Eradication of Helicobacter pylori prevents cancer development in subjects with mild gastric atrophy identified by serum pepsinogen levels

Pathogenesis and potential reversibility of intestinal metaplasia - a milestone in gastric carcinogenesis

BACKGROUND

Non-cardia gastric cancer remains a major cause of cancer-related mortality worldwide, despite declining incidence rates in many industrialized countries. The development of intestinal-type gastric cancer occurs through a multistep process in which normal mucosa is sequentially transformed into hyperproliferative epithelium, followed by metaplastic processes leading to carcinogenesis. Chronic infection with Helicobacter pylori is the primary etiological agent that causes chronic inflammation of the gastric mucosa, induces atrophic gastritis, and can lead to intestinal metaplasia and dysplasia. Both intestinal metaplasia and dysplasia are precancerous lesions, in which gastric cancer is more likely to occur. Atrophic gastritis often improves after eradication of Helicobacter pylori; however, the occurrence of intestinal metaplasia has been traditionally regarded as "the point of no return" in the carcinogenesis sequence. Helicobacter pylori eradication heals non-atrophic chronic gastritis, may lead to regression of atrophic gastritis, and reduces the risk of gastric cancer in patients with these conditions. In this article, we discuss the pathogenesis, epigenomics, and reversibility of intestinal metaplasia and briefly touch upon potential treatment strategy.

CONCLUSIONS

Gastric intestinal metaplasia no longer appears to be an irreversible precancerous lesion. However, there are still many controversies regarding the improvement of intestinal metaplasia after Helicobacter pylori eradication.

Dynamic variations of the gastric microbiota: Key therapeutic points in the reversal of Correa's cascade

Correa's cascade is a dynamic process in the development of intestinal-type gastric cancer (GC), and its pathological features, gastric microbiota and interactions between microorganisms and their hosts vary at different developmental stages. The characteristics of cells, tissues and gastric microbiota before or after key therapeutic points are critical for monitoring malignant transformation and early tumour reversal. This review summarises the pathological features of gastric mucosa, characteristics of gastric microbiota, specific microbial markers, microbe-microbe interactions and microbe-host interactions at different stages in Correa's cascade. The markers related to each Correa's cascade point were analysed in detail. We attempted to identify key therapeutic points for early cancer reversal and provide a novel approach to reduce the incidence of GC and improve precise treatment.

Association between Age at Helicobacter pylori Eradication and the Risk of Gastric Cancer Stratified by Family History of Gastric Cancer: A Nationwide Population-Based Study

INTRODUCTION

This study compares the risk of GC according to age at H. pylori eradication, stratified based on the presence of family history of GC using a population-based large cohort.

METHOD

We analyzed individuals who underwent GC screening between 2013 and 2014 and received H. pylori eradication therapy before screening.

RESULTS

Among 1,888,815 H. pylori-treated patients, 2610/294,706 and 9332/1,594,109 patients with and without a family history of GC, respectively, developed GC. After adjusting for confounders, including age at screening, the adjusted hazard ratios (95% confidence intervals) for GC comparison, 70-74, 65-69, 60-64, 55-59, 50-54, 45-49, and <45 years with ≥75 years at H. pylori eradication were 0.98 (0.79-1.21), 0.88 (0.74-1.05), 0.76 (0.59-0.99), 0.62 (0.44-0.88), 0.57 (0.36-0.90), 0.38 (0.22-0.66), and 0.34 (0.17-0.67), respectively, among patients with a family history of GC (p < 0.001) and 1.01 (0.91-1.13), 0.95 (0.86-1.04), 0.86 (0.75-0.98), 0.67 (0.56-0.81), 0.56 (0.44-0.71), 0.51 (0.38-0.68), and 0.33 (0.23-0.47), respectively, among patients without a family history of GC (p < 0.001).

CONCLUSION

In patients with and without a family history of GC, young age at H. pylori eradication was significantly associated with a reduced risk of GC, suggesting that the early treatment of H. pylori infection can maximize GC prevention.

Effect of Helicobacter pylori Eradication Treatment on Metachronous Gastric Neoplasm Prevention Following Endoscopic Submucosal Dissection for Gastric Adenoma

The long-term effect of Helicobacter pylori eradication on metachronous gastric neoplasm prevention after endoscopic submucosal dissection (ESD) of gastric adenoma is unclear. This study included patients with confirmed H. pylori infection after ESD with curative resection for gastric adenoma. Patients were divided based on the success of H. pylori eradication treatment into two groups: eradication and non-eradication. Patients with any newly detected lesion within 1 year after ESD and recurrence at the ESD site were excluded from the analysis. Further, 1:1 propensity score matching was also performed to eliminate baseline differences between the two groups. H. pylori eradication treatment was administered to 673 patients after ESD (163 in the successful eradication group and 510 in the non-eradication group). During the median follow-up periods of 25 and 39 months in the eradication and non-eradication groups, metachronous gastric neoplasm was identified in 6 (3.7%) and 22 patients (4.3%), respectively. Adjusted Cox analysis revealed that H. pylori eradication was not associated with increased risk of metachronous gastric neoplasm after ESD. Kaplan-Meier analysis in the matched population yielded similar findings (p = 0.546). H. pylori eradication treatment was not associated with metachronous gastric neoplasm after ESD with curative resection for gastric adenoma.

Discussion on the common controversies of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori ( H. pylori ) can persistently colonize on the gastric mucosa after infection and cause gastritis, atrophy, metaplasia, and even gastric cancer (GC).

METHODS

Therefore, the detection and eradication of H. pylori are the prerequisite.

RESULTS

Clinically, there are some controversial issues, such as why H. pylori infection is persistent, why it translocases along with the lesser curvature of the stomach, why there is oxyntic antralization, what the immunological characteristic of gastric chronic inflammation caused by H. pylori is, whether H. pylori infection is associated with extra-gastric diseases, whether chronic atrophic gastritis (CAG) is reversible, and what the potential problems are after H. pylori eradication. What are the possible answers?

CONCLUSION

In the review, we will discuss these issues from the attachment to eradication in detail.

Differences in clinical features and morphology between differentiated and undifferentiated gastric cancer after Helicobacter pylori eradication

BACKGROUND/AIMS

Although undifferentiated gastric cancer (UGC) diagnosed after Helicobacter pylori eradication (HPE) carries a poor prognosis, characteristics of post-HPE UGC have not been evaluated in detail because of its low incidence. Therefore, we compared the clinicopathologic characteristics of UGC and differentiated gastric cancers (DGC) diagnosed after successful HPE.

METHODS

GC lesions from patients who had successfully completed HPE and who had undergone upper gastrointestinal endoscopy between January 2004 and March 2016 were analyzed. Tumors were divided into DGC and UGC groups. Clinicopathologic factors of background and tumor characteristics were compared using univariate and multiple logistic analyses.

RESULTS

A total of 129 tumors from 115 patients were evaluated; 113 tumors were in the DGC group and 16 in the UGC group. Depressed-type tumors (P = 0.024) and sub-submucosal invasion (P<0.001) were significantly higher in the UGC group. The UGC group had larger tumor diameters (25.9±7.3 mm) than the DGC group (13.2±10.2 mm) (P<0.001). Multivariate analysis showed that female sex (odds ratio [OR] 3.24, 95%CI:1.02-10.37; P = 0.047) and absent follow-up (OR 4.99, 95%CI:1.60-15.57; P = 0.006) were significant independent risk factors for UGC. The DGC group showed a gradually decreasing temporal trend by trend test (P = 0.015), while the UGC group showed a relatively constant incidence over time, although the number of cases was small.

CONCLUSION

UGC was diagnosed even after long time spans following HPE, although the number of cases was small. Female sex, and especially absent follow-up, were risks for post-HPE UGC, suggesting that diligent long-term follow-up after HPE is essential.

Mass screening and eradication of Helicobacter pylori as the policy recommendations for gastric cancer prevention

Gastric cancer is an inflammation-related cancer triggered by Helicobacter pylori infection. Understanding of the natural disease course has prompted the hypothesis that gastric cancer can be prevented by administering a short-course antibiotic treatment to eradicate the H. pylori infection and interrupt this carcinogenic cascade. Results from randomized controlled trials and cohort studies have repeatedly confirmed this concept, which has moved attention from individual management of H. pylori infection to population-wide implementation of screening programs. Such a paradigm shift follows a three-tier architecture. First, healthcare policy-makers determine the most feasible and applicable eligibility, invitation, testing, referral, treatment, and evaluation methods for an organized screening program to maximize the population benefits and cost-effectiveness. Second, provision of knowledge and effective feedback to frontline general practitioners, including choice of diagnostic tests, selection of eradication regimens, and the indication of endoscopic examination, ensures the quality of care and increases the likelihood of desired treatment responses. Third, initiatives to raise population awareness are designed regarding the impact of H. pylori infection and risky lifestyle habits on the stomach health. These programs, with increased accessibility and geographic coverage in progress, will accelerate the decline in morbidity, mortality, and associated costs of this preventable malignancy.

