Time Trends in Helicobacter pylori Infection and Atrophic Gastritis Over 40 Years in Japan

Prevalence of Gastric Precursor Lesions in Countries With Differential Gastric Cancer Burden: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The prevalence of precursor lesions for gastric cancer (GC) and the differential burden between countries of varying GC risk is not well-understood. We conducted a systematic review and meta-analysis to estimate the global prevalence of precursor lesions.

METHODS

We estimated the prevalence of atrophic gastritis (AG), gastric intestinal metaplasia (IM), and dysplasia in regions with low, medium, and high GC incidence. Because IM is an advanced manifestation of AG, we assessed the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. Prevalence was sub-stratified by Helicobacter pylori infection, symptomatology, and period (<2000, 2000-2010, and >2010).

RESULTS

Among the 582 articles that underwent full-text review, 166 studies met inclusion criteria. The global prevalence estimates of AG, IM, and dysplasia were 25.4%, 16.2%, and 2.0%, respectively, on the basis of 126 studies that reported the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. The prevalence of all precursor lesions was higher in high and medium compared with low GC incidence countries (P < .01). Prevalence of AG and IM was significantly higher among H pylori-infected individuals (P < .01) but not statistically different between symptomatic and asymptomatic individuals (P > .17). All precursors demonstrated a secular decrease in prevalence over time.

CONCLUSIONS

Gastric precursor lesions have differences in prevalence in regions with differential GC incidence and are associated with H pylori infection. Because of the substantial prevalence of precursor lesions in both symptomatic and asymptomatic individuals, symptomatic evaluation may not be sufficient to identify individuals at risk. These estimates provide important insights for tailoring GC prevention strategies.

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.

RE.GA.IN.: the Real-world Gastritis Initiative-updating the updates

At the end of the last century, a far-sighted 'working party' held in Sydney, Australia addressed the clinicopathological issues related to gastric inflammatory diseases. A few years later, an international conference held in Houston, Texas, USA critically updated the seminal Sydney classification. In line with these initiatives, Kyoto Global Consensus Report, flanked by the Maastricht-Florence conferences, added new clinical evidence to the gastritis clinicopathological puzzle.The most relevant topics related to the gastric inflammatory diseases have been addressed by the Real-world Gastritis Initiative (RE.GA.IN.), from disease definitions to the clinical diagnosis and prognosis. This paper reports the conclusions of the RE.GA.IN. consensus process, which culminated in Venice in November 2022 after more than 8 months of intense global scientific deliberations. A forum of gastritis scholars from five continents participated in the multidisciplinary RE.GA.IN. consensus. After lively debates on the most controversial aspects of the gastritis spectrum, the RE.GA.IN. Faculty amalgamated complementary knowledge to distil patient-centred, evidence-based statements to assist health professionals in their real-world clinical practice. The sections of this report focus on: the epidemiology of gastritis; Helicobacter pylori as dominant aetiology of environmental gastritis and as the most important determinant of the gastric oncogenetic field; the evolving knowledge on gastric autoimmunity; the clinicopathological relevance of gastric microbiota; the new diagnostic horizons of endoscopy; and the clinical priority of histologically reporting gastritis in terms of staging. The ultimate goal of RE.GA.IN. was and remains the promotion of further improvement in the clinical management of patients with gastritis.

Prevalence of Raspberry-type Gastric Foveolar-type Tumor in Individuals Undergoing Medical Checkups

Objective This study was performed to clarify the prevalence of raspberry-type gastric foveolar-type tumors, along with the time-course changes in the size and clinical course. Methods The subjects were 10,663 consecutive patients who underwent a medical checkup between April 2016 and March 2022, including an esophagogastroduodenoscopy (EGD) examination and determination of Helicobacter pylori infection status (uninfected, positive, post-eradication). The presence of characteristic reddish polypoid lesions in the stomach was investigated, and a diagnosis of raspberry-type gastric foveolar-type tumor was made based on histological findings. Results Thirty-eight cases had gastric polyps with a raspberry-like appearance on endoscopy, with 29 lesions in 28 cases endoscopically and histologically diagnosed as a raspberry-type gastric foveolar-type tumor. All of the affected subjects were determined to be H. pylori-uninfected. The prevalence of this type of lesion in all subjects was 0.26%, while that in the 6,635 H. pylori-uninfected subjects was 0.42%. An older age and the presence of a fundic gland polyp were found to be significant risk factors associated with the occurrence of the tumor. The mean size was 3.8±1.9 (range: 2-10) mm, and the location was in a fundic gland area in all affected subjects. Furthermore, examinations of previous EGD images revealed that two-thirds of the lesions had not changed in size, while follow-up EGD findings showed that lesions ≤5 mm in size had disappeared after a biopsy procedure. Conclusion The prevalence of raspberry-type gastric foveolar-type tumors was 0.42% in H. pylori-uninfected subjects. More than half of the lesions were too small to be removed by an endoscopic biopsy.

Rising Trends of Endoscopic Barrett's Esophagus and Gastric Fundic Gland Polyps in Young Japanese Adults

BACKGROUND/AIMS

This study examined changes in the esophageal-gastric junction and gastric mucosa in young Japanese adults undergoing endoscopy in the last 15 years.

MATERIALS AND METHODS

This was a retrospective study of young Japanese adults (aged 19-30 years) who underwent esophagogastrod uodenoscopy between 2006 and 2020. The indications were upper gastrointestinal symptoms and anemia. Changes in the appearance of the esophago-gastric junction (i.e., the Z line and distal esophagitis) and gastric mucosa were examined. Endoscopic Barrett's esophagus was defined using the Japanese criteria.

RESULTS

One thousand eight hundred forty-five patients were examined: 848 from 2006 to 2012 [400 males, mean age 26.5 years (range 19-30)] and 997 from 2013 to 2020 [433 males, mean age 26.2 years (range 19-30)]. The proportion showing endoscopic Barrett's esophagus and gastric fundic gland polyps increased significantly between the 2 periods (12.5% vs. 22.4%, P < .001; 3.4% vs. 7.2%, P < .001) with a significant correlation between the prevalence trends for endoscopic Barrett's esophagus and gastric fundic gland polyps (r = 0.789, P = .0008). Pathological examination showed that the prevalence of traditional fundic gland polyps unrelated to the use of proton pump inhibitors significantly increased from 40% (4/10) to 81% (25/31) between the 2 periods (P = .04).

CONCLUSION

The prevalence of both endoscopic Barrett's esophagus and gastric fundic gland polyps among young Japanese adults significantly increased in the last 15 years. The trend in endoscopic Barrett's esophagus was significantly correlated with that of nonproton pump inhibitor-related gastric fundic gland polyps.

The burden of stomach cancer mortality by county, race, and ethnicity in the USA, 2000-2019: a systematic analysis of health disparities

Background

There are persistent disparities in stomach cancer mortality among racial-ethnic groups in the USA, but the extent to which these patterns vary geographically is not well understood. This analysis estimated age-standardised mortality for five racial-ethnic groups, in 3110 USA counties over 20 years, to describe spatial-temporal variations in stomach cancer mortality and disparities between racial-ethnic groups.

Methods

Redistribution methods for insufficient cause of death codes and validated small area estimation methods were applied to death registration data from the US National Vital Statistics System and population data from the US National Center for Health Statistics to estimate annual stomach cancer mortality rates. Estimates were stratified by county and racial-ethnic group (non-Latino and non-Hispanic [NL] American Indian or Alaska Native [AIAN], NL Asian or Pacific Islander [Asian], NL Black [Black], Latino or Hispanic [Latino], and NL White [White]) from 2000 to 2019. Estimates were corrected for misreporting of racial-ethnic group on death certificates using published misclassification ratios. We masked (ie, did not display) estimates for county and racial-ethnic group combinations with a mean annual population of less than 1000; thus, we report estimates for 3079 (of 3110) counties for the total population, and 474, 667, 1488, 1478, and 3051 counties for the AIAN, Asian, Black, Latino, and White populations, respectively.

