Incidence and risk factor of fundic gland polyp and hyperplastic polyp in long-term proton pump inhibitor therapy: a prospective study in Japan

Endoscopic findings and outcomes of gastric mucosal changes relating to potassium-competitive acid blocker and proton pump inhibitor therapy

Gastric mucosal changes associated with long-term potassium-competitive acid blocker and proton pump inhibitor (PPI) therapy may raise concern. In contrast to that for PPIs, the evidence concerning the safety of long-term potassium-competitive acid blocker use is scant. Vonoprazan (VPZ) is a representative potassium-competitive acid blocker released in Japan in 2015. In order to shed some comparative light regarding the outcomes of gastric mucosal lesions associated with a long-term acid blockade, we have reviewed six representative gastric mucosal lesions: fundic gland polyps, gastric hyperplastic polyps, multiple white and flat elevated lesions, cobblestone-like gastric mucosal changes, gastric black spots, and stardust gastric mucosal changes. For these mucosal lesions, we have evaluated the association with the type of acid blockade, patient gender, Helicobacter pylori infection status, the degree of gastric atrophy, and serum gastrin levels. There is no concrete evidence to support a significant relationship between VPZ/PPI use and the development of neuroendocrine tumors. Current data also shows that the risk of gastric mucosal changes is similar for long-term VPZ and PPI use. Serum hypergastrinemia is not correlated with the development of some gastric mucosal lesions. Therefore, serum gastrin level is unhelpful for risk estimation and for decision-making relating to the cessation of these drugs in routine clinical practice. Given the confounding potential neoplastic risk relating to H. pylori infection, this should be eradicated before VPZ/PPI therapy is commenced. The evidence to date does not support the cessation of clinically appropriate VPZ/PPI therapy solely because of the presence of these associated gastric mucosal lesions.

Profound gastric mucosal changes and severe rebound acid hypersecretion after long-term Vonoprazan use: A case report

Vonoprazan is a novel acid blocker with greater potency than proton pump inhibitors. A Japanese study reported no significant safety concerns over 5 years of Vonoprazan use; however, elevated serum gastrin and increased parietal cell and foveolar hyperplasia were observed, and long-term safety data beyond 5 years are limited. We report a case that used Vonoprazan for 6 years, complicated by significant gastric epithelial changes during treatment and acute duodenal mucosal lesions following its discontinuation. A 76-year-old, treated with proton pump inhibitors for over 10 years, was switched to Vonoprazan due to his worsening symptoms. After its use, hemorrhagic hyperplastic polyps became prominent. Given concerns about Vonoprazan's effect on the gastric epithelium, the medication was changed to high-dose H2 blocker therapy. Two months later, the patient complained of vomiting and black tarry stools. Esophagogastroduodenoscopy revealed a significant reduction of gastric polyps but multiple erosions and ulcers in the duodenum. This case indicates the potent effects of Vonoprazan on the gastric mucosa and the risk of severe rebound acid hypersecretion after its long-term use.

Effects of Medication Period and Gastrin Levels on Endoscopic Gastric Mucosal Changes in Long-Term Proton Pump Inhibitor Users

Background/Objectives: Proton pump inhibitor (PPI) use has increased worldwide, including in continuous and longer-term users. Recent reports highlight PPI-related endoscopic gastric mucosal changes, including fundic gland polyps, hyperplastic polyps, multiple white and flat elevated lesions, cracked and cobblestone-like mucosa (CCLM), and black spots. PPI use elevates gastrin levels because of acid inhibition, and hypergastrinemia might be relevant to these findings. In this cross-sectional study, we retrospectively examined gastric mucosal changes in long-term PPI users, focusing on medication period and gastrin levels. Methods: We enrolled 57 patients who received a PPI (>1 year) at two clinics between January 2021 and March 2022. Participants were classified according to medication period: 1 < 5, 5-10, and ≥10 years. Gastrin levels were categorized as low, middle, and high (<250, 250-500, and ≥500 pg/mL, respectively). Odds ratios (OR) were estimated to assess the risk of endoscopic findings. Results: Of the 57 patients, 6 (10.5%), 25 (43.9%), and 26 (45.6%) were PPI users of 1 < 5, 5-10, and ≥10 years, respectively. There were no significant differences in the incidence of endoscopic findings among the medication periods. Low, middle, and high gastrin groups included 21 (36.8%), 21 (36.8%), and 15 (26.3%) patients, respectively. CCLM incidence was significantly elevated in higher gastrin level groups: middle (OR, 6.60; 95% confidence interval [CI], 1.46-29.75; p = 0.014) and high (OR, 9.00; 95% CI, 1.79-45.23; p = 0.0008) (p-trend = 0.0171). No significant differences were observed for other findings. Conclusions: No elevated risk of PPI-related gastric epithelial changes in long-term PPI users was observed time-dependently. Notably, higher gastrin levels were positively associated with CCLM development, irrespective of the medication period.

Enlargement of Gastric Hyperplastic Polyps Arising from Helicobacter heilmannii sensu strico-infected Mucosa after the Successful Eradication of Helicobacter pylori and the Long-Term Use of a Proton Pump Inhibitor

Helicobacter pylori eradication is effective for the regression of gastric hyperplastic polyps (GHPs). We report a case which demonstrated an enlargement of GHPs after H. pylori eradication. The patient, who received long-term proton-pump inhibitor (PPI) therapy, lived with a dog, a natural host of Helicobacter heilmanii sensu stricto. Gastric colonization with Helicobacter heilmannii s.s. was observed after H. pylori eradication, thus suggesting the involvement of non-H. pylori Helicobacter species (NHPHs) infection for the enlargement of GHPs, in addition to the proliferative effects of PPI use on the gastric epithelium. Screening for NHPHs may be necessary in dog lovers to avoid paradoxical responses to H. pylori eradication.

