Atrophic gastritis and Helicobacter pylori infection in patients with reflux esophagitis treated with omeprazole or fundoplication

The preclinical discovery and development of zolbetuximab for the treatment of gastric cancer

INTRODUCTION

Gastric cancer remains a formidable challenge in oncology with high mortality rates and few advancements in treatment. Claudin-18.2 (CLDN18.2) is a tight junction protein primarily expressed in the stomach and is frequently overexpressed in certain subsets of gastric cancers. Targeting CLDN18.2 with monoclonal antibodies, such as zolbetuximab (IMAB362), has shown promising efficacy results in combination with chemotherapy.

AREAS COVERED

The molecular cell biology of CLDN18.2 is discussed along with studies demonstrating the utility of CLDN18.2 expression as a biomarker and therapeutic target. Important clinical studies are reviewed, including Phase III trials, SPOTLIGHT and GLOW, which demonstrate the efficacy of zolbetuximab in combination with chemotherapy in patients with CLDN18.2-positive advanced gastric cancer.

EXPERT OPINION

CLDN18.2 is involved in gastric differentiation through maintenance of epithelial barrier function and coordination of signaling pathways, and its expression in gastric cancers reflects a 'gastric differentiation' program. Targeting Claudin-18.2 represents the first gastric cancer specific 'targeted' treatment. Further studies are needed to determine its role within current gastric cancer treatment sequencing, including HER2-targeted therapies and immunotherapies. Management strategies will also be needed to better mitigate zolbetuximab-related treatment side effects, including gastrointestinal (GI) toxicities.

Impact of obesity and roux-en-Y gastric bypass on the pharmacokinetics of (R)- and (S)-omeprazole and intragastric pH

This study employed physiologically-based pharmacokinetic-pharmacodynamics (PBPK/PD) modeling to predict the effect of obesity and gastric bypass surgery on the pharmacokinetics and intragastric pH following omeprazole treatment. The simulated plasma concentrations closely matched the observed data from non-obese, morbidly obese, and post-gastric bypass populations. Obesity significantly reduces CYP3A4 and CYP2C19 activities, as reflected by the metabolic ratio [omeprazole sulphone]/[omeprazole] and [5-hydroxy-omeprazole]/[omeprazole]. The morbidly obese model accounted for the down-regulation of CYP2C19 and CYP3A4 to recapitulate the observed data. Sensitivity analysis showed that intestinal CYP3A4, gastric pH, small intestine bypass, and the delay in bile release do not have a major influence on omeprazole exposure. Hepatic CYP3A4 had a significant impact on the AUC of (S)-omeprazole, while hepatic CYP2C19 affected both (R)- and (S)-omeprazole AUC. After gastric bypass surgery, the activity of CYP3A4 and CYP2C19 is restored. The PBPK model was linked to a mechanism-based PD model to assess the effect of omeprazole on intragastric pH. Following 40 mg omeprazole, the mean intragastric pH was 4.3, 4.6, and 6.6 in non-obese, obese, and post-gastric bypass populations, and the daily time with pH >4 was 14.7, 16.4, and 24 h. Our PBPK/PD approach provides a comprehensive understating of the impact of obesity and weight loss on CYP3A4 and CYP2C19 activity and omeprazole pharmacokinetics. Given that simulated intragastric pH is relatively high in post-RYGB patients, irrespective of the dose of omeprazole, additional clinical outcomes are imperative to assess the effect of proton pump inhibitor in preventing marginal ulcers in this population.

Comparison of gastric inflammation and metaplasia induced by Helicobacter pylori or Helicobacter felis colonization in mice

Gastric cancer is the fifth most diagnosed cancer in the world. Infection by the bacteria Helicobacter pylori (HP) is associated with approximately 75% of gastric cancer cases. HP infection induces chronic gastric inflammation, damaging the stomach and fostering carcinogenesis. Most mechanistic studies on gastric cancer initiation are performed in mice and utilize either mouse-adapted strains of HP or the natural mouse pathogen Helicobacter felis (HF). Here, we identified the differences in gastric inflammation, atrophy, and metaplasia associated with HP and HF infection in mice. PMSS1 HP strain or the CS1 HF strain were co-cultured with mouse peritoneal macrophages to assess their immunostimulatory effects. HP and HF induced similar cytokine production from cultured mouse peritoneal macrophages revealing that both bacteria exhibit similar immunostimulatory effects in vitro. Next, C57BL/6J mice were infected with HP or HF and were assessed 2 months post-infection. HP-infected mice caused modest inflammation within both the gastric corpus and antrum, and did not induce significant atrophy within the gastric corpus. In contrast, HF induced significant inflammation throughout the gastric corpus and antrum. Moreover, HF infection was associated with significant atrophy of the chief and parietal cell compartments and induced the expression of pyloric metaplasia (PM) markers. HP is poorly immunogenic compared to HF. HF induces dramatic CD4+ T cell activation, which is associated with increased gastric cancer risk in humans. Thus, HP studies in mice are better suited for studies on colonization, while HF is more strongly suited for studies on the effects of gastric inflammation on tumorigenesis.  .

IMPORTANCE

Mouse infection models with Helicobacter species are widely used to study Helicobacter pathogenesis and gastric cancer initiation. However, Helicobacter pylori is not a natural mouse pathogen, and mouse-adapted H. pylori strains are poorly immunogenic. In contrast, Helicobacter felis is a natural mouse pathogen that induces robust gastric inflammation and is often used in mice to investigate gastric cancer initiation. Although both bacterial strains are widely used, their disease pathogenesis in mice differs dramatically. However, few studies have directly compared the pathogenesis of these bacterial species in mice, and the contrasting features of these two models are not clearly defined. This study directly compares the gastric inflammation, atrophy, and metaplasia development triggered by the widely used PMSS1 H. pylori and CS1 H. felis strains in mice. It serves as a useful resource for researchers to select the experimental model best suited for their studies.

Big data approach in the field of gastric and colorectal cancer research

Big data is characterized by three attributes: volume, variety,, and velocity. In healthcare setting, big data refers to vast dataset that is electronically stored and managed in an automated manner and has the potential to enhance human health and healthcare system. In this review, gastric cancer (GC) and postcolonoscopy colorectal cancer (PCCRC) will be used to illustrate application of big data approach in the field of gastrointestinal cancer research. Helicobacter pylori (HP) eradication only reduces GC risk by 46% due to preexisting precancerous lesions. Apart from endoscopy surveillance, identifying medications that modify GC risk is another strategy. Population-based cohort studies showed that long-term use of proton pump inhibitors (PPIs) associated with higher GC risk after HP eradication, while aspirin and statins associated with lower risk. While diabetes mellitus conferred 73% higher GC risk, metformin use associated with 51% lower risk, effect of which was independent of glycemic control. Nonetheless, nonsteroidal anti-inflammatory drugs (NA-NSAIDs) are not associated with lower GC risk. CRC can still occur after initial colonoscopy in which no cancer was detected (i.e. PCCRC). Between 2005 and 2013, the rate of interval-type PCCRC-3y (defined as CRC diagnosed between 6 and 36 months of index colonoscopy which was negative for CRC) was 7.9% in Hong Kong, with >80% being distal cancers and higher cancer-specific mortality compared with detected CRC. Certain clinical and endoscopy-related factors were associated with PCCRC-3 risk. Medications shown to have chemopreventive effects on PCCRC include statins, NA-NSAIDs, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers.

Global status and trends of gastric cancer and gastric microbiota research: a bibliometric analysis

Background

Numerous studies have cast light on the relationship between the gastric microbiota and gastric carcinogenesis. In this study, we conducted a bibliometric analysis of the relevant literature in the field of gastric cancer and the gastric microbiota and clarified its research status, hotspots, and development trends.

Materials and methods

Publications were retrieved from the Web of Science Core Collection on 18 July 2023. CiteSpace 6.2.R4, VOSviewer 1.6.19.0, and Biblioshiny were used for the co-occurrence and cooperation analyses of countries, institutions, authors, references, and keywords. A keyword cluster analysis and an emergence analysis were performed, and relevant knowledge maps were drawn.

