proximal (n = 73) and distal (n = 79) GC. H.pylori prevalence and CagA-status were determined by serology. Intestinal metaplasia (IM), glandular atrophy and mucosal inflammation were diagnosed from histological specimens and graded according to the updated Sydney-classification.

RESULTS

H.pylori prevalence (78.1 vs. 82.3%) and CagA-status (77.2 vs. 84.6%) were similar in proximal and distal GC as well as in intestinal and diffuse GC. IM (79.8 vs. 60.3%; P = 0.012) and atrophy (50.0 vs. 19.1%; P < 0.001) were more frequent in the mucosa surrounding intestinal tumors. There was a higher degree of surrounding IM in case of distally located compared to proximal tumors (P = 0.001). Overall, IM was more severe in the antrum than the corpus. In contrast, there was more severe active inflammation in the corpus than the antrum (P = 0.017).

CONCLUSION

The prevalence of H.pylori is similar in proximal and distal GC if precise allocation of the primary tumor has been performed, especially at the esophagogastric junction. Distal tumors of the intestinal type are more often associated with local IM than proximal and diffuse type carcinomas. This suggests a distinct pathophysiological relevance of these mucosal alterations.

Genetic predisposition to Helicobacter pylori-induced gastric precancerous conditions

Gastric cancer is the most common malignancy of the gastrointestinal tract in East Asian populations and the second most frequent cause of cancer-related mortality in the world. While previous studies have investigated the genetic factors involved in gastric carcinogenesis, there still exist relatively few studies that have investigated the genetic traits associated with the risk of gastric precancerous conditions. In this paper we will review the biology and genetic polymorphisms involved in the genesis of gastric precancerous conditions reported to date and discuss the future prospects of this field of study. The associations of gastric precancerous conditions with polymorphisms in the cytotoxin-associated gene A-related genes (e.g. PTPN11 G/A at intron 3, rs2301756), those in the genes involved in host immunity against Helicobacter pylori (H. pylori) infection (e.g. TLR4 +3725G/C, rs11536889) or polymorphisms of the genes essential for the development/ differentiation of the gastric epithelial cells (e.g. RUNX3 T/A polymorphism at intron 3, rs760805) have been reported to date. Genetic epidemiological studies of the associations between H. pylori-induced gastric precancerous conditions and other gene polymorphisms in these pathways as well as polymorphisms of the genes involved in other pathways like oxidative DNA damage repair pathways would provide useful evidence for the individualized prevention of these H. pylori-induced gastric precancerous conditions.

Recent knowledge of the relationship between Helicobacter pylori and gastric cancer and recent progress of gastroendoscopic diagnosis and treatment for gastric cancer

Gastric cancer is a multi-step process and multi-factorial disease. However, Helicobacter pylori plays the most important role in gastric carcinogenesis because most gastric cancers including both intestinal type and diffuse type arise from mucosa infected by H. pylori. The relationship between H. pylori infection and gastric cancer has been proved in epidemiological studies, animal experiments with Mongolian gerbils, and clinical prospective studies. Significant preventive effect of H. pylori eradication was reported in Japanese randomized study for secondary gastric cancer after endoscopic resection of primary gastric cancer and meta-analysis of randomized studies. The Japanese Society for Helicobacter Research has published a guideline recommending that H. pylori infection should be treated by eradication therapy to suppress the incidence of gastric cancer. The development of endoscopic technology has advanced the diagnosis and treatment of gastric cancer. In the diagnosis of gastric cancer, image enhancement endoscopy including magnifying observation with narrow-band imaging system and microscopic magnifying observation opens the possibility of optical biopsy. Endoscopic resection for early stage of gastric cancer has been established as proper treatment of early gastric cancer. Recently endoscopic submucosal dissection had made en bloc resection possible for mucosal cancers >2 cm in diameter. Because of endoscopic submucosal dissection, endoscopic resection is indicated in a greater number of cases. Although the use of endoscopic treatment for gastric cancer has been increasing steadily, long-term outcome data is necessary.