The 'reversibility' of chronic atrophic gastritis after the eradication of Helicobacter pylori

Gram-negative bacterium Helicobacter pylori (H. pylori) infection is lifelong and usually acquired in childhood, which is etiologically linked to gastric cancer (GC). H. pylori gastritis is defined as an infectious disease with varying severity in virtually all infected subjects. Chronic atrophic gastritis (CAG) is the precancerous condition with the decrease or the loss of gastric glands, which can further be replaced by metaplasia or fibrosis. Patients with advanced stages of CAG are at higher risk of GC and should be followed up with a high-quality endoscopy every 3 years. H. pylori infection is the most common cause and its eradication is recommended, which may contribute to the regression of CAG. However, it is controversial whether CAG is reversible after eradication therapy. In the review, we discuss recent studies which provide important insights into whether CAG is 'reversibility' and when it may progress into GC after eradicating H. pylori.

The risk of diffuse-type gastric cancer following diagnosis with gastric precancerous lesions: a systematic review and meta-analysis

PURPOSE

Gastric cancers are classified as diffuse-type (DTGC) or intestinal-type (ITGC). DTGCs have distinct clinical and histopathologic features, and carry a worse overall prognosis compared to ITGCs. Atrophic gastritis (AG) and intestinal metaplasia (IM) are known precursors to ITGC. It is unknown if AG and IM increase risk for DTGC.

METHODS

We performed a systematic review to identify studies reporting on the association of AG/IM and DTGC. We extracted the odds ratio (OR) of the association from studies, and performed pool analysis. Subgroup analysis was performed on studies reporting histologic severity (using operative link systems) to assess if histologic severity of AG/IM was associated with higher risk.

RESULTS

We identified six case-control and eight cohort studies for inclusion. Both AG (pooled OR = 1.9, 95% CI 1.5 to 2.4, p < 0.001) and IM (pooled OR = 2.3, 95% CI 1.9 to 2.9, p < 0.001) demonstrated an association with DTGC. High AG severity was associated with increased risk for DTGC compared to low AG severity (OR = 1.7, 95% CI 1.2 to 2.3, p = 0.002). Similarly, high IM severity was associated with increased risk compared to low IM severity (OR = 1.9, 95% CI 1.3 to 2.7, p = 0.001).

CONCLUSION

Both AG and IM are associated with DTGC. Increasing histologic severity of both AG and IM increases risk for DTGC. There may exist a common pathway between ITGC and some DTGCs mediated through mucosal precursor lesions. These data may inform future strategies of cancer risk attenuation and control.

Helicobacter pylori eradication prevents secondary gastric cancer in patients with mild-to-moderate atrophic gastritis

BACKGROUND AND AIM

Whether Helicobacter pylori eradication prevents metachronous recurrence after endoscopic resection (ER) of early gastric cancer remains controversial. This multicenter retrospective study aimed to evaluate the long-term (> 5 years) effects of H. pylori eradication by stratifying patients' baseline degrees of atrophic gastritis.

METHODS

A total of 483 H. pylori-positive patients who had undergone ER for early gastric cancer were divided into two groups-(i) those having undergone successful H. pylori eradication within 1 year after ER (eradicated group, n = 294) and (ii) those with failed or not attempted H. pylori eradication (non-eradicated group, n = 189). The cumulative incidences of metachronous gastric cancer between the two groups were compared for all patients, for patients with mild-to-moderate atrophic gastritis (n = 182), and for patients with severe atrophic gastritis (n = 301).

RESULTS

During a median follow-up of 5.2 years (range 1.1-14.8), metachronous cancer developed in 52 (17.7%) patients in the eradicated group and in 35 (18.5%) patients in the non-eradicated group (P = 0.11, log-rank test). In patients with mild-to-moderate atrophic gastritis (111 and 71 in the eradicated and non-eradicated groups, respectively), the cumulative incidence of metachronous cancer was significantly lower in the eradicated group than that in the non-eradicated group (P = 0.03, log-rank test). However, no significant intergroup difference was observed in patients with severe atrophic gastritis (P = 0.69, log-rank test).

CONCLUSIONS

Helicobacter pylori eradication had a preventive effect on the development of metachronous gastric cancer in patients with mild-to-moderate atrophic gastritis.

Effects of Helicobacter pylori eradication on gastric cancer incidence in the Japanese population: a systematic evidence review

BACKGROUND

In Japan, there are ongoing efforts to shift the gastric cancer prevention and control policy priorities from barium-based screening to Helicobacter pylori (H. pylori)-oriented primary prevention. A comprehensive summary of the evidence regarding the effects of H. pylori eradication on the risk of gastric cancer could inform policy decisions.

METHODS

We conducted a systematic review and meta-analysis of published studies evaluating the effectiveness of H. pylori eradication for the prevention of gastric cancer in otherwise healthy individuals (primary prevention) and early gastric cancer patients (tertiary prevention).

RESULTS

In total, 19 studies were included. Three moderate-quality observational cohort studies showed that H. pylori eradication may be associated with a decreased risk of gastric cancer in healthy asymptomatic Japanese people. There is moderate certainty regarding the effectiveness of H. pylori eradication in patients with gastrointestinal diseases, such as peptic ulcers. A meta-analysis of 10 observational studies with otherwise healthy individuals (mainly peptic ulcer patients) yielded an overall odds ratio of 0.34 (95% CI: 0.25-0.46). Regarding tertiary prevention, the overall odds ratio for developing metachronous gastric cancer was 0.42 (95% CI: 0.35-0.51) in the eradication group in a meta-analysis of nine studies involving early gastric cancer patients who underwent endoscopic resection.

CONCLUSION

H. pylori eradication is effective in preventing gastric cancer in the Japanese population, regardless of symptoms. Well-designed, large cohort studies are warranted to determine the long-term efficacy and safety of H. pylori eradication in the context of reducing the gastric cancer burden through population-based screening and treatment.

Evidence based guidelines for the treatment of Helicobacter pylori infection in Korea 2020

Helicobacter pylori infection is one of the most common infectious diseases worldwide. H. pylori is responsible for substantial gastrointestinal morbidity with a high disease burden. Since the revision of the H. pylori Clinical Practice Guidelines in 2013 in Korea, the eradication rate of H. pylori has gradually decreased with the use of a clarithromycin based triple therapy. According to a nationwide randomized controlled study by the Korean College of Helicobacter and Upper Gastrointestinal Research released in 2018, the intention-to-treat eradication rate was only 63.9%, which was mostly due to increased antimicrobial resistance to clarithromycin. The clinical practice guidelines for treatment of H. pylori were updated based on evidence-based medicine from a meta-analysis conducted on a target group receiving the latest level of eradication therapy. The draft recommendations developed based on the meta-analysis were finalized after expert consensus on three recommendations regarding the indication for treatment and eight recommendations on the treatment itself. These guidelines were designed to provide clinical evidence for the treatment of H. pylori to patients, nurses, medical school students, policymakers, and clinicians. These may differ from current medical insurance standards, and will be revised if more evidence emerges in the future.

Epidemiological study of Helicobacter pylori infection and its relationship with pathologic changes of the antral mucosa in rural areas of Yangzhou

BACKGROUND

Helicobacter pylori (H. pylori) infection remains one of the world's public health problems, and socioeconomic conditions and modifiable lifestyle factors may influence the rate of H. pylori infection. As the most important controllable cause of gastric cancer, eradication of H. pylori is of great significance for the prevention of gastric cancer.

AIM

To investigate the status of Helicobacter pylori infection and its relationship with the pathological change of the antral mucosa.

METHODS

A total of 1412 subjects were selected from the program of Endoscopy Screening of Upper Gastrointestinal Tumor in Yangzhou from January 2019 to December 2019. Questionnaire survey, ¹⁴C-urea breath test, gastroscopy, and tissue biopsy were performed among the selected population. Statistical software was used to calculate the prevalence rate of H. pylori infection, the related influencing factors, and the relationship between H. pylori infection and the pathological changes of the antral mucosa.

RESULTS

In this study, the male-to-female ratio was 1:1.5 and the age ranged from 36 to 76 years old. The prevalence rate of H. pylori infection was 43.8% in rural areas of Yangzhou city. According to the univariate analysis, there was a correlation between smoking, dietary preference, level of H. pylori awareness, gastrointestinal symptoms and H. pylori infection (P < 0.05). Multivariate analysis showed that smoking was an independent risk factor for H. pylori infection (odds ratio = 1.427, 95% confidence interval: 1.103-1.847). In the analysis of the relationship between H. pylori infection and the pathological changes of the gastric mucosa, the proportion of H. pylori-positive people exhibiting atrophic gastritis, intestinal chemosis, heterogeneous hyperplasia, and gastric cancer was significantly higher than that of H. pylori-negative participants.