Results

The number of published papers in this field totaled 215 and showed an increasing trend. The analysis of funding suggested that the input in this field is increasing steadily. China had the highest number of publications, while the United States had the highest betweenness centrality. Baylor College of Medicine published the most articles cumulatively. Both Ferreira RM and Cooker OO had the highest citation frequency. The journal Helicobacter showed the most interest in this field, while Gut provided a substantial research foundation. A total of 280 keywords were obtained using CiteSpace, which were primarily focused on the eradication and pathogenic mechanisms of Helicobacter pylori, as well as the application of the gastric microbiota in the evaluation and treatment of gastric cancer. The burst analysis suggested that in the future, research may focus on the application of gastric microorganisms, particularly Fusobacterium nucleatum, in the diagnosis and treatment of gastric cancer, along with their pathogenic mechanisms.

Conclusion

Current studies have been tracking the eradication of Helicobacter pylori and its pathogenic mechanisms, as well as changes in the gastric microbiota during gastric carcinogenesis. Future research may focus on the clinical application and pathogenesis of stomach microorganisms through bacteria such as Fusobacterium nucleatum.

A puzzling case report of well-differentiated neuroendocrine tumor mixed with gastric adenocarcinoma of the fundic gland type associated with autoimmune gastritis

Gastric adenocarcinoma of the fundic gland type (GA-FG) is a rare gastric neoplasm. We present a unique case of multiple GA-FG that coexisted with the well-differentiated neuroendocrine tumors in a patient with autoimmune gastritis. To our knowledge, this is the first documented instance of such a co-occurrence and the molecular mechanism of their origin has been reviewed systematically. A 47-year-old male presented to our hospital with abdominal distension for over 10 years. Gastroscopy revealed multiple gastric eminence lesions (0.2-1.5 cm). After endoscopic mucosal resection, the pathological morphology showed mixed tumor components infiltrating into the submucosa with puzzling similarity. One with uniform-sized tumor cells arranged in nests or tubes and the other a well-differentiated tubular adenocarcinoma with irregular branching and visible gland fusion. Immunohistochemistry findings revealed the first component expressed typical markers of neuroendocrine tumor, whereas the second component expressed pepsinogen and mucin-6, indicating the presence of oxyntic gland adenocarcinoma. Due to the tumors' proximity to the surgical margins, the patient underwent laparoscopic subtotal gastrectomy three months after the diagnosis without any tumor residue and showed no recurrence or metastasis occurred in the following regular checkups.

Comparison of gastric inflammation and metaplasia induced by Helicobacter pylori or Helicobacter felis colonization in mice

Background

Gastric cancer is the fifth most diagnosed cancer in the world. Infection by the bacteria Helicobacter pylori (HP) is associated with approximately 75% of gastric cancer cases. HP infection induces chronic gastric inflammation, damaging the stomach and fostering carcinogenesis. Most mechanistic studies on Helicobacter- induced gastric cancer initiation are performed in mice and utilize either mouse-adapted strains of HP or the natural mouse pathogen Helicobacter felis (HF). Each of these infection models is associated with strengths and weaknesses. Here, we identified the differences in immunogenicity and gastric pathological changes associated with HP and HF infection in mice.

Material and Methods

PMSS1 HP strain or with the CS1 HF strain were co-cultured with mouse peritoneal macrophages to assess their immunostimulatory effects. C57BL/6J mice were infected with HP or HF, and gastric inflammation, atrophy, and metaplasia development were assessed 2 months post-infection.

Results

HP and HF induced similar cytokine production from cultured mouse peritoneal macrophages. HP-infected mice caused modest inflammation within both the gastric corpus and antrum and did not induce significant atrophy within the gastric corpus. In contrast, HF induced significant inflammation throughout the gastric corpus and antrum. Moreover, HF infection was associated with significant atrophy of the chief and parietal cell compartments and induced expression of pyloric metaplasia markers.

Conclusions

HP is poorly immunogenic compared to HF. HF induces dramatic CD4+ T cell activation, which is associated with increased gastric cancer risk in humans. Thus, HP studies in mice are better suited for studies on colonization, while HF is more strongly suited for pathogenesis and cancer initiation studies.

Risk of gastric cancer among long-term proton pump inhibitor users: a population-based cohort study

PURPOSE

To elucidate whether long-term proton pump inhibitor (PPI) users have an increased gastric cancer (GC) risk.

METHODS

We searched the 2009-2019 Korean National Health Insurance Services Database for patients aged > 40 years who claimed for Helicobacter pylori eradication (HPE) during 2009-2014. The GC incidence following a PPI exposure of > 180 cumulative defined daily dose (cDDD) and that following an exposure of < 180 cDDD were compared. The outcome was GC development at least 1 year following HPE. A propensity score (PS)-matched dataset was used for analysis within the same quartiles of the follow-up duration. Additionally, dose-response associations were assessed, and the mortality rates were compared between long-term PPI users and non-users.

RESULTS

After PS matching, 144,091 pairs of PPI users and non-users were analyzed. During a median follow-up of 8.3 (interquartile range, 6.8-9.6) years, 1053 and 948 GC cases in PPI users and non-users, respectively, were identified, with the GC incidence (95% confidence interval (CI)) being 0.90 (0.85-0.96) and 0.81 (0.76-0.86) per 1000 person-years, respectively. The adjusted hazard ratio (aHR) for GC with PPI use was 1.15 (95% CI, 1.06-1.25). Among PPI users, patients in the highest tertile for annual PPI dose showed higher GC development than those in the lowest tertile (aHR (95% CI): 3.87 (3.25-4.60)). GC-related mortality did not differ significantly between PPI users and non-users.

CONCLUSION

In this nationwide analysis in Korea, where the GC prevalence is high, long-term PPI use after HPE showed a significant increase in GC, with a positive dose-response relationship.

Relevance of early management by proton-pump inhibitor in acute upper gastro-intestinal tract disorder: A scoping review

BACKGROUND

Proton-pump inhibitors (PPI) are frequently used in the emergency and general practice settings in several clinical presentations linked to acute upper gastro-intestinal tract disorders as abdominal or chest pain without recommendations.

OBJECTIVE

The aim of this scoping review was to assess pain reduction, diagnostic performance, and safety in the first 24 h-management in primary care or emergency medicine.

METHODS

Search was realized by 2 independent reviewers in PubMed, Embase, and Web of Science following PRISMA-ScR guidelines. Only original articles or systematic reviews in English were included. Studies about chronic and/or bleeding conditions, therapeutic cocktails and studies without pain evaluation were excluded. Two methodologies were used for bias estimation.

RESULTS

From 4442 titles, 79 full-text articles were assessed, and 9 were included. There is no strong evidence supporting the use of PPI as a first line analgesic or diagnostic test in acute syndromes linked to acute upper gastro-intestinal tract disorder. A small effect in pain reduction was retrieved in patients with low pain scores. A poor additional value in patients with gastric reflux, and a low specificity compared to other diagnostic tests were observed. A short-term PPI administration appears to be safe with low risk of serious allergic reactions, and poor adverse effects (moderate evidence).

CONCLUSION

Although PPIs may contribute to the multimodal analgesia in acute settings, with few and/or minor side effects, no recommendation can be drawn for their use as a primary analgesic. Data regarding the relevance of the PPI test are much less clear, no data regarding care pathways are available.

Whether long-term use of proton pump inhibitor increases the risk of precancerous lesions in the stomach: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

To evaluate through meta-analysis whether long-term use of proton pump inhibitor (PPI) increases the risk of precancerous lesions in the stomach.

METHODS

Randomized controlled trials that compared the occurrence and progression of precancerous lesions in patients receiving PPI treatment versus non-PPI treatment were retrieved from CNKI, VIP, Wanfang, CBM, Pubmed, Embase, Web of Science, and Cochrane Library databases (from database inception to May 1, 2023). The Revman 5.3 and STATA 17.0 software were used for analysis, and subgroup analysis was conducted based on follow-up time (≤12 months and > 12 months) and lesion type (atrophic gastritis, intestinal metaplasia, and epithelial dysplasia).

RESULTS

Six randomized controlled trials with a total of 1623 cases were included, including 1015 cases in the experimental group and 608 cases in the control group. The meta-analysis results showed that the overall abnormal lesion rate combined with statistical relative risk (RR) = 1.31 (0.85-2.02), P = .23. Subgroup analysis showed that the follow-up time > 12 months combined result was RR = 2.21 (1.47-3.33), P = .0001, the intestinal metaplasia group combined result was RR = 1.96 (0.91-2.47), P = .04.

