Effect of Helicobacter pylori eradication on chronic gastritis during omeprazole therapy

Gastric acid-responsive deformable sodium alginate/Bletilla striata polysaccharide in situ gel for the protection and treatment of alcohol-induced peptic ulcers

First-line drugs for peptic ulcer (PU) treatment are typically limited by poor targeting and adverse effects associated with long-term use. Despite recent advancements in novel therapeutic approaches for PU, the development of sustained-release delivery systems tailored to specific pathological characteristics remains challenging. Persistent inflammation, particularly gastric inflammatory microenvironment imbalance, characterizes the PU. In this study, we prepared an in situ gel composed of sodium alginate, deacetylated gellan gum, calcium citrate, and Bletilla striata polysaccharide (BSP) to achieve sustained release of BSP. The BSP in situ gel demonstrated favorable fluidity in vitro and completed self-assembly in vivo in response to the acidic milieu at a pH of 1.5. Furthermore, the shear, extrusion, and deformation properties increased by 26.4 %, 103.7 %, and 46.3 %, respectively, with long-term gastric retention (4 h) and mucosal adaptation. Animal experiments confirmed that the BSP in situ gel could attenuate necrotic injury and inflammatory cell infiltration, maintain mucosal barrier integrity, regulate cytokine imbalance and inflammation-associated hyperapoptosis, thus effectively alleviate the inflammatory microenvironmental imbalance in PU without significant side effects. Overall, our findings demonstrated that the BSP in situ gel is a promising therapeutic strategy for PU and opens avenues for developing self-assembled formulations targeting the pathological features of PUs.

Effectiveness and Safety of Histamine H2 Receptor Antagonists: An Umbrella Review of Meta-Analyses

Histamine H2 receptor antagonists (H2RAs) were widely used to inhibit gastric acid secretion, but its association with adverse events remains controversial and unclear. We conducted an umbrella review of meta-analyses to systematically assess the quality and credibility of the correlations between H2RA use with the risk of adverse outcomes through searching 4 major databases from inception to April 30, 2022. Forty-six individual meta-analyses were identified, including 29 meta-analyses of observation studies with 32 unique outcomes and 19 meta-analyses of randomized controlled trials with 3 unique outcomes for comparing the H2RA versus non-H2RA group. A Measurement Tool to Assess Systematic Reviews 2 rating for the included meta-analyses showed that 4 of 46 meta-analyses were assigned as high scores, 3 were assigned as "moderate," and 25 were assigned as low scores. Grading of Recommendations Assessment, Development and Evaluation assessment for combined results demonstrated that 6 outcomes were rated as "moderate," 9 outcomes were rated as "low," and 17 outcomes were rated as "very low." We confirmed significant associations of H2RA use with pneumonia, peritonitis, necrotizing enterocolitis, Clostridium difficile infection, liver cancer, gastric cancer, and hip fracture diseases. No associations for colorectal cancer, melanoma, kidney cancer, lung cancer, or common reproductive system cancer or renal, neurological, and cardiovascular system diseases were observed. We found a variety of evidence for the associations between H2RAs and adverse outcomes, which would give clinicians more positive guidance on prescription of H2RAs in clinical practice.

Clinical Practice Guidelines of Russian Gastroenterological Association, Scientific Society for the Clinical Study of Human Microbiome, Russian Society for the Prevention of Non-Communicable Diseases, Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy for <i>H. pylori</i> Diagnostics and Treatment in Adults

Aim: bring to the attention of practitioners indications for anti-Helicobacter therapy, methods and procedure for diagnostics and eradication therapy of Н. pylori infection.

Key points. Chronic gastritis caused by Н. pylori infection, including asymptomatic persons, may be considered as an indication for eradication therapy of Н. pylori as etiological therapy and opportunistic screening for gastric cancer prevention. Indications, for obligatory anti-Helicobacter therapy include peptic ulcer, gastric MALT lymphoma, early gastric cancer (EGC) with endoscopic resection. H. pylori primary diagnostics methods include 13C-urea breath test, H. pylori stool antigen lab test, rapid urease test and serological method. The serological method cannot be used after anti-Helicobacter therapy.

In Russia H. pylori strains' resistance to clarithromycin does not exceed 15 % in most regional studies. The first line therapy for Н. pylori infection eradication is the standard triple therapy including a proton pump inhibitor (PPI), clarithromycin and amoxicillin, enhanced with bismuthate tripotassium dicitrate. A classic four-component therapy based on bismuthate tripotassium dicitrate or quadrotherapy without bismuth drug products which includes PPI, amoxicillin, clarithromycin and metronidazole, may be used as alternative to the first line eradication therapy. The standard triple therapy may be prescribed for 14 days only in those regions, where it has been proven to be effective. Quadrotherapy with bismuthate tripotassium dicitrate is also used as main second line therapy in case of standard triple therapy, bismuth enhanced standard triple therapy or combined therapy failure. Another second line therapy includes PPI, levofloxacin and amoxicillin, to which a bismuth-containing drug product may be added. The third line therapy is selected individually based on previously used treatment settings.

Conclusion. In each case of H. pylori infection the decision for eradication therapy should be made, which is especially relevant as eradication of H. pylori has been recognized as an effective measure for the prevention of gastric cancer.

Clinical Practice Guidelines of Russian Gastroenterological Association, Scientific Society for the Clinical Study of Human Microbiome, Russian Society for the Prevention of Non-Communicable Diseases, Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy for <i>H. pylori</i> Diagnostics and Treatment in Adults

Aim: bring to the attention of practitioners indications for anti-Helicobacter therapy, methods and procedure for diagnostics and eradication therapy of Н. pylori infection.

Key points. Chronic gastritis caused by Н. pylori infection, including asymptomatic persons, may be considered as an indication for eradication therapy of Н. pylori as etiological therapy and opportunistic screening for gastric cancer prevention. Indications, for obligatory anti-Helicobacter therapy include peptic ulcer, gastric MALT lymphoma, early gastric cancer (EGC) with endoscopic resection. H. pylori primary diagnostics methods include 13C-urea breath test, H. pylori stool antigen lab test, rapid urease test and serological method. The serological method cannot be used after anti-Helicobacter therapy.

In Russia H. pylori strains' resistance to clarithromycin does not exceed 15 % in most regional studies. The first line therapy for Н. pylori infection eradication is the standard triple therapy including a proton pump inhibitor (PPI), clarithromycin and amoxicillin, enhanced with bismuthate tripotassium dicitrate. A classic four-component therapy based on bismuthate tripotassium dicitrate or quadrotherapy without bismuth drug products which includes PPI, amoxicillin, clarithromycin and metronidazole, may be used as alternative to the first line eradication therapy. The standard triple therapy may be prescribed for 14 days only in those regions, where it has been proven to be effective. Quadrotherapy with bismuthate tripotassium dicitrate is also used as main second line therapy in case of standard triple therapy, bismuth enhanced standard triple therapy or combined therapy failure. Another second line therapy includes PPI, levofloxacin and amoxicillin, to which a bismuth-containing drug product may be added. The third line therapy is selected individually based on previously used treatment settings.

Conclusion. In each case of H. pylori infection the decision for eradication therapy should be made, which is especially relevant as eradication of H. pylori has been recognized as an effective measure for the prevention of gastric cancer.

Nocturnal acid breakthrough and esophageal acidification during treatment with dexlansoprazole as compared to omeprazole in patients with gastroesophageal reflux disease

BACKGROUND

Nocturnal acid breakthrough (NAB) may differ based on duration of proton pump inhibitor (PPI) action and Helicobacter pylori (H. pylori) infection; NAB may influence esophageal acidification (EA) and mucosal damage. Dexlansoprazole, a long-acting PPI, was not compared with omeprazole for NAB, gastric acid suppression, and EA in relation to H. pylori infection.