CONCLUSION

The H. pylori infection rate in Yangzhou is high, and bad habit can affect the prevalence of H. pylori infection. H. pylori infection is associated with the progression of gastric mucosal pathology. It is recommended to strengthen education among the population to improve the prevention and control of H. pylori in the region and reduce the incidence of gastric cancer.

Evidence-Based Guidelines for the Treatment of Helicobacter pylori Infection in Korea 2020

Helicobacter pylori infection is one of the most common infectious diseases worldwide. Although the prevalence of H. pylori is gradually decreasing, approximately half of the world&#039;s population still becomes infected with this disease. H. pylori is responsible for substantial gastrointestinal morbidity worldwide, with a high disease burden. It is the most common cause of gastric and duodenal ulcers and gastric cancer. Since the revision of the H. pylori clinical practice guidelines in 2013 in Korea, the eradication rate of H. pylori has gradually decreased with the use of a clarithromycin-based triple therapy for 7 days. According to a nationwide randomized controlled study conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research released in 2018, the intention-to-treat eradication rate was only 63.9%, which was mostly due to increased antimicrobial resistance, especially from clarithromycin. The clinical practice guidelines for the treatment of H. pylori were updated according to evidence-based medicine from a meta-analysis conducted on a target group receiving the latest level of eradication therapy. The draft recommendations developed based on the meta-analysis were finalized after an expert consensus on three recommendations regarding the indication for treatment and eight recommendations for the treatment itself. These guidelines were designed to provide clinical evidence for the treatment (including primary care treatment) of H. pylori infection to patients, nurses, medical school students, policymakers, and clinicians. These may differ from current medical insurance standards and will be revised if more evidence emerges in the future.

Evidence-based Guidelines for the Treatment of Helicobacter pylori Infection in Korea: 2020 Revised Edition

Helicobacter pylori (H. pylori) infection is one of the most common infectious diseases worldwide. Although its incidence is gradually decreasing, about half of the world's population still get infected. H. pylori infection is responsible for substantial gastrointestinal morbidity worldwide. It is the most common cause of gastric and duodenal ulcers as well as gastric cancer. Since the revision of the H. pylori Clinical Practice Guidelines in 2013, the eradication rate of H. pylori has gradually decreased with the use of classical triple therapy, wherein amoxicillin, clarithromycin, and proton pump inhibitors are administered, for 7 days. According to a nationwide randomized controlled study conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research released in 2018, the intention-to-treat eradication rate was only 63.9%, which was due to increased antimicrobial resistance induced by the use of antibiotics, especially clarithromycin. The update of clinical practice guideline for treatment of H. pylori was developed based on evidence-based medicine by conducting a meta-analysis. The draft recommendations were finalized after expert consensus on three recommendations regarding the indication for treatment and eight recommendations on the treatment itself. These guidelines are designed to provide patients, nurses, medical school students, policymakers, and clinicians with clinical evidence to guide primary care and treatment of H. pylori infection. These may differ from current medical insurance standards and will be revised further, if necessary, based on research-based evidence.

Evaluation of the Epidemiologic Efficacy of Eradicating Helicobacter pylori on Development of Gastric Cancer

Eradication of Helicobacter pylori colonization has been reported to affect the progression of gastric cancer. A comprehensive literature search was performed from 1997 to 2017 using electronic databases. All randomized controlled trials (RCTs) and nonrandomized controlled trials (non-RCT) evaluated the effect of H. pylori eradication on development of gastric cancer. Four RCTs and 9 non-RCTs were included (n = 40,740 participants; 321,269 person-years). Overall, H. pylori eradication therapy was associated with a significantly reduced risk of gastric cancer (incidence rate ratio (IRR) = 0.52, 95% confidence interval (CI): 0.41, 0.65). Results of mixed-effect Poisson regression meta-analysis were similar to those of traditional meta-analyses. In stratified analyses, the IRRs were 0.59 (95% CI: 0.41, 0.86) in RCTs and 0.48 (95% CI: 0.36, 0.64) in non-RCTs. The IRRs were 0.45 (95% CI: 0.34, 0.61) in patients and 0.63 (95% CI: 0.44, 0.90) in the general population. Moreover, the relative risk reduction was approximately 77% on the development of noncardiac gastric cancer with H. pylori eradication therapy in China. Attributable risk percentage and population attributable risk percentage for Chinese patients were 77.08% and 75.33%, respectively, and for Japanese patients were 57.80% and 45.99%, respectively. H. pylori eradication therapy reduces the risk of noncardiac gastric cancer development. The findings indicate the importance of early intervention with H. pylori eradication therapy from the perspective of epidemiology.

Helicobacter pylori eradication for the prevention of gastric neoplasia

BACKGROUND

Gastric cancer is the third most common cause of cancer death worldwide. Individuals infected with Helicobacter pylori have a higher likelihood of developing gastric cancer than individuals who are not infected. Eradication of H. pylori in healthy asymptomatic individuals in the general population may reduce the incidence of gastric cancer, but the magnitude of this effect is unclear.

OBJECTIVES

To assess the effectiveness of eradication of H. pylori in healthy asymptomatic individuals in the general population in reducing the incidence of gastric cancer.

SEARCH METHODS

We identified trials by searching the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 1), MEDLINE (1946 to February 2020), and EMBASE (1974 to February 2020). We handsearched reference lists from trials selected by electronic searching to identify further relevant trials. We handsearched published abstracts from conference proceedings from the United European Gastroenterology Week (published in Gut) and Digestive Disease Week (published in Gastroenterology) between 2001 and 2019. We contacted members of the Cochrane Upper Gastrointestinal and Pancreatic Diseases Review Group and experts in the field and asked them to provide details of outstanding clinical trials and any relevant unpublished materials.

SELECTION CRITERIA

We analysed randomised controlled trials comparing at least one week of H. pylori therapy with placebo or no treatment in preventing subsequent development of gastric cancer in otherwise healthy and asymptomatic H. pylori-positive adults. Trials had to follow up participants for at least two years and needed to have at least two participants with gastric cancer as an outcome. We defined gastric cancer as any gastric adenocarcinoma, including intestinal (differentiated) or diffuse (undifferentiated) type, with or without specified histology.

DATA COLLECTION AND ANALYSIS

We collected data on incidence of gastric cancer, incidence of oesophageal cancer, deaths from gastric cancer, deaths from any cause, and adverse effects arising due to therapy.

MAIN RESULTS

Six trials met all our eligibility criteria and provided extractable data in the previous version. Following our updated search, one new RCT was identified, meaning that seven trials were included in this updated review. In addition, one previously included trial provided fully published data out to 10 years, and another previously included trial provided fully published data out to 22 years of follow-up. Four trials were at low risk of bias, one trial was at unclear risk, and two trials were at high risk of bias. Six trials were conducted in Asian populations. In preventing development of subsequent gastric cancer, H. pylori eradication therapy was superior to placebo or no treatment (RR 0.54, 95% confidence interval (CI) 0.40 to 0.72, 7 trials, 8323 participants, moderate certainty evidence). Only two trials reported the effect of eradication of H. pylori on the development of subsequent oesophageal cancer. Sixteen (0.8%) of 1947 participants assigned to eradication therapy subsequently developed oesophageal cancer compared with 13 (0.7%) of 1941 participants allocated to placebo (RR 1.22, 95% CI 0.59 to 2.54, moderate certainty evidence). H. pylori eradication reduced mortality from gastric cancer compared with placebo or no treatment (RR 0.61, 95% CI 0.40 to 0.92, 4 trials, 6301 participants, moderate certainty evidence). There was little or no evidence in all-cause mortality (RR 0.97, 95% CI 0.85 to 1.12, 5 trials, 7079 participants, moderate certainty evidence). Adverse events data were poorly reported.

AUTHORS' CONCLUSIONS

We found moderate certainty evidence that searching for and eradicating H. pylori reduces the incidence of gastric cancer and death from gastric cancer in healthy asymptomatic infected Asian individuals, but we cannot necessarily extrapolate this data to other populations.

Optimized diagnosis of Helicobacter pylori and tailored eradication therapy for preventing gastric cancer: a proposal for SHAKE strategy

INTRODUCTION

To decrease gastric cancer-related mortality, the Korean National Cancer Screening Program provides biennial screening gastroscopy to all individuals aged >40 years. However, a test-and-treat strategy of Helicobacter pylori for preventing gastric cancer has not been established.

AREAS COVERED

In this review, we present up-to-date results of endoscopic findings of H. pylori gastritis, optimal sites for H. pylori detection, gastric cancer risk assessment using serum pepsinogen, tailored eradication based on the antimicrobial resistance against H. pylori, and post-eradication surveillance.

