Prevalence of Helicobacter pylori infection by birth year and geographic area in Japan

Helicobacter pylori Seroprevalence in Rheumatoid Arthritis Patients with Interstitial Lung Disease

Background

Rheumatoid arthritis (RA) is complicated with interstitial lung disease (ILD). Gastroesophageal reflux disease is prevented by Helicobacter pylori infection and is a predisposing factor for idiopathic pulmonary fibrosis. However, the prevalence of H. pylori infection in RA patients with ILD has not been sufficiently investigated.

Objective

In this study, we analyzed anti-H. pylori antibodies in RA patients with ILD.

Design

Case-control observational study.

Methods

Anti-H. pylori antibodies were analyzed in the sera of RA patients using a commercially available enzyme-linked immunosorbent assay kit.

Results

The positivity of anti-H. pylori antibodies in RA with ILD (n = 30 [18.0%], P = .0227), usual interstitial pneumonia (n = 10 [14.3%], P = .0212), and airway disease (n = 30 [18.0%], P = .0227) was significantly lower than that of RA without chronic lung disease (n = 78 [27.5%]). The positivity of anti-H. pylori antibodies was also lower in RA with chronic lung disease (n = 68 [18.2%], P = .0059). Multiple logistic regression analyses showed that the presence of anti-H. pylori antibodies was independently and protectively associated with chronic lung disease in RA.

Conclusion

The seroprevalence of H. pylori was lower in RA with ILD. H. pylori infection prevented ILD in patients with RA by protecting them from gastroesophageal reflux disease.

Adenocarcinoma of the esophagogastric junction: characteristics of female patients and young adult patients based on a 12-year retrospective and prospective multicenter clinicoepidemiological cohort study in Japan

BACKGROUND

Adenocarcinoma of the esophagogastric junction (AEGJ) is most common in men and the elderly, but the disease is becoming more common in female and young adult persons. We have investigated the clinicoepidemiological characteristics of female and young adult patients with AEGJ and the 12-year trends in the Kurashiki area for young adult patients with AEGJ.

METHODS

Patients diagnosed with AEGJ in 12 hospitals between January 2008 and December 2019 were included in this study. Patients were divided into three groups by age (young adult [≤50 years], middle-aged [51 to 70 years], and elderly [>70 years]). Factors associated with AEGJ such as obesity, smoking, hiatal hernia and male, which were reported in our previous study, were identified.

RESULTS

One hundred and eighty-eight AEGJ patients, including 36 females and 20 young adults, were characterized. There was no significant change in the annual incidence of AEGJ among female (p=0.078) and young adult patients (p=0.89). Female patients without any associated factors, accounting for 53% (19/36) of the female patients and young adult patients, had significantly more histologically undifferentiated cancers than patients with at least one associated factor (58% [11/19] vs. 30% [50/169], p=0.025) and middle-aged and elderly patients (60% [12/20] vs. 30% [25/83] vs. 28% [24/85], p =0.026). Smoking was significantly less common in women than in men (8% [3/36] vs. 57% [87/152], p < 0.01). There were no significant differences between ages in the proportions of these associated factors.

CONCLUSIONS

Histologically undifferentiated AEGJ cancers were more frequent in female patients without any associated factors and in young adult patients. Factors associated with AEGJ may differ between women and men, but they are similar in young adults and older adults. No increase in young adult patients with AEGJ was observed in the 12-year study.

Helicobacter pylori antibiotic resistance profile in Chinese children with upper gastrointestinal symptoms and a literature review for developing personalized eradicating strategies

Background: H. pylori (Helicobacter pylori) infections typically occur in early childhood. Although the prevalence of H. pylori in children is lower than that in adults, the eradication rate of this infection in children is relatively low because of resistance. In this study, we analyzed personalized treatment strategies to achieve treatment goals based on H. pylori resistance characteristics. This retrospective single-center study was conducted between January 2019 and December 2022 and enrolled 1,587 children who presented with upper gastrointestinal symptoms and underwent endoscopy. H. pylori culturing and antimicrobial susceptibility testing were performed. Results: Culture-positive results for H. pylori were obtained in 535 children. The resistance rates to clarithromycin (CLA), metronidazole (MET), and levofloxacin (LEV) were 39.8%, 78.1%, and 20.2%, respectively. None of the isolates were resistant to tetracycline (TET), amoxicillin (AMO), or furazolidone (FZD). Double resistance rates to CLA + MET, CLA + LEV, and MET + LEV were 19.1%, 3.0%, and 5.8%, respectively. Notably, triple-resistant to CLA + MET + LEV was 9.7%. Based on susceptibility tests, individualized triple therapy [proton pump inhibitor (PPI) +AMO + CLA/MET] was selected for 380 children with H. pylori sensitive to MET and/or CLA. In 155 children resistant to CLA and MET, bismuth-based quadruple therapy was recommended; for unable to receive bismuth, concomitant therapy was recommended for 14 children (<8 years of age); triple therapy with TET was recommended for 141 children (>8 years of age), with 43 children (>14 years of age) requiring FZD rather than TET. Conclusion: Resistance to H. pylori in Chinese children was relatively poor. Personalized therapy regimens should be based on susceptibility tests and avoided factors associated with treatment failure.

Impact of metabolic dysfunction-associated fatty liver disease on the incidence of Helicobacter pylori-negative gastric cancer

AIM

The incidence of Helicobacter pylori-negative gastric cancer (HPNGC) is increasing worldwide. Recently, metabolic dysfunction-associated fatty liver disease (MAFLD) has been reported to be associated with various cancers, but its association with HPNGC has not been reported. We aimed to identify important independent factors associated with HPNGC, including MAFLD.

METHODS

This multicenter observational cohort study enrolled patients with gastric cancer (n = 1078) and health checkup examinees (n = 17 408). We analyzed patients with HPNGC (n = 26) and healthy participants with no H. pylori infection or any abnormal findings on upper gastrointestinal endoscopy (n = 1130). A logistic regression model was used to identify independent factors associated with HPNGC. The priority of the factors associated with HPNGC was evaluated using a decision-tree algorithm and random forest analysis.

RESULTS

Among all patients with gastric cancer, 2.4% (26/1078) were diagnosed with HPNGC (mean age, 64 years; male/female, 13/13). In the logistic regression analysis, age, smoking, and MAFLD (odds ratio, 6.5359; 95% confidence interval, 2.5451-16.7841; p < 0.0001) were identified as independent factors associated with HPNGC. Metabolic dysfunction-associated fatty liver disease was also identified as the most important classifier for the presence of HPNGC in decision-tree analyses. Helicobacter pylori-negative gastric cancer was observed in 5.2% of patients with MAFLD and 0.8% of patients without MAFLD. In the random forest analysis of the HPNGC, MAFLD was identified as the distinguishing factor with the highest variable importance (0.32).

CONCLUSIONS

Metabolic dysfunction-associated fatty liver disease was the most influential independent factor associated with HPNGC. These findings suggest that fatty liver and metabolic dysfunction could be involved in the pathogenesis of HPNGC.

Widespread use of proton pump inhibitors or potassium-competitive acid blocker has changed the status of gastrointestinal bleeding in patients with ischemic heart disease: real-world data from high volume centers

BACKGROUND

Although proton pump inhibitors (PPIs) or potassium-competitive acid blocker (PCAB) are useful in peptic ulcer prevention, their efficacy in preventing other gastrointestinal bleeding remains unclear. This study aimed to identify the status of gastrointestinal bleeding in the modern era when PPIs are widely used.

METHODS

This study included patients who underwent percutaneous coronary intervention (PCI) between 2018 and 2019 at two high-volume centers. Patients were categorized based on whether they experienced gastrointestinal bleeding within 2 years of PCI into groups A (patients who experienced gastrointestinal bleeding within 2 years after PCI) and B (patients who did not experience gastrointestinal bleeding).

RESULTS

Groups A and B included 21 (4.1%) and 494 (95.9%) patients, respectively (a total of 515 patients). Age at the initial PCI (77.8±2.4 and 72.0±0.5 years in groups A and B, respectively; p = 0.02), weight (53.8±3.2 and 61.8±0.7 kg in groups A and B, respectively; p = 0.01), and concomitant warfarin use (14.3% and 2.0% in groups A and B, respectively; p = 0.0005) were significantly different between the groups. The high bleeding risk rate (90.5% and 47.6% in groups A and B, respectively; p = 0.0001) was significantly different between the groups. A total of 95.9% of patients were taking PPIs or PCAB without significant differences between the groups. However, only one patient, who was taking steroids, had a gastric ulcer during PCAB treatment.

CONCLUSIONS

Acid-related upper gastrointestinal bleeding is largely controlled by PPIs in post-PCI patients. Furthermore, the risk factors for non-acid-related bleeding include older age, lower weight, and concomitant warfarin use.