Vonoprazan-Associated Mucosal Redness: A Report of Two Cases

Vonoprazan, a potassium-competitive acid blocker, is effective at treating acid-related gastrointestinal disorders but has been linked to gastric mucosal redness, a novel condition. This report describes two cases of vonoprazan-associated mucosal redness. Case 1 involved a 73-year-old woman who developed longitudinal erythema and mild mucosal changes after starting vonoprazan seven years ago. Case 2 involved a 70-year-old man who exhibited significant erythema and atrophic gastritis after seven months of treatment. In both cases, the pathological findings included hemorrhage in the superficial mucosa, highlighting that microhemorrhage may be the corresponding pathological finding for vonoprazan-associated mucosal redness.

Gastric dysplastic lesions in Helicobacter pylori-naïve stomach: Foveolar-type adenoma and intestinal-type dysplasia

Reports of Helicobacter pylori (Hp)-naïve gastric neoplasm (HpNGN) cases have been rapidly increasing due to the recent increase in the Hp-naïve population in Japan. Most HpNGNs exhibit the gastric immunophenotype and a low malignant potential regardless of histological type. Especially, foveolar-type gastric adenoma (FGA) and intestinal-type gastric dysplasia (IGD) rarely progress to invasive carcinoma. FGA is a foveolar epithelial neoplasm that occurs in the fundic gland (oxyntic gland) mucosa and is classified as the flat type or raspberry type (FGA-RA). The flat type is a large, whitish flatly elevated lesion while FGA-RA is a small reddish polyp. Genomically, the flat type is characterized by APC and KRAS gene mutations and FGA-RA by a common single nucleotide variant in the KLF4 gene. This KLF4 single-nucleotide variant reportedly induces gastric foveolar epithelial tumorigenesis and activates both cell proliferation and apoptosis, leading to its slow-growing nature. IGD consists of an intestinalized epithelial dysplasia that develops in the pyloric gland mucosa, characterized as a superficial depressed lesion surrounded by raised mucosa showing a gastritis-like appearance. Immunohistochemically, it exhibits an intestinal or gastrointestinal phenotype and, frequently, p53 overexpression. Thus, IGD shows unique characteristics in HpNGNs and a potential multistep tumorigenic process.

Long-term endoscopic change of gastric polyp associated with administration of vonoprazan

Vonoprazan (VPZ) has been available in Japan since 2015. Endoscopic features of proton-pump inhibitor (PPI)-related gastric mucosal changes, including fundic gland and hyperplastic polyps, have been observed. However, the relationship between gastric polyps and VPZ remains unclear. A 65-year-old man with reflux esophagitis-associated symptoms refractory to PPI was referred to our hospital. VPZ (20 mg) was administered for 3 weeks, which proved effective. Afterward, VPZ dose was reduced to 10 mg; the reflux symptoms worsened, and 20 mg VPZ was restarted. Afterward, esophagogastroduodenoscopy (EGD) revealed a gradually enlarging gastric polyp in the cardia. After 5 years of VPZ administration, the patient developed a reddish polyp (approximately 10 mm) with a whitish substance in the cardia. Based on the clinical course, the polyp was considered to have enlarged because of the long-term VPZ administration. After being informed of the endoscopic findings, the patient decided to discontinue VPZ. One year after VPZ discontinuation, EGD revealed a shrunken polyp (5 mm). Long-term acid suppression causes hypergastrinemia, which may lead to gastric mucosal changes, including gastric polyps. There are few case reports of a decrease in the number and size of gastric polyps after VPZ discontinuation. Hence, some VPZ-induced endoscopic changes may be reversible.

Multiple Gastric Neuroendocrine Tumors Associated with Long-term Use of a Proton Pump Inhibitor and a Potassium-competitive Acid Blocker

A 52-year-old man who had been using a proton pump inhibitor (PPI) and a potassium-competitive acid blocker (P-CAB) for 14 years underwent esophagogastroduodenoscopy and was found to have three neuroendocrine tumors (NETs) in the gastric body. Following detailed examinations, parietal cell dysfunction was excluded, and the NETs did not meet the criteria for the Rindi classification types I-III. The lesions were ultimately considered to be associated with the long-term use of the PPI and P-CAB. We performed endoscopic submucosal dissection of the lesions, with no recurrence or new lesions noted after discontinuation of the PPI and P-CAB.

Potassium-competitive acid blocker-associated gastric mucosal lesions

Since the introduction of vonoprazan, a potassium-competitive acid blocker (P-CAB), it has been demonstrated to reversibly inhibit gastric acid secretion by engaging in potassium-competitive ionic binding to H+/K+-ATPase. In contrast, proton pump inhibitors (PPIs) achieve H+/K+-ATPase inhibition through covalent binding to cysteine residues of the proton pump. Reported cases have indicated an emerging trend of P-CAB-related gastropathies, similar to those associated with PPIs, as well as unique gastropathies specific to P-CAB use, such as the identification of web-like mucus. Pathologically, parietal cell profusions, which show a positively correlated with hypergastrinemia, have a higher incidence in P-CAB users compared to PPI users. Thus, this review aims to summarize the endoscopic and pathological findings reported to date concerning P-CAB-related gastric mucosal lesions. Additionally, it seeks to discuss the differences between the PPIs and P-CABs in terms of the formation and frequency of associated gastropathies. This review highlights the evident differences in the mechanism of action and potency of acid inhibition between P-CABs and PPIs, notably contributing to differences in the formation and frequency of associated gastropathies. It emphasizes the necessity to distinguish between P-CAB-related and PPI-related gastropathies in the clinical setting.