EXPERT OPINION

Here we propose approaches to H. pylori diagnosis and treatment for preventing gastric cancer, termed 'Screening for H. pylori in Korea and Eradication (SHAKE)' strategy. This strategy consists of the following: (1) optimized H. pylori diagnosis, (2) individualized management based on the H. pylori infection status, and (3) tailored eradication therapy. H. pylori gastritis can be diagnosed by endoscopic observation of the gastric mucosal pattern at the greater curvature of the corpus. Measurement of the serum pepsinogen I/II ratio is useful for assessing the risk of gastric cancer. As a first-line treatment, tailored eradication based on the results of molecular testing is effective in a country with a high rate of clarithromycin-resistant H. pylori.

Chemoprevention of gastric cancer development after Helicobacter pylori eradication therapy in an East Asian population: Meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori) infection is a risk factor for gastric cancer (GC), especially in East Asian populations. Most East Asian populations infected with H. pylori are at higher risk for GC than H. pylori-positive European and United States populations. H. pylori eradication therapy reduces gastric cancer risk in patients after endoscopic and operative resection for GC, as well as in non-GC patients with atrophic gastritis.

AIM

To clarify the chemopreventive effects of H. pylori eradication therapy in an East Asian population with a high incidence of GC.

METHODS

PubMed and the Cochrane library were searched for randomized control trials (RCTs) and cohort studies published in English up to March 2019. Subgroup analyses were conducted with regard to study designs (i.e., RCTs or cohort studies), country where the study was conducted (i.e., Japan, China, and South Korea), and observation periods (i.e., ≤ 5 years and > 5 years). The heterogeneity and publication bias were also measured.

RESULTS

For non-GC patients with atrophic gastritis and patients after resection for GC, 4 and 4 RCTs and 12 and 18 cohort studies were included, respectively. In RCTs, the median incidence of GC for the untreated control groups and the treatment groups was 272.7 (180.4–322.4) and 162.3 (72.5–588.2) per 100000 person-years in non-GC cases with atrophic gastritis and 1790.7 (406.5–2941.2) and 1126.2 (678.7–1223.1) per 100000 person-years in cases of after resection for GC. Compared with non-treated H. pylori-positive controls, the eradication groups had a significantly reduced risk of GC, with a relative risk of 0.67 [95% confidence interval (CI): 0.47–0.96] for non-GC patients with atrophic gastritis and 0.51 (0.36–0.73) for patients after resection for GC in the RCTs, and 0.39 (0.30–0.51) for patients with gastritis and 0.54 (0.44–0.67) for patients after resection in cohort studies.

CONCLUSION

In the East Asian population with a high risk of GC, H. pylori eradication effectively reduced the risk of GC, irrespective of past history of previous cancer.

The Mexican consensus on the detection and treatment of early gastric cancer

Gastric cancer is one of the most frequent neoplasias in the digestive tract and is the result of premalignant lesion progression in the majority of cases. Opportune detection of those lesions is relevant, given that timely treatment offers the possibility of cure. There is no consensus in Mexico on the early detection of gastric cancer, and therefore, the Asociación Mexicana de Gastroenterología brought together a group of experts and produced the "Mexican consensus on the detection and treatment of early gastric cancer" to establish useful recommendations for the medical community. The Delphi methodology was employed, and 38 recommendations related to early gastric cancer were formulated. The consensus defines early gastric cancer as that which at diagnosis is limited to the mucosa and submucosa, irrespective of lymph node metástasis. In Mexico, as in other parts of the world, factors associated with early gastric cancer include Helicobacter pylori infection, a family history of the disease, smoking, and diet. Chromoendoscopy, magnification endoscopy, and equipment-based image-enhanced endoscopy are recommended for making the diagnosis, and accurate histopathologic diagnosis is invaluable for making therapeutic decisions. The endoscopic treatment of early gastric cancer, whether dissection or resection of the mucosa, should be preferred to surgical management, when similar oncologic cure results can be obtained. Endoscopic surveillance should be individualized.

Analysis of factors associated with recovery of the serum pepsinogen ratio after Helicobacter pylori eradication: a long-term follow-up study in Korea

Objective: Serum levels of pepsinogen (PG) are related to Helicobacter pylori-induced inflammation of the gastric mucosa. This study aimed to examine the influence of H. pylori eradication on serum PG, analyze its associated factors, and evaluate the long-term outcomes.Methods: H. pylori-positive patients who underwent gastroscopy and serum PG measurement were enrolled in a single academic hospital. After H. pylori eradication, the measurement of serum PG level was performed. Recovery of serum PG I/II ratio was defined as a PG I/II ratio after eradication of >3.0 in patients with a PG I/II ratio ≤ 3.0 before eradication. Follow-up involved serum PG measurement and gastroscopy with a rapid urease test annually.Results: In all, 327 patients were eligible for study inclusion. Compared to those before H. pylori eradication, serum PG I (74.9 vs. 44.3 ng/mL, p < .001) and PG II (25.4 vs. 9.1 ng/mL, p < .001) levels significantly decreased after successful eradication. In addition, there was a significant increase in serum PG I/II ratio after eradication (3.07 vs. 4.98, p < .001). In multivariate analyses, the following were independently associated with failed recovery of serum PG I/II ratio despite successful eradication: age ≥ 60 years (odds ratio [OR] = 0.231, 95% confidence interval [CI] = 0.084-0.629, p = .004) and severe gastric atrophy (OR = 0.156, 95% CI = 0.055-0.440, p < .001).Conclusions: Recovery of serum PG I/II ratio after H. pylori eradication may be achieved in H. pylori-infected patients aged <60 years without severe gastric atrophy.

Effect of Helicobacter pylori eradication and high-density lipoprotein on the risk of de novo gastric cancer development

BACKGROUND AND AIMS

The effect of Helicobacter pylori eradication on de novo gastric cancer is controversial, although meta-analyses suggest a reduction in gastric cancer after eradication. The effect of high-density lipoprotein (HDL) on gastric cancer has been rarely reported.

METHODS

In this large retrospective cohort study, participants underwent endoscopy and H pylori testing from 2003 to 2011 and underwent follow-up endoscopy and H pylori testing until 2013. H pylori infection was detected using a rapid urease test or histologic test. The H pylori eradication group was defined as successful eradication, whereas the H pylori persistent group was defined as noneradication or eradication failure. The risk of cancer was measured with hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Among 10,328 healthy subjects (5951 men; mean age, 48.7 years), 31 gastric cancers were detected during a median follow-up of 5.5 years. De novo gastric cancer developed in 21 of 3508 subjects (.6%) in the noneradication group, 4 of 2050 subjects (.2%) in the successful eradication group, and 6 of 4770 participants (.13%) in the absence of H pylori group. In the adjusted analysis, H pylori eradication decreased de novo gastric cancer risk (HR, .29; 95% CI, .10-.86) compared with the persistent group. The risk of de novo gastric cancer in absence of H pylori was also much lower compared with the persistent group (HR, .24; 95% CI, .09-.60). Low serum HDL increased the risk of de novo gastric cancer (HR, 2.67; 95% CI, 1.14-6.16).

CONCLUSIONS

Successful H pylori eradication reduced de novo gastric cancer, whereas low HDL increased its risk.

Gastric cancer in patients with gastric atrophy and intestinal metaplasia: A systematic review and meta-analysis

AIM

Intestinal metaplasia (IM) and gastric atrophy (GA) are precancerous lesions in the stomach. There is a large debate on natural course of these lesions and surveillance strategy in these patients. This meta-analysis was aimed to find the most appropriate follow up and the rate of progression from IM and GA to GC.

METHODS

This meta-analysis is followed and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic databases including EMBASE, PubMed, Web of Science databases, Scopus, and the Cochrane Library were searched until July 2018. Cochran's Q test and I-square (I2) test were used to examine heterogeneity across included studies. We pooled data using random-effect or fixed effect models indicated as incidence rate or proportion with 95% confidence intervals (CI). The variables of study included demographic data, endoscopy interval, follow up interval and time, GA and IM type and GC stage. Moreover, incidence rate of GC and progress rate, regress and persistence proportion in both GA and IM patients were assessed.

RESULTS

Overall, 68 original articles out of 32981 citations were included in our meta-analysis. The pooled GC incidence rate in patients with GA was 1.24 (95% CI, 0.80, 1.76; I2: 83.6%) cases per 1,000 person-years. The rates of later diagnosis of IM and gastric dysplasia in patients with GA were estimated as 41.42 (95% CI, 3.11, 64.45; I2: 95.6%) and 6.23 (95% CI, 2.34, 11.46; I2: 83.0%) cases per 1,000 person-years, respectively. The pooled regressed proportion was 32.23 (95% CI, 18.07-48.02; I2: 94.0%) and the persistence proportion was 38.83 (95% CI, 20.20-59.13; I2: 97.0%) per 100 observations in GA patients. In IM studies, the pooled incidence rate of GC was 3.38 (95% CI, 2.13, 4.85; I2: 93.4%) cases per 1,000 person-years. The progressed rate to dysplasia in IM patient was estimated to be 12.51 (95% CI, 5.45, 22.03; I2: 95.1%) cases per 1,000 person-years. The pooled regressed proportion was 31.83 (95% CI, 25.48-38.51; I2: 91.0%) and the persistence proportion was 43.46 (95% CI, 32.52-54.71; I2: 96.0%) per 100 observations in IM patients.