Cost-effectiveness analysis of the artificial intelligence diagnosis support system for early gastric cancers

Objectives

The introduction of artificial intelligence into the medical field has improved the diagnostic capabilities of physicians. However, few studies have analyzed the economic impact of employing artificial intelligence technologies in the clinical environment. This study evaluated the cost-effectiveness of a computer-assisted diagnosis (CADx) system designed to support clinicians in differentiating early gastric cancers from non-cancerous lesions in Japan, where the universal health insurance system was introduced.

Methods

The target population to be used for the CADx was estimated as those with moderate to severe gastritis caused by Helicobacter pylori infection. Decision trees with Markov models were built to analyze the cumulative cost-effectiveness of using CADx relative to the pre-artificial intelligence status quo, a condition reconstructed from data in published reports. After conducting a base-case analysis, we performed sensitivity analyses by modifying several parameters. The primary outcome was the incremental cost-effectiveness ratio.

Results

Compared with the status quo as represented in the base-case analysis, the incremental cost-effectiveness ratio of CADx in the Japanese market was forecasted to be 11,093 USD per quality-adjusted life year. The sensitivity analyses demonstrated that the expected incremental cost-effectiveness ratios were within the willingness-to-pay threshold of 50,000 USD per quality-adjusted life year when the cost of the CAD was less than 104 USD.

Conclusions

Using CADx for EGCs may decrease their misdiagnosis, contributing to improved cost-effectiveness in Japan.

Population-based X-ray gastric cancer screening in Hiroshima prefecture, Japan

BACKGROUND

X-ray gastric cancer (GC) screening has been shown to decrease mortality. Population-based X-ray GC screening has been performed in Hiroshima Prefecture, Japan, since 1983 but time trends and the efficacy of the method over 39 years have not been assessed.

AIM

To evaluate time trends and efficacy of population-based X-ray GC screening and identify challenges and suggested solutions for the future.

METHODS

This was a population-based retrospective study. The data were derived from aggregated data of the Hiroshima Regional Health Medical Promotion Organization, including the number and rate of participants and those requiring esophagogastroduodenoscopies (EGDs), the number and rate of participants diagnosed as having GC, and the positive predictive value of the abnormal findings detected by X-ray and confirmed by EGDs. The number and rate of esophageal cancers were also collected. Further, the cost of detecting one GC was evaluated.

RESULTS

The number of participants has decreased during the last four decades, from 39925 in 1983 to 12923 in 2021. The rate of those requiring EGDs decreased significantly in recent years (P < 0.001). The number of participants diagnosed as having GC has also declined, from 76 to 10 cases. However, the rate of cases diagnosed as GC among the participants remained around 0.1%. The positive predictive value increased significantly in recent years except during 1983-1991. The number and rate of accidentally detected esophageal cancers have risen recently, from 0% in 2008 to 0.02% in 2021, one-fifth of the diagnosis rate of GC. One GC diagnosis costs approximately 4200000 Japanese Yen (30000 United States Dollars) for the X-ray screenings and EGDs.

CONCLUSION

X-ray GC screening in Hiroshima has been efficient, but one challenge is the cost. Esophageal cancers may also need to be considered because they have gradually increased in recent years.

Randomized controlled trial comparing the costs of gastric cancer screening systems between serological risk-based upper gastrointestinal endoscopy and the existing barium photofluorography: gastric cancer screening labeled by serum examination in place of aged gastric cancer organized screening systems (GALAPAGOS study)

BACKGROUND

Although the risk of gastric cancer can be stratified according to Helicobacter pylori (H. pylori) IgG antibody titer and pepsinogen levels (ABC classification), a population-based gastric cancer screening system combining serological tests and endoscopy has not been introduced. This study aimed to compare the total testing cost per participant between the ABC classification method and the existing protocol.

METHODS

Using the minimization method with sex and age as allocation factors, 1206 participants were randomly assigned to the following two methods for a 5-year intervention: barium photofluorography as primary examination followed by detailed examination with upper gastrointestinal endoscopy (Ba-Endo) and risk-based upper gastrointestinal endoscopy by ABC classification (ABC-Endo). The primary endpoint was the total testing cost per participant over a 5-year period. The secondary endpoint was the expense required to detect one gastric cancer.

RESULTS

The total testing cost per participant was 39,711 yen in Ba-Endo (604 participants) and 45,227 yen in ABC-Endo (602 participants), with the latter being significantly higher (p < 0.001). During the intervention period, gastric cancer was found in 11 and eight participants in Ba-Endo and ABC-Endo, respectively. The expenses required to detect one gastric cancer were 2,240,931 yen in Ba-Endo and 3,486,662 yen in ABC-Endo.

CONCLUSIONS

The testing cost per participant turned out to be higher in the ABC-Endo group than in the Ba-Endo group. This superiority trial, based on the hypothesis that the cost of testing is lower for ABC-Endo than for Ba-Endo, was rejected.

Precision endoscopy in the era of climate change and sustainability

Global warming caused by increased greenhouse gas (GHG) emissions has a direct impact on human health. Gastrointestinal (GI) endoscopy contributes significantly to GHG emissions due to energy consumption, reprocessing of endoscopes and accessories, production of equipment, safe disposal of biohazardous waste, and travel by patients. Moreover, GHGs are also generated in histopathology through tissue processing and the production of biopsy specimen bottles. The reduction in unnecessary surveillance endoscopies and biopsies is a practical approach to decrease GHG emissions without affecting disease outcomes. This narrative review explores the role of precision medicine in GI endoscopy, such as image-enhanced endoscopy and artificial intelligence, with a focus on decreasing unnecessary endoscopic procedures and biopsies in the surveillance and diagnosis of premalignant lesions in the esophagus, stomach, and colon. This review offers strategies to minimize unnecessary endoscopic procedures and biopsies, decrease GHG emissions, and maintain high-quality patient care, thereby contributing to sustainable healthcare practices.

Current status of gastric and oral infection/diseases caused by Helicobacter pylori

Helicobacter pylori is found in the stomach, which is its optimal habitat, and is considered an important factor in various serious diseases, including stomach cancer. The World Health Organization has identified H. pylori as a causative agent of gastric cancer, as confirmed by animal experiments in rodents. The fact that H. pylori can live in the harsh environment of stomach acid was the greatest hindrance to the discovery of H. pylori. It was not so long ago, in 1983, that it was successfully isolated and cultured. Subsequently, H. pylori eradication therapy was established, and it became possible to control gastric cancer to some extent. However, the mechanism, route, and mode of H. pylori infection still remain unclear. Furthermore, currently, the prevention of first‐episode gastric cancer and control of recurrent gastric cancer are not perfect. One of the reasons for this may be that the status of H. pylori in the oral cavity, which is the entry point for the organism (the beginning of the digestive system: the first route of infection), is still unknown. Therefore, we reviewed the current status of H. pylori infection in the stomach and oral cavity, focusing on (1) the mechanism of infection, (2) pathogenic factors, (3) the actual status of eradication therapy, and (4) control strategies.

Endoscopic evaluation by the Kyoto classification of gastritis combined with serum anti-Helicobacter pylori antibody testing reliably risk-stratifies subjects in a population-based gastric cancer screening program

BACKGROUND

We previously demonstrated that the Kyoto classification of gastritis was useful for judging the status of Helicobacter pylori infection in a population-based screening program, and that adding H. pylori antibody test improved its accuracy (UMIN000028629). Here, we tested whether our endoscopic diagnosis of H. pylori infection status reliably estimated gastric cancer risk in the program.

METHODS

Data were collected from1345 subjects who underwent endoscopic follow-up 4 years after the end of the registration. We analyzed the association of three diagnostic methods of H. pylori infection with gastric cancer detection: (1) endoscopic diagnosis based on the Kyoto classification of gastritis; (2) serum diagnosis according to the ABC method (H. pylori antibody and pepsinogen I and II); and (3) endoscopic diagnosis together with H. pylori antibody test.

RESULTS

During the follow-up, 19 cases of gastric cancer were detected. By Kaplan-Meier analysis, the detection rates of cancer were significantly higher in the past or current H. pylori infection groups than in the never-infected group with all 3 methods. By the Cox proportional hazards model, the hazard ratio for cancer detection was highest in evaluation with the combined endoscopic diagnosis and the antibody test (method 3; hazard ratio 22.6, 95% confidence interval 2.99-171) among the three methods (the endoscopic diagnosis (method 1); 11.3, 2.58-49.8, and the ABC method (method 2); 7.52, 2.49-22.7).

CONCLUSIONS

Endoscopic evaluation of H. pylori status with the Kyoto classification of gastritis, especially combined with serum anti-Helicobacter pylori antibody testing, reliably risk-stratified subjects in a population-based gastric cancer screening program.

Long-term Response of Helicobacter pylori Antibody Titer After Eradication Treatment in Middle-aged Japanese: JPHC-NEXT Study

BACKGROUND

Helicobacter pylori (H. pylori) is an established causative factor of gastric cancer. Although the expansion of insurance coverage has led to an increase in the number of patients treated for H. pylori, the population impact of eradication treatment for H. pylori has been scarcely investigated. This study aimed to clarify the long-term responses of H. pylori antibody titer after eradication treatment using large scale cross-sectional data from the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT Study).