CONCLUSION SUBSECTIONS

During long-term follow-up, patients using PPI exhibited a significantly higher incidence of overall abnormal lesions compared to the control group, particularly with a higher risk observed for intestinal metaplasia. However, there were no statistically significant differences between the 2 groups in terms of short-term follow-up and other types of lesions. It is important to exercise caution when interpreting these findings due to the limited number of nominated investigations included in the meta-analysis.

Twenty-four-hour pH metry alone is inferior to additional impedance monitoring in the diagnosis of gastroesophageal reflux disease, particularly in presence of reduced gastric acid secretion

BACKGROUND

Current gold standard for the diagnosis of gastroesophageal reflux disease (GERD) is 24-hour pH metry though it fails to detect non-acidic reflux. The sensitivity of 24-hour pH metry alone (both catheter-based and Bravo capsule) is questionable, especially if gastric acid secretion is low due to reduced parietal cell mass, Helicobacter pylori-induced gastric atrophy and antisecretory therapy. Accordingly, we analyzed the diagnostic ability of 24-hour pH metry as compared to impedance monitoring in relation to the gastric pH without antisecretory therapy.

METHODS

A retrospective analysis of prospectively collected data from 150 patients with suspected GERD undergoing a 24-hour pH impedance study was done.

RESULTS

Among 150 patients with symptoms suggestive of GERD, 106 (70.6%) had confirmed GERD diagnosed either by 24-hour pH metry alone (10 [9.4%]), impedance monitoring alone (49 [46.2%]) or both (47 [44.3%]). Abnormal reflux of acidic and non-acidic gastric contents was detected by 24-hour pH metry and 24-hour impedance monitoring in 57/106 (53.7%) and 96/106 (90.5%) of patients, respectively (p < .00001). Patients with GERD diagnosed by 24-hour impedance monitoring had a higher mean gastric pH (2.9 [median 1.3, IQR 5.3]) than those diagnosed by 24-hour pH metry (2.1 [median 1.4, IQR 2.6]) or both (1.6 [median 1.2, IQR 2.1]) (p = 0.001).

CONCLUSION

Twenty-four-hour impedance monitoring detects GERD more often than 24-hour pH metry. Patients with higher mean gastric pH leading to non-acidic reflux were more often diagnosed by 24-hour impedance monitoring than 24-hour pH metry. Thus, 24-hour pH metry alone is inferior to additional impedance monitoring in the diagnosis of GERD, particularly in presence of reduced gastric acid secretion.

Randomised clinical trial: 3-year interim analysis results of the VISION trial to evaluate the long-term safety of vonoprazan as maintenance treatment in patients with erosive oesophagitis

BACKGROUND

VISION is a randomised, phase 4, open-label, parallel-group, multicentre study conducted in 33 centres in Japan. The aim of this study was to assess the long-term safety of vonoprazan for maintenance treatment of healed erosive oesophagitis versus lansoprazole.

METHODS

Patients with endoscopically diagnosed erosive oesophagitis were randomised 2:1 to once-daily vonoprazan 20 mg or lansoprazole 30 mg, for a 4- to 8-week healing phase. Patients with endoscopically confirmed healing entered a 260-week maintenance phase with a once-daily starting dose of vonoprazan 10 mg or lansoprazole 15 mg. Primary endpoint was change in gastric mucosal histopathology.

RESULTS

Of 208 patients (vonoprazan, n = 139; lansoprazole, n = 69) entering the healing phase, 202 entered the maintenance phase (vonoprazan, n = 135; lansoprazole, n = 67). At 3 years, 109 vonoprazan-treated and 58 lansoprazole-treated patients remained on treatment. Histopathological evaluation of gastric mucosa showed that hyperplasia of parietal, foveolar and G cells was more common with vonoprazan than lansoprazole at week 156 of the maintenance phase. There was no marked increase in the occurrence of parietal, foveolar and G cell hyperplasia among patients in the vonoprazan group from week 48 to week 156. Histopathological evaluation of the gastric mucosa also showed no neoplastic changes in either group. No new safety issues were identified.

CONCLUSIONS

In this interim analysis of VISION, no new safety concerns were identified in Japanese patients with healed erosive oesophagitis receiving vonoprazan or lansoprazole as maintenance treatment for 3 years. (CT.gov identifier: NCT02679508; JapicCTI-163153; Japan Registry of Clinical Trials: jRCTs031180040).

Use of proton pump inhibitors for the risk of gastric cancer

BACKGROUND

This study aimed to systematically analyze the association between long-term use of proton pump inhibitors (PPIs) and the risk of gastric cancer (GC).

METHODS

We performed a systematic search of articles on the relationship between long-term use of PPIs and the risk of GC from PubMed and EMBASE. We calculated the pooled odds ratio of GC in PPI users compared to non-PPI users using random-effects models.

RESULTS

This meta-analysis included 18 studies from 20 different databases with 4348,905 patients enrolled. In the random effects model, we found that an increased risk of GC among PPI users (OR = 1.94; 95% CI [1.43, 2.64]). The long-term use of PPIs compared with histamine-2 receptor antagonist users did not increase the risk of GC (OR = 1.65; 95% CI [0.92, 2.97]). Stratified analysis showed that PPI users had a significantly increased risk of noncardia GC (OR = 2.53; 95% CI [2.03, 3.15]), but had a relatively small relationship with the risk of gastric cardia cancer. (OR = 1.79; 95% CI [1.06, 3.03]). With the extension of PPI use time, the estimated risk value decreases (<1 year: OR = 6.33, 95% CI [3.76, 10.65]; 1-3 years: OR = 1.82, 95% CI [1.30, 2.55]; >3 years: OR = 1.25, 95% CI [1.00, 1.56]). Despite Helicobacter pylori eradication, the long-term use of PPIs did not alter the increased risk of GC (OR = 2.29; 95% CI [1.57, 3.33]).

CONCLUSION

Our meta-analysis found that PPI use may be associated with an increased risk of GC. Further research on the causal relationship between these factors is necessary.

Risk of gastric and oesophageal adenocarcinoma following discontinuation of long-term proton-pump inhibitor therapy

BACKGROUND

There is uncertainty whether long-term use of proton-pump inhibitors can cause gastric adenocarcinoma (GAC) and oesophageal adenocarcinoma (OAC). This study aimed to determine how discontinuation of long-term PPI therapy influences the risk of GAC and OAC.

METHODS

This population-based cohort study included all long-term users of PPI therapy in Sweden in 2005-2018 was based on Swedish nationwide health registry data. The exposure was discontinuation of long-term PPI therapy, defined as no dispensation of PPI following inclusion and used as a time-varying variable, compared to remaining on PPI. Main outcomes were GAC and OAC, while oesophageal squamous cell carcinoma (OSCC) was included as a comparison outcome. Incidence rate ratios (IRR) with 95% CI adjusted for age, sex, comorbidity, obesity, diabetes, hyperlipidaemia, NSAIDs/aspirin, and statins were calculated with Poisson regression.

RESULTS

Among 730,176 long-term PPI users (mean age 65.6 years, 58.4% females) with 4,210,925 person-years at risk (median 5.5 person-years), 439,390 (60.2%) discontinued PPIs. In total, 495 developed GAC, 598 OAC, and 188 developed OSCC. PPI discontinuation was associated with decreased risk of GAC (IRR 0.81, 95% CI 0.67-0.98) and OAC (IRR 0.80, 95% CI 0.68-0.96), but not OSCC (IRR 1.10, 95% CI 0.82-1.49) compared to continued PPI use. Stratified analyses showed decreased point estimates across most age categories and both sexes for GAC and OAC risk among participants discontinuing PPI therapy.

CONCLUSION

Discontinuation of long-term PPI therapy may decrease the risk of GAC and OAC, suggesting that physicians should consider ceasing prescribing long-term PPI in patients without continued indication for its use.

Management of Helicobacter pylori infection: Guidelines of the Italian Society of Gastroenterology (SIGE) and the Italian Society of Digestive Endoscopy (SIED)

Helicobacter pylori infection is very common and affects more than one-third of adults in Italy. Helicobacter pylori causes several gastro-duodenal diseases, such as gastritis, peptic ulcer and gastric malignancy, and extra-gastric diseases. The eradication of the bacteria is becoming complex to achieve due to increasing antimicrobial resistance. To address clinical questions related to the diagnosis and treatment of Helicobacter pylori infection, three working groups examined the following topics: (1) non-invasive and invasive diagnostic tests, (2) first-line treatment, and (3) rescue therapies for Helicobacter pylori infection. Recommendations are based on the best available evidence to help physicians manage Helicobacter pylori infection in Italy, and have been endorsed by the Italian Society of Gastroenterology and the Italian Society of Digestive Endoscopy.