CONCLUSION

Overall, the incidence of GC in patients with IM and GA are low but there is heterogeneity in data with the highest rate in Asian, males with those with incomplete IM. There is probability of regression or persistence without progression in patients with IM and GA who receive appropriate management.

The Epidemiology of Gastric Cancers in the Era of Helicobacter pylori Eradication: A Nationwide Cancer Registry-Based Study in Taiwan

BACKGROUND

Helicobacter pylori eradication has been shown to decrease gastric adenocarcinoma risk. The epidemiology of gastric lymphoma, which is also associated with H. pylori, and other rare subtypes of gastric cancer is less clear. This study comprehensively evaluated the incidence trend and the survival of gastric cancer in Taiwan by histologic subtype.

METHODS

The incidence trends of gastric cancer in Taiwan from 1996 and 2013 were evaluated using data from the Taiwan Cancer Registry. The life-table method and the Cox proportional hazards analysis were used to evaluate the survival of gastric cancer.

RESULTS

The incidence of all gastric cancers in Taiwan decreased from 15.97 per 100,000 in 1996 to 11.57 per 100,000 in 2013. The most frequent histologic subtype of gastric cancer in Taiwan was adenocarcinoma, followed by lymphoma and sarcoma (mainly gastrointestinal stromal tumor). The best survival was in patients with sarcoma, followed by lymphoma, neuroendocrine tumor, and adenocarcinoma. Generally, women had a better survival than men. The incidence of adenocarcinoma significantly decreased from 13.56 per 100,000 in 1996 to 9.82 per 100,000 in 2013 (P < 0.0001). In contrast, the incidences of mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma did not decrease.

CONCLUSIONS

The incidence of adenocarcinoma and lymphoma, both of which are associated with H. pylori, showed diverging trends. The survival of gastric cancer differed by histologic subtype and sex.

IMPACT

The disparity in the incidence trends between gastric lymphoma and adenocarcinoma, both associated with H. pylori, warranted the need to search for additional risk factors of gastric lymphoma.

Prediction of Chronic Atrophic Gastritis and Gastric Neoplasms by Serum Pepsinogen Assay: A Systematic Review and Meta-Analysis of Diagnostic Test Accuracy

Serum pepsinogen assay (sPGA), which reveals serum pepsinogen (PG) I concentration and the PG I/PG II ratio, is a non-invasive test for predicting chronic atrophic gastritis (CAG) and gastric neoplasms. Although various cut-off values have been suggested, PG I ≤70 ng/mL and a PG I/PG II ratio of ≤3 have been proposed. However, previous meta-analyses reported insufficient systematic reviews and only pooled outcomes, which cannot determine the diagnostic validity of sPGA with a cut-off value of PG I ≤70 ng/mL and/or PG I/PG II ratio ≤3. We searched the core databases (MEDLINE, Cochrane Library, and Embase) from their inception to April 2018. Fourteen and 43 studies were identified and analyzed for the diagnostic performance in CAG and gastric neoplasms, respectively. Values for sensitivity, specificity, diagnostic odds ratio, and area under the curve with a cut-off value of PG I ≤70 ng/mL and PG I/PG II ratio ≤3 to diagnose CAG were 0.59, 0.89, 12, and 0.81, respectively and for diagnosis of gastric cancer (GC) these values were 0.59, 0.73, 4, and 0.7, respectively. Methodological quality and ethnicity of enrolled studies were found to be the reason for the heterogeneity in CAG diagnosis. Considering the high specificity, non-invasiveness, and easily interpretable characteristics, sPGA has potential for screening of CAG or GC.

Effect of Helicobacter pylori eradication on the incidence of gastric cancer: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori) is considered to be the most important risk factor for gastric cancer (GC). The International Agency for Research on Cancer reported that H. pylori eradication could reduce the risk of developing GC. Several clinical studies have investigated this relationship as well; however, their results are inconsistent owing to the varied inclusion criteria. To address the effect of H. pylori eradication on GC incidence, we conducted a comprehensive meta-analysis with several subgroup analyses to resolve these inconsistencies.

METHODS

We searched MEDLINE and Ichushi-Web to identify randomized control trial and cohort study articles (English or Japanese) through December 2016. Manual searches were also conducted to identify unlisted references in these databases. Eligible studies reported GC incidence as an outcome, with comparisons between H. pylori eradication and control groups. Subgroup analyses were conducted by country, conditions at baseline, and follow-up periods.

RESULTS

We selected 28 studies among 1583 references in the databases and 4 studies by manual searches. The H. pylori eradication group showed significantly lower risk of GC [odds ratio (OR) 0.46; 95% confidence interval 0.39-0.55]. The subgroup analyses indicated that the beneficial effect of eradication was greater in Japan (OR 0.39; 95% CI 0.31-0.49), particularly among those with benign conditions (OR 0.32; 95% CI 0.19-0.54), although none of them was statistically significant. However, reduction of gastric cancer after eradication was significantly greater (p = 0.01) in the groups with long-term (5 years or longer) follow-up (OR 0.32; 95% CI 0.24-0.43) as compared to those with shorter follow-up (less than 5 years) (OR 0.55; 95% CI 0.41-0.72).

CONCLUSION

Real world data showed that large-scale eradication therapy has been performed mostly for benign conditions in Japan. Since eradication effects in preventing gastric cancer are conceivably greater there, GC incidence may decline faster in Japan than expected from the previous meta-analyses data which were based on multi-national, mixed populations with differing screening quality and disease progression.

Eradication of Helicobacter pylori Induces Immediate Regressive Changes in Early Gastric Adenocarcinomas

OBJECTIVE

Helicobacter pylori eradication is expected to prevent gastric cancer. However, morphological alterations after eradication often hinder accurate diagnosis. Therefore, we evaluated endoscopic and histological changes in gastric tumors after eradication of H. pylori in a time-dependent manner.

METHODS

We classified 144 cases of endoscopic submucosal dissection (ESD) of early gastric cancer into the following categories: (i) patients positive for H. pylori with no eradication history, (ii) patients positive for H. pylori who underwent ESD 2 months after eradication, (iii) patients negative for H. pylori with an eradication history of at least 6 months before ESD, and (iv) patients negative for H. pylori with an unknown history. We compared endoscopic and histological factors between the groups.

RESULTS

The characteristics of cancers positive for H. pylori were exploding shape, superficial high-grade atypical epithelium, and a surface proliferating zone. H. pylori eradication induced a series of endoscopic and histological changes, including shape -depression, appearance of surface regenerative and lower-grade atypical epithelium, and a downward shift of the proliferative zone within a period as short as 2 months.

CONCLUSION

H. pylori eradication rapidly causes cancer regression and leads to tumor shrinkage, diminished atypism, and shortened proliferative zone, resulting in drastic morphological changes.

Gastric Xanthoma Is a Predictive Marker for Early Gastric Cancer Detected after Helicobacter pylori Eradication

Objective The detection of early gastric cancer (GC) after Helicobacter pylori eradication is expected to increase in Japan. However, the predictive markers for early GC detected after H. pylori eradication have not been extensively studied. We conducted a retrospective, single-center observational study to investigate the predictive markers for early GC detected after H. pylori eradiation. Methods A total of 421 patients underwent endoscopic submucosal dissection for early GC at NTT West Osaka Hospital between June 2006 and August 2017. Data from patients with GC (Group C; n=70) and without GC (Group NC; n=114) after H. pylori eradication were analyzed. Results The proportion of men was significantly higher in Group C than in Group NC (92.9% vs. 65.8%; p<0.0001). Complications with other malignant diseases were more prevalent in Group C than in Group NC. A significantly greater proportion of patients had gastric xanthoma (GX) in Group C than in Group NC (64.3% vs. 14.9%; p<0.0001). Regarding scores for endoscopic findings related to the risk of GC, the atrophy score, intestinal metaplasia score and total score were significantly higher in Group C than in Group NC. A multivariate logistic regression analysis identified male sex, atrophy (open type), the presence of intestinal metaplasia and GX as independent predictors for early GC detected after H. pylori eradication. An atrophy-matched control analysis also identified GX as an independent predictor. Conclusion GX is a novel predictive marker for early GC detected after H. pylori eradication.

Combined Gastric and Colorectal Cancer Screening-A New Strategy

BACKGROUND

Our aim was to evaluate the feasibility of a serological assessment of gastric cancer risk in patients undergoing colonoscopy in countries with low-to-moderate incidence rates.