Findings

Between 2000 and 2019, national age-standardised stomach cancer mortality was lowest among the White population in every year. Nationally, stomach cancer mortality declined for all racial-ethnic groups across this time period, with the most rapid declines occurring among the Asian (percent decline 48.3% [45.1-51.1]) and Black populations (42.6% [40.2-44.6]). Mortality among the other racial-ethnic groups declined more moderately, decreasing by 36.7% (35.3-38.1), 35.1% (32.2-37.7), and 31.6% (23.9-38.0) among the White, Latino, and AIAN populations, respectively. Similar patterns were observed at the county level, although with wide geographic variation. In 2019, a majority of counties had higher mortality rates among minoritised racial-ethnic populations compared to the White population: 81.1% (377 of 465 counties with unmasked estimates for both racial-ethnic groups) among the AIAN population, 88.2% (1295 of 1469) among the Latino population, 99.4% (663 of 667) among the Asian population, and 99.9% (1484 of 1486) among the Black population. However, the size of these disparities ranged widely across counties, with the largest range from 0.3 to 17.1 among the AIAN population.

Interpretation

Stomach cancer mortality has decreased substantially across populations and geographies in the USA. However, disparities in stomach cancer mortality among racial-ethnic groups are widespread and have persisted over the last two decades. Local-level data are crucial to understanding the scope of this unequal burden among minoritised groups in the USA.

Funding

National Institute on Minority Health and Health Disparities; National Heart, Lung, and Blood Institute; National Cancer Institute; National Institute on Aging; National Institute of Arthritis and Musculoskeletal and Skin Diseases; Office of Disease Prevention; and Office of Behavioral and Social Sciences Research, National Institutes of Health (contract #75N94019C00016).

The impact of early‐stage COVID‐19 pandemic on the diagnosis and treatment of gastric cancer: A cross‐sectional study using a large‐scale cancer registry in Hiroshima, Japan

Background

After the confirmation of coronavirus infection in Japan, a behavioral change caused people and physicians to refrain from visiting hospitals or undergoing examinations. This study aimed to assess how the trend of diagnosis in gastric cancers changed, and how it affected the therapeutic strategies and the interval from diagnosis to treatment during the COVID‐19 pandemic.

Methods

We use 15 cancer‐designated hospitals’ registries in Hiroshima, Japan. The target period was March to December 2020, and the same period in 2019 was set as the control period. The monthly mean of diagnoses and the interval from diagnosis to treatment were compared overall and separately by age, treatment procedure, diagnostic process, and clinical stage.

Result

In 2020, the monthly mean (standard deviation [SD]) of patients was 192.2 (29.9), a significant 20.1% decrease from 240.7 (20.7) in 2019 due to older age and curative treatment groups. By reason for performing endoscopy, the change rate in cancer screening, endoscopic follow‐up, and symptomatic status were ‐27.0%, ‐18.0%, and ‐17.3%, respectively. Meanwhile, the interval (days) from diagnosis to treatment (SD) was 37.8 (26.5) in 2020, significantly shorter than 46 (31.5) in 2019.

Conclusion

From 2019 to 2020, we observed a significant decrease in the diagnosis of curable early‐stage gastric cancer and treatments, although the interval from diagnosis to treatment decreased. This study suggests that cancer screening played a significant role in the decline in cancer diagnosis that occurred during the COVID‐19 pandemic. Even under COVID‐19 pandemic conditions, there should be an awareness of cancer screening and endoscopic follow‐up.

Two Cases of Acute Gastric Mucosal Lesions Due to Helicobacter pylori Infection Confirmed to be Transient Infection

Two adult cases of acute gastric mucosal lesions (AGML) caused by Helicobacter pylori infection were confirmed by spontaneous eradication during the follow-up period. The clinical course of the initial infection by H. pylori in adults with AGML remains unclear, whether it is transient or progresses to a persistent infection. In these two reported cases, gastric biopsies at the time of the onset revealed the presence of H. pylori; however, serum H. pylori antibodies performed at the same time were negative. Retesting for H. pylori serum antibody, after six months in one and after two months in the other, was negative, confirming spontaneous eradication.

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.

Non-atrophic gastric mucosa is an independently associated factor for superficial non-ampullary duodenal epithelial tumors: a multicenter, matched, case-control study

BACKGROUND/AIMS

The etiology of superficial non-ampullary duodenal epithelial tumors (SNADETs) remains unclear. Recent studies have reported conflicting associations between duodenal tumor development and Helicobacter pylori infection or endoscopic gastric mucosal atrophy. As such, the present study aimed to clarify the relationship between SNADETs and H. pylori infection and/or endoscopic gastric mucosal atrophy.

METHODS

This retrospective case-control study reviewed data from 177 consecutive patients with SNADETs who underwent endoscopic or surgical resection at seven institutions in Japan over a three-year period. The prevalence of endoscopic gastric mucosal atrophy and the status of H. pylori infection were compared in 531 sex- and age-matched controls selected from screening endoscopies at two of the seven participating institutions.

RESULTS

For H. pylori infection, 85 of 177 (48.0%) patients exhibited SNADETs and 112 of 531 (21.1%) control patients were non-infected (p<0.001). Non-atrophic mucosa (C0 to C1) was observed in 96 of 177 (54.2%) patients with SNADETs and 112 of 531 (21.1%) control patients (p<0.001). Conditional logistic regression analysis revealed that non-atrophic gastric mucosa was an independent risk factor for SNADETs (odds ratio, 5.10; 95% confidence interval, 2.44-8.40; p<0.001).

CONCLUSION

Non-atrophic gastric mucosa, regardless of H. pylori infection status, was a factor independently associated with SNADETs.

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.

A multicenter prospective study of the treatment and outcome of patients with gastroduodenal peptic ulcer bleeding in Japan

Gastroduodenal peptic ulcers are the main cause of nonvariceal upper gastrointestinal bleeding (UGIB). We believe that recent advances in endoscopic techniques and devices for diagnosing upper gastrointestinal tract tumors have advanced hemostasis for UGIB. However, few prospective multicenter studies have examined how these changes affect the prognosis. This prospective study included 246 patients with gastroduodenal peptic ulcers treated at 14 participating facilities. The primary endpoint was in-hospital mortality within 4 weeks, and the secondary endpoints required intervention and refractory bleeding. Subsequently, risk factors affecting these outcomes were examined using various clinical items. Furthermore, the usefulness of the risk stratification using the Glasgow-Blatchford score, rockall score and AIMS65 based on data from the day of the first urgent endoscopy were examined in 205 cases in which all items were complete there are two periods. Thirteen (5%) patients died within 4 weeks; and only 2 died from bleeding. Significant risk factors for poor outcomes were older age and severe comorbidities. Hemostasis was required in 177 (72%) cases, with 20 cases of refractory bleeding (2 due to unsuccessful endoscopic treatment and 18 due to rebleeding). Soft coagulation was the first choice for endoscopic hemostasis in 57% of the cases and was selected in more than 70% of the cases where combined use was required. Rockall score and AIMS65 predicted mortality equally, and Glasgow-Blatchford score was the most useful in predicting the requirement for intervention. All scores predicted refractory bleeding similarly. Although endoscopic hemostasis for UGIB due to peptic ulcer had a favorable outcome, old age and severe comorbidities were risk factors for poor prognosis. We recommend that patients with UGIB should undergo early risk stratification using a risk scoring system.

Incidence trends and disparities in Helicobacter pylori related malignancy among US adults, 2000-2019

Background

Helicobacter pylori (H. pylori) is closely related to the carcinogenesis of gastric cancer (GC) and gastric non-Hodgkin lymphoma (NHL). However, the systemic trend analysis in H. pylori-related malignancy is limited. We aimed to determine the national incidence trend in non-cardia GC, cardia GC, and gastric NHL in the US during 2000-2019.