METHODS

A total of 55,282 Japanese participants aged 40 to 74 years residing in 16 areas provided blood samples from 2011 through 2016. From these, treated (n = 6,276) and untreated subjects who were seropositive for H. pylori or had serological atrophy (n = 22,420) formed the study population (n = 28,696). Seropositivity was defined as an anti-H. pylori IgG titer of ≥10 U/mL. Antibody level was compared among subjects according to self-reported treatment history as untreated, and treated for less than 1 year (<1Y), 1 through 5 years (1-5Y), and 6 or more years ago (6Y+).

RESULTS

Median serum antibody titer was 34.0 U/mL, 7.9 U/mL, 4.0 U/mL, and 2.9 U/mL for the untreated, <1Y, 1-5Y, and 6Y+ groups, respectively. While those treated for H. pylori within the previous year had a 76.8% lower antibody titer compared to untreated subjects, approximately 41% of subjects were still seropositive.

CONCLUSION

A significant reduction in H. pylori antibody titer occurs within 1 year after eradication treatment, but that a long period is needed to achieve complete negative conversion.

Confusion and prospects for carcinogenesis of gastric adenoma and dysplasia: What is the correct answer currently?

There are differences in the diagnoses of superficial gastric lesions between Japan and other countries. In Japan, superficial gastric lesions are classified as adenoma or cancer. Conversely, outside Japan, the same lesion is classified as low-grade dysplasia (LGD), high-grade dysplasia, or invasive neoplasia. Gastric carcinogenesis occurs mostly de novo, and the adenoma-carcinoma sequence does not appear to be the main pathway of carcinogenesis. Superficial gastric tumors can be roughly divided into the APC mutation type and the TP53 mutation type, which are mutually exclusive. APC-type tumors have low malignancy and develop into LGD, whereas TP53-type tumors have high malignancy and are considered cancerous even if small. For lesions diagnosed as category 3 or 4 in the Vienna classification, it is desirable to perform complete en bloc resection by endoscopic submucosal dissection followed by staging. If there is lymphovascular or submucosal invasion after mucosal resection, additional surgical treatment of gastrectomy with lymph node dissection is required. In such cases, function-preserving curative gastrectomy guided by sentinel lymph node biopsy may be a good alternative.

Prevalence Difference of Helicobacter pylori Infection Between Tibetan and Han Ethnics in China: A Meta-analysis on Epidemiologic Studies (SIGES)

China is a multi-ethnic country, and the prevalence of Helicobacter pylori ( H pylori) infection may be diverse among ethnics. This meta-analysis was conducted to compare the prevalence of H pylori infection between Tibetans and Han ethnics. Ten studies that reported the prevalence of H pylori infection between Tibetans and Hans in China were eligible. The pooled prevalence of H pylori infection was 62.2% versus 55.3% among Tibetans and Hans, respectively. Tibetans had a higher risk of H pylori infection than Hans (odds ratio [OR] = 1.38, 95% confidence interval [CI] [1.05, 1.80]). In subgroup analysis, Tibetans with upper gastrointestinal symptoms (OR = 1.51, 95% CI [1.06-2.16]), inhabiting in Tibet (OR = 1.51, 95% CI [1.22, 1.87]), or inhabiting in Northwestern region (OR = 1.15, 95% CI [1.00, 1.31]) had significantly higher risks of H pylori infection. In addition, in the recent 10 years, Hans showed a decreased risk of H pylori infection (OR = 1.81, 95% CI [1.42, 2.30]). Heterogeneity was common, while sensitivity analyses showed partially inconsistent results against main findings. This study demonstrated higher prevalence of H pylori infection in Tibetans compared with Hans, especially in recent years, or in Tibet and northwest China, as well as symptomatic Tibetans. The results suggest tailored strategy and robustness need to be further considered for H pylori screening and eradication among Tibetans.

Changes in prevalence of Helicobacter pylori in Japan from 2008 to 2018: a repeated cross-sectional study

OBJECTIVES

To understand the recent prevalence and time trends of Helicobacter pylori infection rates in the Japanese population.

DESIGN

Repeated cross-sectional study.

PARTICIPANTS

A total of 22 120 workers (age: 35-65 years) from one Japanese company, who underwent serum H. pylori antibody tests in a health check-up between 2008 and 2018.

MEASURES

H. pylori infection rates among participants aged 35 years from 2008 to 2018, and participants aged 35, 40, 45, and 50-65 years in 2018, based on the results of serum antibody tests, were analysed. In the 2018 analysis, in addition to the antibody test results, all participants who had undergone eradication treatment for H. pylori were considered as infected. Trends were examined using joinpoint analysis.

RESULTS

H. pylori was detected in 1100 of 7586 male and 190 of 1739 female participants aged 35 years. Annual infection rates among those aged 35 years showed linear downward trends as follows: men, 17.5% in 2008 to 10.1% in 2018 (slope: -0.66); women, 12.3% in 2008 to 9.2% in 2018 (slope: -0.51) without joinpoints. In the 2018 analysis, 2432 of 9580 men and 431 of 1854 women were H. pylori positive. Infection rates tended to increase with older age (men: 11.0% (35 years) to 47.7% (65 years); women: 10.0% (35 years) to 40.0% (65 years)), and showed joinpoints in both sexes (men: 54 years; women: 45 years). Although both the first and second trends were upward, the second trend for both men and women was steeper than the first trend (p<0.05).

CONCLUSIONS

Our study demonstrated that in the previous 11 years, infection rates of H. pylori in 35-year-old male and female Japanese workers have constantly decreased, and furthermore, analysis of various age groups showed joinpoints around 50 years, suggesting a consistent declining trend in H. pylori infection rates in Japan.

Worldwide Prevalence and Risk Factors of Helicobacter pylori Infection in Children

Helicobacter pylori is usually acquired during childhood. The reports from the last two decades pointed out a decrease in H. pylori prevalence across geographical areas worldwide compared to previously reported data. Most of the studies performed in America found an overall H. pylori infection prevalence of approximately 50%. The most important risk factors in America include being male, poor adherence or difficult access to treatment, and the lack of in-home water service. Despite the descending trend in prevalence worldwide, the overall prevalence in Africa remains very high (70%). Nevertheless, the prevalence of H. pylori in children without gastrointestinal who underwent screening was reported to be only 14.2%. The main risk factors in Africa are having a traditional pit or no toilet, poverty, birth order, source of drinking water, or being a farmer. Asia seems to have the widest variations in terms of H. pylori prevalence. Several risk factors were reported in Asia to be associated with this infection, such as lower income and educational level, house crowding, rural residence, ethnicity, the use of tanks as water supplies, alcohol drinking, active smoking, eating spicy food or raw uncooked vegetables, poor living conditions and sanitation. The overall prevalence of H. pylori infection in European children is almost 25%. Portugal has the highest prevalence of all European countries at 66.2% in children 13 years of age. The risk factors in European individuals consist of living in rural areas, eating unwashed fruits and vegetables, not washing hands after school, low parental education and unemployment, and short education duration. Further studies are required to identify the precise mechanisms involved in the discrepancies of H. pylori prevalence worldwide.

Gastric Cancer Screening in Japan: A Narrative Review

Gastric cancer is the second leading cause of cancer incidence in Japan, although gastric cancer mortality has decreased over the past few decades. This decrease is attributed to a decline in the prevalence of H. pylori infection. Radiographic examination has long been performed as the only method of gastric screening with evidence of reduction in mortality in the past. The revised 2014 Japanese Guidelines for Gastric Cancer Screening approved gastric endoscopy for use in population-based screening, together with radiography. While endoscopic gastric cancer screening has begun, there are some problems associated with its implementation, including endoscopic capacity, equal access, and cost-effectiveness. As H. pylori infection and atrophic gastritis are well-known risk factors for gastric cancer, a different screening method might be considered, depending on its association with the individual's background and gastric cancer risk. In this review, we summarize the current status and problems of gastric cancer screening in Japan. We also introduce and discuss the results of gastric cancer screening using H. pylori infection status in Hoki-cho, Tottori prefecture. Further, we review risk stratification as a system for improving gastric cancer screening in the future.

Current guidelines for Helicobacter pylori treatment in East Asia 2022: Differences among China, Japan, and South Korea

Helicobacter pylori (H. pylori) infection is highly prevalent in East Asia. The overall seroprevalence rate of H. pylori infection is 44.2% in China, 37.6%-43.2% in Japan, and 51.0% in South Korea. H. pylori can cause peptic ulcer disease and gastric cancer. East Asian countries have high rates of gastric cancer (age-standardized incidence rate: 20-30 per 100000). The Kyoto global consensus report emphasized that H. pylori gastritis should be considered the main cause for the development of gastric cancer. H. pylori treatment guidelines in China, Japan, and South Korea have recently been revised according to data from each of those countries. However, emerging antibiotic resistance is an important barrier to H. pylori eradication. The recommended H. pylori treatment regimens differ among those three East Asian countries. In this review, recent guidelines and up-to-date research on H. pylori treatment regimens from China, Japan, and South Korea are discussed.