METHODS

Serum samples were prospectively collected from 453 patients (>50 years old) undergoing colonoscopies. Of these, 279 (61.6%) also underwent gastroscopy to correlate the results for serum pepsinogen I and II (sPG-I and sPG-II), sPG-I/II ratio, and anti-H. pylori antibodies with gastric histopathology findings (graded according to the updated Sydney classification and the Operative Link of Gastritis Assessment (OLGA) and the Operative Link for Gastric Intestinal Metaplasia assessment (OLGIM) systems).

RESULTS

H. pylori was found in 85 patients (30.5%). Chronic atrophic gastritis was diagnosed in 89 (31.9%) patients. High-risk OLGA (III⁻IV) stages were present in 24 patients, and high-risk OLGIM stages were present in 14 patients. There was an inverse correlation of sPG-I with the degree of atrophy and intestinal metaplasia (IM), as well as with the respective OLGA (r = -0.425; p < 0.001) and OLGIM (r = -0.303; p < 0.001) stages. A pathological sPG-I result was associated with a relative risk (RR) of 12.2 (95% confidence interval: 6.29⁻23.54; p < 0.001) for gastric preneoplastic changes.

CONCLUSIONS

The assessment of serum pepsinogen allows the identification of patients at increased risk of gastric cancer. A prevention strategy of combining a screening colonoscopy with a serological screening for preneoplastic gastric changes should be considered in the general population.

Long-term outcome of group D patients with negative serum anti-Helicobacter pylori antibody and positive serum pepsinogen test in healthy Koreans

OBJECTIVE

The aim of this study was to assess the clinical characteristics and long-term outcomes of group D patients (negative H. pylori antibodies and positive pepsinogen level).

METHODS

Group D patients were divided into two groups, that is, the limited endoscopic atrophic gastritis (EAG) group with EAG confined to the antrum and angle (C1 and C2) and the advanced EAG group with gastric body-involved EAG (C3 to O3). We compared the progression of precursor lesions and the occurrence of gastric neoplasms between the two groups.

RESULTS

Among 107 group D patients, the advanced EAG group (n = 60) was elder and had a lower pepsinogen I level and a lower pepsinogen I to II ratio (PGI/II) than the limited EAG group (n = 47). Among the 52 patients who underwent a follow-up endoscopy, three gastric neoplasms were detected (one in the limited and two in the advanced EAG groups). During a median follow-up of 44 months, 10 (43.5%) patients in the limited and 13 (52.0%) in the advanced EAG groups showed EAG progression or newly occurred intestinal metaplasia. A family history of GC (odds ratio [OR] 44.974, 95% confidence interval [CI] 1.360-1487.087), a lower PGI/II (OR 0.247, 95% CI 0.085-0.717) and a longer follow-up duration (OR 1.832, 95% CI 1.200-2.796) increased the risk of progression.

CONCLUSION

A family history of GC and low baseline PGI/II were independently associated with an increased risk of progression of precursor lesions of GC.

Gastritis Associated with Initially Pediatric Crohn's Disease and Ulcerative Colitis

PURPOSE

The aim of this study is to determine the involvement of the upper gastrointestinal system (GIS) in patients diagnosed with Crohn's disease (CD), ulcerative colitis (UC), and non-inflammatory bowel disease (IBD) and to compare their differences.

METHODS

This study included patients aged between 2 and 18 years who underwent colonoscopy and esophagogastroduodenoscopy (EGD) for the first time due to the prediagnosis of IBD. In EGD, samples were taken from duodenum, antrum, corpus, and esophagus; and gastritis, duodenitis, and esophagitis were identified through histopathologic examination. The data gathered the ends of the research were compared between IBD with non-IBD groups and between CD-UC with non-IBD groups, and the presence of significant differences between groups were determined.

RESULTS

In our study, 16 patients were diagnosed with CD, 13 with UC, 3 with undeterminate colitis, and 13 with non-IBD. In the histopathological examination of the groups, GIS involvement was found in 94.1% of patients diagnosed with IBD and in 38.5% of non-IBD patients. Moreover, the difference was found to be statistically significant (p=0.032). No significant difference was found between the CD and UC groups. Gastritis was mostly observed in 93.8% of CD-diagnosed patients, 76.8% of UC-diagnosed patients, 81.2% of IBD-diagnosed patients, and 38.5% of non-IBD-diagnosed patients. On the other hand, significant differences were found between CD and non-IBD groups (p=0.03), UC and non-IBD groups (p=0.047), and IBD and non-IBD groups (p=0.03).

CONCLUSION

The results of the study show that gastritis was highly observed in UC- and CD-diagnosed patients than in non-IBD-diagnosed patients.

Safety of first-line triple therapy with a potassium-competitive acid blocker for Helicobacter pylori eradication in children

BACKGROUND

Helicobacter pylori infection is a risk factor for gastric cancer, and it has been reported that eradication of H. pylori is effective for preventing such cancer. Recently, H. pylori eradication has been performed in children as first-line therapy against gastric cancer. Here, we report use of triple therapy with a potassium-competitive acid blocker (P-CAB) for H. pylori eradication in children.

METHODS

H. pylori infection testing and eradication therapy began in fiscal year 2015 in junior high school students located in Yurihonjo city and Nikaho city, Akita prefecture, Japan. Urine-based immunochromatography, stool antigen enzyme-linked immunosorbent assay tests, and serum antibody tests were performed as the initial screening examination. Those who tested positive on one of the three examinations then underwent a urea breath test (¹³C-UBT). Those who tested positive on ¹³C-UBT and expressed the desire to undergo H. pylori eradication then received eradication therapy comprising 20 mg P-CAB, 750 mg amoxicillin, and 200 mg clarithromycin twice a day for 7 days. At least 8 weeks after treatment, eradication success was evaluated using ¹³C-UBT.

RESULTS

A total of 118 students received eradication therapy. Eradication rates were 81.3% (95% confidence interval: 74.3-88.4, 96/118) in ITT analysis and 85.7% (95% confidence interval: 79.1-92.9 96/112) in PP analysis. Adverse effects associated with eradication therapy were observed in 25 of 118 subjects (21.1%), seven of whom required hospital treatment (rash in five, vomiting in two). All seven subjects either discontinued therapy or were administered anti-allergy drugs, which resulted in swift alleviation of symptoms.

CONCLUSIONS

First-line triple therapy with a P-CAB for H. pylori eradication in children was found to be safe.

Characteristics and predictors of gastric cancer after Helicobacter pylori eradication

Helicobacter pylori (H. pylori) eradication can reduce gastric cancer. However, gastric cancer still develops after eradication, and cases who received eradication therapy are increasing. In this study, we have reviewed the characteristics and predictors of primary gastric cancer developing after H. pylori eradication. In terms of the characteristics, endoscopic, histologic, and molecular characteristics are reported. Endoscopically, gastric cancer after eradication is often depressed-type and shows a gastritis-like appearance, which sometimes makes the diagnosis difficult. Histologically, most gastric cancer after eradication is intestinal type, and non-neoplastic epithelium, also called epithelium with low-grade atypia, is frequently seen over the tumor, which is presumably the cause of the endoscopic gastritis-like appearance. As for molecular characteristics, some markers, such as Ki67, MUC2, and Wnt5a expression, are lower in cancer from patients in whom H. pylori has been eradicated. In terms of predictors, several Japanese studies have reported that severe endoscopic atrophy at eradication is a risk factor for gastric cancer development. Histologic intestinal metaplasia, especially in the corpus, and long-term use of proton pump inhibitors, are also reported as risk factors for gastric cancer after H. pylori eradication. These studies on the characteristics and predictors of gastric cancer development will become the cornerstone for establishing a novel surveillance program based on the gastric cancer risk stratification specific to H. pylori-eradicated patients.

Immunopathological and Modulatory Effects of Cag A+ Genotype on Gastric Mucosa, Inflammatory Response, Pepsinogens, and Gastrin-17 Secretion in Iraqi Patients infected with H. pylori

OBJECTIVE

To determine the immunopathological correlation between Cag A+ H. pylori-specific IgG; pepsinogen I&II (PI&PII); gastrin-17 (G-17); status of gastric and duodenal mucosa and inflammatory activities on different gastroduodenal disorders.

METHODOLOGY

Eighty gastroduodenal biopsies were taken from patients with gastroduodenal disorders for histopathological evaluation and H. pylori diagnosis. Serum samples were used for evaluation of gastric hormones and detection of H. pylori-specific IgG antibodies. The tissue expression of H. pylori Cag A gene was detected by in situ hybridisation.