METHODS

In this prospective open-label comparative observational study, gastroesophageal reflux disease (GERD) patients were evaluated using 24-h dual-channel pH-impedance monitoring while on dexlansoprazole (60 mg, n = 39) and omeprazole (20 mg, n = 41) to study the degree of gastric acid suppression, esophageal acid exposure, and NAB (primary outcome measures). H. pylori was detected by rapid urease test and histology.

RESULTS

NAB tended to be frequent with omeprazole than dexlansoprazole (33/41 [80.5%] vs. 23/39 [59%]; p = 0.06). Though nocturnal mean esophageal pH was comparable between the dexlansoprazole and omeprazole groups, its duration was less with the former (181.5 [15.2-334.2] vs. 283 [158-366] min, p = 0.03). NAB was as frequent in the H. pylori-infected than the non-infected group (11/19 [57.9%] vs. 45/61 [73.8%]; p = 0.1). The nocturnal gastric and esophageal pH in the H. pylori-infected group was higher than in the non-infected group (4.6 ± 1.7 vs. 4 ± 1.6, p = 0.157; 6.1 ± 0.6 vs. 5.8 ± 0.6, p = 0.128). Dexlansoprazole tended to increase 24-h and nocturnal mean gastric pH among H. pylori-infected more than omeprazole (5.9 ± 1.1 vs. 4.2 ± 1.7, p = 0.023; 5.7 ± 1.2 vs. 3.8 ± 1.5, p = 0.006).

CONCLUSION

Dexlansoprazole is more effective than omeprazole in suppressing gastric acid secretion, resulting in lesser EA and NAB, particularly in the presence of H. pylori.

Mucosal microbiome associates with progression to gastric cancer

Background & Aims: Dysbiosis is associated with gastric cancer (GC) development. However, no longitudinal study was carried out to identify key bacteria that could predict for GC progression. Here, we aimed to investigate changes in bacterial metagenome prior to GC and develop a microbiome-based predictive model to accurately classify patients at risk of GC.

Methods: Bacterial 16S rDNA was sequenced from 89 gastric antral biopsies obtained from 43 participants. This study was nested in a prospective, longitudinal study, whereby study participants underwent screening gastroscopy, with further 1-2 yearly surveillance gastroscopies for at least 5 years. Putative bacterial taxonomic and functional features associated with GC carcinogenesis were identified by comparing between controls, patients with gastric intestinal metaplasia (IM) and patients with early gastric neoplasia (EGN).

Results: Patients with EGN had enrichment of Proteobacteria (in particular Proteus genus) and depletion of Bacteroidetes (in particular S24-7 family) in their gastric mucosa. Sequencing identified more patients with Helicobacter pylori compared to histopathological assessment, while H. pylori was also significantly enriched in EGN. Furthermore, a total of 261 functional features, attributing to 97 KEGG pathways were differentially abundant at baseline between patients who subsequent developed EGN (n = 13/39) and those who did not. At the same time, a constellation of six microbial taxonomic features present at baseline, provided the highest classifying power for subsequent EGN (AUC = 0.82).

Conclusion: Our study highlights early microbial changes associated with GC carcinogenesis, suggesting a potential role for prospective microbiome surveillance for GC.

CYP2C19 Polymorphisms in Indonesia: Comparison among Ethnicities and the Association with Clinical Outcomes

Simple Summary

CYP2C19 is known as an enzyme primarily responsible for metabolizing various drugs, such as proton pump inhibitor, antiplatelet, anti-epileptic, and anticoagulant. CYP2C19 is known to be polymorphic and can result in the clinical efficacy of drugs. To examine the prevalence and the distribution of the CYP2C19 genetic polymorphisms in Indonesia, we performed polymerase chain reaction-restriction fragment length polymorphism to the genomic DNA of Indonesian participants. In addition, we also analyzed the distribution of CYP2C19 polymorphisms among ethnicities and clinical outcomes. We found that the prevalence of intermediate metabolizers were the highest in Indonesia, followed by rapid metabolizers and poor metabolizers, respectively. The distribution of metabolizer groups were different between ethnic groups in Indonesia. Therefore, dosage adjustment should be considered when administering drugs-affected by CYP2C19 in Indonesia. The results presented in this study showed the distribution of CYP2C19 variant alleles at the population level in Indonesia and might be used as a consideration for providing personalized treatment in clinical practice.

Abstract

CYP2C19 polymorphisms are important factors for proton pump inhibitor-based therapy. We examined the CYP2C19 genotypes and analyzed the distribution among ethnicities and clinical outcomes in Indonesia. We employed the polymerase chain reaction-restriction fragment length polymorphism method to determine the CYP2C19 genotypes and evaluated inflammation severity with the updated Sydney system. For CYP2C19*2, 46.4% were the homozygous wild-type allele, 14.5% were the homozygous mutated allele, and 39.2% were the heterozygous allele. For CYP2C19*3, 88.6% were the homozygous wild-type allele, 2.4% were the homozygous mutated allele, and 9.0% were the heterozygous allele. Overall, the prevalence of rapid, intermediate, and poor metabolizers in Indonesia was 38.5, 41.6, and 19.9%, respectively. In the poor metabolizer group, the frequency of allele *2 (78.8%) was higher than the frequency of allele *3 (21.2%). The Papuan had a significantly higher likelihood of possessing poor metabolizers than the Balinese (OR 11.0; P = 0.002). The prevalence of poor metabolizers was lower compared with the rapid and intermediate metabolizers among patients with gastritis and gastroesophageal reflux disease. Intermediate metabolizers had the highest prevalence, followed by rapid metabolizers and poor metabolizers. Dosage adjustment should therefore be considered when administering proton pump inhibitor-based therapy in Indonesia.

Fermented-Rhus verniciflua extract ameliorate Helicobacter pylori eradication rate and gastritis

An antibacterial effect of fermented-Rhus verniciflua extract (FRVE), an urushiol-free extract fermented by Fomitella fraxinea, on Helicobacter pylori was evaluated in mice. Minimal inhibitory concentration of FRVE against H. pylori eradication was checked with serial dilution method in vitro. H. pylori infection-induced mice were utilized to determine the effect of oral administration of FRVE with/without standard triple therapy (STT: metronidazole, omeprazole, and clarithromycin) on H. pylori colonization and gastric inflammation. H. pylori was clearly eradicated by FRVE at a concentration of ≥2 mg/ml in vitro. In animal study, FRVE at a concentration of ≥6 mg/ml significantly reduced colonized H. pylori grading (0.2 vs. 2.2, p < .01) and improved gastric inflammation (0.4 vs. 1.6, p < .01) compared to control. STT with FRVE (3 mg/ml) exerted synergistic effect on both H. pylori colonization grade (STT, 0.6 ± 0.9; FRVE, 1.4 ± 0.5; STT + FRVE, 0.8 ± 0.4) and gastric inflammation (STT, 0.4 ± 0.5; FRVE, 1.4 ± 0.5; STT + FRVE,1.0 ± 0.1) compared with single therapy (p < .01). H. pylori eradication rate of FRVE (6 mg/ml) was higher than that of STT (60% vs. 20%). FRVE has potential antibacterial activity against H. pylori infection and can be used as an additional therapy on STT.