The Impact of Proton Pump Inhibitors on the Development of Gastric Neoplastic Lesions in Patients With Autoimmune Atrophic Gastritis

Introduction

Proton pump inhibitors (PPIs) have been widely prescribed as a primary treatment for acid-related disorders. A large body of literature reported several adverse outcomes due to PPI therapy, including an increased risk of gastric cancer (GC). Autoimmune atrophic gastritis (AAG) is a chronic inflammatory disorder affecting the oxyntic mucosa, leading to mucosal atrophy, intestinal metaplasia, and reduced gastric acid secretion, up to the possible development of dysplasia and intestinal-type GC. Whether PPI use may increase the GC risk in AAG patients has not yet been investigated. We conducted a case–control study in AAG patients to assess the association between the PPI use before AAG diagnosis and the development of GC at follow-up (FU).

Materials and Methods

Patients were included from a prospective cohort of AAG patients (diagnosed 1992–2021) in a referral center for gastric autoimmunity; all patients adhered to an endoscopic–histological FU program according to Management of precancerous conditions and lesions in the stomach (MAPS) I/II (management of epithelial precancerous conditions) guidelines. At diagnosis, clinical/biochemical data and PPI use before AAG diagnosis (withdrawn at the time of diagnosis), for at least 12 months, were evaluated. Patients who developed gastric neoplastic lesions (GNLs) at FU were considered as cases; patients without a diagnosis of GNLs at FU were considered as controls. At a total FU of 2.3 years (1–13), 35 cases were identified, and controls were matched 2:1 by age ( ± 3 years), gender, and years of FU (n=70); therefore, a total of n=105 patients were included in the study.

Results

The proportion of PPI users before AAG diagnosis was significantly higher in cases than in controls (54.3% vs. 18.6%, p<0.001). At logistic regression, considering as a dependent variable the development of GNLs at FU, a positive association was shown for PPI use before AAG diagnosis (OR 9.6, 95%CI 2.3–40.3), while other independent variables as the use of antiplatelets/anticoagulants (OR 2.8, 95%CI 0.7–12.0), age ≥ 50 years (OR 2.0, 95%CI 0.2–18.1), 1st-degree family history for GC (OR 2.4, 95%CI 0.4–15.2), and smoking habit (OR 0.4, 95%CI 0.1–2.1) were not associated.

Conclusions

PPI use before the diagnosis of AAG appears to considerably increase the risk of subsequent GNL development. Considering the common misuse of PPIs, physicians should regularly reevaluate the appropriateness of ongoing PPI therapy, in particular in patients with a clinical suspicion of or already diagnosed AAG.

Topical issues of prevention of stomach cancer: A review

Prevention of gastric cancer, both primary and secondary, is an extremely important component of the management of gastroenterological patients. The correct collection of anamnesis with an assessment of the hereditary (family) cancer risk, the action of risk factors (eating disorders, habitual/chronic intoxication, obesity, Helicobacter pylori infection, etc.), as well as the use of gastroprotectors (in particular, the drug Regastim Gastro), especially in persons with potentially precancerous the condition is chronic atrophic gastritis. According to the data of a double-blind placebo-controlled randomized study Regastim Gastro (active ingredient alpha-glutamyl tryptophan) in the treatment of chronic atrophic gastritis, it was found that this drug has a powerful anti-inflammatory effect and regenerative activity. Taking the drug Regastim Gastro, compared with placebo, statistically significantly contributed to a decrease in the number of inflammatory infiltration cells per 1 mm2 of the gastric mucosa. Regastim Gastro decreases in eosinophilic (3 times) and neutrophilic (4 times) infiltration of the gastric mucosa and also reduced the number of macrophages, lymphocytes and plasmocytes. In addition to anti-inflammatory properties, the drug also had a pronounced regenerative effect. Taking of Regastim Gastro statistically significant (p=0.028) increases in the number of glands per 1 mm2 of the gastric mucosa by 26.1% compared with the initial screening indicators. In the group of patients taking placebo, on the contrary, there was a further progression of the pathological process, accompanied by a decrease in the number of glands per 1 mm2 of the gastric mucosa after the end of treatment in comparison with the initial indicators. After the course of therapy, the number of glands per 1 mm2 of the gastric mucosa in patients taking the drug Regastim Gastro was statistically significantly higher in comparison with the results in the placebo group (p=0.013). After the course of Regastim Gastro, there was an improvement in acid production: a shift in the acidic side of the average pH value (1.6 times) and an increase in the value of the acidity index, both when compared with the initial values (5.4 times) and in comparison with the placebo group (2.9 times). The intake of Regastim Gastro to patients with gastritis, both H. pylori (+) and H. pylori (-) before the development of atrophy of the gastric mucosa can reduce the inflammatory factor, prevent the occurrence of atrophy and may have maximum anti-carcinogenic action.

Efficacy and safety of peroral endoscopic myotomy in 100 older patients

BACKGROUND

Peroral endoscopic myotomy (POEM) is a standard treatment for achalasia. Several reports have described the efficacy and safety of POEM for elderly patients, but none has reported the efficacy and safety of POEM in a large number of elderly patients for > 3 years postoperatively. In this study, we examined the safety and outcome of POEM for 3 years postoperatively in 100 elderly patients.

METHODS

One hundred consecutive patients aged > 65 years who underwent POEM from September 2011 to March 2020 were included in this study. In analysis 1, we retrospectively investigated the safety and efficacy of POEM in all patients. In analysis 2, the efficacy and safety of POEM were statistically compared between two groups: the early elderly (65-74 years of age, 55 patients) and late elderly (≥ 75 years of age, 45 patients).

RESULTS

The technical success rate of POEM was 100%. In analysis 1, the 3-month, 1-year, 2-year, and 3-year efficacies of POEM (Eckardt score of ≤ 3) were 100% (92/92 cases), 100% (91/91 cases), 97.8% (88/90 cases), and 100% (92/92 cases), respectively. Procedure-related adverse events occurred in 11% of patients, but none was fatal. Two late elderly patients developed aspiration pneumonia due to delirium and underwent long-term hospitalization. In analysis 2, there were no significant differences in the efficacy and safety of POEM between the two age groups.

CONCLUSIONS

POEM is effective and safe for elderly patients. However, precautions are needed regarding the risk of adverse events associated with delirium when POEM is performed in elderly patients.

Proton pump inhibitors and risk of gastric cancer: population-based cohort study

OBJECTIVE

To determine whether new users of proton pump inhibitors (PPIs) are at an increased risk of gastric cancer compared with new users of histamine-2 receptor antagonists (H2RAs).

DESIGN

Using the UK Clinical Practice Research Datalink, we conducted a population-based cohort study using a new-user active comparator design. From 1 January 1990 to 30 April 2018, we identified 973 281 new users of PPIs and 193 306 new users of H2RAs. Cox proportional hazards models were fit to estimate HRs and 95% CIs of gastric cancer, and the number needed to harm was estimated using the Kaplan-Meier method. The models were weighted using standardised mortality ratio weights using calendar time-specific propensity scores. Secondary analyses assessed duration and dose-response associations.

RESULTS

After a median follow-up of 5.0 years, the use of PPIs was associated with a 45% increased risk of gastric cancer compared with the use of H2RAs (HR 1.45, 95% CI 1.06 to 1.98). The number needed to harm was 2121 and 1191 for five and 10 years after treatment initiation, respectively. The HRs increased with cumulative duration, cumulative omeprazole equivalents and time since treatment initiation. The results were consistent across several sensitivity analyses.

CONCLUSION

The findings of this large population-based cohort study indicate that the use of PPIs is associated with an increased risk of gastric cancer compared with the use of H2RAs, although the absolute risk remains low.