Method

In this population-based study, we included 186,769 patients with a newly diagnosed H. pylori-related malignancy, including non-cardia GC, cardia GC, and gastric NHL from the Surveillance, Epidemiology, and End Results (SEER) Registry from January 1, 2000 to December 31, 2019. We determined the age-adjusted incidence of three H. pylori-related malignancies respectively. Average annual percentage change (AAPC) in 2000-2019 was calculated to describe the incidence trends. Analyses were stratified by sex, age, race and ethnicity, geographic location and SEER registries. We also determined the 5-year incidence (during 2015-2019) by SEER registries to examine the geographic variance.

Results

The incidence in non-cardia GC and gastric NHL significantly decreased during 2000-2019, while the rate plateaued for cardia GC (AAPCs, -1.0% [95% CI, -1.1%-0.9%], -2.6% [95% CI, -2.9%-2.3%], and -0.2% [95% CI, -0.7%-0.3%], respectively). For non-cardia GC, the incidence significantly increased among individuals aged 20-64 years (AAPC, 0.8% [95% CI, 0.6-1.0%]). A relative slower decline in incidence was also observed for women (AAPC, -0.4% [95% CI, -0.6%-0.2%], P for interaction < 0.05). The incidence of cardia GC reduced dramatically among Hispanics (AAPC, -0.8% [95% CI, -1.4%-0.3%]), however it increased significantly among nonmetropolitan residents (AAPC, 0.8% [95% CI, 0.4-1.3%]). For gastric NHL, the decreasing incidence were significantly slower for those aged 20-64 years (AAPC, -1.5% [95% CI, -1.9-1.1%]) and Black individuals (AAPC, -1.3% [95% CI, -1.9-1.1%]). Additionally, the highest incidence was observed among Asian and the Black for non-cardia GC, while Whites had the highest incidence of cardia GC and Hispanics had the highest incidence of gastric NHL (incidence rate, 8.0, 8.0, 3.1, and 1.2, respectively) in 2019. Geographic variance in incidence rates and trends were observed for all three H. pylori-related malignancies. The geographic disparities were more pronounced for non-cardia GC, with the most rapid decline occurring in Hawaii (AAPC, -4.5% [95% CI, -5.5-3.6%]) and a constant trend in New York (AAPC 0.0% [95% CI, -0.4-0.4%]), the highest incidence in Alaska Natives, and the lowest incidence among Iowans (14.3 and 2.3, respectively).

Conclusion

The incidence of H. pylori-related cancer declined dramatically in the US between 2000 and 2019, with the exception of cardia GC. For young people, a rising trend in non-cardia GC was noted. Existence of racial/ethnic difference and geographic diversity persists. More cost-effective strategies of detection and management for H. pylori are still in demand.

Safety and Efficacy of Sedation During Emergency Endoscopy for Upper Gastrointestinal Bleeding: A Propensity Score Matching Analysis

BACKGROUND AND AIM

This study aimed to compare patients with and without sedation during emergency endoscopy for upper gastrointestinal bleeding (UGIB) and to clarify the safety and efficacy of sedation in emergency endoscopy.

METHODS

We retrospectively collected 389 patients who underwent emergency endoscopy for UGIB at Ureshino Medical Center from 2016 to 2021. Patients were divided into two groups: sedation group during emergency endoscopy and nonsedation group. Clinical characteristics, patient status on admission, and UGIB etiology were evaluated. Treatment outcomes and adverse events were evaluated using propensity score matching (PSM), and risk factors for mortality from UGIB were investigated using Cox multivariate analysis.

RESULTS

The sedation group was significantly younger, composed of a higher proportion of males, and had chronic liver disease. Blood pressure and hemoglobin level on admission were significantly higher in the sedation group. The main cause of bleeding was peptic ulcer, which was significantly higher in the nonsedation group. PSM created 133 matched pairs. The success rate of endoscopic hemostasis was similar in both groups, and procedure time was significantly shorter in the sedation group than in the nonsedation group (17.6 ± 10.0 versus 20.2 ± 10.2 min, P = 0.04). There were no significant differences in adverse events between groups. Cox multivariate analyses revealed that red blood cell transfusion [hazard ratio (HR) 4.45, P < 0.02] and rebleeding (HR 3.30, P = 0.03) were associated with increased risk of 30-day mortality from UGIB.

CONCLUSIONS

Sedation reduced the procedure time during emergency endoscopy for UGIB. Sedation during emergency endoscopy for UGIB is acceptable for safe endoscopic procedures.

Assigning a different endoscopist for each annual follow-up may contribute to improved gastric cancer detection rates

Background and study aims  Esophagogastroduodenoscopy (EGD) is an effective and important diagnostic tool to detect gastric cancer (GC). Although previous studies show that examiner, patient, and instrumental factors influence the detection of GC, we analyzed whether assigning a different examiner to surveillance EGD would improve the detection of GC compared to assigning the same examiner as in the previous endoscopy. Patients and methods  We retrospectively reviewed patients who underwent two or more consecutive surveillance EGDs at a single center between 2017 and 2019. We identified factors associated with GC detection using multivariable regression analysis and propensity-score matching. Results  Among 7794 patients, 99 GC lesions in 93 patients were detected by surveillance EGD (detection rate; 1.2 %), with a mean surveillance interval of 11.2 months. Among the detected 99 lesions, 87 (87.9 %) were curatively treated with endoscopy. There were no differences in the clinicopathologic characteristics of GC detected by the same or different endoscopists. GC detection in the group examined by different endoscopists was more statistically significant than in the group examined by the same endoscopist, even after propensity-score matching (1.6 % and 0.7 %; P  < 0.05). Endoscopic experience and other factors were not statistically significant between the two groups. Conclusions  In surveillance EGD, having a different endoscopist for each exam may improve GC detection rates, regardless of the endoscopist's experience.

Helicobacter pylori infection prevalence in ambulatory settings in 2017-2019 in RUSSIA: The data of real-world national multicenter trial

BACKGROUND

The recent data on the prevalence of Helicobacter pylori (H. pylori) infection in Russia are limited. The aim of the study was to compare Helicobacter pylori infection prevalence in ambulatory settings in Russia in 2017 and 2019 years.

MATERIALS AND METHODS

Subjects visiting primary care centers were invited to take part in the study. H. pylori status was assessed by ¹³ C-urea breath test (UBT). Data on subjects' demography, previous treatment exposure, and place of residence were collected in all federal districts of Russia in 2017 and in 2019 calendar years and processed centrally.

RESULTS

The data of 19,875 subjects were available for analysis. The prevalence of H. pylori infection assessed by positive UBT in treatment-naive subjects was highest in the Southern (54.9%) and the North Caucasian (45.1%) federal districts. A significant difference (p < 0.05) in H. pylori prevalence between two testing periods was found only in a half of federal districts: the Central (46.2% in 2017 vs. 36.2% in 2019), the Northwestern (38.6% vs. 35.5% accordingly), the Volga (40.6% vs. 33.0%, accordingly), and the Ural (40.4% vs. 32.7%, accordingly). The lowest prevalence of H. pylori infection was revealed in the age group <18 years old (20.2%), while the highest in the age group of 41-50 years old (43.9%). In 2017, the prevalence of H. pylori was significantly (p < 0.05) higher than in 2019 in all age groups but younger than 18 and older than 70 y.o., where similar rates were found during both study periods.

CONCLUSIONS

The prevalence of H. pylori according to ¹³ C-UBT testing of primary care visitors in Russia is lower than expected (38.8%). The highest prevalence of H. pylori infection found in the Southern and the North Caucasian federal districts of Russia and in the age group of 41-50 years old. This study was registered at clinicaltrials.gov (NCT04892238).