Structural modification of a specific antimicrobial lead against Helicobacter pylori discovered from traditional Chinese medicine and a structure-activity relationship study

Psoralen (1a) was found to be a specific and potent antimicrobial lead against Helicobacter pylori (H. pylori) from a traditional Chinese medicine (TCM) in the bioassay directed isolation. A series of structurally diverse analogues of 1a were thus designed and synthesized to improve the antimicrobial potency, some of which showed more potent activities than the lead compound (1a) against H. pylori. Among them, compound 25a is 16-fold stronger (MIC = 0.39 μg/mL) than 1a (MIC = 6.25 μg/mL), and is even potent than the positive control metronidazole (MIC = 0.50 μg/mL). The in vitro antimicrobial activities against H. pylori of these structurally diverse analogues based on the scaffold of 1a have also led to an outline of structure-activity relationship.

Helicobacter pylori infection and gastric histology in first-degree relatives of gastric cancer patients: a meta-analysis

OBJECTIVES

Helicobacter pylori (H. pylori) is believed to predispose to gastric cancer by inducing the precancerous changes, that is, atrophy and intestinal metaplasia (IM). First-degree relatives of patients with gastric cancer might be at an increased risk of developing gastric cancer. However, this evidence is based on the scattered individual studies. The aim of this study was to examine the risk of first-degree relatives developing gastric cancer, in comparison with controls that have no family history of gastric cancer, by meta-analyzing all relevant studies.

METHODS

Extensive English language medical literature searches for human studies were performed up to the end of November 2009, using suitable keywords. Inclusion and exclusion criteria were identified and in eligible studies data on three parameters, that is, H. pylori prevalence, atrophy and IM, were extracted. Pooled estimates (odds ratio with 95% confidence intervals) were obtained using either the fixed or random-effects model as appropriate. Heterogeneity between studies was evaluated with the Cochran Q test, whereas the likelihood of publication bias was assessed by constructing funnel plots. Their symmetry was estimated by the Egger's regression asymmetry test.

RESULTS

Out of 155 initially identified studies, 11 studies, from various countries, fulfilling the inclusion criteria, examined the risk of first-degree relatives developing gastric cancer (n=1500) in comparison with controls (n=2638). For H. pylori prevalence, the pooled odds ratio with 95% confidence interval was 1.925 (1.419-2.611) and the test for overall effect Z was 4.211 (P=0.000). The respective values for atrophy and IM were 2.200 (1.266-3.824), Z=2.797, (P=0.005) and 1.982 (1.363-2.881), Z=3.582 (P=0.000) respectively.

CONCLUSION

The results of this meta-analysis showed that first-degree relatives of patients with gastric cancer might be at an increased risk of developing gastric cancer, as judged by significantly higher prevalence of H. pylori, gastric atrophy and IM, in comparison with controls. Consequently, H. pylori detection and prophylactic eradication of the infection should be offered to such individuals. However, follow-up studies are required to prove the above.

Epidemiological aspects of gastric adenocarcinoma: are predictive diagnostics and targeted preventive measures possible?

The incidence of gastric cancer has witnessed major changes over the past decades. Until recently, gastric cancer was a common malignancy in most countries. A striking decline in incidence in most Western populations has occurred since the 1970s, and elucidating the detailed causes for this trend can potentially be of great value for targeted preventive measures. Furthermore, it can add to the understanding of malignant disease and prevention in general. Moreover, the absolute number of cases worldwide is predicted to increase during many years to come. Gastric cancer is typically diagnosed at an advanced stage in symptomatic patients, and there are often no effective curative or palliative or therapeutic options. This fact highlights the need for research aiming to increase our understanding of the etiology of this cancer, facilitating the design of successful targeted preventive strategies for different populations. The future outlook in terms of decreasing gastric cancer deaths would be to identify such intelligent diagnostic tools. In this article, we present a summary of the epidemiology of gastric cancer, with special focus on its etiology.

Mechanisms by which inflammation may increase intestinal cancer risk in inflammatory bowel disease

Patients with ulcerative colitis and Crohn's disease are at increased risk of developing intestinal cancers via mechanisms that remain incompletely understood. However, chronic inflammation and repeated events of inflammatory relapse in inflammatory bowel disease (IBD) expose these patients to a number of signals known to have tumorigenic effects including persistent activation of the nuclear factor-kappaB and cyclooxygenase-2/prostaglandin pathways, release of proinflammatory mediators such as tumor necrosis factor-alpha and interleukin-6, and enhanced local levels of reactive oxygen and nitrogen species. These inflammatory signals can contribute to carcinogenesis via 3 major processes: 1) by increasing oxidative stress, which promotes DNA mutagenesis thus contributing to tumor initiation; 2) by activating prosurvival and antiapoptotic pathways in epithelial cells, thereby contributing to tumor promotion; and 3) by creating an environment that supports sustained growth, angiogenesis, migration, and invasion of tumor cells, thus supporting tumor progression and metastasis. The present review integrates clinical and basic research observations in an attempt to provide a comprehensive understanding of how inflammatory processes may contribute to intestinal cancer development in IBD patients.