Follow the Metaplasia: Characteristics and Oncogenic Implications of Metaplasia's Pattern of Spread Throughout the Stomach

The human stomach functions as both a digestive and innate immune organ. Its main product, acid, rapidly breaks down ingested products and equally serves as a highly effective microbial filter. The gastric epithelium has evolved mechanisms to appropriately handle the myriad of injurious substances, both exogenous and endogenous, to maintain the epithelial barrier and restore homeostasis. The most significant chronic insult that the stomach must face is Helicobacter pylori (Hp), a stomach-adapted bacterium that can colonize the stomach and induce chronic inflammatory and pre-neoplastic changes. The progression from chronic inflammation to dysplasia relies on the decades-long interplay between this oncobacterium and its gastric host. This review summarizes the functional and molecular regionalization of the stomach at homeostasis and details how chronic inflammation can lead to characteristic alterations in these developmental demarcations, both at the topographic and glandular levels. More importantly, this review illustrates our current understanding of the epithelial mechanisms that underlie the pre-malignant gastric landscape, how Hp adapts to and exploits these changes, and the clinical implications of identifying these changes in order to stratify patients at risk of developing gastric cancer, a leading cause of cancer-related deaths worldwide.

Association between proton pump inhibitor use and gastric cancer: a population-based cohort study using two different types of nationwide databases in Korea

OBJECTIVE

The association between proton pump inhibitor (PPI) use and gastric cancer related to Helicobacter pylori eradication has not been fully investigated in geographical regions with high risk of gastric cancer. We aimed to evaluate the association between PPIs and gastric cancer in Korea.

DESIGN

This study analysed the original and common data model versions of the Korean National Health Insurance Service database from 2002 to 2013. We compared the incidence rates of gastric cancer after 1-year drug exposure, between new users of PPIs and other drugs excluding PPIs, by Cox proportional hazards model. We also analysed the incidence of gastric cancer among PPI users after H. pylori eradication.

RESULTS

The analysis included 11 741 patients in matched PPI and non-PPI cohorts after large-scale propensity score matching. During a median follow-up of 4.3 years, PPI use was associated with a 2.37-fold increased incidence of gastric cancer (PPI≥30 days vs non-PPI; 118/51 813 person-years vs 40/49 729 person-years; HR 2.37, 95% CI 1.56 to 3.68, p=0.001). The incidence rates of gastric cancer showed an increasing trend parallel to the duration of PPI use. In H. pylori-eradicated subjects, the incidence of gastric cancer was significantly associated with PPI use over 180 days compared with the non-PPI group (PPI≥180 days vs non-PPI; 30/12 470 person-years vs 9/7814 person-years; HR 2.22, 95% CI 1.05 to 4.67, p=0.036).

CONCLUSION

PPI use was associated with gastric cancer, regardless of H. pylori eradication status. Long-term PPIs should be used with caution in high-risk regions for gastric cancer.

Proton Pump Inhibitors and Gastric Cancer

Concerns have been raised regarding the long-term use of proton pump inhibitors (PPIs) as an important risk factor for gastric cancer in clinical practice. PPIs can cause hypergastrinemia at clinical doses, and hypergastrinemia has been reported to induce malignant neoplasms in the stomach in previous animal studies. In humans, the proliferation of enterochromaffin-like (ECL) cells induced by hypergastrinemia is suspected as a potential mechanism of gastric cancer. Meanwhile, persistent Helicobacter pylori (H. pylori) infection causes gastric atrophic change, which itself is a major cause of gastric cancer, and it can further increase the risk of gastric cancer by strengthening corpus atrophy through interaction with PPIs. Recent epidemiologic studies have reported an important link between long-term PPI intake and gastric cancer risk even after successful eradication of H. pylori. However, due to the methodological limitations of observational clinical studies, the causal relationship is still not clear, and a recent big data-based study reported that long-term PPI use was not related to gastric cancer incidence. Taken together, despite the potential detrimental effects of PPIs, it is currently difficult to draw a definite conclusion about its association with gastric cancer. To minimize the possibility of gastric cancer in H. pylori-infected patients or precancerous lesions in long-term PPI users, long-term PPI administration should be limited to the minimum effective dose, and antibacterial treatment for H. pylori should be considered.

Chemopreventive Effect of Metformin on Gastric Cancer Development

Although Helicobacterpylori infection is the most important causative factor for gastric cancer (GC), H. pylori eradication alone does not completely eliminate the GC risk. In addition to H. pylori eradication, other risk factors for GC should be identified and targeted. Diabetes mellitus (DM) confers a 20% increased risk of GC, which could be mediated via several biological mechanisms including the stimulation of cell proliferation via hyperinsulinemia and increased insulin-growth factor production, the promotion of angiogenesis, and DNA damage. With a current global prevalence of 9.3% and a predicted rise to 10.2% by 2030, DM could contribute substantially to the burden of GC cases worldwide. Emerging evidence showed that metformin possesses chemopreventive effects via both direct (e.g., adenosine monophosphate-activated protein kinase activation and subsequent inhibition of the mammalian target of rapamycin pathway) and indirect (e.g., modulation of the interaction between tumor cells and their microenvironment and gut microbiota) pathways. A recent meta-analysis of observational studies showed that metformin use was associated with 24% lower GC risk. However, many available observational studies related to metformin effects suffered from biases including the failure to adjust for the H. pylori infection status and serial glycemic control and time-related biases. Future prospective studies addressing these pitfalls are needed.

Controversial link between proton pump inhibitors and anticancer agents: review of the literature

Drug-drug interactions represent a topic of great interest, not only due to the risk of unexpected adverse events but also due to the possibility of altering the effectiveness of a specific treatment. Inappropriate or concomitant use of drugs can often lead to changes in the bioavailability of various compounds, resulting in pharmacokinetic alterations. A recent example is the concomitant administration of proton pump inhibitors (PPIs) and anticancer agents. PPIs are overused beyond their classic indications, resulting in a high risk of interactions with other drugs, such as anticancer agents, both PO and intravenous. However, the real clinical impact of concomitant acid suppression therapy and anticancer therapies remains controversial and is not yet fully understood. Certainly, the gut microbiota plays a key role in regulating the response of the immune system, and PPIs can significantly alter the gut microbiome, resulting in gut dysbiosis. Indeed, while the link sometimes appears to lead to negative outcomes, as in the case of immunotherapy, oral capecitabine, or tyrosine kinase inhibitors, in other cases, it seems to enhance the effectiveness of intravenous chemotherapy. In this review, I analyse the possible drug interactions between PPIs and the main classes of anticancer drugs.

Gastritis, Gastric Polyps and Gastric Cancer

Gastric cancer is still an important disease causing many deaths worldwide, although there has been a marked reduction in prevalence during the last few decades. The decline in gastric cancer prevalence is due to a reduction in Helicobacter pylori infection which has occurred for at least 50 years. The most probable mechanism for the carcinogenic effect of H. pylori is hypergastrinemia since H. pylori infected individuals do not have increased risk of gastric cancer before the development of oxyntic atrophy. When atrophy has developed, the carcinogenic process continues independent of H. pylori. Autoimmune gastritis also induces oxyntic atrophy leading to marked hypergastrinemia and development of ECL cell neoplasia as well as adenocarcinoma. Similarly, long-term treatment with efficient inhibitors of acid secretion like the proton pump inhibitors (PPIs) predisposes to ECL cell neoplasia of a different degree of malignancy. Contrasting the colon where most cancers develop from polyps, most polyps in the stomach have a low malignant potential. Nevertheless, gastric polyps may also give rise to cancer and have some risk factors and mechanisms in common with gastric cancer. In this overview the most common gastric polyps, i.e., hyperplastic polyps, adenomatous polyps and fundic gland polyps will be discussed with respect to etiology and particularly use of PPIs and relation to gastric carcinogenesis.

Hypertrophic Gastric folds with Hypomagnesemia, linking the dots

A Caucasian man in early 80s was seen in Gastroenterology Clinic, following, referral from the Endocrinology Clinic for concerns for CT Abdomen requested for tiredness and weight loss of three kilograms. The patient also had microcytic picture with low MCV and Ferritin and hypomagnesemia. The CT suggested gross circumferential thickening of the wall of stomach with advice for invasive investigations to further characterise the CT findings. The Endoscopy suggested grossly enlarged rugae in the stomach, and enlarged gastric polyps. Patient was assured no new sinister abnormality. Treatment challenges to consider were to stop acid suppression by prescribing Proton Pump Inhibitors (PPIs) which would lead to stomach ulcers, or to continue with PPIs with sequalae of worsening of hypertrophic gastric folds, enlarged gastric polyps and hypomagnesemia. It would be necessary to consider risk versus benefits in either situation to determine an appropriate treatment plan in the long term. With background of Zollinger-Ellison Syndrome and MEN1 with heterozygous mutation with gastrinoma of the duodenum, and frailty he was advised to continue with Proton Pump Inhibitors with twice weekly correction of Magnesium infusions, and Iron tablets following Multi-disciplinary meeting.