Gastric Polyps in Long-Term Proton Pump Inhibitor Use: Identification of Risks and Characteristics

Aim Estimate the prevalence of gastric polyps linked to long-term use of proton pump inhibitor (PPI), determine the various risk factors that promote this association, and identify the characteristics associated with these polyps. Methods This prospective cross-sectional study was conducted on approximately 1000 patients presenting to the Gastroenterology Endoscopic Department for upper GI endoscopy at two hospital centers in Beirut, Lebanon, over a period of 12 months from September 2021 to September 2022. The demographic and clinical data of patients who had been taking PPIs for at least one month were collected via a questionnaire. All patients with a previous Helicobacter pylori (H. pylori) infection, presence of hypergastrinemia, or a personal/family history of gastric polyps were excluded from this study. Statistical analyses were performed using SPSS 20 software. Categorical variables were compared by Fisher's exact test; p-values of less than 0.05 were considered statistically significant. Results The prevalence of gastric polyps linked to long-term PPI use was 30%. The minimum duration of daily PPI use required for the formation of polyps is around 24 months. The dosage did not play a significant role in increasing this prevalence. A significant correlation was found between chronic PPI use and factors such as sex, age range, duration, and type of PPI used. These polyps were predominantly found in females (with an OR of 2.9), increased with age, were mostly of the fundic gland type, and their size was proportionally linked to both the dosage and duration of daily PPI use. No cases of dysplasia within the fundic gland polyps (FGPs) were demonstrated in our study. Conclusion To date, there is no current data that prove an association between gastric cancer and PPI-induced FGPs. Additionally, the incidence of FGPs has increased with the widespread chronic use of PPIs. Therefore, attention should be drawn to the potential risk of dysplasia. Thus, the present study highlights the importance of limiting the prescription of PPIs to globally well-defined indications and determining the various risk factors that promote the association between gastric polyps and PPI use. This abstract was recently presented as an E-poster at the ESGE Days 2024 Congress on April 25-27, 2024, in Berlin, Germany.

Omeprazole taken once every other day can effectively prevent aspirin-induced gastrointestinal mucosal damage in rats

BACKGROUND

Proton-pump inhibitors (PPIs) prevent aspirin-associated gastric and duodenal mucosal damage. However, long-term use of PPIs can lead to various adverse reactions, such as gastric polyps and enterochromaffin-like cell hyperplasia. Current research indicates that the abovementioned adverse reactions are mainly related to hypergastrinemia. We investigated whether low-frequency administration of omeprazole could effectively repair aspirin-induced mucosal damage and reduce the increase in gastrin levels associated with long-term use of PPIs.

METHODS

Sprague‒Dawley rats were divided into four treatment groups: daily aspirin, daily aspirin and omeprazole once every day (qd), daily aspirin and omeprazole once every other day (qod), and daily aspirin and omeprazole once every three days (1/d3). After 15 days of feeding, blood samples were collected, and the stomachs of sacrificed rats were subjected to macroscopic, histological, and immunohistochemical studies. Moreover, in clinical practice, patients with peptic ulcers caused by aspirin took a standard dose of omeprazole (20 mg) every other day. Two months later, gastroscopy was performed to examine the healing of the ulcers.

RESULTS

Both the omeprazole qd and omeprazole qod administrations effectively prevented aspirin-induced gastric peptic ulcers, with no significant difference between the two groups in the inhibition of parietal cell secretion of gastric acid and cell apoptosis. However, omeprazole 1/d3 failed to completely prevent aspirin-induced gastric mucosal injury. Notably, the gastrin levels, cell proliferation ability and cholecystokinin B receptor expression of the omeprazole qd group were significantly higher than those of the omeprazole qod group. In clinical work, patients with peptic ulcers caused by aspirin were given a standard dose of omeprazole every other day, and their ulcers healed after 2 months, as observed by gastroscopy.

CONCLUSIONS

Omeprazole administration once every other day can effectively prevent aspirin-induced peptic ulcers and reduce hypergastrinemia, which may reduce the long-term adverse effects of PPI treatment.

Drug-induced mucosal alterations observed during esophagogastroduodenoscopy

Several features of drug-induced mucosal alterations have been observed in the upper gastrointestinal tract, i.e., the esophagus, stomach, and duodenum. These include pill-induced esophagitis, desquamative esophagitis, worsening of gastroesophageal reflux, chemotherapy-induced esophagitis, proton pump inhibitor-induced gastric mucosal changes, medication-induced gastric erosions and ulcers, pseudomelanosis of the stomach, olmesartan-related gastric mucosal inflammation, lanthanum deposition in the stomach, zinc acetate hydrate tablet-induced gastric ulcer, immune-related adverse event gastritis, olmesartan-asso-ciated sprue-like enteropathy, pseudomelanosis of the duodenum, and lanthanum deposition in the duodenum. For endoscopists, acquiring accurate knowledge regarding these diverse drug-induced mucosal alterations is crucial not only for the correct diagnosis of these lesions but also for differential diag-nosis of other conditions. This minireview aims to provide essential information on drug-induced mucosal alterations observed on esophagogastroduodenoscopy, along with representative endoscopic images.

Multidisciplinary Consensus for Rationalizing the Use of Acid Suppressants in Children and Adults: CONFOR

The use of acid suppression therapy (AST) is a common approach for managing a wide spectrum of acid peptic disorders. Histamine type 2-receptor antagonists (H2RAs) and proton pump inhibitors (PPIs) are the most widely prescribed AST in routine clinical practice. However, an exponential surge in the prescriptions of PPIs, such as Omeprazole, Esomeprazole, Pantoprazole, Lansoprazole in recent years and their associated adverse effects have raised concern about their inappropriate and overuse, both in children and adults. To address these issues, a three-step modified Delphi polling process was employed to establish best practice consensus statements for rationalizing the use of acid suppressants. A multidisciplinary expert panel of 13 health professionals across medical specialties, including gastroenterologists, hepatologists, pediatric gastroenterologists, pediatricians, otolaryngologists, cardiologists, nephrologists, gynecologist and orthopedists actively contributed to this collaborative process of consensus development. The expert panel proposed 21 consensus statements providing best practice points on the general use and safety of acid suppressants based on a comprehensive review of scientific literature and clinical expertise. The panel also collaboratively developed a PPI deprescribing algorithm. Altogether, this consensus paper offers evidence-based recommendations and guidance for the rational use of acid suppressants with a blueprint for deprescribing PPIs. This consensus paper contributes to aiding primary care practitioners in improving patient outcomes and minimizing healthcare costs. Additionally, it enhances patient safety and curtail inappropriate usage.