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.

Higher proportions of a healthy gastric mucosa in healthy Japanese adults with later birth year: analysis of 41 957 participants

BACKGROUND

In Japan, most gastric cancers are associated with gastric mucosal atrophy caused by chronic infection with Helicobacter pylori (H. pylori). Recognizing the condition of the gastric mucosa and determining the infection status of H. pylori are important for predicting the individual risk of gastric cancer. This study aimed to determine the proportion of Japanese adults with a healthy gastric mucosa (without H. pylori infection) among 12 birth-year groups encompassing 1935-1990 by morphological images.

METHODS

The gastric mucosa was classified as healthy or having gastritis based on routine double-contrast upper gastrointestinal barium X-ray radiography. The participants included 41 957 healthy Japanese adults. Serum or urine H. pylori antibody levels were also assessed.

RESULTS

In total, 25 424 participants had healthy mucosa without a history of H. pylori eradication. The proportions of participants with a healthy mucosa by birth year were 19.8% (57/288), 27.1% (306/1128), 32.4% (569/1756), 37.6% (1808/4811), 49.2% (3207/6522), 60.1% (3966/6550), 71.2% (5224/7342), 77.2% (5114/6624), 80.6% (3342/4149), 85.0% (1404/1652), 85.3% (302/354) and 94.7% (125/132) in 1935, 1940, 1945, 1950, 1955, 1960, 1965, 1970, 1975, 1980, 1985 and after 1990, respectively (P for trend <0.01). All the participants with a healthy mucosa showed negative results in the H. pylori antibody tests.

CONCLUSIONS

The proportion of participants with normal gastric mucosa linearly increased with the birth years. The prevalence of morphologically healthy gastric mucosa could have consistently increased with decreasing prevalence of H. pylori infection.

Epidemiology of Helicobacter pylori in Australia: a scoping review

Background

Helicobacter pylori (H. pylori), a bacterium implicated in the development of peptic ulcer and gastric cancer, is estimated to infect around half the world's population. Its prevalence in Australia is unclear. This scoping review aimed to evaluate all Australian literature providing estimates of the prevalence of H. pylori.

Methods

Australian studies examining H. pylori prevalence from 1982 onwards were eligible for inclusion. Medline, Embase and Scopus databases, and grey literature sources, were searched. Two independent reviewers undertook a two-stage screening process. Data were extracted by two independent reviewers using a pre-specified template.

Results

Of 444 identified studies, 75 were included in the review. H. pylori prevalence in Australian population-based studies (n = 8) ranged from 38.0% in 1991 to 15.1% in 2002; however, estimated prevalence across all non-clinical population studies in diverse sub-groups (n = 29) has varied dramatically. Decreased prevalence has been more marked in populations with gastrointestinal symptoms and conditions compared to non-clinical populations. Data on H. pyloriprevalence in vulnerable populations are lacking.

Conclusions

This is the first scoping review of Australian studies reporting H. pylori prevalence. A wide range of study designs, population groups, geographic regions, and diagnostic methods was included, involving data collected over a 50-year period (1969 to 2018). The summary of H. pylori prevalence estimates over time in this review points to a decrease in prevalence in Australia, particularly among populations with gastrointestinal symptoms and illnesses; however, it is unknown whether there is inequity in prevalence trends across vulnerable sub-groups of the Australian population. Future research and interventions supporting the health and wellbeing of vulnerable populations is required to ensure equitable health gains are made for all.

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.

Eradication of Helicobacter pylori may improve dyspepsia in the elderly for the long term

Background

Therapy for eradication of Helicobacter pylori (H. pylori) improves symptoms of H. pylori-associated dyspepsia (HPD), but the effects of eradication in elderly patients are unclear. The aim of our study was to investigate dyspepsia symptoms and long-term effects of eradication in elderly patients.

Methods

This retrospective study included 496 patients who received H. pylori eradication therapy. The patients were divided into a group of elderly patients (group E: ≧ 65 years old) and a group of non-elderly patients (group N: < 65 years old). Abdominal symptoms were evaluated using a questionnaire about abdominal symptoms before eradication and after eradication (1–2 months and more than one year). Dyspepsia was defined as a score of 4 points or more for at least one of 4 items (postprandial fullness, early satiety, epigastric pain, and hunger pain). Improvement of symptoms was defined on the basis of changes in Global Overall Systems scores.

Results

There were no differences in abdominal symptoms before eradication between the two groups. Successful eradication improved symptoms in patients with dyspepsia within 2 months (in 75.6% (56/74) of the patients in group N and in 64.5% (20/31) of the patients in group E). The questionnaire showed that 80% (32/40) of the patients in group N and 60% (12/20) of the patients in group E had long-term relief of dyspepsia. The scores for abdominal symptoms in group E continued to improve for a mean period of 54.8 months after eradication.

Conclusions

Eradication of H. pylori age-independently improved dyspepsia symptoms for the long term.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-02027-6.

Indolent feature of Helicobacter pylori-uninfected intramucosal signet ring cell carcinomas with CDH1 mutations

BACKGROUND

In Helicobacter pylori (Hp)-uninfected individuals, diffuse-type gastric cancer (DGC) was reported as the most common type of cancer. However, the carcinogenic mechanism of Hp-uninfected sporadic DGC is largely unknown.

METHODS

We performed whole-exome sequencing of Hp-uninfected DGCs and Hp-uninfected normal gastric mucosa. For advanced DGCs, external datasets were also analyzed.

RESULTS

Eighteen patients (aged 29-78 years) with DGCs and nine normal subjects (28-77 years) were examined. The mutation burden in intramucosal DGCs (10-66 mutations per exome) from individuals aged 29-73 years was not very different from that in the normal gastric glands, which showed a constant mutation accumulation rate (0.33 mutations/exome/year). Unbiased dN/dS analysis showed that CDH1 somatic mutation was a driver mutation for intramucosal DGC. CDH1 mutation was more frequent in intramucosal DGCs (67%) than in advanced DGCs (27%). In contrast, TP53 mutation was more frequent in advanced DGCs (52%) than in intramucosal DGCs (0%). This discrepancy in mutations suggests that CDH1-mutated intramucosal DGCs make a relatively small contribution to advanced DGC formation. Among the 16 intramucosal DGCs (median size, 6.5 mm), 15 DGCs were pure signet ring cell carcinoma (SRCC) with reduced E-cadherin expression and a low proliferative capacity (median Ki-67 index, 2.4%). Five SRCCs reviewed endoscopically over 2-5 years showed no progression.

CONCLUSIONS

Impaired E-cadherin function due to CDH1 mutation was considered as an early carcinogenic event of Hp-uninfected intramucosal SRCC. Genetic and clinical analyses suggest that Hp-uninfected intramucosal SRCCs may be less likely to develop into advanced DGCs.

Evaluations of Gastric Acid Pocket Using Novel Vertical 8-Channel pH Monitoring System and Effects of Acid Secretion Inhibitors

Background/Aims

The gastric acid pocket has an important role in gastroesophageal reflux disease development. In this study, we utilized a novel 8-channel pH monitoring system with sensor intervals of 1 cm on the vertical axis for evaluation of postprandial gastric acid pocket in healthy Japanese adults, as well as the effects of vonoprazan and rabeprazole.

Methods

Twelve healthy volunteers without Helicobacter pylori infection were enrolled. A catheter was inserted transnasally and positioned under X-ray guidance, then postprandial acid pocket formation was monitored over time in a sitting position. Thereafter, acid pocket changes were assessed following administration of vonoprazan (20 mg) or rabeprazole (20 mg).