RESULTS

H. pylori IgG antibodies were detected in (88.8%) of enrolled patients. According to Cag A gene expression, Significant difference (P value ˂ 0.05) was detected in levels of PG I; PGII, PG I/PG II among patients with gastric disorders. Serum G-17 level was negatively correlated with Cag A gene expression (P-value = 0.04). There was a significant correlation between H. pylori IgG and PG I; PG II; G-17. The current study revealed that corpus atrophic gastritis was diagnosed histologically with (5%) gastric ulcer cases; (3.75%) of duodenal ulcer cases; (3.75%) of duodenitis cases; (1.25%) of gastropathy cases and (8.75%) of gastritis cases. At the same time H. pylori gastritis diagnosed concurrently with (8.75%) of gastric ulcer cases; (11.25%) of duodenal ulcer cases; (17.5%) of gastropathy cases; (3.75%) of duodenitis cases and (2.5%) of prepyloric ulcer cases. A significant correlation was reported between the Immunopathological status of gastric mucosa and endoscopic mucosal finding among duodenal ulcer cases and gastritis cases only. A positive correlation was reported between serum levels of PGI; PGII; PGI/PGII; G-17; PMNs grade and Immunopathological status of the gastroduodenal mucosa of H. pylori Infected patients. A significant difference was reported in lymphocyte grades among gastric disorders without correlation with immunohistopathological changes in the mucosa (P-value = 0.002). A significant difference was reported in lymphocyte grades among different disorders according to H. pylori IgG. A significant difference was reported in serum level of PG I; PG II; PG I/PG II; G-17 according to PMN and lymphocyte grades (P-value ˂ 0.01). PMNs grades positively correlated with gastric Cag A expression; H. pylori IgG; PG II; G-17 levels. PG I; PG I/ PG II correlated with lymphocyte grades (P-value ˂ 0.05); while PGII has a negative correlation (P-value = 0.039).

CONCLUSION

Endoscopic mucosal finding does not reflect exactly the actual immunopathological changes of gastric mucosa during H. pylori infection. Secretion of gastrin was not affected by the presence of Cag A in gastric tissue. Instead, the fluctuation in the hormone level appears to be due to the presence of H. pylori infection in gastric tissue. Gastric tissue infiltration with PMNs & lymphocytes inflammatory infiltrates has a direct effect on PGs and gastrin levels in serum of infected patients. The level of PG I; PG II; G-17 secretion correlated with the development of immune response against H. pylori and production of specific H. pylori IgG. Finally, H. pylori can modulate gastric secretions through Cag A dependent and independent pathways.

Early-Stage Gastric Cancer Can Be Found in Improved Atrophic Mucosa over Time from Successful Helicobacter pylori Eradication

BACKGROUND/AIMS

Early-stage gastric cancer (EGC) is detected even after successful Helicobacter pylori eradication. This study is aimed at clarifying the clinicopathological characteristics of EGC detected after successful H. pylori eradication.

METHODS

This retrospective study analyzed 57 cases of EGC detected after successful H. pylori eradication and resected endoscopically at Kyoto Prefectural University of Medicine, between January 2009 and June 2014. Clinicopathological findings of 57 cases (H. pylori-eradicated group) were investigated, and compared with those in active H. pylori infection resected in the same period (H. pylori-positive group).

RESULTS

Most EGCs were detected in patients with severe atrophic mucosa, both in H. pylori-eradicated and H. pylori-positive groups, while the percentage of EGC detected in patients with mild atrophic mucosa gradually increased over time from successful eradication (H. pylori-positive: 7%, up to the fourth year since eradication: 11%, after the fifth year since eradication: 32%). The percentage of EGC detected in patients with mild atrophic mucosa after the fifth year since eradication was significantly higher than that in patients with active H. pylori infection (p = 0.004).

CONCLUSION

After the fifth year following eradication, we should be alert to the incidence of EGC, irrespective of the severity of mucosal atrophic change.

Helicobacter pylori infection and serum level of pepsinogen are associated with the risk of metachronous gastric neoplasm after endoscopic resection

BACKGROUND

Patients who have undergone endoscopic resection of early gastric cancers (EGCs) are at risk for metachronous gastric neoplasm.

AIM

To determine whether serum level of pepsinogen (PG), a marker of gastric atrophy, can determine which patients who have undergone endoscopic submucosal dissection for EGC are at risk for metachronous gastric neoplasm. We also investigated the effects of Helicobacter pylori eradication on metachronous gastric neoplasm incidence.

METHODS

We performed a retrospective study of 590 consecutive patients who underwent endoscopic submucosal dissection for EGC, from January 2008 to May 2013 at a tertiary centre in South Korea; serum levels of PG were measured at the time of endoscopic submucosal dissection and H. pylori infection status were recorded. In case of proven presence of current H. pylori infection, eradication treatment was provided. Patients underwent follow-up endoscopies at 3 months, 9 months, and each year after the procedure to detect neoplasms and were tested for H. pylori infection; serum levels of PG were measured at these time points from 442 of the patients. The main and sub-cohorts were assessed for baseline characteristics, H. pylori infection, serum level of PG, and metachronous gastric neoplasm lesions.

RESULTS

During a median follow-up period of 47.7 months, 64 patients developed metachronous gastric neoplasms. In multivariate analysis of the main cohort (n = 590), risk factors for metachronous gastric neoplasm included persistent H. pylori infection (hazard ratio [HR], 2.532; P = .022) and serum ratio of PGI:PGII of three or less at the time of endoscopic submucosal dissection (HR, 1.881; P = .018). Among patients with serum PG measurements, persistent H. pylori infection (odds ratio [OR], 4.404; P = .009) and persistent decrease in mean serum ratio of PGI:PGII to 3 or less were associated with increased risk of metachronous gastric neoplasm (OR, 2.141; P = .039).

CONCLUSIONS

In a retrospective analysis of patients who underwent endoscopic resection of EGCs, eradication of H. pylori infection reduced risk for metachronous gastric neoplasm. Serum ratio of PGI:PGII of 3 or less also increase risk of metachronous gastric neoplasm after endoscopic submucosal dissection. ClinicalTrials.gov. registry number, NCT02682446.

Association between gastric cancer and the Kyoto classification of gastritis

BACKGROUND AND AIM

Histological gastritis is associated with gastric cancer, but its diagnosis requires biopsy. Many classifications of endoscopic gastritis are available, but not all are useful for risk stratification of gastric cancer. The Kyoto Classification of Gastritis was proposed at the 85th Congress of the Japan Gastroenterological Endoscopy Society. This cross-sectional study evaluated the usefulness of the Kyoto Classification of Gastritis for risk stratification of gastric cancer.

METHODS

From August 2013 to September 2014, esophagogastroduodenoscopy was performed and the gastric findings evaluated according to the Kyoto Classification of Gastritis in a total of 4062 patients. The following five endoscopic findings were selected based on previous reports: atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness.

RESULTS

A total of 3392 patients (1746 [51%] men and 1646 [49%] women) were analyzed. Among them, 107 gastric cancers were diagnosed. Atrophy was found in 2585 (78%) and intestinal metaplasia in 924 (27%). Enlarged folds, nodularity, and diffuse redness were found in 197 (5.8%), 22 (0.6%), and 573 (17%), respectively. In univariate analyses, the severity of atrophy, intestinal metaplasia, diffuse redness, age, and male sex were associated with gastric cancer. In a multivariate analysis, atrophy and male sex were found to be independent risk factors. Younger age and severe atrophy were determined to be associated with diffuse-type gastric cancer.

CONCLUSION

Endoscopic detection of atrophy was associated with the risk of gastric cancer. Thus, patients with severe atrophy should be examined carefully and may require intensive follow-up.

Prevention of Gastric Cancer: Eradication of Helicobacter Pylori and Beyond

Although its prevalence is declining, gastric cancer remains a significant public health issue. The bacterium Helicobacter pylori is known to colonize the human stomach and induce chronic atrophic gastritis, intestinal metaplasia, and gastric cancer. Results using a Mongolian gerbil model revealed that H. pylori infection increased the incidence of carcinogen-induced adenocarcinoma, whereas curative treatment of H. pylori significantly lowered cancer incidence. Furthermore, some epidemiological studies have shown that eradication of H. pylori reduces the development of metachronous cancer in humans. However, other reports have warned that human cases of atrophic metaplastic gastritis are already at risk for gastric cancer development, even after eradication of these bacteria. In this article, we discuss the effectiveness of H. pylori eradication and the morphological changes that occur in gastric dysplasia/cancer lesions. We further assess the control of gastric cancer using various chemopreventive agents.

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

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

A systematic review and meta-analysis of the role of Helicobacter pylori eradication in preventing gastric cancer

BACKGROUND

Increasing evidence has suggested that Helicobacter pylori (H. pylori) eradication might prevent the development of gastric cancer (GC). This systematic review and meta-analysis aimed to better explore the role of H. pylori eradication in preventing GC, with particular reference to patients with precancerous lesions at baseline histology.

METHODS

Searches for human studies were performed through October 2016 and risk ratios (RRs), were obtained. Heterogeneity between studies was estimated using the Cochran Q test and I2 values, whereas the possibility of publication bias was estimated with funnel plots. Additionally, we performed subgroup and sensitivity analyses.