How to cite this article

Prabhoo RY, Pai UA, Wadhwa A, et al. Multidisciplinary Consensus for Rationalizing the Use of Acid Suppressants in Children and Adults: CONFOR. Euroasian J Hepato-Gastroenterol 2024;14(1):99-119.

Severe Anemia from Multiple Gastric Hyperplastic Polyps in a Hemodialysis Patient after Long-term Use of a Proton-pump Inhibitor

A 90-year-old man on maintenance hemodialysis was admitted due to severe symptomatic anemia. Biopsies under esophagogastroduodenoscopy demonstrated that the cause of anemia was intermittent blood oozing from multiple gastric hyperplastic polyps. Even after successful eradication of Helicobacter pylori, he showed hypergastrinemia (480 pg/mL) owing to esomeprazole (proton-pump inhibitor) therapy for the past 4.5 years to treat reflux esophagitis. Seven months after we switched esomeprazole to famotidine (H2-receptor antagonist), those gastric polyps and anemia were remarkably ameliorated with lowered gastrin levels. This case indicates that long-term use of a proton-pump inhibitor triggers chronic hypergastrinemia, leading to gastric hyperplastic polyps and subsequent severe anemia.

Association between occurrence of multiple white and flat elevated gastric lesions and oral proton pump inhibitor intake

BACKGROUND/AIMS

Multiple white and flat elevated lesions (MWFL) that develop from the gastric corpus to the fornix may be strongly associated with oral antacid intake. Therefore, this study aimed to determine the association between the occurrence of MWFL and oral proton pump inhibitor (PPI) intake and clarify the endoscopic and clinicopathological characteristics of MWFL.

METHODS

The study included 163 patients. The history of oral drug intake was collected, and serum gastrin levels and anti-Helicobacter pylori immunoglobulin G antibody titers were measured. Upper gastrointestinal endoscopy was performed. The primary study endpoint was the association between MWFL and oral PPI intake.

RESULTS

In the univariate analyses, MWFL were observed in 35 (49.3%) of 71 patients who received oral PPIs and 10 (10.9%) of 92 patients who did not receive oral PPIs. The occurrence of MWFL was significantly higher among patients who received PPIs than in those who did not (p<0.001). Moreover, the occurrence of MWFL was significantly higher in patients with hypergastrinemia (p=0.005). In the multivariate analyses, oral PPI intake was the only significant independent factor associated with the presence of MWFL (p=0.001; odds ratio, 5.78; 95% confidence interval, 2.06-16.2).

CONCLUSION

Our findings suggest that oral PPI intake is associated with the presence of MWFL (UMINCTR 000030144).

Endoscopic differential diagnosis between foveolar-type gastric adenoma and gastric hyperplastic polyps in Helicobacter pylori-naïve patients

BACKGROUND

Foveolar-type gastric adenoma (FGA) occurs in Helicobacter pylori (Hp)-naïve individuals and morphologically mimics Hp-naïve gastric hyperplastic polyp (HpN-GHP). FGA is often difficult to distinguish from HpN-GHP even by biopsy, due to its low-grade histologic atypia. We conducted a retrospective study to create an endoscopic diagnostic index.

METHODS

We analyzed 51 FGAs in 41 patients and 36 HpN-GHPs in 24 patients. All lesions were photographed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). Three experts and three non-experts reviewed the WLE and WLE+NBIME images to assess six items for lesion diagnosis. We analyzed correlations between the diagnostic items and histologic features and compared the diagnostic accuracy between modalities. We created a composite diagnostic index and calculated its accuracy and consistency.

RESULTS

FGAs more frequently showed the following features vs. HpN-GHPs: bright-red color (94.1% vs. 44.4%), peripheral hyperplasia (58.8% vs. 8.3%), papillary/gyrus-like microstructure (96.1% vs. 33.3%), visible capillaries (70.6% vs. 38.9%), and demarcation line (98.0% vs. 41.7%) (P < 0.05). White-zone thickening was seen only in HpN-GHPs (52.8%). Diagnostic accuracy (mean, WLE vs. WLE+NBIME) was 90.8 ± 1.1% vs. 93.5 ± 2.4% (P = 0.15) for experts and 88.5 ± 3.0% vs. 86.6 ± 3.5% (P = 0.51) for non-experts. When satisfying the four criteria (bright-red color, papillary/gyrus-like microstructure, demarcation line, and absent white-zone thickening), sensitivity and specificity for FGA were 90.2% and 94.4%, respectively, with a kappa value of ≥ 0.6 for interobserver diagnostic agreement.

CONCLUSIONS

Composite diagnostic index contributes to the reproducible, accurate, preoperative differential diagnosis of FGA and HpN-GHP.

Challenges and opportunities in delivering oral peptides and proteins

INTRODUCTION

Rapid advances in bioengineering enable the use of complex proteins as therapeutic agents to treat diseases. Compared with conventional small molecule drugs, proteins have multiple advantages, including high bioactivity and specificity with low toxicity. Developing oral dosage forms with active proteins is a route to improve patient compliance and significantly reduce production costs. However, the gastrointestinal environment remains a challenge to this delivery path due to enzymatic degradation, low permeability, and weak absorption, leading to reduced delivery efficiency and poor clinical outcomes.

AREAS COVERED

This review describes the barriers to oral delivery of peptides and complex proteins, current oral delivery strategies utilized and the opportunities and challenges ahead to try and circumvent these barriers. Oral protein drugs on the market and clinical trials provide insights and approaches for advancing delivery strategies.

EXPERT OPINION

Although most current studies on oral protein delivery rely on in vitro and in vivo animal data, the safety and limitations of the approach in humans remain uncertain. The shortage of clinical data limits the development of new or alternative strategies. Therefore, designing appropriate oral delivery strategies remains a significant challenge and requires new ideas, innovative design strategies and novel model systems.

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).