Results

The gastric acid pocket was successfully measured by use of the present system in 10 cases, while failure occurred in 2 because of inappropriate catheter positioning. Observed acid pockets were visualized with a mean length of 2.2 ± 0.4 channels on the top layer of food contents approximately 20 minutes after finishing a meal. There were some variations for lasting time of the acid pocket. Complete elimination within 3 hours after administration of vonoprazan was noted in all cases. Likewise, following administration of rabeprazole, the acid pocket was eliminated in 7 cases, while acidity was reduced though the pocket remained observable in 3.

Conclusions

Gastric acid pocket observations were possible using our novel vertical 8-channel sensor catheter. The present findings showed that vonoprazan strongly suppressed acid secretion within a short period, suggesting its effectiveness for gastroesophageal reflux disease treatment.

Sporadic fundic gland polyps with dysplasia or carcinoma: Clinical and endoscopic characteristics

Fundic gland polyps (FGPs) are the most common gastric polyps and have been regarded as benign lesions with little malignant potential, except in the setting of familial adenomatous polyposis. However, in recent years, the prevalence of FGPs has been increasing along with the widespread and frequent use of proton pump inhibitors (PPIs). To date, several cases of FGPs with dysplasia or carcinoma (FGPD/CAs) have been reported. In this review, we evaluated the clinical and endoscopic characteristics of sporadic FGPD/CAs. Majority of the patients with sporadic FGPD/CAs were middle-aged women receiving PPI therapy and without Helicobacter pylori (H. pylori) infection. Majority of the sporadic FGPD/ CAs occurred in the body of the stomach and were sessile and small with a mean size of 5.4 mm. The sporadic FGPs with carcinoma showed redness, irregular surface structure, depression, or erosion during white light observation and irregular microvessels on the lesion surface during magnifying narrow-band imaging. In addition, sporadic FGPs, even with dysplasia, are likely to progress to cancer slowly. Therefore, frequent endoscopy is not required for patients with sporadic FGPs. However, histopathological evaluation is necessary if endoscopic findings different from ordinary FGPs are observed, regardless of their size. In the future, the prevalence of FGPs is expected to further increase along with the widespread and frequent use of PPIs and decreasing infection rate of H. pylori. Currently, it is unclear whether FGPD/CAs will also increase in the same way as FGPs. However, the trends of these lesions warrant further attention in the future.

Similarity and difference in the characteristics of eosinophilic esophagitis between Western countries and Japan

Over the past two decades, the incidence and prevalence of eosinophilic esophagitis (EoE) have risen rapidly, especially in Western countries, with cases in Japan also showing a gradual increase in recent years. However, similarities and differences regarding the characteristics of EoE between Western countries and Japan remain to be clearly elucidated. The current clinical guidelines for diagnosis include symptoms related to esophageal dysfunction and dense eosinophilic infiltration in the esophageal epithelium. Most affected patients in Japan are diagnosed incidentally during a medical health check-up and asymptomatic cases with typical endoscopic findings suggestive of EoE are frequently encountered. Clinical characteristics of EoE in Japanese are similar to those seen in Western populations. The predominant symptom is dysphagia, with food impaction extremely rare in Japanese cases. Linear furrows are the most frequently reported characteristic endoscopic finding, while an esophageal stricture or narrow caliber is rarely observed. Treatment strategies for EoE include drugs, dietary restrictions, and endoscopic dilation when the disease is advanced with stricture formation. Although single therapy using a proton-pump inhibitor has been shown to achieve symptomatic and histological response in the majority of patients in Japan, no prospective randomized control studies that evaluated drug or elimination diet therapy have been presented. Overall, EoE has similar clinical characteristics between Japanese and Western populations, while disease severity seems to be milder in Japan. Additional studies are necessary to determine genetic factors, natural history of the disease, and treatment efficacy of drugs and elimination diet as compared to Western populations.

Endoscopy and Barrett's Esophagus: Current Perspectives in the US and Japan

Barrett's esophagus (BE) is a precancerous disease that can lead to esophageal adenocarcinoma (EAC). Recently, the incidence of EAC arising from BE has been increasing, and EAC has now become a threat in many countries. However, there are many gaps among the various countries in terms of definitions and concepts and these gaps prevent discussing BE on the same footing. In order to eradicate BE, it is a global necessity to fill in these remaining gaps. We focused on the gaps and reviewed recent evidence and trends as well as the background of gaps between the US and Japan as two of the leading countries in the field of medical research. We also review the rapid advances in endoscopic techniques in relation to both diagnosis and therapy that are considered to be useful to eliminate the gaps between countries.

Differences in emergency endoscopy outcomes according to gastrointestinal bleeding location

BACKGROUND AND AIM

With recent technological advances in the field of endoscopic hemostasis, the prognosis of patients with gastrointestinal (GI) bleeding has improved. However, few studies have reported on the clinical course of patients with GI bleeding. This study aimed to evaluate the differences in clinical outcomes of patients with lower GI bleeding (LGIB) compared with upper GI bleeding (UGIB) and the factors related to their prognosis.

METHODS

Patients who had undergone emergency endoscopy for GI bleeding were retrospectively reviewed. The severity of GI bleeding was evaluated using the Glasgow-Blatchford (GB), AIMS65, and NOBLADS scores. Patients in whom obvious GI bleeding relapsed and/or iron deficiency anemia persisted after emergency endoscopy were considered to exhibit rebleeding.

RESULTS

We reviewed 1697 consecutive patients and divided them into UGIB (1054 patients) and LGIB (643 patients) groups. The proportion of patients with rebleeding was significantly greater in the UGIB group than in the LGIB group; the mortality rate was significantly higher in the UGIB group than in the LGIB group. Multivariate analysis showed that a GB score ≥12 and an AIMS65 score ≥2 were significantly associated with rebleeding in the UGIB group, whereas a NOBLADS score ≥4 was significantly associated with rebleeding in the LGIB group. Notably, the influence of emergency endoscopy differed according to GI bleeding location.

CONCLUSIONS

The clinical course was significantly worse in patients with UGIB than in patients with LGIB. The influence of emergency endoscopy differed according to GI bleeding location.

Trends in gastroesophageal reflux disease in Japanese children and adolescents

BACKGROUND

Although the prevalence of gastroesophageal reflux disease (GERD) has been increasing in Japan, little is known about the prevalence and severity of GERD in pediatric patients. This study compared the prevalence and severity of endoscopically proven GERD in pediatric patients seen at an endoscopy center in Japan over a 15-year period.

METHODS

This was a retrospective chart review of Japanese children aged 5-18 years undergoing esophagogastroduodenoscopy for upper gastrointestinal symptoms or anemia between 2005 and 2019. The prevalence and severity of reflux esophagitis and endoscopic Barrett's esophagus were compared between the periods 2005-2012 and 2013-2019.

RESULTS

A total of 564 patients were evaluated: 315 from 2005 to 2012 (mean ± SD) age 13.8 ± 3.0 (range, 5-18 years; 147 boys; and 249 from 2013 to 2019 (mean ± SD) 14.7 ± 2.8 (range, 5-18) years; 108 boys. Demographics and clinical features were similar between the two groups. The proportion with erosive esophagitis or endoscopic Barrett's esophagus increased significantly between the two periods (9.8% to 18.1% for GERD, P = 0.0045 and 2.5% to 9.6% for Barrett's esophagus, P = 0.0003). The proportion of GERD patients with endoscopic Barrett's esophagus also significantly increased between the two periods (24/45 [53.3%]) vs (8/31 [25.8%]), P = 0.017].

CONCLUSION

The prevalence and severity of endoscopically proven GERDs has significantly increased over the past 15 years at an endoscopy center in Japan. Detailed population-based studies are needed to assess whether this is occurring throughout Japan.