Effect of frequently prescribed drugs on gastric cancer risk

Gastric cancer is the fifth leading cancer worldwide. Infection with Helicobacter pylori represents the major risk factor, but only a small fraction of infected individuals will develop neoplasia. The progression of advanced gastric lesions to cancer is influenced by characteristics of the bacterial strain, host genetic and environmental factors. Recently, the effect of medications on gastric cancer risk has gained interest, because many commonly prescribed drugs affect gastric homeostasis. While non-steroidal anti-inflammatory drugs (NSAIDs) are a frequent cause of gastric ulcer disease, low-dose aspirin has been propagated for chemoprevention of various tumour entities. Beneficial effects of cyclooxygenase-inhibition for gastric cancer prevention is plausible, but its clinical relevance remains unclear. Furthermore, anti-tumorous effects have been postulated for statins and metformin. On the contrary, proton pump inhibitors (PPIs), which are commonly used for prevention of gastric ulcers and bleeding, have been associated with an increased gastric cancer risk in large observational studies. Most of these observations still require confirmation in prospective controlled trials. NSAIDs, statins and metformin have also been investigated as concomitant cancer treatment, but studies did not show convincing results to date. Here, we review the available evidence and possible mechanisms for the role of PPIs, NSAIDs, statins and metformin in gastric carcinogenesis, and discuss possible implications for clinical practice.

[Proton Pump Inhibitors and their Microbiome-Mediated Side Effects]

Proton pump inhibitors are valuable treatment options for gastric acid associated diseases, such as peptic ulcer disease or reflux diseases. Due to their irreversible inhibition of the proton pumps in the parietal cells of the stomach, gastric acid secretion can be effectively reduced. With the reduction in gastric acid, however, proton pump inhibitors also block a highly conserved, crucial part of the unspecific immune system. The gastric barrier protects the body - and here mainly the intestinal microbiome - from food-borne pathogens and oral bacteria that can reach more distal parts of the gastrointestinal tract during proton pump inhibitor therapy. Resulting changes in the intestinal microbiome, such as the reduction in microbial diversity or small intestinal bacterial overgrowth, can be linked to side effects of (long-term) proton pump inhibitor therapy, such as the increased risk of Clostridium difficile infections or gastrointestinal discomfort. In liver cirrhosis patients, the increase in oral bacteria in the intestine is associated with intestinal inflammation and permeability, and can even be used as a biomarker for 3-year liver related mortality. Therefore, microbiome-mediated side effects should be included in the risk assessment of proton pump inhibitor therapy and the evaluation of potential alternatives.

Screening and eradication of Helicobacter pylori for gastric cancer prevention: the Taipei global consensus

OBJECTIVE

A global consensus meeting was held to review current evidence and knowledge gaps and propose collaborative studies on population-wide screening and eradication of Helicobacter pylori for prevention of gastric cancer (GC).

METHODS

28 experts from 11 countries reviewed the evidence and modified the statements using the Delphi method, with consensus level predefined as ≥80% of agreement on each statement. The Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach was followed.

RESULTS

Consensus was reached in 26 statements. At an individual level, eradication of H. pylori reduces the risk of GC in asymptomatic subjects and is recommended unless there are competing considerations. In cohorts of vulnerable subjects (eg, first-degree relatives of patients with GC), a screen-and-treat strategy is also beneficial. H. pylori eradication in patients with early GC after curative endoscopic resection reduces the risk of metachronous cancer and calls for a re-examination on the hypothesis of 'the point of no return'. At the general population level, the strategy of screen-and-treat for H. pylori infection is most cost-effective in young adults in regions with a high incidence of GC and is recommended preferably before the development of atrophic gastritis and intestinal metaplasia. However, such a strategy may still be effective in people aged over 50, and may be integrated or included into national healthcare priorities, such as colorectal cancer screening programmes, to optimise the resources. Reliable locally effective regimens based on the principles of antibiotic stewardship are recommended. Subjects at higher risk of GC, such as those with advanced gastric atrophy or intestinal metaplasia, should receive surveillance endoscopy after eradication of H. pylori.

CONCLUSION

Evidence supports the proposal that eradication therapy should be offered to all individuals infected with H. pylori. Vulnerable subjects should be tested, and treated if the test is positive. Mass screening and eradication of H. pylori should be considered in populations at higher risk of GC.

Gastric cancer screening in low incidence populations: Position statement of AEG, SEED and SEAP

This positioning document, sponsored by the Asociación Española de Gastroenterología, the Sociedad Española de Endoscopia Digestiva and the Sociedad Española de Anatomía Patológica, aims to establish recommendations for the screening of gastric cancer (GC) in low incidence populations, such as the Spanish. To establish the quality of the evidence and the levels of recommendation, we used the methodology based on the GRADE system (Grading of Recommendations Assessment, Development and Evaluation). We obtained a consensus among experts using a Delphi method. The document evaluates screening in the general population, individuals with relatives with GC and subjects with GC precursor lesions (GCPL). The goal of the interventions should be to reduce GC related mortality. We recommend the use of the OLGIM classification and determine the intestinal metaplasia (IM) subtype in the evaluation of GCPL. We do not recommend to establish endoscopic mass screening for GC or Helicobacter pylori. However, the document strongly recommends to treat H.pylori if the infection is detected, and the investigation and treatment in individuals with a family history of GC or with GCPL. Instead, we recommend against the use of serological tests to detect GCPL. Endoscopic screening is suggested only in individuals that meet familial GC criteria. As for individuals with GCPL, endoscopic surveillance is only suggested in extensive IM associated with additional risk factors (incomplete IM and/or a family history of GC), after resection of dysplastic lesions or in patients with dysplasia without visible lesion after a high quality gastroscopy with chromoendoscopy.

New treatment method for refractory gastroesophageal reflux disease (GERD): C-BLART (clip band ligation anti-reflux therapy)-a short-term study

OBJECTIVES

C-BLART (clip band ligation anti-reflux therapy) has been reported as a new alternative endoscopic treatment for refractory gastroesophageal reflux disease (GERD). This study evaluated the short-term efficacy of C-BLART for controlling GERD symptoms, esophageal acid exposure, esophagitis, and quality of life.

METHODS

Patients with refractory GERD were recruited for a nonrandomized concurrent comparison, with 60 patients in the C-BLART with tailored PPI use group and 43 patients in the BID proton pump inhibitor (PPI) group. The primary outcomes were esophageal acid exposure and the lower esophageal sphincter (LES) pressure. The GERD-Q score, esophagitis grade, and adherence degree were also recorded. Crossover from the BID PPI group to the C-BLART with tailored PPI use group was allowed after 6 months.

RESULTS

The LES pressure and GERD-Q score improved more in the C-BLART with tailored PPI use group (P < 0.001) after 6 months, with no significant difference in the decrease in esophagitis compared with the baseline endoscopic results (P = 0.268). Treatment with PPIs had been halted in 43% of the patients at 6 months after C-BLART. At 12 months after C-BLART, the DeMeester score showed a significant improvement compared with the baseline measurements (P = 0.025). The GERD-Q score and LES pressure did not significantly improve compared with the baseline values (P = 0.102, P = 0.184) in C-BLART with tailored PPI use group. At 6 to 12 months, n = 6 (10%) patients had undergone laparoscopic fundoplication to control their symptoms in all the patients after C-BLART.

CONCLUSION

C-BLART is a novel treatment for controlling refractory GERD symptoms, esophageal acid exposure, and LES pressure according to this short-term analysis, safely performed endoscopically to create an anti-reflux barrier with ligated bands. Despite improvements in DeMeester score, LES pressure, and GERD-Q scores in the C-BLART with tailored PPI use group, many patients continue to demonstrate objective evidence of GERD.

Omeprazole and adenocarcinoma in the stomach of rats submitted to duodenogastric reflux. Is there a protective effect?

Purpose:

To investigate the role of omeprazole and nitrites on the gastric mucosa of rats submitted to specific techniques to induce duodenogastric reflux.