Houston Consensus Conference on Testing for Helicobacter pylori Infection in the United States

Despite guidelines for detection and treatment of Helicobacter pylori infection, recommendations to test patients before and after therapy are commonly not followed in the United States. At the Houston Consensus Conference, 11 experts on management of adult and pediatric patients with H pylori, from different geographic regions of the United States, met to discuss key factors in diagnosis of H pylori infection, including identification of appropriate patients for testing, effects of antibiotic susceptibility on testing and treatment, appropriate methods for confirmation of infection and eradication, and relevant health system considerations. The experts divided into groups that used a modified Delphi panel approach to assess appropriate patients for testing, testing for antibiotic susceptibility and treatment, and test methods and confirmation of eradication. The quality of evidence and strength of recommendations were evaluated using the GRADE system. The results of the individual workshops were presented for a final consensus vote by all panel members. After the Expert Consensus Development meeting, the conclusions were validated by a separate panel of gastroenterologists, who assessed their level of agreement with each of the 29 statements developed at the Expert Consensus Development. The final recommendations are provided, on the basis of the best available evidence, and provide consensus statements with supporting literature to implement testing for H pylori infection at health care systems across the United States.

Fifth Chinese National Consensus Report on the management of Helicobacter pylori infection

BACKGROUND

Since the 'Fourth Chinese National Consensus Report on the management of H. pylori infection' was published in 2012, three important consensuses (Kyoto global consensus report on H. pylori gastritis, The Toronto Consensus for the Treatment of H. pylori Infection in Adults and Management of H. pylori infection-the Maastricht V/Florence Consensus Report) have been published regarding the management of H. pylori infection.

MATERIALS AND METHODS

A Delphi method was adopted to develop the consensus of relevant 'statements'. First, the established 'statements' were sent to experts via email. Second, after undergoing two rounds of consultation, the initial statements were discussed face to face and revised in the conference item by item on 16 December 2016. Finally, 21 core members of conferees participated in the final vote of statements. Voting for each statement was performed using an electronic system with levels of agreements shown on the screen in real time.

RESULTS

Consensus contents contained a total of 48 "statements" and related 6 parts, including indications for H. pylori eradication, diagnosis, treatment, H. pylori and gastric cancer, H. pylori infection in special populations, H. pylori and gastrointestinal microbiota.

CONCLUSIONS

Recommendations are provided on the basis of the best available evidence.

Long-term proton pump inhibitors and risk of gastric cancer development after treatment for Helicobacter pylori: a population-based study

OBJECTIVE

Proton pump inhibitors (PPIs) is associated with worsening of gastric atrophy, particularly in Helicobacter pylori (HP)-infected subjects. We determined the association between PPIs use and gastric cancer (GC) among HP-infected subjects who had received HP therapy.

DESIGNS

This study was based on a territory-wide health database of Hong Kong. We identified adults who had received an outpatient prescription of clarithromycin-based triple therapy between year 2003 and 2012. Patients who failed this regimen, and those diagnosed to have GC within 12 months after HP therapy, or gastric ulcer after therapy were excluded. Prescriptions of PPIs or histamine-2 receptor antagonists (H2RA) started within 6 months before GC were excluded to avoid protopathic bias. We evaluated GC risk with PPIs by Cox proportional hazards model with propensity score adjustment. H2RA was used as a negative control exposure.

RESULT

Among the 63 397 eligible subjects, 153 (0.24%) developed GC during a median follow-up of 7.6 years. PPIs use was associated with an increased GC risk (HR 2.44, 95% CI 1.42 to 4.20), while H2RA was not (HR 0.72, 95% CI 0.48 to 1.07). The risk increased with duration of PPIs use (HR 5.04, 95% CI 1.23 to 20.61; 6.65, 95% CI 1.62 to 27.26 and 8.34, 95% CI 2.02 to 34.41 for ≥1 year, ≥2 years and ≥3 years, respectively). The adjusted absolute risk difference for PPIs versus non-PPIs use was 4.29 excess GC (95% CI 1.25 to 9.54) per 10 000 person-years.

CONCLUSION

Long-term use of PPIs was still associated with an increased GC risk in subjects even after HP eradication therapy.

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

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

Recapitulating Human Gastric Cancer Pathogenesis: Experimental Models of Gastric Cancer

This review focuses on the various experimental models to study gastric cancer pathogenesis, with the role of genetically engineered mouse models (GEMMs) used as the major examples. We review differences in human stomach anatomy compared to the stomachs of the experimental models, including the mouse and invertebrate models such as Drosophila and C. elegans. The contribution of major signaling pathways, e.g., Notch, Hedgehog, AKT/PI3K is discussed in the context of their potential contribution to foregut tumorigenesis. We critically examine the rationale behind specific GEMMs, chemical carcinogens, dietary promoters, Helicobacter infection, and direct mutagenesis of relevant oncogenes and tumor suppressor that have been developed to study gastric cancer pathogenesis. Despite species differences, more efficient and effective models to test specific genes and pathways disrupted in human gastric carcinogenesis have yet to emerge. As we better understand these species differences, "humanized" versions of mouse models will more closely approximate human gastric cancer pathogenesis. Towards that end, epigenetic marks on chromatin, the gut microbiota, and ways of manipulating the immune system will likely move center stage, permitting greater overlap between rodent and human cancer phenotypes thus providing a unified progression model.

Helicobacter pylori eradication cannot reduce the risk of gastric cancer in patients with intestinal metaplasia and dysplasia: evidence from a meta-analysis

BACKGROUND

The effect of Helicobacter pylori (H. pylori) eradication on gastric cancer (GC) prevention is controversial. Intestinal metaplasia (IM) seems to be a "point of no return" in the precancerous cascade. We performed a meta-analysis of randomized controlled trials (RCTs) to illustrate this issue.

MATERIALS AND METHODS

The MEDLINE, EMBASE, Cochrane Library were searched for relevant RCTs that were published in any language up to March 2014. By dividing participants into subgroups based on their baseline diagnoses as group <IM (normal, non-atrophic gastritis, atrophic gastritis) and group ≥ IM(intestinal metaplasia, dysplasia), the relative risk (RR) of GC in each study compared treatment group with control group were pooled using Mantel-Haenszel fixed-effect model and publication bias analyses were performed.

RESULTS

Ten studies from eight RCTs were included in this analysis, for a total of 7,955 participants. H. pylori treatment compared with control significantly reduced the risk of GC, with a pooled RR of 0.64 (95% CI, 0.48-0.85). Subgroup analysis for patients with non-atrophic gastritis, atrophic gastritis (<IM) yielded a similar results (RR = 0.25, 95% CI, 0.08-0.81). But this difference was not observed in patients with intestinal metaplasia, dysplasia (≥ IM) (RR = 0.88; 95% CI, 0.59-1.31).

CONCLUSIONS

Our results suggested that patients with Intestinal metaplasia or dysplasia could not benefit from the H. pylori treatment on the risk of GC.

Long-term proton pump inhibitor (PPI) use and the development of gastric pre-malignant lesions

BACKGROUND

Proton pump inhibitors (PPIs) are the most effective drugs to reduce gastric acid secretion. PPIs are one of the most commonly prescribed classes of medications worldwide. Apart from short-term application, maintenance therapy with PPIs is recommended and increasingly used in certain diseases, such as Zollinger-Ellison syndrome and gastro-oesophageal reflux disease, especially for people with erosive oesophagitis or Barrett's oesophagus. Although PPIs are generally safe, their efficacy and safety of long-term use remains unclear. The question of whether the long-term use of PPIs could promote the development of gastric pre-malignant lesions has been widely investigated, but results are inconsistent. Limited insight on this problem leads to a dilemma in decision making for long-term PPI prescription.

OBJECTIVES

To compare the development or progression of gastric pre-malignant lesions, such as atrophic gastritis, intestinal metaplasia, enterochromaffin-like (ECL) cell hyperplasia, and dysplasia, in people taking long-term (six months or greater) PPI maintenance therapy.