Effect of the mucolytic erdosteine on the success rate of PPI-based first-line triple therapy for Helicobacter pylori eradication: a prospective, double-blind, randomized, placebo-controlled study

OBJECTIVE

Because Helicobacter pylori creates a well-sheltered microenvironment within the gastric mucus layer, it has been speculated that the disruption of this space by a mucolytic agent may enhance the eradication rate. The aim of the present study was to investigate the effect of erdosteine, a strong mucolytic agent, on the effectiveness of PPI-based, first-line triple therapy in the eradication of H. pylori.

MATERIAL AND METHODS

Initially, 196 patients were enrolled to the study. Of these, 79 H. pylori-positive patients were randomized to the erdosteine group (triple therapy consisting of pantoprazole, amoxicillin and clarithromycin plus erdosteine; n = 40) or the placebo group (triple therapy plus placebo; n = 39) for 14 days. Endoscopic biopsies and (13)C-urea breath tests were performed at entry and at 4-6 weeks after the completion of the treatment. Additionally, rapid urease tests were performed at entry.

RESULTS

The eradication of H. pylori was achieved in 30 (75%) of the 40 patients in the erdosteine group and in 20 (51.3%) of the 39 patients in the placebo group, according to the ITT analysis (p = 0.028). When the PP analysis was performed as well, H. pylori eradication was achieved in 30 (78.9%) of the 38 patients in the erdosteine group and in 20 (52.6%) of the 38 patients in the placebo group (p = 0.016).

CONCLUSIONS

Erdosteine is an efficient adjuvant therapy that could be used in conjunction with first-line triple therapy in the treatment of H. pylori.

Molecular identification of Helicobacter DNA in human gastric adenocarcinoma tissues using Helicobacter species-specific 16S rRNA PCR amplification and pyrosequencing analysis

Helicobacter pylori (H. pylori) is a microaerophilic gram-negative bacterium known to be associated with chronic gastritis, peptic ulcer and gastric adenocarcinoma. In the present study, the presence of Helicobacter DNA was investigated using a Helicobacter species-specific 16S rRNA PCR amplification and pyrosequencing analysis in 51 resected gastric adenocarcinomas. DNA was extracted from paraffin-embedded tissues of resected gastric adenocarcinomas. PCR primers were designed to amplify the 133-bp PCR fragment in highly conserved regions of the 16S rRNA gene. The sequence of the PCR products was analyzed using a PSQ 96 system with SQA software. The pyrosequencing analysis of 16S rRNA showed that H. pylori was present in 47 (92.2%) of the 51 gastric adenocarcinomas. In the 4 H. pylori-negative cases, Helicobacter cinaedi (2 cases), Helicobacter mustelae (1 case) and Campylobacter hyointestinalis (1 case) were detected. Pyrosequencing technology was useful in the identification and differentiation of H. pylori from other species by analyzing the gene encoding 16S rRNA. Gastric adenocarcinoma tissues contain bacteria, and the majority are H. pylori. Helicobacter cinaedi, Helicobacter mustelae and Campylobacter hyointestinalis rarely occur. The roles of these organisms in the pathogenesis of gastric adenocarcinoma remain unclear.

Factors contributing to the underestimation of Helicobacter pylori-associated gastric cancer risk in a high-prevalence population

OBJECTIVE

This study aimed to identify sources of underestimation of the association between Helicobacter pylori infection and non-cardia gastric cancer, in a high-risk European population.

METHODS

Non-cardia gastric cancer patients (n = 420) recruited in two major hospitals in North of Portugal and population controls (n = 1,389) were evaluated. Whole-cell IgG antibodies against H. pylori were quantified by ELISA and Western Blot testing was conducted in a subsample (272 cases and 186 controls) allowing for the detection of current infection marker and CagA. Sex- and age-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were computed.