Methods:

One hundred and twenty Wistar rats were divided into three groups: Group I (n=40) -gastrotomy; Group II (n=40) - duodenogastric reflux after gastrojejunoanastomosis latero-lateral (DGR); Group III (n=40) - retrograde duodenogastric reflux through the pylorus (DGR-P). The groups were divided into 4 subgroups of 10 animals, respectively treated for 16 weeks with water, omeprazole 1.6 mg / rat / day, nitrite 600 mg / kg / day and omeprazole plus nitrite simultaneously.

Results:

The proliferative lesions found were: squamous hyperplasia - 69.1%, adenomatous hyperplasia in the anastomosis - 29.1% and prepyloric adenomatous hyperplasia - 42.5%. Adenocarcinomas were registered in 7 animals (5.8%): one in Group I (omeprazole plus nitrite), two in Group II (omeprazole and nitrite plus omeprazole) and four in Group III (water, nitrite, omeprazole and omeprazole plus nitrite).

Conclusions:

The occurrence of squamous hyperplasia, adenomatous hyperplasia and adenocarcinoma increased after gastrojejunal anastomoses, which cause duodenogastric reflux. The association of omeprazole did not protect the development of proliferative lesions and cancer induced by duodenogastric reflux in rats.

Increase in the Lipopolysaccharide Activity and Accumulation of Gram-Negative Bacteria in the Stomach With Low Acidity

INTRODUCTION:

Lipopolysaccharides (LPSs) of Gram-negative bacteria (GNB) are highly toxic and induce inflammation. Therefore, we investigated both the LPS activity and composition of GNB in the gastric fluid (GF) to assess the potential toxicity of them accumulated in the stomach.

METHODS:

GF and saliva samples were obtained from 158 outpatients who were undergoing upper gastrointestinal endoscopy and 36 volunteers using a nasogastric tube. The LPS activity was measured by assay kits including recombinant Factor C or Limulus amebocyte lysate. To assess the bacterial composition in the samples, a 16S ribosomal DNA-based operational taxonomic unit analysis was performed. We focused on the genera representing >0.1% of the whole microbiota.

RESULTS:

We found a high LPS activity in the GF samples with weak acidity (approximately > pH 4), whereas little/no activity in those with strong acidity (approximately < pH 2). Spearman test also demonstrated a close correlation between pH and LPS in those samples (r = 0.872). The relative abundance of GNB in the saliva showed no significant difference between the subject groups with weak- and strong-acidity GF. In addition, in the subjects whose GF acidity was weak, the GNB abundance in the GF was almost the same as that in the saliva. By contrast, in the subjects whose GF acidity was strong, the GNB abundance in the GF was significantly lower than that in the saliva.

DISCUSSION:

GNB that have recently moved from the oral cavity might account for the prominent LPS activity in a stomach with weak acidity.

Latest insights into the hot question of proton pump inhibitor safety - a narrative review

Proton pump inhibitors (PPIs) are among the most widely prescribed medications worldwide and their use is continuously increasing. Although they have been shown to combine high therapeutic efficacy and good safety profile in many studies, in last years we have witnessed the publication of many articles reporting the possible association of long-term PPI therapy with important unexpected adverse events and these observations have created alarmism in both patients and physicians. However, the majority of these studies are observational, retrospective and prone to residual confounding. Also, the odds ratio values are generally comprised between 1 and 2 and therefore devoid of strong clinical relevance. As it is unlikely that prospective randomized trials will be ever done to reinforce these associations, we can only attempt to distinguish clear- from unclear-defined adverse events from the available literature. Nowadays we can reasonably exclude cardiovascular diseases, community-acquired pneumonia, all-cause mortality, dementia and bone fractures from PPI-related adverse events. However, physicians should be aware of the existence of possible risks when treating their patients, especially the elderly and frail ones, with long-term PPIs, which should be prescribed only to persons with defined indications and at lowest dose and duration.

Chronic atrophic gastritis detection with a convolutional neural network considering stomach regions

BACKGROUND

The risk of gastric cancer increases in patients with Helicobacter pylori-associated chronic atrophic gastritis (CAG). X-ray examination can evaluate the condition of the stomach, and it can be used for gastric cancer mass screening. However, skilled doctors for interpretation of X-ray examination are decreasing due to the diverse of inspections.

AIM

To evaluate the effectiveness of stomach regions that are automatically estimated by a deep learning-based model for CAG detection.

METHODS

We used 815 gastric X-ray images (GXIs) obtained from 815 subjects. The ground truth of this study was the diagnostic results in X-ray and endoscopic examinations. For a part of GXIs for training, the stomach regions are manually annotated. A model for automatic estimation of the stomach regions is trained with the GXIs. For the rest of them, the stomach regions are automatically estimated. Finally, a model for automatic CAG detection is trained with all GXIs for training.

RESULTS

In the case that the stomach regions were manually annotated for only 10 GXIs and 30 GXIs, the harmonic mean of sensitivity and specificity of CAG detection were 0.955 ± 0.002 and 0.963 ± 0.004, respectively.

CONCLUSION

By estimating stomach regions automatically, our method contributes to the reduction of the workload of manual annotation and the accurate detection of the CAG.

Generation and use of gastric organoids for the study of Helicobacter pylori pathogenesis

While the incidence of gastric cancer in the United States is relatively low due to the diagnosis and treatment of the major risk factor Helicobacter pylori (H. pylori), 5-year patient survival is only approximately 29%. Even after H. pylori infection has been eradicated there is still a risk of developing gastric cancer. Gastric cancer is the final clinical outcome that is often initiated by a sustained inflammatory response and altered epithelial cell differentiation and metaplasia in response to H. pylori infection. Identifying the early epithelial responses to H. pylori infection is important in advancing our understanding of the events that shape a conducive environment for the progression of gastric cancer. Thus, we developed a human gastric tissue-derived organoid-based approach to identify the initiating molecular events that trigger gastric cancer development in response to bacterial infection.

Bibliometric Analysis of 100 Top-Cited Articles in Gastric Disease

Objectives

The bibliometric analysis uses the citation count of an article to measure its impact in the scientific community, yet there is still no comprehensive summary of gastric disease researches via bibliometric analysis. We aimed to evaluate the situations and trends of the most cited articles in gastric disease via bibliometric analysis and to provide physicians a practical guide in assessing the most influential articles written on this subject.

Methods

The 100 top-cited articles in gastric disease were compiled using Web of Science. The articles selected were evaluated for their number of citations, year of publication, country of origin, type of study, and others.

Results

The database had 484,281 articles published between 1965 and 2019. The most cited article received 4,017 citations and the least received 604, with a mean of 1,149 citations. We classified the articles into seven categories: gastric cancer (n = 53), Helicobacter pylori (n = 17), ulcer (n = 7), gastrointestinal stromal tumors (n = 6), gastritis (n = 5), gastric bypass surgery (n = 2), and others (n = 10). Altogether, 69 of the articles were from the USA (n = 41), the UK (n = 17), and Japan (n = 11). Among all the institutions, Royal Perth Hospital led the list with 5 articles. One-quarter of authors owned three or more of these top-cited articles. The 100 papers were published in 33 journals, and most of them were clinical researches (n = 47).

Conclusions

Our study provides a historical perspective for the scientific progress of gastric disease, and the articles of significant findings that contributed great impact on the prevention and treatment of gastric disease had been identified.

Systematic review: the effects of proton pump inhibitors on the microbiome of the digestive tract-evidence from next-generation sequencing studies

BACKGROUND

Proton pump inhibitors (PPI) are widely used to treat acid-related disorders of the upper gastrointestinal tract. However, large observational studies have raised concerns about PPI-associated adverse events. In recent years, data from next-generation sequencing studies suggested that PPIs affect the composition of the intestinal microbiota, while a balanced gut microbiome is essential for maintaining health.

AIM

To review the available evidence from next-generation sequencing studies on the effect of PPIs on the intestinal microbiome and to discuss possible implications of PPI-induced dysbiosis in health and disease.

METHODS

A systematic review was conducted following the recommendations of the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. A PubMed query yielded 197 results. 19 publications met the prespecified eligibility criteria.