RESULTS

In 26 studies suitable for meta-analysis (10 randomized controlled trials and 16 cohort studies) 52,363 subjects were included. The risk of GC among patients in whom H. pylori was successfully eradicated was significantly lower than that among controls: pooled RRs [95% CI] 0.56 [0.48-0.66], Z= -7.27, P=0.00001. This finding applied separately for randomized controlled trials (0.65 [0.51-0.84], Z= -3.33, P=0.0009) and for cohort studies (0.51 [0.42-0.62], Z= -6.63, P=0.00001). Concerning H. pylori eradication in patients with precancerous lesions, subgroup analyses showed that patients with non-atrophic or atrophic gastritis benefited from H. pylori eradication for the risk of GC development, whereas those with intestinal metaplasia or dysplasia did not.

CONCLUSION

H. pylori eradication is associated with a significantly lower risk of GC; this finding has significant implications for the prevention of this cancer. The benefit is maximized when H. pylori eradication is applied at early stages of the infection.

Histologic intestinal metaplasia and endoscopic atrophy are predictors of gastric cancer development after Helicobacter pylori eradication

BACKGROUND AND AIMS

Helicobacter pylori eradication therapy is effective at reducing the incidence of gastric cancer; however, gastric cancer still develops after eradication. We conducted a cohort study to elucidate the risk factors for gastric cancer development after successful H pylori eradication therapy.

METHODS

From June 1998 to December 2012 we assessed histologic and endoscopic findings of gastritis and performed H pylori eradication therapy in 748 patients without a history of gastric cancer. Patients were classified according to the distribution of intestinal metaplasia (IM) as follows: no IM (IM group A), IM in the antrum only (IM group B), and IM in the corpus (IM group C). We assessed atrophy endoscopically according to the Kimura-Takemoto classification system. Gastric cancer incidence was assessed.

RESULTS

A total of 573 patients underwent follow-up endoscopy; the mean duration of follow-up was 6.2 ± 4.8 years. Gastric cancer developed in 21 (20 intestinal type). The cumulative 5-year incidences of gastric cancer were 3.2% overall; 1.5%, 5.3%, and 9.8% in IM groups A, B, and C; and 0.7%, 1.9%, and 10% in the none/mild, moderate, and severe endoscopic atrophy groups, respectively. Compared with IM group A, the hazard ratio for IM group B was 3.6 (95% confidence interval [CI], 1.2-11), and that for IM group C was 3.7 (95% CI, 1.1-12). Compared with the none/mild endoscopic atrophy group, the hazard ratio for severe atrophy was 9.3 (95% CI, 1.7-174).

CONCLUSIONS

Patients with histologic IM or severe endoscopic atrophy were at increased risk of gastric cancer development after H pylori eradication.

Endoscopic gastric atrophy is strongly associated with gastric cancer development after Helicobacter pylori eradication

Background

Risk factors for gastric cancer during continuous infection with Helicobacter pylori have been well documented; however, little has been reported on the risk factors for primary gastric cancer after H. pylori eradication. We conducted a retrospective, endoscopy-based, long-term, large-cohort study to clarify the risk factors for gastric cancer following H. pylori eradication.

Methods

Patients who achieved successful H. pylori eradication and periodically underwent esophagogastroduodenoscopy surveillance thereafter at Toyoshima Endoscopy Clinic were enrolled. The primary endpoint was the development of gastric cancer. Statistical analysis was performed using the Kaplan–Meier method and Cox’s proportional hazards models.

Results

Gastric cancer developed in 15 of 1232 patients. The cumulative incidence rates were 1.0 % at 2 years, 2.6 % at 5 years, and 6.8 % at 10 years. Histology showed that all gastric cancers (17 lesions) in the 15 patients were of the intestinal type, within the mucosal layer, and <20 mm in diameter. Based on univariate analysis, older age and higher endoscopic grade of gastric atrophy were significantly associated with gastric cancer development after eradication of H. pylori, and gastric ulcers were marginally associated. Multivariate analysis identified higher grade of gastric atrophy (hazard ratio 1.77; 95 % confidence interval 1.12–2.78; P = 0.01) as the only independently associated parameter.

Conclusions

Endoscopic gastric atrophy is a major risk factor for gastric cancer development after H. pylori eradication. Further long-term studies are required to determine whether H. pylori eradication leads to regression of H. pylori-related gastritis and reduces the risk of gastric cancer.

Endoscopic gastritis, serum pepsinogen assay, and Helicobacter pylori infection

Endoscopic findings of the background gastric mucosa are important in the Helicobacter pylori-seroprevalent population. It is strongly correlated not only with the risk of gastric cancer, but also with the excretion ability of gastric mucosa cells. In noninfected subjects, common endoscopic findings are regular arrangement of collecting venules, chronic superficial gastritis, and erosive gastritis. In cases of active H. pylori infection, nodularity on the antrum, hemorrhagic spots on the fundus, and thickened gastric folds are common endoscopic findings. The secreting ability of the gastric mucosa cells is usually intact in both noninfected and actively infected stomachs, and the intragastric condition becomes hyperacidic upon inflammation. Increased serum pepsinogen II concentration correlates well with active H. pylori infection, and also indicates an increased risk of diffuse-type gastric cancer. In chronic inactive H. pylori infection, metaplastic gastritis and atrophic gastritis extending from the antrum (closed-type chronic atrophic gastritis) toward the corpus (open-type chronic atrophic gastritis) are common endoscopic findings. The intragastric environment is hypoacidic and the risk of intestinal-type gastric cancer is increased in such conditions. Furthermore, there is a decrease in serum pepsinogen I concentration when the secreting ability of the gastric mucosa cells is damaged. Serologic and endoscopic changes that occur upon H. pylori infection are important findings for estimating the secreting ability of the gastric mucosa cells, and could be applied for the secondary prevention of gastric cancer.

Eradication of Helicobacter pylori and Gastric Cancer: A Systematic Review and Meta-analysis of Cohort Studies

BACKGROUND

Helicobacter pylori (H. pylori) is associated with an increased risk of gastric adenocarcinoma and gastric mucosa associated lymphoid tissue (MALT) lymphoma and a decreased risk of esophageal adenocarcinoma. We aimed to assess how eradication therapy for H. pylori influences the risk of developing these cancers.

METHODS

This was a systematic review and meta-analysis. We searched PubMed, Web of Science, Embase, and the Cochrane Library and selected articles that examined the risk of gastric cancer, MALT lymphoma, or esophageal cancer following eradication therapy, compared with a noneradicated control group.

RESULTS

Among 3629 articles that were considered, nine met the inclusion criteria. Of these, eight cohort studies assessed gastric cancer while one randomized trial assessed esophageal cancer. Out of 12 899 successfully eradicated patients, 119 (0.9%) developed gastric cancer, compared with 208 (1.1%) out of 18 654 noneradicated patients. The pooled relative risk of gastric cancer in all eight studies was 0.46 (95% confidence interval [CI] = 0.32 to 0.66, I(2) = 32.3%) favoring eradication therapy. The four studies adjusting for time of follow-up and confounders showed a relative risk of 0.46 (95% CI = 0.29 to 0.72, I(2) = 44.4%).

CONCLUSIONS

This systematic review and meta-analysis indicates that eradication therapy for H. pylori prevents gastric cancer. There was insufficient literature for meta-analysis of MALT lymphoma or esophageal cancer.

Incidence of and risk factors for metachronous gastric cancer after endoscopic resection and successful Helicobacter pylori eradication: results of a large-scale, multicenter cohort study in Japan

BACKGROUND

A previous multicenter prospective randomized study from Japan showed that Helicobacter pylori eradication reduced the development of metachronous gastric cancer (MGC) after endoscopic resection for early gastric cancer. MGC risk, however, is not eliminated; yet few studies have evaluated its long-term incidence and risk factors. In this study, we investigated the incidence of and risk factors for MGC in patients who underwent endoscopic resection for early gastric cancer with successful H. pylori eradication.

METHODS

A total of 594 patients who underwent endoscopic resection for early gastric cancer and successful H. pylori eradication at three institutions (National Cancer Center Hospital, University of Tokyo Hospital, and Wakayama Medical University Hospital) were analyzed retrospectively. Annual endoscopic surveillance was performed after initial endoscopic resection. MGC was defined as a gastric cancer newly detected at least 1 year after successful H. pylori eradication.

RESULTS

Ninety-four MGCs were detected in 79 patients during the 4.5-year median follow-up period. Kaplan-Meier analysis showed the cumulative incidence of MGC 5 years after successful H. pylori eradication was 15.0 %; the incidence of MGC calculated by use of the person-year method was 29.9 cases per 1000 person-years. Multivariate analysis using the Cox proportional hazards model revealed that male sex, severe gastric mucosal atrophy, and multiple gastric cancers before successful H. pylori eradication were independent risk factors for MGC. Eleven percent of MGCs (10 of 94) were detected more than 5 years after successful H. pylori eradication.

CONCLUSION

Surveillance endoscopy for MGC in patients who have undergone endoscopic resection for early gastric cancer should be performed even after successful H. pylori eradication.