Endoscopic screening for gastric cancer in Japan: Current status and future perspectives

The revised 2014 Japanese Guidelines for Gastric Cancer Screening approved gastric endoscopy for use in population-based screening. Thus, it is expected that gastric cancer will be detected earlier, and gastric cancer mortality further decreased, with the widespread use of endoscopy and Helicobacter pylori eradication therapy. However, due to an increasingly aging population and relatively low gastric cancer screening rates, gastric cancer remains the leading cause of cancer death in Japan. While the era of endoscopic gastric cancer screening has begun, it does present challenges, such as limited/varying regional availability of endoscopists. This review describes the history of gastric cancer screening in Japan, achievements in endoscopic gastric cancer screening in Japan and Korea, efforts underway to improve screening by stratifying individuals according to gastric cancer risk, and initiatives by the Japan Gastroenterological Endoscopy Society aimed at improving screening, including the implementation of a board certification program for screening endoscopists.

Time trends in the prevalence of Helicobacter pylori infection in patients with peptic ulcer disease: a single-center retrospective study in Shanghai

Objective

The present study aimed to investigate the recent trends in Helicobacter pylori infection associated with peptic ulcer disease in a large population in Shanghai.

Methods

We analyzed the medical records of all patients who had undergone upper gastrointestinal endoscopy (EGD) for uninvestigated dyspepsia at Ren Ji Hospital between 2013 and 2019 to determine the prevalence of H. pylori infection in patients with peptic ulcers.

Results

Peptic ulcers were found in 40,385 of the 383,413 patients who underwent EGD during the study period. Over the 7-year study period, the annual prevalence of H. pylori among patients receiving EGD declined from 32.2% to 26.5%. H. pylori was present in 60% of ulcers and the incidence was higher (66.9%) in duodenal compared with gastric ulcers (48.5%). The proportion of H. pylori-associated gastric ulcers declined from 52.2% to 49.3% and that of H. pylori-positive duodenal ulcers declined from 70.0% to 63.9%.

Conclusion

The prevalence of H. pylori-positive peptic ulcers, mainly duodenal ulcers, fell from 2013 to 2019. However, the proportion of non-H. pylori-associated peptic ulcer disease increased, especially in elderly people, possibly due to the use of nonsteroidal anti-inflammatory drugs. Further research is needed to confirm this hypothesis.

Prevalence and risk factors of Helicobacter pylori infection in Wuwei, a high-risk area for gastric cancer in northwest China: An all-ages population-based cross-sectional study

OBJECTIVE

This study aimed to determine the prevalence and risk factors of Helicobacter pylori infection across all age groups in Wuwei City, a high-risk area for gastric cancer in Northwest China.

METHODS

We conducted this study from 2016 to 2017 in an urban and a rural community in Wuwei City. Stool antigen tests targeted individuals aged 0 to 3 years old, and ¹³ C-urea breath tests targeted individuals aged above 3 years. We selected participants based on hierarchical cluster sampling. We assessed the association between variables and H. pylori infection based on logistic regression models.

RESULTS

Ultimately, the results of 2,163 participants (age: 0 to 77 years old) were included (1,238 minors and 925 adults) in the analysis. The overall prevalence of H. pylori infection was 35.6%. It increased with age, reaching the peak in the 30 to 39 age group, and then began to decline. In multivariate analysis, age was positively associated with prevalence of H. pylori infection, and factors negatively associated with the prevalence were drinking running water, the frequency of yoghurt consumption, and an annual household income of Renminbi (¥) 30,000-100,000 or 100,000 above. In the subgroup analyses, however, the same variables associated differently in different age groups. Additionally, we interestingly noticed that boarding, eating at school cafeterias over six times per week, and frequently drinking untreated water were independent predictors of H. pylori infection in junior and senior high school students.

CONCLUSION

The prevalence of H. pylori infection is moderate and closely associated with the socioeconomic conditions of Wuwei City, as well as the sanitary situations and dietary habits of the participants in the city. Boarding, eating at school, and drinking untreated water are the main factors explaining the rising infection rate in junior-senior high school students.

Prevalence of Helicobacter pylori Infection in Military Personnel from Northeast China: A Cross-Sectional Study

PURPOSE

Helicobacter pylori infection is an important cause of peptic ulcer disease and gastric cancer. Current knowledge regarding epidemiology of H. pylori infection in military personnel has insufficiently been updated. This cross-sectional study aimed to estimate the prevalence of H. pylori infection in military personnel and to compare the prevalences in military and civilian groups.

PATIENTS AND METHODS

We retrospectively enrolled the subjects who underwent ¹⁴C-urea breath tests at the Department of Gastroenterology of the General Hospital of Northern Theater Command between January 2017 and July 2020. Subjects were divided into military and civilian groups. H. pylori infection and major endoscopic findings were reviewed.

RESULTS

Overall, 23,496 subjects were eligible, including 2282 subjects in the military group and 21,214 subjects in the civilian group. In the overall analysis, the prevalence of H. pylori infection was not significantly different between military and civilian groups (33.9% versus 34.4%, P=0.592). In the population aged 17-25 years, the prevalence of H. pylori infection was significantly higher in the military group than in the civilian group (35.6% versus 25.9%, P=0.001). Both ¹⁴C-UBT and endoscopy were performed in 547 inpatients, including 83 military inpatients and 464 civilian inpatients. There was a significantly higher prevalence of H. pylori in inpatients with peptic ulcer and/or gastric cancer than in those without (65.5% versus 41.4%, P=0.001).

CONCLUSION

Among the adolescent population, H. pylori infection may be more common in military personnel as compared to the civilians. Well-designed prospective studies should be required to validate such a high prevalence and to explain its potential causes.

Differences in Cancer Mortality Trends between Metropolitan and Non-Metropolitan Areas in Japan, 1999-2018

Background:

Although socioeconomic statuses affect cancer mortality rates, the specific difference between metropolitan and non-metropolitan areas in Japan has not been evaluated. This study analyzed differences in cancer mortality between metropolitan and non-metropolitan areas in Japan, using an age-period-cohort (APC) analysis.

Methods:

Data on cancer mortality from 1999 to 2018 for metropolitan and non-metropolitan areas in Japan were used. Here metropolitan areas were defined as government ordinance-designated municipalities in 1999 and special wards of Tokyo. In addition to general mortality data for all cancer sites, data on mortality for stomach, colorectal, liver, gallbladder, pancreatic, lung, prostate, and breast cancers were used for analysis. A Bayesian APC analysis was administered to the data for each type of cancer for area and for sex-distinguished data. Additionally, the ratios for estimated mortality rate by periods and cohorts between the two areas were calculated.

Results:

The age-standardized mortality rate for cancer in all sites in non-metropolitan areas was lower than that in metropolitan areas throughout the analyzed years for both men and women, but the mortality difference decreased during the periods for men. The rates of decrease in mortality rate in cohorts differed for some cancers between the two area types, and the mortality rate ratios of metropolitan compared with non-metropolitan areas decreased for cancer in all sites over the analyzed cohorts for men. Also, the rate of decrease in mortality rate over the cohorts was completely different between the areas for stomach cancer in men and for liver cancer for women.

Conclusion:

Mortality rates for cancer in all sites tended to diverge between the two area types in younger cohorts for men, and people in younger cohorts in non-metropolitan areas should take more extensive preventive measures against cancer than their counterparts in metropolitan areas.

Association of tea consumption and the risk of gastric cancer in Japanese adults: the Japan Collaborative Cohort Study

OBJECTIVE

To examine the possible relationship between tea consumption and risk of gastric cancer (GC) among Japanese men and women included in a large Japanese population-based study titled the Japan Collaborative Cohort (JACC) Study.

DESIGN

Prospective cohort study.

SETTING

A population-based cohort included subjects who were recruited from 24 areas of JACC Study, in which data regarding the incidence of cancer were available.

PARTICIPANTS

63 848 participants (26 025 men and 37 823 women), aged 40-79, were included in the analyses and underwent follow-up (median 13.3 years) prospectively in research on cancer incidence.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome variable was the risk of GC according to the frequency intakes of total tea, green tea, black tea and oolong tea. The adjusted HRs for the risk of GC associated with tea consumption were calculated using the Cox proportional hazards model.

RESULTS

1494 cases of GC were detected (960 men and 534 women) during the follow-up period. The multivariable-adjusted HRs for the risk of GC in the highest versus lowest quintiles of total tea intake were 1.05 (0.83-1.33); p trend=0.50 in men, and 0.82 (0.60-1.12); p trend=0.45 in women. There was no association found between the consumption of green tea, black tea or oolong tea with the risk for GC in either gender.

CONCLUSIONS

In this large community-based prospective cohort study, tea consumption was not associated with the risk of GC in either gender.