RESULTS

Twelve observational study cohorts with 708 PPI users and 11 interventional cohorts with 180 PPI users were included in the review. In most studies, PPI treatment did not affect microbiological richness and diversity, but was associated with distinct taxonomic alterations: In the upper gastrointestinal tract, PPI users showed overgrowth of orally derived bacteria, mostly Streptococcaceae (findings based on six independent cohorts with 126 PPI users). In faecal samples, PPIs increased multiple taxa from the orders Bacillales (eg, Staphylococcaceae), Lactobacillales (eg, Enterococcaceae, Lactobacillaceae, Streptococcaceae) and Actinomycetales (eg, Actinomycetaceae, Micrococcaceae), the families Pasteurellaceae and Enterobacteriaceae and the genus Veillonella. Taxa decreased by PPIs include Bifidobacteriaceae, Ruminococcaceae, Lachnospiraceae and Mollicutes (findings in faecal samples based on 19 independent cohorts with 790 PPI users).

CONCLUSION

PPI use is associated with moderate alterations to upper and distal gut microbiota. The available data suggest that PPI-induced hypochlorhydria facilitates colonization of more distal parts of the digestive tract by upper gastrointestinal microbiota.

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.

Long-term use of proton pump inhibitors does not affect ectopic and metachronous recurrence of gastric cancer after endoscopic treatment

Objective: Long-term administration of proton pump inhibitors (PPIs) after eradication of Helicobacter pylori infection has been reported to increase the risk for development of gastric cancer (GC). We investigated whether long-term administration of PPI affects ectopic and metachronous recurrence of GC after endoscopic treatment.Methods: Participants were 687 patients who underwent endoscopic treatment for GC from January 2005 to March 2018. Questionnaire surveys and medical record reviews of medications, including PPIs, H₂ receptor antagonists and low-dose aspirin (LDA) were conducted for all patients. The influence of PPI in ectopic and metachronous recurrence of GC was evaluated with Cox's proportional hazard analysis.Results: Patients who did not respond to the questionnaire and those who underwent additional treatment after endoscopic treatment were excluded from analyses; 418 patients were included. During an average observation period of 1608 days (range, 375-4993 days), 136 patients (32.5%) took PPIs for more than 1 year and 94 took PPIs for more than 3 years; of those, 40 had ectopic and metachronous recurrences. Cox's proportional hazards analysis revealed that long-term use of PPIs (for both 1 year and 3 years) was not a risk factor for recurrence. In addition, age, severity of gastric atrophy, long-term use of LDA, current infection with H. pylori, and cure achieved with the first endoscopic treatment were also not risk factors for recurrence.Conclusions: Long-term use of PPIs does not affect ectopic and metachronous recurrence of GC after endoscopic treatment.

Chronic atrophic gastritis: Natural history, diagnosis and therapeutic management. A position paper by the Italian Society of Hospital Gastroenterologists and Digestive Endoscopists [AIGO], the Italian Society of Digestive Endoscopy [SIED], the Italian Society of Gastroenterology [SIGE], and the Italian Society of Internal Medicine [SIMI]

Chronic atrophic gastritis (CAG) is an underdiagnosed condition characterised by translational features going beyond the strict field of gastroenterology as it may manifest itself by a variable spectrum of gastric and extra-gastric symptoms and signs. It is relatively common among older adults in different parts of the world, but large variations exist. Helicobacter pylori-related CAG [multifocal] and autoimmune CAG (corpus-restricted) are apparently two different diseases, but they display overlapping features. Patients with cobalamin and/or iron deficiency anaemia or autoimmune disorders, including autoimmune thyroiditis and type 1 diabetes mellitus, should be offered screening for CAG. Pepsinogens, gastrin-17, and anti-H. pylori antibodies serum assays seem to be reliable non-invasive screening tools for the presence of CAG, helpful to identify individuals to refer to gastroscopy with five standard gastric biopsies in order to obtain histological confirmation of diagnosis. Patients with CAG are at increased risk of developing gastric cancer, and they should be estimated with histological staging systems (OLGA or OLGIM). H. pylori eradication may be beneficial by modifying the natural history of atrophy, but not that of intestinal metaplasia. Patients with advanced stages of CAG (Stage III/IV OLGA or OLGIM) should undergo endoscopic surveillance every three years, those with autoimmune CAG every three-five years. In patients with CAG, a screening for autoimmune thyroid disease and micronutrient deficiencies, including iron and vitamin B₁₂, should be performed. The optimal treatment for dyspeptic symptoms in patients with CAG remains to be defined. Proton pump inhibitors are not indicated in hypochlorhydric CAG patients.

The Clinician's Guide to Proton Pump Inhibitor Related Adverse Events

A substantial volume of literature exists linking proton pump inhibitor (PPI) use with a multitude of serious adverse events. There is uncertainty, however, over whether these associations are clinically important. Excessive concern about PPI-related adverse events may leave patients at risk of harm by leaving acid-related upper gastrointestinal disease untreated. Conversely, the risk of treatments may outweigh the benefits if any of the purported adverse events are directly caused by PPI use; this is of particular concern where indications for PPI use are not present. In this paper, we review the studies which have reported associations between adverse events and PPI use, discuss the proposed mechanisms of action, grade the confidence in whether these associations are truly causal, and provide advice regarding balancing the benefits of PPI use against their possible harms.

Relationship between long-term use of proton pump inhibitors and risk of gastric cancer: A systematic analysis

BACKGROUND AND AIM

This study aims to systematically analyze the effect of long-term therapy with proton pump inhibitors (PPIs) on the risk of gastric cancer.

METHODS

PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), and China biomedical literature database (CBM) were searched for studies before February 2019. We evaluated the quality of the included articles through the Newcastle-Ottawa Scale and gathered relevant data to calculate the pooled odds ratio (OR) through Stata14.0.

RESULTS

Seven relevant articles conformed to the inclusion criteria; 943 070 patients were included. The pooled OR was 2.50; 95% CI (1.74, 3.85); the subgroup analysis results showed that patients who had used PPIs for more than 36 months were most likely to develop gastric cancer, and an increased risk was observed among patients after Helicobacter pylori eradication. Noncardia gastric cancer was more likely to develop.

CONCLUSIONS

Long-term use of PPIs can possibly increase the risk of gastric cancer even among patients after H. pylori eradication; in particular, for noncardia gastric cancer, the risk increases with longer durations of PPI use. Due to the limited number of studies, more high-quality studies are required to be designed.

Adverse Effects of Proton Pump Inhibitors-Evidence and Plausibility

Proton pump inhibitors (PPIs) have been increasingly used over the last decades and there are concerns about overuse and the numerous reported side-effects. It is uncertain whether associations between PPI use and potential side effects are causal. However, important evidence from experimental and mechanistic studies that could support a causal relationship may have been underestimated by epidemiologists and meta-analysists. In the current manuscript we review the combined epidemiological and mechanistic evidence of the adverse effects of PPI use.

Insights into Effects/Risks of Chronic Hypergastrinemia and Lifelong PPI Treatment in Man Based on Studies of Patients with Zollinger-Ellison Syndrome

The use of proton pump inhibitors (PPIs) over the last 30 years has rapidly increased both in the United States and worldwide. PPIs are not only very widely used both for approved indications (peptic ulcer disease, gastroesophageal reflux disease (GERD), Helicobacter pylori eradication regimens, stress ulcer prevention), but are also one of the most frequently off-label used drugs (25–70% of total). An increasing number of patients with moderate to advanced gastroesophageal reflux disease are remaining on PPI indefinitely. Whereas numerous studies show PPIs remain effective and safe, most of these studies are <5 years of duration and little data exist for >10 years of treatment. Recently, based primarily on observational/epidemiological studies, there have been an increasing number of reports raising issues about safety and side-effects with very long-term chronic treatment. Some of these safety issues are related to the possible long-term effects of chronic hypergastrinemia, which occurs in all patients taking chronic PPIs, others are related to the hypo-/achlorhydria that frequently occurs with chronic PPI treatment, and in others the mechanisms are unclear. These issues have raised considerable controversy in large part because of lack of long-term PPI treatment data (>10–20 years). Zollinger–Ellison syndrome (ZES) is caused by ectopic secretion of gastrin from a neuroendocrine tumor resulting in severe acid hypersecretion requiring life-long antisecretory treatment with PPIs, which are the drugs of choice. Because in <30% of patients with ZES, a long-term cure is not possible, these patients have life-long hypergastrinemia and require life-long treatment with PPIs. Therefore, ZES patients have been proposed as a good model of the long-term effects of hypergastrinemia in man as well as the effects/side-effects of very long-term PPI treatment. In this article, the insights from studies on ZES into these controversial issues with pertinence to chronic PPI use in non-ZES patients is reviewed, primarily concentrating on data from the prospective long-term studies of ZES patients at NIH.