RESULTS

When assessing infection by ELISA, the OR for its association with gastric cancer decreases and reverts as IgG titers increased, from 1.96 (95% CI: 1.09-3.54) for borderline positive results (16.0-21.9 RU/ml) to 0.52 (95% CI: 0.36-0.74) for the highest IgG levels (> or = 102.0 RU/ml). The same pattern was observed across strata of age and blood collection timing with stronger associations among younger subjects and those providing blood samples earlier after diagnosis. The presence of CagA (Western Blot) was associated with an increased risk of gastric cancer (OR = 11.32; 95% CI: 5.64-22.73).

CONCLUSION

The use of methods with low sensitivity to detect past infection leads to a substantial underestimation of gastric cancer risk in high-prevalence settings.

Salt intake and risk of gastric intestinal metaplasia: systematic review and meta-analysis

The understanding of the association between salt intake and precancerous lesions may contribute to clarify the causal relation with gastric cancer. We systematically reviewed 17 articles addressing the association between dietary salt exposure and gastric intestinal metaplasia and conducted meta-analyses for quantitative synthesis (random effects model). Salt exposure was estimated assessing salted/salty food consumption, preference for salted/salty foods, use of table salt, or sodium urinary excretion. Heterogeneity was also large regarding food items evaluated, consumption categories, and data analysis. The combined odds ratio (OR) was 1.68 (95% confidence interval (CI) = 0.98-2.90; I(2) = 55.4%) for the association between salted/salty meat and intestinal metaplasia (4 studies) and the OR was 1.53 (95% CI = 0.72-3.24; I(2) = 76.8%) for salt preference. There was a positive, nonstatistically significant association between intestinal metaplasia and urinary sodium excretion. The heterogeneity of methodological options and results preclude quantitative synthesis or its proper interpretation, even if the available evidence may suggest a positive association between salt and intestinal metaplasia.

Significant association of RUNX3 T/A polymorphism at intron 3 (rs760805) with the risk of gastric atrophy in Helicobacter pylori seropositive Japanese

BACKGROUND

This study aimed to examine the associations of a RUNX3 T/A polymorphism at exon 1 (Asn18Ile) (rs6672420) and another RUNX3 intronic T/A polymorphism (rs760805) with the risk of gastric cancer together with the risk of H. pylori seropositivity and gastric atrophy in Japanese people.

METHODS

Study subjects were 583 histologically diagnosed gastric cancer patients and age- and sex-frequency-matched 1,742 control outpatients (among whom 1,637 subjects were eligible for the analyses), who visited Aichi Cancer Center Hospital from 2001 to 2005. Serum pepsinogens were measured to evaluate gastric atrophy.

RESULTS

There was no significant association between the RUNX3 polymorphisms and the seropositivity. Among H. pylori seropositive subjects, we found a significant association between RUNX3 rs760805 polymorphism and the risk of gastric atrophy with the age- and sex-adjusted OR of 1.51 (95% CI 1.11-2.05, P = 0.008) in T/A, 1.59 (95% CI 1.08-2.33, P = 0.019) in A/A, and 1.53 (95% CI 1.14-2.05, P = 0.004) in T/A + A/A, compared with T/T genotype. We found no statistically significant associations between RUNX3 rs6672420 polymorphism and risk of gastric atrophy, nor between these two RUNX3 polymorphisms and the risk of gastric cancer relative to the subjects with gastric atrophy.

CONCLUSIONS

Our study results revealed that the RUNX3 intronic T/A polymorphism (rs760805) might modulate the risk of gastric atrophy among H. pylori seropositive subjects, and the RUNX3 T/A polymorphism at exon 1 (rs6672420) had little influence on the risks of H. pylori infection, gastric atrophy or gastric cancer in Japanese people. Further investigation is required to verify our findings.

Interleukin-1 receptor phosphorylation activates Rho kinase to disrupt human gastric tight junctional claudin-4 during Helicobacter pylori infection

Helicobacter pylori infects more than half of the human population worldwide. In the absence of treatment, this persistent infection leads to asymptomatic gastritis, which in some cases can progress into gastric ulcers and adenocarcinomas. The host-microbial interactions that govern the clinical outcome of infection remain incompletely understood. H. pylori is known to disrupt gastric epithelial tight junctions, which may represent a significant component of disease pathogenesis. The present study demonstrates that H. pylori disrupt epithelial tight junctional claudin-4 in a Rho kinase (ROCK)-dependent manner in human gastric epithelial (HGE-20) cell monolayers, independently of the virulence factors CagA and VacA, and without altering claudin-4 transcription. In the same epithelial cell model, interleukin (IL)-1beta, mediated a similar ROCK-dependent pattern of tight junction disruption. Further experiments revealed that H. pylori infection induced IL-1 receptor type I (IL-1RI) phosphorylation, independently of epithelial secretion of its endogenous ligands IL-1alpha, IL-1beta or IL-18. Finally, inhibition of IL-1RI activation prevented H. pylori-induced ROCK activation and claudin-4 disruption. Taken together, these findings identify a novel pathophysiological mechanism by which H. pylori disrupts gastric epithelial barrier structure via IL-1RI-dependent activation of ROCK, which in turn mediates tight junctional claudin-4 disruption.