Epidemiological investigation of Helicobacter pylori infection in elderly people in Beijing

BACKGROUND

The Helicobacter pylori (H. pylori) infection rate in China is approximately 50%. H. pylori is a pathogenic factor of peptic ulcer and chronic gastritis. In addition, H. pylori infection may also be associated with a variety of cardiovascular diseases in elderly people, such as arteriosclerosis, coronary heart disease, and cerebral infarction, having deleterious effect on their health. With the aging of the population, the disease characteristics of the elderly population have been increasingly valued by the whole society. We conducted an epidemiological survey of H. pylori infection among elderly people in Beijing to provide a basis for health management of H. pylori infection.

AIM

To understand the epidemiological characteristics of H. pylori infection in elderly people in Beijing.

METHODS

A total of 1090 elderly people aged more than 60 years from different parts of Beijing (urban and rural areas) were selected using the random cluster sampling method. Structured questionnaires were completed during home visits and the ¹³C-urea breath test was conducted for H. pylori detection.

RESULTS

The prevalence of H. pylori infection was 46.5% (507/1090). The infection rate in men was 51.8%, which was significantly higher than that in women (42.5%; P < 0.05). The H. pylori infection rate in illiterate people was significantly higher than that in literate persons (53.5% vs 44.8%, P < 0.05). The total infection rate of H. pylori gradually increased with age and the difference was statistically significant (P < 0.01). The H. pylori infection rate in smokers was significantly higher than that in non-smokers and those who had quit smoking (P < 0.05).

CONCLUSION

The prevalence of H. pylori infection among elderly people is 46.5% and the infection rate gradually increases with age. Sex, education level, age, and smoking were determined to be H. pylori infection risk factors. The relationship of H. pylori infection with region, occupation, drinking, and diet structure needs to be further studied.

Clinicopathological features of early gastric cancers arising in Helicobacter pylori uninfected patients

BACKGROUND

Persistent Helicobacter pylori (H. pylori) infection causes chronic inflammation, atrophy of the gastric mucosa, and a high risk of developing gastric cancer. In recent years, awareness of eradication therapy has increased in Japan. As H. pylori infections decrease, the proportion of gastric cancers arising from H. pylori uninfected gastric mucosa will increase. The emergence of gastric cancer arising in H. pylori uninfected patients though rarely reported, is a concern to be addressed and needs elucidation of its clinicopathological features.

AIM

To evaluate the clinicopathological features of early gastric cancer in H. pylori-uninfected patients.

METHODS

A total of 2462 patients with 3375 instances of early gastric cancers that were treated by endoscopic submucosal dissection were enrolled in our study between May 2000 and September 2019. Of these, 30 lesions in 30 patients were diagnosed as H. pylori-uninfected gastric cancer (HpUIGC). We defined a patient as H. pylori-uninfected using the following three criteria: (1) The patient did not receive treatment for H. pylori, which was determined by investigating medical records and conducting patient interviews; (2) Lack of endoscopic atrophy; and (3) The patient was negative for H. pylori after being tested at least twice using various diagnostic methods, including serum anti-H. pylori-IgG antibody, urease breath test, rapid urease test, and microscopic examination.

RESULTS

The frequency of HpUIGC was 1.2% (30/2462) for the patients in our study. The study included 19 males and 11 females with a mean age of 59 years. The location of the stomach lesions was divided into three sections; upper third (U), middle third (M), lower third (L). Of the 30 lesions, 15 were U, 1 was M, and 14 were L. Morphologically, 17 lesions were protruded and flat elevated type (0-I, 0-IIa, 0-IIa + IIc), and 13 lesions were flat and depressed type (0-IIb, 0-IIc). The median tumor diameter was 8 mm (range 2-98 mm). Histological analysis revealed that 22 lesions (73.3%) were differentiated type.The HpUIGC lesions were classified into fundic gland type adenocarcinoma (7 cases), foveolar type well-differentiated adenocarcinoma (8 cases), intestinal phenotype adenocarcinoma (7 cases), and pure signet-ring cell carcinoma (8 cases). Among 30 HpUIGCs, 24 lesions (80%) were limited to the mucosa; wherein, the remaining 6 lesions showed submucosal invasion. One of the submucosal invasive lesions showed more than 500 μm invasion. The mucin phenotype analysis identified 7 HpUIGC with intestinal phenotype and 23 with gastric phenotype.

CONCLUSION

We elucidated the clinicopathological characteristics of HpUIGC, revealing recognition not only undifferentiated-type but also differentiated-type. In addition, intestinal phenotype tumors were also observed and could be an important tip.

Validity of endoscopic features for the diagnosis of Helicobacter pylori infection status based on the Kyoto classification of gastritis

OBJECTIVES

Evaluation of Helicobacter pylori infection status (non-infection, past infection, current infection) has become important. This study aimed to determine the usefulness of the Kyoto classification of gastritis for diagnosing H. pylori infection status by endoscopy.

METHODS

In this prospective study, 498 subjects were recruited. Seven well-experienced endoscopists blinded to the history of eradication therapy performed the examinations. Endoscopic findings were assessed according to the Kyoto classification of gastritis: diffuse redness, regular arrangement of collecting venules (RAC), fundic gland polyp (FGP), atrophy, xanthoma, hyperplastic polyp, map-like redness, intestinal metaplasia, nodularity, mucosal swelling, white and flat elevated lesion, sticky mucus, depressive erosion, raised erosion, red streak, and enlarged folds. We established prediction models according to a machine learning procedure and compared them with general assessment by endoscopists using the Kyoto classification of gastritis.

RESULTS

Significantly higher diagnostic odds were obtained for RAC (32.2), FGP (7.7), and red streak (4.7) in subjects with non-infection, map-like redness (12.9) in subjects with past infection, and diffuse redness (26.8), mucosal swelling (13.3), sticky mucus (10.2) and enlarged fold (8.6) in subjects with current infection. The overall diagnostic accuracy rate was 82.9% with the Kyoto classification of gastritis. The diagnostic accuracy of the prediction model was 88.6% for the model without H. pylori eradication history and 93.4% for the model with eradication history.

CONCLUSIONS

The Kyoto classification of gastritis is useful for diagnosing H. pylori infection status based on endoscopic findings. Our prediction model is helpful for novice endoscopists. (UMIN000016674).

Risk factors for reflux esophagitis after eradication of Helicobacter pylori

Objective: While there is an association between successful eradication of Helicobacter pylori (HP) and reflux esophagitis (RE), risk factors associated with RE remain obscure. The aim of this study is to determine risk factors associated with the development of RE after HP eradication.Materials and methods: Among all patients treated with successful HP eradication from 2008 to 2016, we retrospectively analyzed those who were free from RE at initial esophagogastroduodenoscopy (EGD) and who were followed up with EGD after eradication. Patients were classified according to the presence or absence of RE at the follow-up EGD. RE was defined as mucosal breaks proximal to the squamous-columnar junction. Demographic data, underlying diseases, medications and endoscopic findings at the initial EGD were compared between patients with and without RE.Results: Among 1575 patients, 142 (9.0%) had RE at the follow-up EGD. The time interval from HP eradication until EGD ranged from 4 to 24 months. The endoscopic grade of RE was higher in males than in females. Multivariate analysis revealed that male sex (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.04-2.24), body mass index ≥25 kg/m² (OR, 2.91; 95% CI, 2.00-4.22), use of calcium channel blockers (OR, 1.70; 95% CI, 1.12-2.55), and hiatal hernia (OR, 3.46; 95% CI, 2.41-5.00) were associated with the development of RE.Conclusions: Calcium channel blocker use was found to be a risk factor for the development of RE after eradication of HP.

Helicobacter pylori infection in rehabilitation staff younger than 35 years: Infection surveillance for three years

Background:

Screening for Helicobacter pylori infection is important because of the high risk of gastric cancer development. The H. pylori carrier rate among elderly Japanese patients is still high; therefore, rehabilitation (RH) workers who are in frequent contact with such individuals could be assumed to be at a higher risk of H. pylori infection.

Aim/Objective:

We surveyed RH workers to investigate the initial occurrence of H. pylori infections in adults.

Methods:

Urine samples of RH workers aged < 35 years were screened for H. pylori antibodies to confirm infection. H. pylori infection rates were stratified according to the type of RH work and duration of employment. Infection surveillance was performed at six-month intervals for H. pylori-negative individuals.

Findings/Results:

The H. pylori infection rate among 173 workers was 16.8%. Infection rates were 26.3%, 16.3% and 15.3% among speech, occupational and physiotherapists, respectively. The employment duration was divided into < 24, 24–47, 48–60 and ⩾ 61 months; the respective infection rates were 5.0%, 12.0%, 17.6% and 28.6%. However, no new H. pylori infection was detected in a total of seven surveillance studies of H. pylori-negative workers over a three-year period.

Discussion:

The results of the initial examination showed that the infection rate increased with the duration of employment. However, subsequent surveillance detected no new H. pylori infections.

Guidelines for the management of Helicobacter pylori infection in Japan: 2016 Revised Edition

BACKGROUND

Since "Helicobacter pylori (H. pylori) infection" was set as the indication in the Japanese Society for Helicobacter Research (JSHR) Guidelines 2009, eradication treatment for H. pylori gastritis is covered under insurance since 2013 in Japan, and the number of H. pylori eradication has rapidly increased. Under such circumstances, JSHR has made the third revision to the "Guidelines for diagnosis and treatment of H. pylori infection" for the first time in 7 years.