Long-term vonoprazan administration causes gastric fundic gland-type hyperplastic polyps and chronic bleeding

A patient experienced gastric fundic gland-type hyperplastic polyps, consisting of foveolar epithelium and parietal cells, complicated with chronic bleeding due to long-term treatment with vonoprazan. The patient had progressive anemia, probably caused by bleeding from the polyps. After switching from vonoprazan to a histamine-2 (H2) receptor antagonist, the polyps markedly shrank and the anemia improved. Vonoprazan can produce reversible hyperplastic polyps and anemia. In case of anemia in patients receiving long-term vonoprazan, it is important to consider drug cessation or change to an H2 blocker.

Gastric Hyperplastic Polyps Can Shrink After Discontinuation of Proton Pump Inhibitors: A Case Series Compared With Continuation of Proton Pump Inhibitors

GOAL

This study investigated whether gastric hyperplastic polyps (GHPs) shrink after discontinuation of proton pump inhibitor (PPI) alone.

BACKGROUND

Long-term use of PPIs has been reported to increase the incidence of GHPs, which sometimes bleed and cause anemia. We experienced a patient whose recurrent hemorrhagic GHPs associated with long-term use of PPIs had disappeared after discontinuation of PPIs.

STUDY

This study was conducted retrospectively at Kyoto University Hospital. Patients with histologically confirmed GHPs who had been taking PPIs for >6 months and who had undergone a repeat endoscopy within 2 years were included. Polyp shrinkage was defined as the disappearance of polyps or a reduction of >50% in the long diameter of the largest polyp.

RESULTS

Six patients who discontinued PPIs were compared with 17 patients who continued PPIs. Polyp shrinkage was significantly more frequent in the PPI-discontinuation group (5/6, 83%) than in the PPI continuation group (0/17, 0%) (P<0.001). In 2 patients in the PPI-discontinuation group, the polyps completely disappeared finally.

CONCLUSION

These findings suggest that discontinuation of PPIs can shrink GHPs in patients using PPIs.

Occurrence of a Duodenal Polypoid Lesion During Long-Term Acid Suppression Therapy and Its Regression After Drug Discontinuation

Formation of multiple fundic gland polyps or hyperplastic polyps in the gastric mucosa is one of the well-known adverse effects of the long-term acid suppression therapy for peptic ulcer disease. However, similar phenomenon has not been reported to occur in the duodenum. We report a case of duodenal polypoid lesion that developed after the long-term use of acid suppressants and disappeared after the cessation of the treatment. The patient was a 76-year-old man with a history of heavy cigarette smoking and excessive alcohol intake who had been treated with medication of gastric acid suppressants, including proton pump inhibitors and potassium-competitive acid blockers, for refractory gastroesophageal reflux disease. After receiving the acid suppression therapy for 3 years, a polypoid lesion of 10 mm in diameter was found at the portion of the duodenal bulb. This polypoid lesion disappeared 1.5 months after the cessation of treatment. We hypothesized that changes in serum gastrin levels caused by acid suppression therapy might have been associated with the development and regression of the duodenal polypoid lesion.

Proton Pump Inhibitor-Associated Large Hyperplastic Polyp in Non-Helicobacter pylori-Infected Stomach

A proton pump inhibitor (PPI)-associated hyperplastic polyp (HP) in the non-Helicobacter pylori-infected stomach is rare, and its endoscopic features remain poorly described. A 42-year-old man with tarry stool was referred to our hospital for examination and treatment. He had taken PPI for 14 years and was confirmed to be H. pylori-negative. Transnasal endoscopy revealed bleeding from a 20-mm, reddish pedunculated polyp with a nodular surface, located in the greater curvature of the upper gastric body. Endoscopic mucosal resection was performed, and the lesion was diagnosed as an HP. To our knowledge, this report represents a valuable addition to the HP literature describing a rare case of PPI-associated large HP in the non-H. pylori-infected stomach.

Sporadic foveolar-type gastric adenoma with a raspberry-like appearance in Helicobacter pylori-naïve patients

Sporadic foveolar-type gastric adenoma (FGA) has been described as an extremely rare polyp that is whitish and flatly elevated. However, we recently found that sporadic FGA with a raspberry-like appearance (FGA-RA) is not rare in Helicobacter pylori (H. pylori)-naïve gastric mucosa. We endoscopically or surgically treated 647 patients with gastric epithelial neoplasms in the last 5 years, with 7.7% (50/647) being H. pylori-naïve. Among these, 43 FGA-RAs were diagnosed based on histologic and endoscopic features in 34 patients, who were all enrolled in this retrospective study. All lesions were observed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). We subsequently analyzed their endoscopic and microscopic features and patient characteristics. The patients were 22 males and 12 females aged 57±23 years (mean±2SD). WLE showed raspberry-like small polyps mimicking gastric hyperplastic polyps in the oxyntic gastric compartment (body/fundus). Multiple growths were confirmed in 20.6% (7/34) of the patients. NBIME revealed irregularly shaped papillary/gyrus-like microstructures with abnormal capillaries. Histologically, all lesions were intraepithelial neoplasms, and most of lesions (62.8%, 27/43) exhibited low-grade dysplasia. Immunohistochemically, neoplastic cells featured strong and diffuse MUC5AC expression, negative or very low MUC6 expression, and negative MUC2/CD10 expression. They also showed Ki-67 hyperexpression with a mean labeling index of 59.4±48.7%. The coexistence of fundic gland polyps in the background mucosa was significantly higher in multiple FGA-RA cases than in solitary cases (100% vs. 55.5%, P< 0.05). FGA-RA is a newly suggested histologic variant of sporadic FGA whose occurrence is not rare in daily endoscopic practice.