SEARCH METHODS

We searched the following databases (from inception to 6 August 2013): the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL. In addition, we searched the reference lists of included trials and contacted experts in the field.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) in adults (aged 18 years or greater) concerning the effects of long-term (six months or greater) PPI use on gastric mucosa changes, confirmed by endoscopy or biopsy sampling (or both).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed selection of eligible trials, assessment of trial quality, and data extraction. We calculated odds ratios (OR) for analysis of dichotomous data and mean differences for continuous data, with 95% confidence intervals (CI).

MAIN RESULTS

We included seven trials (1789 participants). Four studies had high risk of bias and the risk of bias in the other three trials was unclear. In addition, it was difficult to assess possible reporting bias. We pooled 1070 participants from four RCTs to evaluate corporal atrophy development revealing an insignificantly increased OR of 1.50 (95% CI 0.59 to 3.80; P value = 0.39; low-quality evidence) for long-term PPI users relative to non-PPI users. In five eligible trials, corporal intestinal metaplasia was assessed among 1408 participants, also with uncertain results (OR 1.46; 95% CI 0.43 to 5.03; P value = 0.55; low-quality evidence). However, by pooling data of 1705 participants from six RCTs, our meta-analysis showed that participants with PPI maintenance treatment were more likely to experience either diffuse (simple) (OR 5.01; 95% CI 1.54 to 16.26; P value = 0.007; very-low-quality evidence) or linear/micronodular (focal) ECL hyperplasia (OR 3.98; 95% CI 1.31 to 12.16; P value = 0.02; low-quality evidence) than controls. No participant showed any dysplastic or neoplastic change in any included studies.

AUTHORS' CONCLUSIONS

There is presently no clear evidence that the long-term use of PPIs can cause or accelerate the progression of corpus gastric atrophy or intestinal metaplasia, although results were imprecise. People with PPI maintenance treatment may have a higher possibility of experiencing either diffuse (simple) or linear/micronodular (focal) ECL cell hyperplasia. However, the clinical importance of this outcome is currently uncertain.

Helicobacter pylori and gastric cancer

Infection with Helicobacter pylori is established as the major risk factor for gastric cancer development. Damage of the mucosal barrier due to H. pylori-induced inflammation enhances the carcinogenic effect of other risk factors such as salt intake or tobacco smoking. The genetic disposition of both the bacterial strain and the host can increase the potential towards gastric cancer formation. Genetic variance of the bacterial proteins CagA and VacA is associated with a higher gastric cancer risk, as are polymorphisms and epigenetic changes in host gene coding for interleukins (IL1β, IL8), transcription factors (CDX2, RUNX3) and DNA repair enzymes. Application of high-throughput assays for genome-wide assessment of either genetic structural variance or gene expression patterns may lead to a better understanding of the pathobiological background of these processes, including the underlying signaling pathways. Understanding of the stepwise alterations that take place in the transition from chronic atrophic gastritis, via metaplastic changes, to invasive neoplasia is vital to define the 'point of no return' before which eradication of H. pylori has the potential to prevent gastric cancer. Currently, eradication as preventive strategy is only recommended for high-incidence regions in Asia; large population studies with an adequate follow-up are required to demonstrate the effectiveness of such an approach in Western populations.

Acid suppressive drugs and gastric cancer: A meta-analysis of observational studies

AIM: To evaluate the association between acid suppressive drug use and the development of gastric cancer.

METHODS: A systematic search of relevant studies that were published through June 2012 was conducted using the MEDLINE (PubMed), EMBASE, and Cochrane Library databases. The search included observational studies on the use of histamine 2-receptor antagonists (H₂RAs) or proton pump inhibitors and the associated risk of gastric cancer, which was measured using the adjusted odds ratio (OR) or the relative risk and 95%CI. An independent extraction was performed by two of the authors, and a consensus was reached.

RESULTS: Of 4595 screened articles, 11 observational studies (n = 94558) with 5980 gastric cancer patients were included in the final analyses. When all the studies were pooled, acid suppressive drug use was associated with an increased risk of gastric cancer risk (adjusted OR = 1.42; 95%CI: 1.29-1.56, I² = 48.9%, P = 0.034). The overall risk of gastric cancer increased among H₂RA users (adjusted OR = 1.40; 95%CI: 1.24-1.59, I² = 59.5%, P = 0.008) and PPI users (adjusted OR = 1.39; 95%CI: 1.19-1.64, I² = 0.0%, P = 0.377).

CONCLUSION: Acid suppressive drugs are associated with an increased risk of gastric cancer. Further studies are needed to test the effect of acid suppressive drugs on gastric cancer.

Gastric exocrine and endocrine cell morphology under prolonged acid inhibition therapy: results of a 5-year follow-up in the LOTUS trial

BACKGROUND

Sustained acid inhibition with PPI stimulates gastrin secretion, exerting a proliferative drive on enterochromaffin-like cells (ECL cells) of the oxyntic mucosa. It may also accelerate development of gastric gland atrophy in Helicobacter pylori-infected individuals.

AIMS

To evaluate gastric exocrine and endocrine cell changes in GERD patients randomised to laparoscopic antireflux surgery (LARS, n = 288) or long-term (5 years) esomeprazole (ESO) treatment (n = 266).

METHODS

Antral and corpus biopsies were taken at endoscopy and serum gastrin and chromogranin A levels were assayed, at baseline and after 1, 3 and 5 years' therapy.

RESULTS

Biopsies were available at each time point for 158 LARS patients and 180 ESO patients. In H. pylori-infected subjects, antral mucosal inflammation and activity improved significantly (P < 0.001) and stabilised after 3 years on esomeprazole while no change in inflammation was observed after LARS. Oxyntic mucosal inflammation and activity remained stable on esomeprazole but decreased slightly over time after LARS. Neither intestinal metaplasia nor atrophy developed in the oxyntic mucosa. ECL cell density increased significantly after ESO (P < 0.001), corresponding with an increase in circulating gastrin and chromogranin A. After LARS, there was a significant decrease in ECL cell density (P < 0.05), accompanied by a marginal decrease in gastrin and chromogranin.

CONCLUSIONS

Antral gastritis improved in H. pylori-infected GERD patients after 5 years on esomeprazole, with little change in laparoscopic antireflux surgery patients, who acted as a control. Despite a continued proliferative drive on enterochromaffin-like cells during esomeprazole treatment, no dysplastic or neoplastic lesions were found and no safety concerns were raised. NCT 00251927.

Prescribing proton pump inhibitors: is it time to pause and rethink?

Proton pump inhibitors (PPIs) are among the most widely used agents in the world. The prevalence of reflux disease is increasing, as is the incidence of oesophageal adenocarcinoma, a complication that is strongly correlated with chronic reflux disease. Although these agents are generally safe, a number of potential side effects have been described and a careful assessment of the risks and benefits of PPI therapy is required in all patients being prescribed long-term therapy. Overutilization of PPIs is a problem in clinical practice and needs further attention. PPI use has been associated with osteoporosis and bone fracture, hypomagnesaemia, the development of gastric polyps, enteric infections, interstitial nephritis and pneumonia. Patients on long-term therapy should be periodically evaluated for the indications for continued therapy. Despite widespread publicity in the lay press, and regulatory guidance regarding a number of associations, the evidence for serious side effects is poor and the risk of confounding remains a real possibility for many associations. Patients are more concerned about the absolute risk of developing a complication than a relative risk. The absolute risk of all the complications attributed to PPIs is low and patients who need long-term PPI therapy need a clear discussion of the available data on the risk of therapy and also a discussion of the risk of continued reflux.