METHODS

The Guideline Committee held 10 meetings. Articles published between the establishment of the 2009 Guidelines and March 2016 were reviewed and classified according to the evidence level; the statements were revised on the basis of this review. After inviting public comments, the revised statements were finalized using the Delphi method.

RESULTS

There was no change in the basic policy that H. pylori infectious disease is an indication for eradication. Other diseases presumed to be associated with H. pylori infection were added as indications. Serum pepsinogen level, endoscopic examination, and X-ray examination were added to the diagnostic methods. The effects of 1-week triple therapy consisting of potassium-competitive acid blocker (P-CAB), amoxicillin, and clarithromycin have improved, and high eradication rates can also be expected with proton pump inhibitors (PPI) or P-CAB combined with amoxicillin and metronidazole. If the susceptibility test is not performed, the triple PPI or P-CAB/amoxicillin/metronidazole therapy should be chosen, because the PPI/amoxicillin/metronidazole combination demonstrated a significantly higher eradication rate than PPI/amoxicillin/clarithromycin. In the proposal for gastric cancer prevention, we divided gastric cancer prevention measures by age from adolescent to elderly, who are at an increased gastric cancer risk, and presented measures for gastric cancer prevention primarily based on H. pylori eradication.

CONCLUSION

We expect the revised guidelines to facilitate appropriate interventions for patients with H. pylori infection and accomplish its eradication and prevention of gastric cancer.

Prevention of gastric cancer by Helicobacter pylori eradication: A review from Japan

Japan introduced a Helicobacter pylori eradication therapy strategy in 2013, with the aim of decreasing the number of gastric cancer‐related death, the number of new cases of gastric cancer, and associated medical costs. Five years have passed since then, but no reduction in the annual number of gastric cancer has been observed. In addition, it was suggested that the number of deaths due to gastric cancer could be reduced to 30,000 a year by 2020, but the annual death toll in 2017 remained at more than 45,000. Based on the above evidence, it was examined whether it was possible to reach the target value based on the data from the last 5 years. The number of deaths per year in 2020 is predicted to be more than 40,000, which is clearly different from the target value. Logically, the effect of the strategy might appear by 2023. However, there is a possibility that the risk of gastric cancer may increase in some populations due to the influence of proton pump inhibitors and dysbiosis in the gastric microbiome. To solve these problems, combined therapy with PPIs and aspirin for patients after H pylori eradication should be considered.

Clinical features of Helicobacter pylori antibody-positive junior high school students in Nagano Prefecture, Japan

BACKGROUND

Previously, we conducted an epidemiological study screening for Helicobacter pylori antibody positivity among Japanese junior high school students. In this study, we updated the epidemiological data and assessed the clinical features of H pylori antibody-positive junior high school students.

MATERIALS AND METHODS

We assessed H pylori antibody-positive subjects who were identified between 2012 and 2015 at four junior high schools in Nagano Prefecture, Japan. H pylori infection was confirmed by urea breath test (UBT) or endoscopic examination. Endoscopy was performed after obtaining consent from the subject and their guardians. Eradication therapy consisted of triple therapy with proton pump inhibitor (PPI), amoxicillin (AMPC), and clarithromycin (CAM) or metronidazole (MNZ) for seven days. Eradication of H pylori was confirmed by UBT. We reviewed subjects' characteristics, endoscopic findings, histological findings, eradication regimes, outcomes, and adverse effects.

RESULTS

The overall prevalence of H pylori antibody positivity was 3.2% (42/1298). We assessed thirteen H pylori antibody-positive subjects. Eight subjects had a family history of H pylori infection. Six subjects had abdominal pain, and two subjects had iron deficiency anemia (IDA). Twelve subjects underwent endoscopy; one subject had duodenal ulcer, eleven subjects had antral nodular gastritis, and six subjects showed grade 2 closed type atrophic border according to the Kimura-Takemoto classification. All subjects received eradication therapy; CAM was used in five subjects with CAM susceptibility as well as in three subjects with unknown information on CAM susceptibility, and MNZ was used in five subjects with CAM resistance. Eradication was successful in twelve subjects (one unconfirmed). There were three mild adverse effects (abdominal pain or diarrhea).

CONCLUSIONS

Helicobacter pylori test for junior high school students represents an opportunity to diagnose the peptic ulcer, iron deficiency anemia, and gastric atrophy.

Prevalence and genotyping of Helicobacter pylori in endoscopic biopsy samples from a Chinese population

Background:

Helicobacter pylori inhabit the gastric mucosa of humans and are associated with several gastrointestinal diseases which include gastric cancer, peptic ulcer, chronic gastritis and gastric mucosa-associated lymphoid tissue lymphoma. Helicobacter pylori exhibit a high degree of genetic variability and are associated with its epidemiological, pathological characteristics and dynamics of transmission. The objective of the study was to determine the prevalence and genetic heterogeneity of H. pylori isolated from endoscopic biopsy samples from a Chinese population.

Methods:

Gastric biopsy samples from 86 patients (males, 55; females, 35) who presented to the endoscopic section for various gastrointestinal abnormalities were collected. The samples were subjected to a real-time polymerase chain reaction (PCR) and microbial culture for the isolation of H. pylori. Further, the isolates were subjected to randomly amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) analysis.

Results:

Of the 86 gastric biopsy samples, 61 (70.9%) samples were positive for rapid urease test and 37 (43%) samples (28 from male and nine from female) grew H. pylori. Among the biopsy samples subjected to real-time PCR, 39 (45.3%) samples were found to be positive for H. pylori. The RAPD analysis yielded 15 different patterns (four to 17 different sized fragments per strain). The phylogenetic analysis of RAPD yielded 22 clusters at a similarity level ranging from 63% to 100%. RFLP analysis yielded nine different patterns (two to six different sized fragments per strain). Two major restriction patterns were identified, of which 14 (37.8%) strains forms the most common pattern (genotype I) followed by five (13.5%, genotype II) strains with an intra-strain similarity of 100%.

Conclusions:

The overall prevalence of H. pylori was 45.3%. Despite reports on the declining trend in the prevalence of H. pylori infections, our prevalence rate was still higher than those reported from other developed countries. However, further studies involving a large sample size and covering more regions of China is highly warranted.

Estimating the Force of Infection with Helicobacter pylori in Japan

Background

Although the seroprevalence against Helicobacter pylori (H. pylori) in Japan has declined over the birth year, Japanese people have yet exhibited a relatively high risk of gastric cancer. The present study employed mathematical models to estimate the time- and age-dependent force of infection with H. pylori in Japan, predicting the future seroprevalence by time and age.

Methods

We investigated the published seroprevalence data against H. pylori in Japan from 1980–2018. Solving the McKendrick partial differential equation model, the seroprevalence was modeled as a function of survey year and age. Maximum likelihood estimation was conducted to estimate parameters governing the time- and age-dependent force of infection.

Results

Among all fitted models, the time-dependent and age-independent model with an exponentially decaying force of infection over years was most favored. Fitted models indicated that the force of infection started to decrease during and/or shortly after the World War II. Using the parameterized model, the predicted fraction seropositive at the age of 40 years in 2018 was 0.22, but it is expected to decrease to 0.13 in 2030 and 0.05 in 2050, respectively.

Conclusion

The time dependence was consistent with the decline in the force of infection as a function of the birth year. The force of infection has continuously and greatly declined over time, implying the diminished transmission of H. pylori through the time course and small chance of persistence. These findings are critical to anticipate the future decline in gastric cancer incidence.

Gastric cancer in children and adolescents in Japan

BACKGROUND

Very limited data are available on childhood gastric cancer. Using a retrospective survey and literature review, we assessed the clinical features of gastric cancer in children and adolescents.

METHODS

We collected information on childhood gastric cancer from pediatricians of 518 hospitals that issue the title of "certified board pediatrician" approved by Japan Pediatric Society, using a questionnaire on background, diagnosis year, onset symptoms, tumor location, histology, nodular gastritis, Helicobacter pylori testing, treatment, and prognosis. Studies were collected using PubMed and the NPO Japan Medical Abstracts Society database. Data for childhood gastric cancer were abstracted from the Japanese Vital Statistics database.

RESULTS

Of the 518 hospitals, 349 returned the questionnaire, which identified four patients. Literature review identified 77 cases of gastric cancer, and we analyzed data for 80 children <16 years old. Most patients were >10 years old, and there were no sex differences. Onset symptoms ranged from abdominal pain to non-localized. Sixteen of 44 children had a family history of cancer; 10 had a family history of gastric cancer. Histologically, approximately 80% had undifferentiated-type carcinoma. Prognosis was extremely poor, and two of three tested children were positive for H. pylori infection. Childhood gastric cancer death has been declining.

CONCLUSIONS

Childhood gastric cancer is rare in Japan, and information on H. pylori in childhood gastric cancer patients is limited. Declining childhood gastric cancer rates may reflect the decreasing prevalence of infection but further study is necessary to clarify the relationship between H. pylori and gastric cancer.