Diagnostic limitations of magnifying endoscopy with narrow-band imaging in early gastric cancer

Background and study aims  Magnifying endoscopy with narrow band imaging (M-NBI) has made a huge contribution to endoscopic diagnosis of early gastric cancer (EGC). However, we sometimes encountered false-negative cases with M-NBI diagnosis (i. e., M-NBI diagnostic limitation lesion: M-NBI-DLL). However, clinicopathological features of M-NBI-DLLs have not been well elucidated. We aimed to clarify the clinicopathological features and histological reasons of M-NBI-DLLs. Patients and methods  In this single-center retrospective study, M-NBI-DLLs were extracted from 456 EGCs resected endoscopically at our hospital. We defined histological types of M-NBI-DLLs and analyzed clinicopathologically to clarify histological reasons of M-NBI-DLLs. Results  Of 456 EGCs, 48 lesions (10.5 %) of M-NBI-DLLs were enrolled. M-NBI-DLLs was classified into four histological types as follows: gastric adenocarcinoma of fundic-gland type (GA-FG, n = 25), gastric adenocarcinoma of fundic-gland mucosal type (GA-FGM, n = 1), differentiated adenocarcinoma (n = 14), and undifferentiated adenocarcinoma (n = 8). Thirty-nine lesions of M-NBI-DLLs were H. pylori -negative gastric cancers (39/47, 82.9 %). Histological reasons for M-NBI-DLLs were as follows: 1) completely covered with non-neoplastic mucosa (25/25 GA-FG, 8/8 undifferentiated adenocarcinoma); 2) well-differentiated adenocarcinoma with low-grade atypia (1/1 GA-FGM, 14/14 differentiated adenocarcinoma); 3) similarity of surface structure (10/14 differentiated adenocarcinoma); and 4) partially covered and/or mixed with a non-neoplastic mucosa (1/1 GA-FGM, 6/14 differentiated adenocarcinoma). Conclusions  Diagnostic limitations of M-NBI depend on four distinct histological characteristics. For accurate diagnosis of M-NBI-DLLs, it may be necessary to fully understand endoscopic features of these lesions using white light imaging and M-NBI based on these histological characteristics and to take a precise biopsy.

Gastric cancer deaths by age group in Japan: Outlook on preventive measures for elderly adults

In February 2013, Japan became the first country in the world to cover Helicobacter pylori eradication for chronic gastritis under its National Health Insurance (NHI) system. Now that eradication therapy is covered by NHI, its usage has increased dramatically, and gastric cancer deaths have begun to decrease. We undertook a detailed epidemiological analysis to investigate effects of expanded NHI coverage for H. pylori eradication therapy on gastric cancer deaths in specific age groups. Numbers of gastric cancer deaths were determined by referencing data from Ministry of Health, Labour and Welfare reports and “Cancer Statistics in Japan – 2018” published by the Foundation for Promotion of Cancer Research. Gastric cancer deaths across all age groups have been clearly decreasing since 2013, but deaths of people aged 80 years and older are still increasing. The number of gastric cancer deaths in people aged in their 80s was 2 times higher than in people aged in their 70s and 4 times higher than in people aged in their 60s. The number of people in their 80s who had an endoscopy was less than half that of people in their 60s and 70s. The eradication therapy has increased dramatically, and gastric cancer deaths are clearly decreasing in Japan. However, this decrease in deaths has not extended to elderly adults aged in their 80s, which suggests that measures to prevent gastric cancer in people aged 80 years and older will be critical to achieving the mission of eliminating gastric cancer in Japan.

A Recent Argument for the Use of Endoscopic Submucosal Dissection for Early Gastric Cancers

Endoscopic submucosal dissection (ESD) has become the standard treatment method for early gastric cancers (EGCs) due to the negligible risk for lymph node metastasis (LNM) in Eastern Asian countries. According to the guidelines, the curability of EGC after endoscopic resection was classified into three groups: curative resection, expanded curative resection, and noncurative resection. In Eastern Asian countries, a structured follow-up schedule is needed for patients undergoing curative resection and expanded curative resection. Conversely, in Western countries, additional surgery may be recommended for some patients undergoing expanded curative resection (ulcerated, undifferentiated, or slight submucosal invasion) due to the potential risk for LNM, even though specimens of ESD and surgery may not be handled with the same methodology as that used in Japan, which may lead to this slightly higher risk. In noncurative resection, additional surgery is the standard method after ESD because of the risk for LNM. However, in elderly patients and/or those with severe underlying diseases, the advantages and disadvantages of additional surgery should be considered when selecting a post-ESD treatment strategy for patients undergoing noncurative resection. Risk-scoring systems for LNM may facilitate clinical decisions for these patients. However, it should be noted that when recurrence was detected in patients who were followed up with no additional treatment after ESD with noncurative resection, most of them had a poor prognosis. To select an appropriate treatment method, especially in elderly patients undergoing ESD with noncurative resection, a new tool for evaluating the condition of patients should be established.

Structure of cytotoxic associated antigen A protein of Helicobacter pylori from Bali and Lombok isolates of Indonesia

Background and Aim:

Helicobacterpylori is a well-known zoonotic agent with worldwide distribution. In Indonesia, only one report regarding the variation within the cytotoxic associated antigen A (CagA) protein of H. pylori has been described in the literature, which was conducted in Manado, South Sulawesi. There remains no report concerning the structure of this protein, particularly for the Bali and Lombok isolates. The objective of this study was to investigate the diversity of H. pylori CagA amino acid sequences of Bali and Lombok isolates, to predict their molecular structures and conduct toxicity examination of CagA on gastric cells.

Materials and Methods:

A total of 36 samples were used in equal proportions for each pathologic condition. DNA extraction was performed to subculture H. pylori Bali isolates. The amplification of the CagA 3′ variable region was carried out using the primers P1 (5′-GATAACAGGCAAGCTTTTTGAGG-3′) and P2 (5′-CTGCAAAAGATTGTTTGGCAG-3′). The W2, W9, and W35 fragments were selected as a representation of H. pylori Bali isolates, which were modeled through the threading modeling approach using I-TASSER.

Results:

According to the 12 CagA sequences obtained and phylogenetic analyses, the H. pylori strain originating from Bali can be grouped within the East Asian genotypes and is identical to the Lombok strain. In addition, the Bali isolates are phylogenetically more closely related to Southeast Asian strains, particularly the Filipino strain. The relationship between degree of inflammation induced and CagA-positive infection was not statistically significant.

Conclusion:

The structure of the H. pylori Bali isolate is identical to that of Lombok isolate, which belongs to the same group of East Asian genotypes, and bacterial virulence is not related to structure.

Guidelines for endoscopic diagnosis of early gastric cancer

The Japan Gastroenterological Endoscopy Society developed the Guideline for Endoscopic Diagnosis of Early Gastric Cancer based on scientific methods. Endoscopy for the diagnosis of early gastric cancer has been acknowledged as a useful and highly precise examination, and its use has become increasingly more common in recent years. However, the level of evidence in this field is low, and it is often necessary to determine recommendations based on expert consensus only. This clinical practice guideline consists of the following sections to provide the current guideline: [I] Risk stratification of gastric cancer before endoscopic examination, [II] Detection of early gastric cancer, [III] Qualitative diagnosis of early gastric cancer, [IV] Diagnosis to choose the therapeutic strategy for gastric cancer, [V] Risk stratification after endoscopic examination, and [VI] Surveillance of early gastric cancer.

Are Helicobacter pylori Infection and Fucoidan Consumption Associated with Fucoidan Absorption?