Quality of RCTs exploring Helicobacter pylori eradication for the prevention of gastric cancer and preneoplastic lesions

Randomized controlled trials (RCTs) are considered the gold standard for evaluating the efficacy of clinical interventions and developing evidence-based clinical practice guidelines; however, they can yield biased results when their methodology is less than rigorous, or their published reports fail to report key items. A number of RCTs have been carried out to explore the relationship between Helicobacter pylori eradication and gastric cancer, but their results remain controversial. In this article, we will comprehensively review searched medical electronic databases, and appraise the reporting and methodological quality of these relevant RCTs according to the Consolidated Standards of Reporting Trials 2010 statement and the Cochrane Handbook in order to learn about the internal and external validity of these RCTs.

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.

Comparative study of Nigella Sativa and triple therapy in eradication of Helicobacter Pylori in patients with non-ulcer dyspepsia

BACKGROUND/AIM

A large number of diseases are ascribed to Helicobacter pylori (H. pylori), particularly chronic active gastritis, peptic ulcer disease and gastric cancer. Successful treatment of H. pylori infection with antimicrobial agents can lead to regression of H. pylori-associated disorders. Antibiotic resistance against H. pylori is increasing, and it is necessary to find new effective agents. Nigella sativa seed (NS), a commonly used herb, possesses in vitro anti-helicobacter activity. The present study was undertaken to evaluate the efficacy of NS in eradication of H. pylori infection in non-ulcer dyspeptic patients.

MATERIALS AND METHODS

The study was conducted on 88 adult patients attending King Fahd Hospital of the University, Al-Khobar, Saudi Arabia, from 2007 to 2008, with dyspeptic symptoms and found positive for H. pylori infection by histopathology and urease test. Patients were randomly assigned to four groups, receiving i) triple therapy (TT) comprising of clarithromycin, amoxicillin, omeprazole [n= 23], ii) 1 g NS + 40 mg omeprazole (OM) [n= 21], iii) 2 g NS + OM [n= 21] or iv) 3 g NS + OM [n= 23]. Negative H. pylori stool antigen test four weeks after end of treatment was considered as eradication.

RESULTS

H. pylori eradication was 82.6, 47.6, 66.7 and 47.8% with TT, 1 g NS, 2 g NS and 3 g NS, respectively. Eradication rates with 2 g NS and TT were statistically not different from each other, whereas H. pylori eradication with other doses was significantly less than that with TT (P < 0.05). Dyspepsia symptoms improved in all groups to a similar extent.

CONCLUSIONS

N. sativa seeds possess clinically useful anti-H. pylori activity, comparable to triple therapy. Further clinical studies combining N. sativa with antibiotics are suggested.

Guidelines for the management of Helicobacter pylori infection in Japan: 2009 revised edition

BACKGROUND

Over the past few years, the profile of Helicobacter pylori infection has changed in Japan. In particular, the relationship between H. pylori and gastric cancer has been demonstrated more clearly. Accordingly, the committee of the Japanese Society for Helicobacter Research has revised the guidelines for diagnosis and treatment of H. pylori infection in Japan.

MATERIALS AND METHODS

Four meetings of guidelines preparation committee were held from July 2007 to December 2008. In the new guidelines, recommendations for treatment have been classified into five grades according to the Minds Recommendation Grades, while the level of evidence has been classified into six grades. The Japanese national health insurance system was not taken into consideration when preparing these guidelines.

RESULTS

Helicobacter pylori eradication therapy achieved a Grade A recommendation, being useful for the treatment of gastric or duodenal ulcer, for the treatment and prevention of H. pylori-associated diseases such as gastric cancer, and for inhibiting the spread of H. pylori infection. Levels of evidence were determined for each disease associated with H. pylori infection. For the diagnosis of H. pylori infection, measurement of H. pylori antigen in the feces was added to the tests not requiring biopsy. One week of proton-pump inhibitor-based triple therapy (including amoxicillin and metronidazole) was recommended as second-line therapy after failure of first-line eradication therapy.

CONCLUSION

The revised Japanese guidelines for H. pylori are based on scientific evidence and avoid the administrative restraints that applied to earlier versions.

H. pylori eradication prevents the progression of gastric intestinal metaplasia in reflux esophagitis patients using long-term esomeprazole

OBJECTIVES

This study aimed to determine whether Helicobacter pylori eradication limits the progression of precancerous changes, manifested as intestinal metaplasia (IM), in patients with reflux esophagitis using long-term esomeprazole.

METHODS

Three hundred twenty-five reflux esophagitis patients were enrolled and randomly assigned to (i) the H. pylori-positive eradication group receiving 1-week triple therapy (n=105); (ii) H. pylori-positive non-eradication controls (n=105); and (iii) H. pylori-negative controls (n=115). All the patients received continuous esomeprazole until sustained symptomatic response, and when possible, shifted to on-demand therapy (ODT) thereafter. Serial gastroscopy was scheduled on enrollment and at the end of the first and second years to assess the prevalence and progression or regression of gastric atrophy (AT) and IM.

RESULTS

There were 93 patients in the H. pylori-eradication group, 83 in the non-eradication controls, and 100 in the negative controls to complete the study. The negative controls had no progression of AT and IM during follow-up. For the H. pylori-positive eradication group, there was significant regression of AT and IM during follow-up (P<0.05). In the H. pylori-positive non-treated controls, the prevalence rates of AT and IM were significantly greater on the second year than on enrollment (P<0.05). During the second-year follow-up, the patients in the eradication group achieved more regression and less development of AT and IM than did the non-eradication controls (P<0.001).

CONCLUSIONS

In patients using long-term esomeprazole for reflux esophagitis, screening for and eradicating H. pylori infection are necessary in order to limit the progression or cause the regression of gastric precancerous changes.

The role of microRNAs in gastrointestinal cancers

MicroRNAs (miRNAs) are small noncoding RNAs that function as endogenous silencers of numerous target genes. Hundreds of human miRNAs have been identified in the human genome, and they are expressed in a tissue-specific manner and play important roles in cell proliferation, apoptosis, and differentiation. Links between miRNAs and human diseases are increasingly apparent, and aberrant expression of miRNAs may contribute to the development and progression of human malignancies. Recent studies have shown that some miRNAs play roles as tumor suppressors or oncogenes in gastrointestinal cancers. miRNA expression is regulated by different mechanisms including transcription factor binding, epigenetic alterations, and chromosomal abnormalities. miRNA expression profiling may be a powerful clinical tool for cancer diagnosis, and regulation of miRNA expression could be a novel strategy for the chemoprevention of human gastrointestinal cancers. In this article, the biological importance of miRNAs in human gastrointestinal cancers is summarized.

Is there a dark side to long-term proton pump inhibitor therapy?

Proton pump inhibitors (PPIs) are among the most widely used of prescription drugs. They have revolutionized the management of gastroesophageal reflux disease and other acid-related disorders. Although generally safe, concerns about possible adverse effects continue to arise. Some of these, such as gastric neoplasms, are of theoretical concern only and are related to suppression of gastric acid secretion and consequent hypergastrinemia; these have not been encountered in clinical practice despite millions of patient-years of use. Others are more idiosyncratic, unpredictable, and rare. In general, the therapeutic benefits of PPIs outweigh these potential risks. However, it is important that PPIs are only given for appropriate indications and that, whenever possible, they are used in the lowest effective dose. At present, there is no need for specific monitoring for adverse events during PPI therapy.

Long-term proton pump inhibitor use and gastrointestinal cancer

Proton pump inhibitors profoundly affect the stomach and have been associated with carcinoid tumors in female rats. There is now sufficient experience with this class of drugs to allow reasonable estimation of their safety in terms of cancer development in humans. Long-term use of proton pump inhibitors is associated with an increase in gastric inflammation and development of atrophy among those with active Helicobacter pylori infections. The actual risk is unknown but is clearly low. However, it can be markedly reduced or eliminated by H. pylori eradication. It is thus recommended that patients being considered for long-term proton pump inhibitor therapy should be tested for H. pylori infection and, if present, this pathogen should be eradicated. Oxyntic cell hyperplasia, glandular dilatations, and fundic gland polyps may develop in patients not infected with H. pylori, but these changes are believed to be reversible and without significant cancer risk.