Relationship between alcohol consumption and active Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H. pylori) is a cause of chronic gastritis and maybe responsible for functional dyspepsia in a subset of patients. Many risk factors, such as alcohol consumption and smoking, may contribute to the colonization and infection of H. pylori in humans. However, studies on the relationship between H. pylori infection and drinking or smoking have produced conflicting results.

OBJECTIVE

The aim of this study was to examine whether consumption of alcohol or smoking is associated with active H. pylori infection in functional dyspepsia patients.

METHODS

H. pylori infection was confirmed by CLOtest and histology on at least two biopsies. Active chronic gastritis was diagnosed using the updated Sydney system. In addition to gender and age, information on drinking and smoking habits was collected using a standard questionnaire. Functional dyspepsia was diagnosed according to the Rome II diagnostic criteria.

RESULTS

H. pylori infection was positive in 27.3% of the 139 functional dyspepsia patients. Both age and gender were not significantly associated with H. pylori infection. A multiple logistic model found that alcohol consumption (OR = 9.05, 95% CI: 1.05-77.98) and pathology (active gastritis) (OR = 595.39, 95% CI: 81.43-4353.33) were associated with H. pylori infection. Active gastritis was associated with alcohol consumption (OR = 2.89, 95% CI: 1.03-8.02), smoking (OR = 2.72, 95% CI: 1.22-6.05) and age (OR = 1.03, 95% CI: 1.01-1.06).

CONCLUSIONS

In patients with functional dyspepsia, there is no significant association between active H. pylori infection and smoking. However, alcohol consumption appears to be associated with H. pylori infection.

Association of the human leukocyte antigen class II alleles with chronic atrophic gastritis and gastric carcinoma in Koreans

OBJECTIVE

Gastric carcinogenesis is a multi-step process and is influenced by several etiological agents, including the host's genetic factors. Since whether a patient remains with chronic superficial gastritis (CSG) or progresses to either chronic atrophic gastritis (CAG) or gastric carcinoma (GC) could be a genetic predisposition unique in each population, we hypothesized that host human leukocyte antigen (HLA) alleles could be discriminative in predicting the risk of CSG progression to precancerous CAG and GC in Koreans.

METHODS

A total of 165 patients with gastric disorders (CSG, 62; CAG, 69 and GC, 34), were selected to investigate the association of HLA class II alleles with the progression of CSG to CAG or GC. HLA genotypes were obtained by the polymerase chain reaction-sequence based typing method.

RESULTS

The phenotypic frequencies of DRB1*1101 and DQA1*0505 were significantly higher in the CAG group compared to those in the CSG group. In the subjects with Helicobacter pylori (H. pypori) (+), the frequencies of DRB1*1501 and DQB1*0602 were significantly lower in the CAG compared to those in the CSG. Further analysis showed that sex (P < 0.05, OR = 0.41-0.42) and age (P < 0.05, OR = 1.05) also affected the risk of progression from CSG to CAG in H. pylori (+) patients carrying the DRB1*1501 or DQB1*0602 allele. Additionally, the frequency of DRB1*0404 in the GC group was significantly higher than that in the gastritis group.

CONCLUSION

Our findings strongly imply an association between HLA class II alleles and the risk of CAG development and GC progression in Koreans.