Proton Pump Inhibitor-Related Gastric Mucosal Changes

Proton pump inhibitors (PPIs) are used worldwide to treat of acid-related disorders such as peptic ulcer and gastroesophageal reflux disease and to prevent gastroduodenal injuries due to nonsteroidal anti-inflammatory drugs. PPIs are the most potent inhibitors of gastric acid secretion currently available, and they are one of the most commonly prescribed classes of drugs because of their high efficacy and low toxicity. However, long-term PPI use causes histopathological changes such as parietal cell protrusion into the gland lumen, cystic dilation of gastric fundic glands, and foveolar epithelial hyperplasia. These changes can manifest on endoscopic examination as fundic gland polyps, hyperplastic polyps, multiple white and flat elevated lesions, cobblestone-like mucosa, or black spots. Clinicians must be aware of PPI-induced endoscopic features in patients with chronic long-term PPI use. Conversely, identifying patients with long-term PPI use based on their endoscopic findings is important. Recently, potassium-competitive acid blockers (P-CABs), a new class of acid suppressants that inhibit gastric acid secretion more strongly than PPIs, have recently been introduced clinically. Further long-term prospective studies on these gastric mucosal lesions in patients with either PPI or P-CAB use are required to investigate their association with histopathological changes and to establish the clinical significance of these findings.

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.

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.

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.

White Spot, a Novel Endoscopic Finding, May Be Associated with Acid-Suppressing Agents and Hypergastrinemia

White globe appearance (WGA) is defined as a microendoscopic white lesion with a globular shape underlying the gastric epithelium and is considered a marker of gastric cancer. We recently reported that endoscopically visualized white spot (WS) corresponding to WGA appeared on the nonatrophic mucosa of patients with acid-suppressing agents (A-SA) use. We evaluated patients undergoing routine esophagogastroduodenoscopy and divided the patients into an A-SA group (n = 112) and a control group (n = 158). We compared the presence of WS in both groups. We also compared WS-positive- (n = 31) and -negative (n = 43) groups within the A-SA group regarding these patients' backgrounds and serum gastrin concentrations. Comparing the A-SA group with controls, the prevalence of WS was significantly higher (31/112 vs. 2/158; p < 0.001). The number of patients with high serum gastrin concentrations was significantly higher in the WS-positive group (18/31) vs. the WS-negative group (5/43) (p < 0.001). Within the A-SA group, the prevalence of WS was also significantly higher in patients taking potassium-competitive acid blockers vs. proton-pump inhibitors (21/31 vs. 10/31, p < 0.001). The WS-positive group had a significantly greater percentage of patients, with a high serum gastrin level (p < 0.001). WS may be associated with hypergastrinemia and potassium-competitive acid blockers.

Gastric Hyperplastic Polyps after Argon Plasma Coagulation for Gastric Antral Vascular Ectasia in Patients with Liver Cirrhosis: A Case Suggesting the "Gastrin Link Theory"

We herein report a case of gastric hyperplastic polyps after argon plasma coagulation (APC) for gastric antral vascular ectasia (GAVE) in the antrum of a 65-year-old man with liver cirrhosis and hypergastrinemia induced by long-term proton pump inhibitor (PPI) use. Two years after APC therapy, endoscopy demonstrated multiple gastric polyps in the antrum and angle. A gastric polyp biopsy indicated foveolar epithelium hyperplasia, which was diagnosed as gastric hyperplastic polyps. One year after switching to an H2 blocker antagonist, endoscopy revealed that the polyps and GAVE had disappeared, with normal gastrin levels suggesting that PPI-induced hypergastrinemia had caused gastric hyperplastic polyps after APC therapy, and the polyps had disappeared after discontinuing PPIs.

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) - A Helicobacter-opposite point

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a rare familial gastric cancer syndrome with an autosomal dominant pattern of inheritance. It is characterised by fundic gland polyposis of the gastric body and is associated with a significant risk of gastric adenocarcinoma. Unlike sporadic gastric cancer, Helicobacter pylori is usually absent in patients with GAPPS. This opposite-point finding has so far not been fully clarified. Prophylactic total gastrectomy is indicated in all cases of GAPPS with fundic gland polyposis and the presence of any dysplasia. If no dysplasia is found at histology, prophylactic gastrectomy is suggested at between 30 and 35 years of age, or at five years earlier than the age at which the youngest family member developed gastric cancer. Different phenotypes of GAPPS demand an individual approach to particular family members.

Large Fundic Gland Polyp Associated with Long-Term Proton Pump Inhibitor Administration Mimicking Gastric-Type Neoplasm

A 57-year-old man with a 10-year history of proton pump inhibitor (PPI) use presented with multiple fundic gland polyps (FGPs) including one >20 mm, whitish, semi-pedunculated polyp. Black spots and cobblestone-like mucosa were also observed in the stomach upon endoscopy; therefore, the lesion was considered to result from long-term PPI administration. Endoscopically, we diagnosed this polyp as a neoplastic lesion with gastric phenotype rather than a non-neoplastic lesion. Biopsy revealed an atypical glandular lesion that was indeterminate for neoplasia; therefore, we performed en bloc resection via endoscopic submucosal dissection (ESD) of the 22 × 22 × 10 mm-sized polyp. Histologically, the polyp was composed of hyperplastic foveolar epithelia in the upper half of the mucosa and hyperplastic fundic glands in the lower half of the mucosa, with luminal dilatation and parietal cell protrusion. The pathological diagnosis for this ESD specimen was FGP associated with PPI administration. We herein describe this rare case of a large FGP in Helicobacter pylori-uninfected gastric mucosa associated with long-term PPI administration, which was mimicking gastric-type neoplasm and resected by endoscopy.

Disappearance of Gastric Hyperplastic Polyps after the Discontinuation of Proton Pump Inhibitor in a Patient with Liver Cirrhosis

Here, we report on a rare case of gastric hyperplastic polyps which disappeared after the discontinuation of proton pump inhibitor (PPI). The patient was an 83-year-old woman with liver cirrhosis and portal hypertension, along with gastroesophageal reflux disease treated by PPI. An initial upper gastrointestinal endoscopy showed unique polypoid lesions in the greater curvature of the stomach. Biopsy specimens of the lesions were diagnosed as hyperplastic polyps and she was followed. One year later, a second endoscopy showed that the lesions had increased in number and size, and an endoscopic mucosal resection (EMR) was performed for the main polyps. The resected specimens indicated a proliferation of foveolar epithelium cells with an increase of capillary ectasia and parietal cell hyperplasia, which was thought to be induced by hypergastrinemia from the PPI. Three months after the EMR, she was admitted because of bleeding from the remaining polyps along with an increase in new polyps. After conservative treatment, PPI was stopped and rebamipide was used. One year and 6 months later, an endoscopy showed the complete disappearance of all gastric polyps.