Helicobacter pylori eradication in patients on long-term treatment with NSAIDs reduces the severity of gastritis: a randomized controlled trial

BACKGROUND

Maintenance use of nonsteroidal anti-inflammatory drugs (NSAIDs) is often complicated by gastropathy. In non-NSAID users, eradication of Helicobacter pylori is associated with decreased mucosal inflammation, and may halt the progression to atrophy and intestinal metaplasia, but the continuous use of NSAIDs may interfere with these processes.

GOAL

To investigate the effect of H. pylori eradication on gastric mucosal histology during long-term NSAID use, with and without gastroprotective therapy.

STUDY

Patients were eligible for inclusion if they were on long-term NSAIDs and were H. pylori-positive on serologic testing. Patients were randomly assigned to either eradication or placebo. Gastritis was assessed according to the updated Sydney classification for activity, chronic inflammation, gastric glandular atrophy, intestinal metaplasia, and H. pylori density.

RESULTS

Biopsy specimens were available for histology of 305 patients. Of these, 48% were on chronic gastroprotective medication. Significant less active gastritis, inflammation, and H. pylori density was found in the eradication group compared with the placebo group in both corpus and antrum (P<0.001). In the corpus, less atrophy was found in the eradication group compared with the placebo group.

CONCLUSIONS

H. pylori eradication in patients on long-term NSAID therapy leads to healing of gastritis despite ongoing NSAID therapy.

Mechanism of cancer cell adaptation to metabolic stress: proteomics identification of a novel thyroid hormone-mediated gastric carcinogenic signaling pathway

Gastric cancer is the second most common cancer worldwide and has a poor prognosis. To determine the mechanism of adaptation to metabolic stress in cancer cells, we used gastric cancer as a model system to reveal the potential signaling pathways involved. Two-dimensional polyacrylamide gel electrophoresis coupled with ESI-Q-TOF MS/MS analysis was used to identify differentially expressed proteins between gastric tumor tissues and the corresponding noncancerous tissues. In total, 107 spots with significant alteration (+/-over 2-fold, p < 0.05) were positively identified by MS/MS analysis. Altered expression of representative proteins was validated by RT-PCR and Western blotting. Cluster analysis of the changed proteins revealed an interesting group of metabolic proteins, which suggested accumulation of triiodothyronine (T(3); the major functional component of thyroid hormone) and overexpression of hypoxia-induced factor (HIF) in gastric carcinoma. These observations were further confirmed by electrochemiluminescence immunoassay and immunohistochemistry. T(3)-induced expression of HIF1-alpha and vascular endothelial growth factor was further verified using a gastric cancer cell line and in vivo mouse model. Because the early accumulation of HIF1-alpha was found to be independent of de novo transcription, we also found that the cytosolic cascade phosphatidylinositol 3-kinase/Akt pathway sensitive to T(3) stimulus was involved. Furthermore we demonstrated that T(3)-induced overexpression of HIF1-alpha was mediated by fumarate accumulation and could be enhanced by fumarate hydratase inactivation but inhibited by 2-oxoglutarate. These results provide evidence for alteration of metabolic proteins and dysfunction of thyroid hormone regulation in gastric tumors, and a novel thyroid hormone-mediated tumorigenic signaling pathway is proposed. Our findings are considered a significant step toward a better understanding of adaptations to metabolic stress in gastric carcinogenesis.

Helicobacter pylori infection: a clinical overview

BACKGROUND

Helicobcater pylori colonizes the stomach of more than half of the world's population, and the infection continues to play a key role in the pathogenesis of a number of gastroduodenal diseases. Colonization of the gastric mucosa with Helicobcater pylori results in the development of chronic gastritis in all infected individuals and in a subset of patients chronic gastritis progresses to complications (i.e. ulcer disease, gastric neoplasias, some distinct extragastric disorders). The clinical outcome of the disease is dependent on many variables, including Helicobcater pylori genotype, innate host physiology, genetic predisposition and environmental factors. Helicobcater pylori eradication decreases the incidence of gastroduodenal ulcer and prevents its recurrence. Helicobcater pylori eradication for gastric cancer prevention has been suggested by preclinical research and clinical trials, showing even reversibility of precancerous lesions (atrophic gastritis and intestinal metaplasia) after Helicobcater pylori eradication.

AIMS

To review the current literature about H. pylori and its related pathologies.

CONCLUSION

At present, several clinical manifestations are recognized to be causally linked to Helicobcater pylori infection, and most of them can be cured by Helicobcater pylori eradication. Besides the relationship of Helicobcater pylori and gastroduodenal diseases, it has been well established that Helicobcater pylori infection is also involved in some extragastrointestinal diseases.

Correlation of T cell response and bacterial clearance in human volunteers challenged with Helicobacter pylori revealed by randomised controlled vaccination with Ty21a-based Salmonella vaccines

BACKGROUND

Helicobacter pylori remains a global health hazard, and vaccination would be ideal for its control. Natural infection appears not to induce protective immunity. Thus, the feasibility of a vaccine for humans is doubtful.

METHODS

In two prospective, randomised, double-blind, controlled studies (Paul Ehrlich Institute application nos 0802/02 and 1097/01), live vaccines against H pylori were tested in human volunteers seronegative for, and without evidence of, active H pylori infection. Volunteers (n = 58) were immunised orally with Salmonella enterica serovar Typhi Ty21a expressing H pylori urease or HP0231, or solely with Ty21a, and then challenged with 2x10(5) cagPAI(-) H pylori. Adverse events, infection, humoral, cellular and mucosal immune response were monitored. Gastric biopsies were taken before and after vaccination, and postchallenge. Infection was terminated with antibiotics.

RESULTS

Vaccines were well tolerated. Challenge infection induced transient, mild to moderate dyspeptic symptoms, and histological and transcriptional changes in the mucosa known from chronic infection. Vaccines did not show satisfactory protection. However, 13 of 58 volunteers, 8 vaccinees and 5 controls, became breath test negative and either cleared H pylori (5/13) completely or reduced the H pylori burden (8/13). H pylori-specific T helper cells were detected in 9 of these 13 (69%), but only in 6 of 45 (13%) breath test-positive volunteers (p = 0.0002; Fisher exact test). T cells were either vaccine induced or pre-existing, depending on the volunteer.

CONCLUSION

Challenge infection offers a controlled model for vaccine testing. Importantly, it revealed evidence for T cell-mediated immunity against H pylori infection in humans.

Asia-Pacific consensus on the management of gastroesophageal reflux disease: update

BACKGROUND AND AIMS

Since the publication of the Asia-Pacific GERD consensus in 2004, more data concerning the epidemiology and management of gastroesophageal reflux disease (GERD) have emerged. An evidence based review and update was needed.

METHODS

A multidisciplinary group developed consensus statements using the Delphi approach. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded.

RESULTS

GERD is increasing in frequency in Asia. Risk factors include older age, male sex, race, family history, higher socioeconomic status, increased body mass index, and smoking. Symptomatic response to a proton pump inhibitor (PPI) test is diagnostic in patients with typical symptoms if alarm symptoms are absent. A negative pH study off therapy excludes GERD if a PPI test fails. The role for narrow band imaging, capsule endoscopy, and wireless pH monitoring has not yet been undefined. Diagnostic strategies in Asia must consider coexistent gastric cancer and peptic ulcer. Weight loss and elevation of head of bed improve reflux symptoms. PPIs are the most effective medical treatment. On-demand therapy is appropriate for nonerosive reflux disease (NERD) patients. Patients with chronic cough, laryngitis, and typical GERD symptoms should be offered twice daily PPI therapy after excluding non-GERD etiologies. Fundoplication could be offered to GERD patients when an experienced surgeon is available. Endoscopic treatment of GERD should not be offered outside clinical trials.