We examined the associations of Helicobacter pylori and mozuku consumption with fucoidan absorption. Overall, 259 Japanese volunteers consumed 3 g fucoidan, and their urine samples were collected to measure fucoidan values and H. pylori titers before and 3, 6, and 9 h after fucoidan ingestion. Compared to the basal levels (3.7 ± 3.4 ng/mL), the urinary fucoidan values significantly increased 3, 6, and 9 h (15.3 ± 18.8, 24.4 ± 35.1, and 24.2 ± 35.2 ng/mL, respectively) after fucoidan ingestion. The basal fucoidan levels were significantly lower in H. pylori-negative subjects who rarely ate mozuku than in those who regularly consumed it. Regarding the ΔMax fucoidan value (highest value − basal value) in H. pylori-positive subjects who ate mozuku at least once a month, those aged ≥40 years exhibited significantly lower values than <40 years old. Among subjects ≥40 years old who regularly consumed mozuku, the ΔMax fucoidan value was significantly lower in H. pylori-positive subjects than in H. pylori-negative ones. In H. pylori-positive subjects who ate mozuku at least once monthly, basal fucoidan values displayed positive correlations with H. pylori titers and ΔMax fucoidan values in subjects <40 years old. No correlations were found in H. pylori-positive subjects who ate mozuku once every 2–3 months or less. Thus, fucoidan absorption is associated with H. pylori infection and frequency of mozuku consumption.

Microbiome and Gastric Cancer

The late 1800s Louis Pasteur and Robert Koch introduced and popularized the germ theory of disease. At that time, gastric cancer was the most common cause of cancer deaths in most countries making the stomach an early site of microbial research with a focus on gastric luminal and mucosal bacteria and the role of Boas-Oppler bacillus (Lactobacillus) in the diagnosis of gastric cancer. In the 1970s, the research focus evolved to studies of the gastric microbiome in the production of nitrosamines and included development of the Correa cascade. Interest in nitrosamine production peaked in the late 1980s and was replaced by studies of the newly described Helicobacter pylori and studies of its role in gastritis, gastric atrophy, and gastric cancer. The last decade has witnessed a rebirth in interest in the gastric microbiota as part of worldwide interest in the human microbiome. Although fungi were prominent in the studies of gastric microbiology in the nineteenth century, their potential role in disease pathogenesis has yet to be addressed using modern techniques. Overall, current studies of the gastric bacterial microbiome do not provide convincing evidence to expand the role of the gastric microbiome in cancer pathogenesis beyond what is directly attributable to the oncogenic potential of H. pylori and its role in persisting acute-on-chronic inflammation.

Multicenter study of autoimmune gastritis in Japan: Clinical and endoscopic characteristics

BACKGROUND AND AIM

In Japan, the prevalence of autoimmune gastritis (AIG) is assumed to be very low. With the recent rapid decrease in Helicobacter pylori (Hp) prevalence, reports on AIG are increasing. This multicenter registry study aimed to clarify the characteristics of AIG, especially its endoscopic appearance.

METHODS

A total of 245 patients with AIG from 11 institutions in Japan from January 2010 to October 2016 were included, and their clinical and endoscopic findings were evaluated.

RESULTS

Mean age was 67.2 ± 11.4 years, and 63.7% of the participants were women. The most common approach to diagnose AIG was endoscopic examination. Repeated incorrect treatment for Hp infection, due to a false-positive result in ¹³ C-urea breath test, ranked third among the basis for diagnosis of AIG. Associated gastric lesions were type 1 neuroendocrine tumor (11.4%), adenocarcinoma (9.8%), and hyperplastic polyps (21.1%). Corpus pan-atrophy was the most common appearance (90.1%); however, remnant oxyntic mucosa was found in 31.5% of the patients (flat, localized type, 48.6%). Sticky adherent dense mucus and scattered minute whitish protrusions were also observed in approximately 30% of the patients. Despite the prevailing presumption of the antral mucosa remaining normal, 42.3% of the patients presented with various extents of atrophy, and patchy redness and circular wrinkle-like patterns were both observed in approximately 20% of the patients.

CONCLUSIONS

The present study showed some prominent clinical characteristics and endoscopic findings of AIG. We believe that our study will facilitate the diagnosis of potential AIG.

A current clinical overview of atrophic gastritis

Introduction: Atrophic gastritis (AG) is a complex syndrome which arises as a consequence of H. pylori infection or in the context of gastric autoimmunity. It often deserves a benign course but may lead to potentially life-threatening complications: cancer and anemia. This review aims to address traditional and innovative knowledge on this often under-diagnosed disorder.Areas covered: This review covers clinical presentation, risk factors, diagnosis, and management of AG and provides an updated resource for clinicians to get insight into this challenging disorder. Updated literature was searched in PubMed. Manual search from reference lists of publications was performed.Expert opinion: A case-finding strategy may be beneficial in individuals with anemia, dyspepsia, autoimmune thyropaties and type 1 diabetes, and family history of gastric cancer. AG is linked to gastric cancer risk and endoscopic surveillance is indicated according to topography of gastric atrophy and risk factors. The direction for future research in AG is summarized.

Previous Helicobacter pylori infection-induced atrophic gastritis: A distinct disease entity in an understudied population without a history of eradication

Individuals with chronic atrophic gastritis who are negative for active H. pylori infection with no history of eradication therapy have been identified in clinical practice. By excluding false-negative and autoimmune gastritis cases, it can be surmised that most of these patients have experienced unintentional eradication of H. pylori after antibiotic treatment for other infectious disease, unreported successful eradication, or H. pylori that spontaneously disappeared. These patients are considered to have previous H. pylori infection-induced atrophic gastritis. In this work, we define these cases based on the following criteria: absence of previous H. pylori eradication; atrophic changes on endoscopy or histologic confirmation of glandular atrophy; negative for a current H. pylori infection diagnosed in the absence of proton-pump inhibitors or antibiotics; and absence of localized corpus atrophy, positivity for autoantibodies, or characteristic histologic findings suggestive of autoimmune gastritis. The risk of developing gastric cancer depends on the atrophic grade. The reported rate of developing gastric cancer is 0.31%-0.62% per year for successfully eradicated severely atrophic cases (pathophysiologically equal to unintentionally eradicated cases and unreported eradicated cases), and 0.53%-0.87% per year for spontaneously resolved cases due to severe atrophy. Therefore, for previous H. pylori infection-induced atrophic gastritis cases, we recommend endoscopic surveillance every 3 years for high-risk patients, including those with endoscopically severe atrophy or intestinal metaplasia. Because of the difficulty involved in the endoscopic diagnosis of gastric cancer in cases of previous infection, appropriate monitoring of the high-risk subgroup of this understudied population is especially important.

Changes of gastric ulcer bleeding in the metropolitan area of Japan

BACKGROUND

The two main causes of gastric ulcer bleeding are Helicobacter pylori (H. pylori) infection and ulcerogenic medicines, although the number of cases caused by each may vary with age. In Japan, the rate of H. pylori infection has fallen over the last decade and the number of prescriptions for non-steroidal anti-inflammatory drugs (NSAIDs) and antithrombotic drugs is increasing as the population ages. Methods of treatment for gastric ulcer bleeding have advanced with the advent of hemostatic forceps and potassium-competitive acid blocker (P-CAB). Thus, causes and treatments for gastric ulcer bleeding have changed over the last decade.

AIM

To examine the trends of gastric ulcer bleeding over 10 years in the metropolitan area of Japan.

METHODS

This is a single-center retrospective study. A total of 564 patients were enrolled from inpatients admitted to our hospital with gastric ulcer bleeding between 2006 and 2016. Age, medication history, H. pylori infection, method of treatment, rate of rebleeding, and the length of hospitalization were analyzed. Factors associated with gastric ulcer bleeding were evaluated using Fisher’s exact test, Pearson’s Chi-squared test or Student’s t-test as appropriate. The Jonckheere-Terpstra test was used to evaluate trends. A per-protocol analysis was used to examine the rate of H. pylori infection.

RESULTS

There was a significant increase in the mean age over time (P < 0.01). The rate of H. pylori infection tended to decrease over the study period (P = 0.10), whereas the proportion of patients taking antithrombotic agents or NSAIDs tended to increase (P = 0.07). Over time, the use of NSAIDs and antithrombotic drugs increased with age. By contrast, the rate of H. pylori infection during the study period fell with age. H. pylori-induced ulcers accounted for the majority of cases in younger patients (< 70 years old); however, the rate decreased with age (P < 0.01). The method of treatment trend has changed significantly over time. The main method of endoscopic hemostasis has changed from clipping and injection to forceps coagulation (P < 0.01), and frequently prescribed medicines have changed from proton pump inhibitor to P-CAB (P < 0.01). The rate of rebleeding during the latter half of the study was significantly lower than that in the first half.