Histopathologic Change of a Case of Gastric Oxyntic Neoplasm (Gastric Adenocarcinoma of Fundic Gland Mucosa Type) Through 5 Years With Concurrent Other Oxyntic Gland Lesions

Some gastric epithelial neoplasms show predominant chief cell differentiation (oxyntic gland neoplasms), in which the entity of "gastric adenocarcinoma of fundic gland type" was firstly designated, whereas a possible more aggressive subgroup "gastric adenocarcinoma of fundic gland mucosa type" (GA-FGM) was subsequently proposed. However, the histopathologic progression mode of these neoplasms has not been sufficiently reported. In this article, we describe a case of GA-FGM in which we could observe its progression during 5 years. The tumor was removed by endoscopic submucosal dissection 5 years after the first biopsy, which had already shown a feature of oxyntic gland neoplasm. During the follow-up period, the endoscopy revealed little change in the tumor appearance. However, the histology of endoscopic submucosal dissection showed submucosal extension with its histological progression. Besides, other oxyntic gland neoplasms of the stomach were observed metachronously or synchronously, giving an implication about a common pathogenetic basis of these lesions.

Fundic gland polyp prevalence according to Helicobacter pylori infection status

BACKGROUND AND AIM

The prevalence of fundic gland polyp (FGP) occurrence has not been clarified in individuals with Helicobacter pylori infection post-eradicated status. This study was performed to examine the relationship between FGP prevalence and H. pylori infection status.

METHODS

We enrolled 3400 subjects (2185 male subjects and 1215 female subjects; mean age 54.7 ± 9.5 years) with known H. pylori infection status and who underwent an upper gastrointestinal endoscopy examination as part of an annual check-up. Subjects without and with H. pylori infection numbered 1617 and 239, respectively, while 1544 had a post-eradication status. The presence of FGP and degree of gastric mucosal atrophy were determined in each subject using an endoscopic method.

RESULTS

Endoscopy findings showed FGPs in 1029 (30.3%) of all subjects. The prevalence ratio of FGP positivity in H. pylori-negative, H. pylori-positive, and post-eradicated subjects was 51.9%, 1.7%, and 12.0%, respectively. Multiple logistic regression analysis revealed that female gender, older age, milder gastric mucosal atrophy, and anti-secretory therapy were significant risk factors for FGP occurrence. As compared with H. pylori-positive subjects, the odds ratios for H. pylori-negative and post-eradication status were 48.3 and 6.6, respectively (P < 0.001). In the post-eradication status subjects, longer duration following bacterial eradication was a significant risk factor for occurrence of FGPs.

CONCLUSION

The risk of FGP occurrence in individuals who have undergone H. pylori eradication treatment is lower as compared with those who have never been infected. However, that risk increases over time following eradication.

Histological analysis of fundic gland polyps secondary to PPI therapy

AIMS

The aim of this study was to clarify the histopathological features of fundic gland polyps (FGPs) in patients treated with proton pump inhibitors (PPIs) and to investigate the mechanism of enlargement of FGPs after PPI treatment.

METHODS AND RESULTS

A total of 196 biopsy specimens of FGPs, which consisted of 87 FGPs in patients treated with PPIs (PPI group) and 109 FGPs in patients treated without PPIs (non-PPI group) were compared histologically using haematoxylin and eosin staining, Ki67 immunohistochemistry and multiplex immunohistochemical stain with Ki67, MUC5AC and MUC6. The significant histological features of FGPs in the PPI group were: larger size of dilated fundic gland cysts, larger number of foveolar and mixture type fundic gland cysts, foveolar cell hyperplasia, parietal cell protrusion, mononuclear cell infiltration and a higher percentage of Ki67-positive cells in the deeper layers of the glands. Multiplex immunohistochemical stain showed that Ki67-positive cells were also positive for MUC5AC, and the Ki67-positive rate was significantly higher in MUC5AC-positive cells of the PPI group than of the non-PPI group. Gene mutations of β-catenin were found in only 9.7% of FGPs in the PPI group.

CONCLUSIONS

Enlargement of fundic gland cysts due to foveolar cell proliferation and parietal cell protrusion might promote the enlargement of FGPs in patients treated with PPIs. β-catenin gene mutations might not be associated with these histological changes of FGPs after PPI treatment.

Synchronous Three Gastric Fundic Gland Polyps with Low-grade Dysplasia Treated with Endoscopic Mucosal Resection after Being Diagnosed to Be Tubular Adenocarcinoma Based on a Biopsy Specimen

A 51-year-old woman had been taking proton pump inhibitor since August 2008. In May, 2016, endoscopic findings showed no atrophy and no intestinal metaplasia in the stomach, and multiple fundic gland polyps were identified in the stomach. A biopsy of a pedunculated polyp measuring 10 millimeters in diameter at the greater curvature of the middle gastric body demonstrated well differentiated tubular adenocarcinoma. In July 2016, we treated this lesion and two other semipedunculated polyps located near the first polyp and also measuring 10 mm in diameter by endoscopic mucosal resection. The final diagnosis of all lesions was a fundic gland polyp with low grade dysplasia and the cutting end was negative.