CONCLUSIONS

Further studies are needed to clarify the role of newer diagnostic modalities and endoscopic therapy. Diagnostic strategies for GERD in Asia must consider coexistent gastric cancer and peptic ulcer. PPIs remain the cornerstone of therapy.

Review article: Helicobacter pylori eradication for the prevention of gastric cancer

BACKGROUND

Gastric cancer is the fourth most common cancer and second leading cause of cancer-related death worldwide. A clear association between Helicobacter pylori infection and gastric cancer was established years ago. H. pylori eradication may be an effective approach to decrease morbidity and mortality of gastric cancer.

AIM

To discuss current evidence of H. pylori eradication for prevention of gastric cancer.

RESULTS

Recent studies have shown that the association between H. pylori and gastric cancer has probably been underestimated. This may have resulted from negative H. pylori status in subjects after loss of colonisation in the presence of atrophic gastritis and intestinal metaplasia, prior to development of gastric cancer. The recognition of the central role of H. pylori in carcinogenesis has increased expectations of gastric cancer prevention by H. pylori eradication. A primary preventive effect of eradication in subjects with H. pylori-induced gastritis has been demonstrated. However, a secondary preventive effect in patients with pre-malignant gastric lesions is still controversial, especially in patients with intestinal metaplasia and dysplasia.

CONCLUSIONS

At this moment, H. pylori eradication seems indicated at the earliest stage of gastric carcinogenesis. This treatment policy requires confirmation; results of ongoing randomised controlled trials are therefore eagerly awaited.

Feasibility and cost-effectiveness of using magnification chromoendoscopy and pepsinogen serum levels for the follow-up of patients with atrophic chronic gastritis and intestinal metaplasia

BACKGROUND

The follow-up of patients with atrophic chronic gastritis or intestinal metaplasia may lead to early diagnosis of gastric cancer. However, to-date no cost-effective model has been proposed. Improved endoscopic examination using magnification chromoendoscopy together with non-invasive functional assessment with pepsinogen serum levels are accurate in the diagnosis of intestinal metaplasia (extension) and minute dysplastic lesions. The aim of this study was to assess the feasibility and cost-effectiveness of a follow-up model for patients with atrophic chronic gastritis and intestinal metaplasia based on gastric mucosal status using magnification chromoendoscopy and pepsinogen.

METHODS

A cohort of patients with lesions as severe as atrophic chronic gastritis were followed-up according to a standardized protocol using magnification chromoendoscopy with methylene blue and measurement of serum pepsinogen I and II levels. A single node decision tree and Markov chain modeling were used to define cost-effectiveness of this follow-up model versus its absence. Transition rates were considered time-independent and calculated using primary data following cohort data analysis. Costs, quality of life and survival were estimated based on published data and extensive sensitivity analysis was performed.

RESULTS

A total of 100 patients were successfully followed-up over 3 years. Seven cases of dysplasia were diagnosed during follow-up, all among patients with incomplete intestinal metaplasia at baseline, six of whom had extensive (pepsinogen I to II ratio <3) incomplete intestinal metaplasia. For those individuals with atrophic chronic gastritis or complete intestinal metaplasia, a yearly measurement of pepsinogen levels or an endoscopic examination on a 3-yearly basis would cost 455 euros per quality-adjusted life year (QALY) gain. Endoscopic examination and pepsinogen serum level measurement on a yearly basis would cost 1868 euros per QALY for patients with extensive intestinal metaplasia.

CONCLUSIONS

The follow-up of patients with atrophic chronic gastritis or intestinal metaplasia is both feasible and cost-effective if improved accurate endoscopic examination of gastric mucosa together with non-invasive assessment of gastric mucosal status are used to identify individuals at high-risk for development of gastric cancer.

Gastric antisecretory drugs induce leukocyte-endothelial cell interactions through gastrin release and activation of CCK-2 receptors

Antisecretory drugs are effective antiulcer agents, but its chronic use generates hypergastrinemia and accelerates the development of atrophic gastritis in Helicobacter pylori-positive patients. We have recently shown that gastrin exerts a proinflammatory effect in rats through CCK-2 receptor activation that contributes to the inflammation induced by H. pylori. The present study was designed to examine whether gastrin hypersecretion in response to treatment with antisecretory drugs induces an inflammatory response that could promote mucosal atrophy. The effects of omeprazole or famotidine on leukocyte/endothelial cell interactions in vivo were analyzed in rat mesenteric venules using intravital microscopy. Administration of a single dose of omeprazole or famotidine acutely increased gastrinemia and leukocyte rolling and adhesion, but not emigration into the interstitium. Daily treatment with omeprazole for a short period (3 days) induced a similar response, but when this treatment was extended to 14 days and a steady hyper-gastrinemic state was established, increased leukocyte rolling, adhesion, and emigration was observed. Pretreatment with the CCK-2 receptor antagonist proglumide prevented these inflammatory events in all cases. Leukocytes from rats treated with omeprazole showed increased expression of CD11b/CD18 initially in granulocytes (3-day protocol) and later in monocytes and lymphocytes (14-day protocol). These changes were not observed in animals pretreated with proglumide, and they were not reproduced by incubation of leukocytes from untreated animals in vitro with gastrin. Thus, hypergastrinemia induced by chronic treatment with antisecretory drugs may promote inflammation, which could partly explain their worsening effect in corpus gastritis observed in H. pylori-infected patients.

Current concepts in the management of Helicobacter pylori infection: the Maastricht III Consensus Report

BACKGROUND

Guidelines on the management of Helicobacter pylori, which cover indications for management and treatment strategies, were produced in 2000.

AIMS

To update the guidelines at the European Helicobacter Study Group (EHSG) Third Maastricht Consensus Conference, with emphasis on the potential of H pylori eradication for the prevention of gastric cancer.

RESULTS

Eradication of H pylori infection is recommended in (a) patients with gastroduodenal diseases such as peptic ulcer disease and low grade gastric, mucosa associated lymphoid tissue (MALT) lymphoma; (b) patients with atrophic gastritis; (c) first degree relatives of patients with gastric cancer; (d) patients with unexplained iron deficiency anaemia; and (e) patients with chronic idiopathic thrombocytopenic purpura. Recurrent abdominal pain in children is not an indication for a "test and treat" strategy if other causes are excluded. Eradication of H pylori infection (a) does not cause gastro-oesophageal reflux disease (GORD) or exacerbate GORD, and (b) may prevent peptic ulcer in patients who are naïve users of non-steroidal anti-inflammatory drugs (NSAIDs). H pylori eradication is less effective than proton pump inhibitor (PPI) treatment in preventing ulcer recurrence in long term NSAID users. In primary care a test and treat strategy using a non-invasive test is recommended in adult patients with persistent dyspepsia under the age of 45. The urea breath test, stool antigen tests, and serological kits with a high accuracy are non-invasive tests which should be used for the diagnosis of H pylori infection. Triple therapy using a PPI with clarithromycin and amoxicillin or metronidazole given twice daily remains the recommended first choice treatment. Bismuth-containing quadruple therapy, if available, is also a first choice treatment option. Rescue treatment should be based on antimicrobial susceptibility.

CONCLUSION

The global burden of gastric cancer is considerable but varies geographically. Eradication of H pylori infection has the potential to reduce the risk of gastric cancer development.