CONCLUSION

These trends, gastric ulcers caused by ulcerogenic drugs were increasing with age and H. pylori-induced ulcers were more common in younger patients, were observed.

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.

Microbial carcinogenesis: Lactic acid bacteria in gastric cancer

While Helicobacter pylori is a fundamental risk factor, gastric cancer (GC) aetiology involves combined effects of microbial (both H. pylori and non-H. pylori), host and environmental factors. Significant differences exist between the gastric microbiome of those with gastritis, intestinal metaplasia and GC, suggesting that dysbiosis in the stomach is dynamic and correlates with progression to GC. Most notably, a consistent increase in abundance of lactic acid bacteria (LAB) has been observed in GC patients including Streptococcus, Lactobacillus, Bifidobacterium and Lactococcus. This review summarises how LAB can influence GC by a number of mechanisms that include supply of exogenous lactate -a fuel source for cancer cells that promotes inflammation, angiogenesis, metastasis, epithelial-mesenchymal transition and immune evasion-, production of reactive oxygen species and N-nitroso compounds, as well as anti-H. pylori properties that enable colonization by other non-H. pylori carcinogenic pathobionts.

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.

Genetic analysis of a case of Helicobacter pylori-uninfected intramucosal gastric cancer in a family with hereditary diffuse gastric cancer

Germline mutations in CDH1, encoding E-cadherin, are known to be the causative mechanism of hereditary diffuse gastric cancer (HDGC). We encountered two cases of gastric cancer in a Japanese family with HDGC. A 28-year-old man (Case 1) died of advanced gastric cancer. His younger sister aged 27 (Case 2) was diagnosed with intramucosal signet ring cell carcinoma (SRCC). Both had identical germline CDH1 mutations, but Case 1 was positive for Helicobacter pylori infection, whereas Case 2 was negative. Case 2 underwent total gastrectomy. Whole-exome sequencing of an intramucosal SRCC in Case 2 revealed seven somatic mutations including one in CDH1. The six non-CDH1 mutations were classified as non-driver mutations. Decreased expression of E-cadherin in intramucosal SRCC was confirmed by immunohistochemistry. Our report demonstrated that CDH1 mutation was the only active driver mutation in Helicobacter pylori-uninfected intramucosal SRCC.

The prevalence of histologic atrophy and intestinal metaplasia in the corpus has decreased over 15 years in females in the Korean population

BACKGROUND

The aim of this study was to investigate the trends of atrophy and intestinal metaplasia (IM) in 2002 subjects without significant gastroduodenal diseases.

MATERIALS AND METHODS

A total of 2002 subjects were prospectively enrolled and divided into three periods (2003-2007, 2008-2012, and 2013-2018). Trends of H pylori and atrophy/IM scored by Updated Sydney System were analyzed according to sex, and multivariate logistic analysis was performed for the risk factors for atrophy/IM.

RESULTS

H pylori-negative and H pylori-positive subjects were 1220 (61.0%) and 782 (38.0%), respectively. H pylori positivity decreased from 149/303 (49.2%), 207/515 (40.2%) and 426/1184 (36.0%), in the three periods, respectively (P < 0.001). The prevalence of atrophy (P < 0.001) and IM in the corpus (P < 0.001) significantly decreased over 15 years in females, but not in males. The mean grade of atrophy and IM was higher in males (0.36 and 0.51) than in females (0.28 and 0.41) in the corpus (P = 0.027) and in the antrum (P = 0.006), respectively. Similarly, the mean grade of IM in males (0.34) was higher in females (0.19; P < 0.001) in the corpus. Multivariate analysis showed that old age, study period, and H pylori were statistically significant in atrophy of antrum and corpus, and IM in the corpus. In cases of IM of antrum, old age, H pylori, and smoking were statistically significant.

CONCLUSION

A significant decrease in atrophy and IM in the corpus in females over 15 years suggests sex- or gender-specific characteristics.

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.

Evaluation of symptomatic reflux esophagitis in proton pump inhibitor users

The aim of the present study was to evaluate symptomatic reflux esophagitis (RE) in proton pump inhibitor (PPI) users. The present study conducted a hospital-based, retrospective cross-sectional study of consecutive RE cases in PPI users at Juntendo University Hospital recruited between 2008 and 2016. Eligible patients were PPI users with a complete patient profile, who completed the Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (FSSG) questionnaire, and who underwent upper gastrointestinal endoscopy for the examination of RE, hiatal hernia (HH) and endoscopic gastric mucosal atrophy (EGA). The patients with RE who were administered PPIs were divided into two groups: Those with symptomatic RE (FSSG≥8) and those with non-symptomatic RE (FSSG<8). The present study investigated the risk factors for symptomatic RE among the patients with RE patients who were administered PPIs. Of the 13,052 cases who underwent patient profiling, the FSSG questionnaire and upper gastrointestinal endoscopy, a total of 2,444 PPI users were eligible. Of the PPI users, 206 cases (8.4%) had RE. Among the 206 patients with RE, 115 (55.8%) had symptomatic RE. The profile of the symptomatic and non-symptomatic RE groups were as follows: A total of 45 females (39.1%) vs. 32 females (35.2%; non-significant); mean ± standard deviation age, 54.8±13.5 vs. 62.9±11.1 years (P<0.01); mean body mass index, 23.5±3.3 vs. 23.2±3.8 (non-significant); severe RE, 12 (10.4%) vs. 2 (2.2%; P<0.05); HH, 70 (60.9%) vs. 40 (44.0%; P<0.05); and mean score of EGA, 1.2±1.8 vs. 1.8±2.1 (P<0.05). Multivariate analysis revealed that a younger age [odds ratio (OR)=0.94; 95% confidence interval (CI): 0.92-0.97, P<0.01] and HH(+) (OR=2.37; 95% CI: 1.30-4.34, P<0.01) were associated with symptomatic RE among patients with RE who were administered PPIs. In conclusion, a younger age and HH were associated with symptomatic RE in patients with RE who were administered PPIs.

Current and Future Treatment of Helicobacter pylori Infections

Helicobacter pylori is one of the most common human pathogens and it has been estimated that about 50% of the world's population is currently infected. The present consensus is that, unless there are compelling reasons, all H. pylori infections should be cured. Since the 1990s, different national and international guidelines for the management of H. pylori-related diseases have been published and periodically updated regarding indications for treatment, diagnostic procedures, and preferred treatment regimens. Most guidelines provide sophisticated meta-analyses examining the outcome of different regimens done in regions with variable, often high rates of resistance to antibiotics, for which the prevalence and effects of resistance was often ignored. Although successful antimicrobial therapy must be susceptibility-based, increasing antimicrobial resistance and general unavailability of susceptibility testing have required clinicians to generally rely on empiric regimens. Antibiotics resistance of H. pylori has reached alarming high levels worldwide, which has an effect to efficacy of treatment. The recommendations should provide regimes for multi-resistant infections or for those where susceptibility testing is unavailable or refused. The first rule is to use only proven locally effective therapies. Because of patient intolerances, drug allergies, and local experiences, the clinicians should have at least two options for first-line therapy. As with any antimicrobial therapy, a thorough review of prior antibiotic use is invaluable to identify the presence of probably resistance. The second key is patient education regarding potential and expected side-effects and the importance of completing the course of antibiotics. We also review here triple therapies, sequential-concomitant, hybrid therapies, bismuth therapies, dual therapy, vonoprazan, modern antibiotic treatments, probiotics and vaccination.