The role of diet and other environmental factors in the causation of gastric cancer in Iran--a population based study

Despite a declining trend in the incidence of gastric cancer (GC), it is still a major global public health concern of the 21st century. The rates of GC reported from Ardabil Province, Iran, are among the highest in the world. To investigate risk factors for GC in Ardabil, we undertook a population-based case-control study. The study aimed to recruit all Ardabil residents newly diagnosed with GC in the time period of 2004-2005, and 2 controls per case. Participants were interviewed using a structured questionnaire. Ten milliliters of blood was collected for blood grouping and investigating the presence of IgG antibodies against Helicobacter pylori. During the study period, 217 people with GC and 394 controls were recruited. In multivariate analysis, diet and Helicobacter pylori infection (OR = 2.41; 95% CI: 1.35-4.32) were found to be the factors that were most strongly related to GC. High intake of Allium vegetables (OR = 0.35) and fruit, especially citrus fruit (OR = 0.31) and consumption of fresh fish (OR = 0.37) were significantly protective. On the other hand, consumption of red meat (OR = 3.40) and dairy products (OR = 2.28) were positively associated with the risk of GC. People who had a preference for higher salt intake (OR = 3.10) and drinking strong and hot tea (OR = 2.64 and 2.85, respectively) were at higher risk. In conclusion, Helicobacter pylori infection as measured by serum IgG as well as the consumption of red meat and dairy products increases the risk of GC in Ardabil, while the intake of fresh fruit and fresh fish decrease the risk.

Nature meets nurture: molecular genetics of gastric cancer

The immensity of genes and molecules implicated in gastric carcinogenesis is overwhelming and the relevant importance of some of these molecules is too often unclear. This review serves to bring us up-to-date with the latest findings as well as to look at the larger picture in terms of how to tackle the problem of solving this multi-piece puzzle. In this review, the environmental nurturing of intestinal cancer is discussed, beginning with epidemiology (known causative factors for inducing molecular change), an update of H. pylori research, including the role of inflammation and stem cells in premalignant lesions. The role of E-cadherin in the nature (genotype) of diffuse gastric cancer is highlighted, and finally the ever growing discipline of SNP analysis (including IL1B) is discussed.

Nature meets nurture: molecular genetics of gastric cancer

The immensity of genes and molecules implicated in gastric carcinogenesis is overwhelming and the relevant importance of some of these molecules is too often unclear. This review serves to bring us up-to-date with the latest findings as well as to look at the larger picture in terms of how to tackle the problem of solving this multi-piece puzzle. In this review, the environmental nurturing of intestinal cancer is discussed, beginning with epidemiology (known causative factors for inducing molecular change), an update of H. pylori research, including the role of inflammation and stem cells in premalignant lesions. The role of E-cadherin in the nature (genotype) of diffuse gastric cancer is highlighted, and finally the ever growing discipline of SNP analysis (including IL1B) is discussed.

Oxidative stress in Helicobacter pylori infection: does supplementation with vitamins C and E increase the eradication rate?

AIM

This study aims to assess the antioxidant property of vitamins E and C in Helicobacter pylori infection, and to determine if adding them to standard triple therapy plus bismuth subcitrate increases the H. pylori eradication rate.

METHODS

This study included 160 patients infected with H. pylori, who were randomized into one of two groups. Patients in group A (n = 80) received lansoprazole (30 mg, b.i.d.), amoxicillin (1000 mg, b.i.d.), clarithromycin (500 mg, b.i.d.), and bismuth subcitrate (300 mg, q.i.d.) for 14 days, while patients in group B (n = 80) received vitamin C (500 mg, b.i.d.) and vitamin E (200 IU, b.i.d.) for 30 days, in addition to lansoprazole (30 mg, b.i.d.), amoxicillin (1000 mg, b.i.d.), clarithromycin (500 mg, b.i.d.), and bismuth subcitrate (300 mg, q.i.d.) for 14 days. Total antioxidant capacity (TAC) was evaluated with a Randox kit. Success rate was calculated using both intention-to-treat (ITT) and per-protocol (PP) analyses.

RESULTS

One hundred and sixty patients were analyzed using ITT analysis. One hundred and fifty-three patients completed the study. In group A, H. pylori eradication was achieved in 48 (60%) of the 80 patients included in the ITT analysis, and in 48 (64%) of the 75 patients included in the PP analysis. In group B, H. pylori eradication was achieved in 73 (91.25%) of the 80 included in the ITT analysis and in 73 (93.5%) of the 78 patients included in the PP analysis. The eradication rate was significantly higher in group B than in group A (p < .005). TAC was at the lower limit of normal in both groups and the difference between them was not statistically significant (p > .05).

CONCLUSION

In group B, H. pylori eradication rate was 91.25%, which is higher than the ideal 80% eradication rate. The results of the present study show that adding the prescribed doses of vitamins E and C to antimicrobial therapy is effective in eradicating H. pylori infection.