Current concepts in the management of Helicobacter pylori infection: the Maastricht III Consensus Report

BACKGROUND

Guidelines on the management of Helicobacter pylori, which cover indications for management and treatment strategies, were produced in 2000.

AIMS

To update the guidelines at the European Helicobacter Study Group (EHSG) Third Maastricht Consensus Conference, with emphasis on the potential of H pylori eradication for the prevention of gastric cancer.

RESULTS

Eradication of H pylori infection is recommended in (a) patients with gastroduodenal diseases such as peptic ulcer disease and low grade gastric, mucosa associated lymphoid tissue (MALT) lymphoma; (b) patients with atrophic gastritis; (c) first degree relatives of patients with gastric cancer; (d) patients with unexplained iron deficiency anaemia; and (e) patients with chronic idiopathic thrombocytopenic purpura. Recurrent abdominal pain in children is not an indication for a "test and treat" strategy if other causes are excluded. Eradication of H pylori infection (a) does not cause gastro-oesophageal reflux disease (GORD) or exacerbate GORD, and (b) may prevent peptic ulcer in patients who are naïve users of non-steroidal anti-inflammatory drugs (NSAIDs). H pylori eradication is less effective than proton pump inhibitor (PPI) treatment in preventing ulcer recurrence in long term NSAID users. In primary care a test and treat strategy using a non-invasive test is recommended in adult patients with persistent dyspepsia under the age of 45. The urea breath test, stool antigen tests, and serological kits with a high accuracy are non-invasive tests which should be used for the diagnosis of H pylori infection. Triple therapy using a PPI with clarithromycin and amoxicillin or metronidazole given twice daily remains the recommended first choice treatment. Bismuth-containing quadruple therapy, if available, is also a first choice treatment option. Rescue treatment should be based on antimicrobial susceptibility.

CONCLUSION

The global burden of gastric cancer is considerable but varies geographically. Eradication of H pylori infection has the potential to reduce the risk of gastric cancer development.

Proton pump inhibitors and Helicobacter pylori gastritis: friends or foes?

H. pylori gastritis and gastric acid closely interact. In H. pylori-positive patients, profound acid suppressive therapy induces a corpus-predominant pangastritis, which is associated with accelerated corpus gland loss and development of atrophic gastritis. Both corpus-predominant and atrophic gastritis have been associated with an increased risk of development of gastric cancer. H. pylori eradication leads to resolution of gastritis and may induce partial regression of pre-existent gland loss. H. pylori eradication does not aggravate GERD nor does it impair the efficacy of proton pump inhibitor maintenance therapy for this condition. This is the background of the advise within the European guidelines for the management of H. pylori infection to offer an H. pylori test and treat policy to patients who require proton pump inhibitor maintenance therapy for GERD. As such a policy fully reverses H. pylori pangastritis even in patients who have been treated for years with proton pump inhibitors, there is no need to eradicate H. pylori before the start of proton pump inhibitors. In fact, the somewhat slower initial response of H. pylori-negative GERD patients to proton pump inhibitor therapy and the fact that many GERD patients will only require short-term therapy suggests to first start the proton pump inhibitor, and only test and treat when maintenance therapy needs to be prescribed. Such considerations prevent the persistent presence of active corpus-predominant gastritis in proton pump inhibitor-treated reflux patients without impairing the clinical efficacy of treatment.

The detection, surveillance and treatment of premalignant gastric lesions related to Helicobacter pylori infection

Gastric cancer is an important worldwide health problem and causes considerable morbidity and mortality. It represents the second leading cause of cancer-related death worldwide. A cascade of recognizable precursor lesions precedes most distal gastric carcinomas. In this multistep model of gastric carcinogenesis, Helicobacter pylori causes chronic active inflammation of the gastric mucosa, which slowly progresses through the premalignant stages of atrophic gastritis, intestinal metaplasia and dysplasia to gastric carcinoma. Detection and treatment of premalignant lesions may thus provide a basis for gastric cancer prevention. However, at present, premalignant changes of the gastric mucosa are frequently disregarded in clinical practice or result in widely varying follow-up frequency or treatment. This review provides an overview of current knowledge on detection, surveillance and treatment of patients with premalignant gastric lesions, and identifies the uncertainties that require further research.

Systematic review: Helicobacter pylori eradication for the prevention of gastric cancer

BACKGROUND

Helicobacter pylori is recognized as one of the most significant risk factors for gastric cancer, and H. pylori eradication has been proposed as a possible primary chemo-preventive strategy to reduce gastric cancer incidence.

AIM

To evaluate the available evidence on the efficacy of H. pylori eradication in the prevention of gastric cancer.

METHODS

Epidemiological, observational and interventional studies, as well as decisional models, were taken into account in this review.

RESULTS

Large-scale epidemiological studies clearly link H. pylori infection with non-cardia gastric cancer. Current evidence suggests that, in a subpopulation of treated subjects, H. pylori eradication prevents the progression of preneoplastic lesions. Studies that have attempted to evaluate the effect of H. pylori eradication on the incidence of gastric cancer have not provided definitive answers. H. pylori eradication seems to reduce the incidence of gastric cancer in patients without baseline precancerous gastric lesions. Decisional models suggest that H. pylori screening could be cost-effective, but there is not yet sufficient evidence to support the setting up of a general screening programme.

CONCLUSION

Helicobacter pylori eradication is a plausible intervention for gastric cancer prevention; however, it seems to be relevant in only a subset of subjects.

Baseline gastric mucosal atrophy is a risk factor associated with the development of gastric cancer after Helicobacter pylori eradication therapy in patients with peptic ulcer diseases

BACKGROUND

We previously reported that eradication of Helicobacter pylori could reduce the risk of developing gastric cancer in patients with peptic ulcer diseases. In the present study, we further followed up our patient groups to identify factors associated with the development of gastric cancer.

METHODS

Prospective posteradication evaluations were conducted in 1342 consecutive patients (1191 men and 151 women; mean age, 50 years) with peptic ulcer disease who had received H. pylori eradication therapy. The patients had undergone endoscopic examination before eradication therapy to evaluate peptic ulcers, background gastric mucosa, and H. pylori infection. After confirmation of eradication, follow-up endoscopy was performed yearly.

RESULTS

A total of 1131 patients were followed for up to 9.5 years (mean, 3.9 years). Gastric cancer developed in 9 of 953 patients cured of infection and in 4 of 178 who had persistent infection (P=0.04). The risk of developing gastric cancer after receiving H. pylori eradication therapy was increased according to the grade of baseline gastric mucosal atrophy (P=0.01). In patients with peptic ulcer diseases, persistent infection of H. pylori (hazard ratio, 3.9; P=0.03), the grade of baseline gastric mucosal atrophy (3.3, P=0.01) and age (2.0, P=0.04) were identified as significant risk factors for developing gastric cancer.

CONCLUSIONS

The grade of gastric atrophy was closely related to the development of gastric cancer after receiving H. pylori eradication therapy. Thus, eradication of H. pylori before the significant expansion of atrophy is most beneficial to prevent gastric cancer.

Helicobacter pylori: present status and future prospects in Japan

The discovery of Helicobacter pylori has already changed the natural history of peptic ulcer disease, with most patients being cured at their first presentation. Similarly, the incidence of gastric cancer and other diseases related to H. pylori are likely to be greatly reduced in the near future. Isolation of the spiral intragastric bacterium H. pylori totally reversed the false dogma that the stomach was sterile, and it taught us that chronic infectious disease can still exist in modern society. Helicobacter pylori's unique location, persistence, and evasion of the immune system offer important insights into the pathophysiology of the gut. Also, the fact that it was overlooked for so long encourages us to think "outside the box" when investigating other diseases with obscure etiologies. We should consider such provocative scientific ideas as bridges to the future disease control.