Analysis of culturable microbiota present in the stomach of children with gastric symptoms

Despite extensive studies on the gastric microbiota, including Helicobacter pylori and non-H. pylori, the bacterial composition in children remains unknown. In this study, we analyzed the culturable gastric bacteria in stomach biopsies from 346 children aged 1-15 years affected by gastric diseases. H. pylori and non-H. pylori were identified by specific PCR and 16S rDNA sequencing, respectively. Antibiotic susceptibilities of H. pylori and non-H. pylori were tested by the E-test and disk diffusion methods, respectively. Rapid diagnosis was also performed by H. pylori-specific PCR. Twenty-two H. pylori strains were obtained from culture, and 92 biopsies were positive by H. pylori-specific PCR. The positive rate was higher in boys (40.3%) than in girls (23.3%) (P = 0.001). Resistance rates of 22 H. pylori strains were as follows: metronidazole, 86.4%; tetracycline, 22.7%; amoxicillin, 22.7%; levofloxacin, 31.8%; clarithromycin, 36.4%. Ten isolates were multidrug-resistant. Additionally, among 366 non-H. pylori strains, 204 exhibited urease activity. Non-H. pylori resistance rates were as follows: metronidazole, 94.8%; tetracycline, 26.2%; amoxicillin, 42.6%; levofloxacin, 15.3%; clarithromycin, 46.7%. Our results showed that children with gastric disorders harbor stomach bacteria with urease activity or nitrate reductase activity. Further studies will determine the effects of non-H. pylori bacteria in gastric diseases.

Optimal Criteria and Diagnostic Ability of Serum Pepsinogen Values for Helicobacter pylori Infection

Background

Practical criteria for the use of serum pepsinogen (PG) values in diagnosing Helicobacter pylori infection have not yet been determined.

Methods

The results of gastric endoscopies, H. pylori infection tests, and PG values were retrospectively reviewed. Subjects were assigned to groups, including never-infected (with neither infection nor gastric mucosal atrophy), infected (with atrophy or findings indicating infection in endoscopy and positive infection tests except for antibody tests), and ex-infected (with gastric mucosal atrophy and negative infection tests, except for antibody tests). The optimal criteria with combined use of the PG II concentrations and the PG I/PG II ratio were investigated separately for PG measurements obtained with the chemiluminescent magnetic particle immunoassay (CLIA) and latex agglutination (LA) methods, such that the specificity was greater than 70% and the sensitivity was no less than 95% among the never-infected and infected subjects. Similar analyses were performed by combining the data from ex-infected and infected subjects.

Results

For the CLIA (LA) method, the optimal criterion among 349 (397) never-infected and 748 (863) infected subjects was a PG II value of at least 10 (12) ng/mL or a PG I/PG II ratio no more than 5.0 (4.0), which produced 96.3% (95.1%) sensitivity and 82.8% (72.8%) specificity. When 172 (236) ex-infected subjects were included, the optimal criterion was the same, and the sensitivity was 89.1% (86.9%).

Conclusions

The above criteria may be practical for clinical use, and PG tests using these criteria might prevent unnecessary endoscopic examinations for never-infected subjects.

Serum anti-Helicobacter pylori antibody titer and its association with gastric nodularity, atrophy, and age: A cross-sectional study

AIM

To clarify the role of serum anti-Helicobacter pylori (H. pylori) antibody titers in gastric cancer.

METHODS

In this cross-sectional study, the effect of patients’ baseline characteristics and endoscopic findings on their serum antibody titers were assessed. We evaluated consecutive patients who underwent esophagogastroduodenoscopy and their first evaluation for H. pylori infection using a serum antibody test. We excluded patients with a history of eradication therapy. The participants were divided into four groups according to their E-plate serum antibody titer. Patients with serum antibody titers < 3, 3-9.9, 10-49.9, and ≥ 50 U/mL were classified into groups A, B, C, and D, respectively.

RESULTS

In total, 874 participants were analyzed with 70%, 16%, 8.7%, and 5.1% of them in the groups A, B, C, and D, respectively. Patients in group C were older than patients in groups A and B. Gastric open-type atrophy, intestinal metaplasia, enlarged folds, diffuse redness, and duodenal ulcers were associated with a high titer. Regular arrangements of collecting venules, fundic gland polyps, superficial gastritis, and gastroesophageal reflux disease were related to a low titer. Multivariate analysis revealed that nodularity (P = 0.0094), atrophy (P = 0.0076), and age 40-59 years (vs age ≥ 60 years, P = 0.0090) were correlated with a high serum antibody titer in H. pylori-infected patients. Intestinal metaplasia and atrophy were related to age ≥ 60 years in group C and D.

CONCLUSION

Serum antibody titer changes with age, reflects gastric mucosal inflammation, and is useful in predicting the risk of gastric cancer.

Epidemiological and Clinical-Pathological Aspects of Helicobacter pylori Infection in Brazilian Children and Adults

Aim

To evaluate the prevalence and risk factors of H. pylori infection in the pediatric and adult population seen at a public hospital in São José do Rio Preto, SP, Brazil.

Methods

This is a retrospective study that evaluated 2406 medical records of children, adolescents, and adults with dyspeptic symptoms who underwent upper gastrointestinal endoscopy. H. pylori diagnosis and demographic and clinical-pathological features were recorded.

Results

A total of 852 subjects were H. pylori positive, with an overall prevalence of infection of 35.4%, occurring mainly in adults over 40 years of age, and a 24.7% prevalence considering only children and adolescents. No association was observed between H. pylori infection and risk factors. However, the H. pylori positive individuals showed a higher frequency of pangastritis (p < 0.01), severe lesions (p = <0.001), and erosive lesions (p = 0.04). The bacterium was eradicated in 83.5% (127) of the patients who received the standard therapy.

Conclusions

The prevalence of H. pylori detected in a public service in São José do Rio Preto, SP, Brazil, is as expected for developed countries, showing growing rates with increasing age. As H. pylori infection occurs during childhood, screening programs for detection and prevention in the pediatric population are important to reduce the prevalence of this infection in adults.

Chronic Gastritis Due to Helicobacter Pylori Associated with Increased Serum Levels of CA54/61: A Report of Three Cases

BACKGROUND The bacterial pathogen Helicobacter pylori (H. pylori) can cause chronic gastritis. CA54/61 is a serum tumor marker that has been shown to be positive in the several types of human malignancy. However, the association of between chronic gastritis due to H. pylori and elevated serum levels of CA54/61 has not been previously reported. This report is of three cases of increased serum levels of CA54/61 associated with H. pylori chronic gastritis. CASE REPORT Case 1 was a 44-year-old Japanese woman with a serum CA54/61 level of 138 U/ml (normal level: 12 U/ml). Following treatment and eradication of H. pylori the serum CA54/61 level decreased to 14 U/ml. Case 2 was a 73-year-old Japanese man with a serum level of less than 2 U/ml before completion of successful eradication therapy of H. pylori with a small peak of 30 U/ml after therapy. Case 3 was a 54-year-old Japanese man who maintained a serum CA54/61 level of approximately 20 U/ml before and until 603 days after eradication therapy. None of the three patients had malignancy, which is usually suggested by this serum marker. CONCLUSIONS These three case reports suggest the possibility of an association between chronic gastritis involving H. pylori infection and an elevated serum level of CA54/61. It is possible that the inflammatory gastric mucosal cells supply CA54/61 to the bloodstream. However, further studies are required to confirm the association between serum levels of CA54/61 and H. pylori chronic gastritis and the underlying mechanisms of this association.

Prevalence of Helicobacter pylori among Alaskans: Factors associated with infection and comparison of urea breath test and anti-Helicobacter pylori IgG antibodies

BACKGROUND

Helicobacter pylori is one of the most common human infections in the world, and studies in Alaska Native people, as well as other Indigenous peoples, have shown a high prevalence of this gastric infection. This study was undertaken to determine the prevalence of H. pylori infection by urea breath test (UBT) and anti- H. pylori IgG among Alaskans living in four regions of the state and to identify factors associated with infection.

METHODS

A convenience sample of persons > 6 months old living in five rural and one urban Alaskan community were recruited from 1996 to 1997. Participants were asked about factors possibly associated with infection. Sera were collected and tested for anti- H. pylori IgG antibodies; a UBT was administered to participants > 5 years old.

RESULTS

We recruited 710 people of whom 571 (80%) were Alaska Native and 467 (66%) were from rural communities. Rural residents were more likely to be Alaska Native compared with urban residents (P < .001). Of the 710 people, 699 (98%) had a serum sample analyzed, and 634 (97%) persons > 5 years old had a UBT performed. H. pylori prevalence was 69% by UBT and 68% by anti- H. pylori IgG. Among those with a result for both tests, there was 94% concordance. Factors associated with H. pylori positivity were Alaska Native racial status, age ≥ 20 years, rural region of residence, living in a crowded home, and drinking water that was not piped or delivered.

CONCLUSIONS

Helicobacter pylori prevalence is high in Alaska, especially in Alaska Native persons and rural residents. Concordance between UBT and serology was also high in this group. Two socioeconomic factors, crowding and drinking water that was not piped or delivered, were found to be associated with H. pylori positivity.

Decrease of Estradiol and Several Lifestyle Factors, but Not Helicobacter pylori Infection, Are Significant Risks for Osteopenia in Japanese Females

BACKGROUND

The primary cause of osteoporosis in women is increased bone resorption and decreased bone density associated with reduced estrogen secretion. Several studies have demonstrated a relationship between Helicobacter pylori infection and osteoporosis regardless of estrogen levels. This study examined the relationship between H. pylori infection and osteopenia together with estrogen levels, calcium intake, and several lifestyle factors.

METHODS

This study included 473 healthy women who underwent a general health examination. Multivariate analysis was performed, with age, body mass index (BMI), smoking habit, drinking habit, exercise habit, schooling duration, estradiol levels, birth history, calcium intake, schooling duration, smoking habit, drinking habit, exercise habit, and H. pylori infection as independent variables and the presence of osteopenia as a dependent variable.

RESULTS

The adjusted OR for osteopenia with H. pylori infection was 0.95 (95% CI 0.55-1.63, p = 0.84). In contrast, osteopenia was significantly associated with age, low BMI, lesser schooling period, low estradiol levels, and low calcium intake.

CONCLUSIONS

H. pylori infection was not a significant risk for osteopenia by the multivariate analysis, which included the primary confounding factors. Significant factors, such as estradiol and calcium intake, should be assessed together to study the association of H. pylori infection and osteopenia.

Eosinophilic esophagitis in Japan: Focus on response to acid suppressive therapy

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition characterized by esophageal dysfunction and dense eosinophilic infiltration of esophageal epithelium. According to clinical consensus and guidelines published in 2011, esophageal eosinophilia was classified into two entities based on response to proton pump inhibitor (PPI) administration: EoE and PPI-responsive esophageal eosinophilia (PPI-REE). We have performed a series of investigations to determine whether EoE is actually different from PPI-REE. Consistent with Western reports, more than half of our examined patients with symptomatic esophageal eosinophilia suggestive of EoE achieved histological remission with single PPI therapy. Furthermore, our comparisons of clinical, endoscopic, and histopathological findings between patients with EoE and those with PPI-REE revealed nearly no differences between them. We also compared gene expression profiles in mucosal biopsy specimens between those groups and found that microarray findings obtained from PPI-REE patients substantially overlapped with those from EoE patients, suggesting that both represent the same condition or are variations of a single disease. In addition, we have noted that more than half of EoE patients who show resistance to a PPI therapy respond to vonoprazan, a novel potassium-competitive acid blocker that has been shown to provide more potent and sustained suppression of gastric acid secretion than PPIs. Our results indicate that PPI-REE may constitute a subtype of EoE. Based on novel evidence including results obtained in our studies, the most recently updated guidelines have included responders to PPI therapy within the spectrum of EoE, abandoning the term PPI-REE.

Effects of alcohol consumption, ALDH2 rs671 polymorphism, and Helicobacter pylori infection on the gastric cancer risk in a Korean population

The effect of alcohol consumption on the risk of gastric cancer (GC) has not yet been fully elucidated, and an aldehyde dehydrogenase 2 (ALDH2) polymorphism, rs671, is a genetic variant that influences alcohol consumption in East Asians. Additionally, the discrepancy between the Helicobacter pylori (H. pylori) infection prevalence and GC incidence across Asian countries has not been explained. This study evaluated the effects of alcohol consumption and genetic susceptibility to defective acetaldehyde metabolism on the GC risk and their interactions with H. pylori infection. This study included 450 Korean GC cases and 1,050 controls recruited at the National Cancer Center. Data for 795 patients and 4,893 controls were used for further confirmation of the effect of rs671. Increased GC risks were evident for rs671 A allele carriers (odds ratio (OR), 1.23; 95% confidence interval (CI), 1.08-1.41) and H. pylori-infected individuals (OR, 7.07; 95% CI, 4.60-10.86), but no dose-response association with alcohol consumption was observed. Furthermore, the interactions between these factors were not significant. This study has demonstrated that alcohol consumption and rs671 should be considered simultaneously when assessing the GC risk. Additionally, alcohol-related factors were not found to interact with H. pylori infection, and further studies evaluating other environmental factors are required to explain the Asian enigma.

Changing trends in the prevalence of H. pylori infection in Japan (1908-2003): a systematic review and meta-regression analysis of 170,752 individuals

Changing trends in the prevalence of H. pylori infection in the general population over time are thought to be the main driving force behind the declining gastric cancer mortality in Japan. However, whether the prevalence of H. pylori infection itself shows a birth-cohort pattern needs to be corroborated. We performed a systematic review of studies that reported the prevalence of H. pylori infection among Japanese individuals. Meta-regression was conducted in the framework of a generalized additive mixed model (GAMM) to account for heterogeneity in the prevalence of H. pylori infection as a function of birth year. The prevalence of H. pylori infection confirmed a clear birth cohort pattern: the predicted prevalence (%, 95% CI) was 60.9 (56.3–65.4), 65.9 (63.9–67.9), 67.4 (66.0–68.7), 64.1 (63.1–65.1), 59.1 (58.2–60.0), 49.1 (49.0–49.2), 34.9 (34.0–35.8), 24.6 (23.5–25.8), 15.6 (14.0–17.3), and 6.6 (4.8–8.9) among those who were born in the year 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990, and 2000, respectively. The present study demonstrated a clear birth-cohort pattern of H. pylori infection in the Japanese population. The decreased prevalence of H. pylori infection in successive generations should be weighed in future gastric cancer control programs.

Global patterns and trends in stomach cancer incidence: Age, period and birth cohort analysis

The cases of stomach cancer (SC) incidence are increasing per year and the SC burden has remained very high in some countries. We aimed to evaluate the global geographical variation in SC incidence and temporal trends from 1978 to 2007, with an emphasis on the effect of birth cohort. Joinpoint regression and age-period-cohort model were applied. From 2003 to 2007, male rate were 1.5- to 3-fold higher than female in all countries. Rates were highest in Eastern Asian and South American countries. Except for Uganda, all countries showed favorable trends. Pronounced cohort-specific increases in risk for recent birth cohorts were seen in Brazil, Colombia, Iceland, New Zealand, Norway, Uganda and US white people for males and in Australia, Brazil, Colombia, Costa Rica, Czech Republic, Ecuador, Iceland, India, Malta, New Zealand, Norway, Switzerland, United Kingdom, Uganda, US black and white people for females. The cohort-specific ratio for male significantly decreased in Japan, Malta and Spain for cohorts born since 1950 and in Austria, China, Croatia, Ecuador, Russia, Switzerland and Thailand for cohorts born since 1960 and for female in Japan for cohorts born since 1950 and in Canada, China, Croatia, Latvia, Russia and Thailand for cohorts born since 1960. Disparities in incidence and carcinogenic risk persist worldwide. The favorable trends may be due to changes in environmental exposure and lifestyle, including decreased Helicobacter pylori prevalence, increased intake of fresh fruits and vegetables, the availability of refrigeration and decreased intake of salted and preserved food and smoking prevalence.

Impact of health insurance coverage for Helicobacter pylori gastritis on the trends in eradication therapy in Japan: retrospective observational study and simulation study based on real-world data

OBJECTIVES

To explore the prevalence of Helicobacter pylori infection in Japan and the trends of its eradication therapy before and after the changes of the insurance coverage policy, first started in 2000, and expanded to cover H. pylori-positive gastritis in 2013. The impacts that the changes brought were estimated.

METHODS

In this retrospective observational study and simulation study based on health insurance claims data, product sales data and relevant studies, individuals who received triple therapy (amoxicillin, clarithromycin, proton-pump inhibitors or potassium-competitive acid blockers) were defined as the first-time patients for H. pylori eradication in two Japanese health insurance claims databases (from approximately 1.6 million and 10.5 million individuals). Each sales data of eradication packages and examination kits were used to estimate the number of H. pylori-eradicated individuals nationwide. The prevalence of H. pylori infection, including the future rate, was predicted using previous studies and the estimated population trend by a national institute. Cases completed prior to the policy change on insurance coverage were simulated to estimate what would have happened had there been no change in the policy.

RESULTS

The numbers of patients first received eradication therapy were 81 119 and 170 993 from two databases. The nationwide estimated number of patients successfully eradicated was approximately 650 000 per year between 2001 and 2012, whereas it rapidly rose to 1 380-000 per year in 2013. The estimated prevalence of infection in 2050 is 5%, this rate was estimated to be 28% and 22% if the policy changes had not occurred in 2000 and 2013, respectively.

CONCLUSIONS

The impact of policy changes for H. pylori eradication therapy on the prevalence of infection was shown. The results suggest that insurance coverage expansion may also reduce the prevalence in other countries with a high prevalence of H. pylori infection if the reinfection is low.