Gastric foveolar-type adenomas endoscopically showing a raspberry-like appearance in the Helicobacter pylori -uninfected stomach

Background and study aims  Foveolar-type adenoma is described as a very rare tumor that occurs in individuals without Helicobacter pylori (HP) infection and diagnosed as adenocarcinoma in the Japanese Classification of Gastric Carcinoma (JCGC). However, we have frequently encountered patients with foveolar-type adenoma that endoscopically resembles a hyperplastic polyp, suggesting that it has just been overlooked to date. Here, we analyzed clinicopathological characteristics of a special subtype of foveolar-type adenoma showing specific endoscopic findings. Patients and methods  From a total of 212 patients with gastric cancer resected during a 22-month period, we enrolled 14 (6.6 %) diagnosed with foveolar-type adenoma (adenocarcinoma in JCGC). HP infection status was determined by eradication history, HP serum IgG antibody level, urea breath test, and endoscopic and histological findings. All lesions were observed using white-light endoscopy and narrow-band imaging with magnification endoscopy (NBIME). Endoscopically resected lesions were histologically examined. Results  None of 14 patients had a current or past history of HP infection. All lesions were visualized on non-atrophic gastric mucosa as small reddish protrusions with fine granular surface, showing a raspberry-like appearance. NBIME showed papillary or gyrus-like microstructures with irregular capillary. Lesions were histologically diagnosed as foveolar-type adenoma showing MUC5AC-positive gastric mucin phenotype. Ki-67 was overexpressed (median labeling index 69.9 %, range 28.4 - 92.1 %), though all lesions were an intraepithelial tumor without stromal invasion. p53 over-staining was not seen in any. Conclusions  Raspberry-like lesions on non-atrophic gastric mucosa in HP-uninfected individuals should be evaluated for the possibility of a special subtype of foveolar-type adenoma.

Hyperplastic polyps arising in autoimmune metaplastic atrophic gastritis patients: is this a distinct clinicopathological entity?

OBJECTIVES

Gastric hyperplastic polyp (GHP) commonly arises in the abnormal surrounding mucosa, including autoimmune metaplastic atrophic gastritis (AMAG). We aimed to compare clinicopathological features in patients with GHPs associated with AMAG with those in patients with GHPs associated with non-AMAG.

PATIENTS AND METHODS

A total of 1170 patients with GHP(s) were enrolled, and their clinical and pathological data were analyzed, retrospectively.

RESULTS

The GHP patients were divided into 181 A-GHP (type A GHP, AMAG-associated GHP) participants, 312 B-GHP (type B GHP, Helicobacter pylori infection-associated GHP) participants, and 677 other GHP participants (non-A-GHP and non-B-GHP) based on pathological status of the surrounding non-polypoid mucosa. The A-GHP patients were older and predominantly female (p < .05). Gastroscopically, A-GHPs showed less distal and more multiple-region distribution in the stomach (p < .001). In addition, the A-GHPs were observed to be usually numerous (55.8%), larger (mean maximum diameter 12.3 mm), and more pedunculated or sub-pedunculated (45.3%) (p < .001). Histopathologically, the intestinal metaplasia, intraepithelial neoplasia, and carcinomatous transformation within GHPs were present in 24.3%, 9.9%, and 2.8% of AMAG patients, respectively, which were significantly higher than those in the B-GHPs and other GHPs (p < .05). However, the differences of intraepithelial neoplasia and adenocarcinoma in surrounding non-polypoid mucosa did not reach statistical significance (p > .05).

CONCLUSIONS

The GHP(s) arising in AMAG patients is a distinct subgroup of GHP(s) and was an important precancerous lesion. The biopsy from surrounding non-polypoid mucosa was essential to evaluate the underlying etiology of the GHPs, and endoscopists should pay attention to these.

Role of Acid Suppression in Acid-related Diseases: Proton Pump Inhibitor and Potassium-competitive Acid Blocker

Proton pump inhibitors are commonly utilized for the treatment of gastric acid-related diseases, such as gastroesophageal reflux disease, peptic ulcer disease, and Helicobacter pylori infection, and for the prevention of low-dose aspirin or nonsteroidal anti-inflammatory drug-induced peptic ulcers. Vonoprazan is a first-in-class potassium-competitive acid blocker, which has distinct advantages compared to other conventional proton pump inhibitors in terms of the efficacy for acid suppression. Due to its strong gastric acid suppression capabilities, vonoprazan serves as an effective drug for the treatment of gastroesophageal reflux disease and H. pylori infection.

Evaluation of gastric acid suppression with vonoprazan using calcium carbonate breath test

Vonoprazan, a potassium-competitive acid blocker, is a new class of acid-suppressing agent. The acid-inhibitory effect of vonoprazan has been well-documented. However, there is no report on the extent to which the amount of gastric acid secretion is suppressed, not pH measurement, by the use of vonoprazan. The aim of this study was to evaluate this suppression effect. This was a single-arm, interventional pilot study involving 7 healthy Japanese men. The subjects were administered 20 mg vonoprazan for 6 days. The amount of gastric acid secretion was determined using the calcium carbonate breath test. The acid outputs were defined as the maximum Δ¹³C‰ (Δ¹³C max) and area under the curve (AUC) during the 30 min sampling period. The Δ¹³C max and AUC values significantly decreased on the administration of 20 mg vonoprazan. The AUC dropped by approximately 78% on day 1 and by 84% on day 6 and subsequently returned to the control level after cessation of vonoprazan therapy (reduction by 68% on day 7 and by 42% on day 8). In conclusion, the amount of gastric acid secretion rapidly decreased by the administration of vonoprazan; this inhibitory effect was found to be potent and long-lasting. (UMIN ID: UMIN000025469).

Magnified Endoscopic Findings of Multiple White Flat Lesions: A New Subtype of Gastric Hyperplastic Polyps in the Stomach

Background/Aims:

While the occurrence of multiple whitish flat elevated lesions (MWFL) was first reported in 2007, no studies on MWFL have been published to date. The present retrospective observational study aimed to clarify the endoscopic findings and clinicopathological features of MWFL.

Methods:

Subjects were consecutive patients who underwent upper gastrointestinal endoscopy as part of routine screening between April 2014 and March 2015. The conventional white-light, non-magnifying and magnifying narrow-band images were reviewed. Clinical features were compared between patients with and without MWFL.

Results:

The conventional endoscopic findings of MWFL include multiple whitish, flat, and slightly elevated lesions of various sizes, mainly located in the gastric body and fundus. Narrow-band imaging enhanced the contrast of MWFL and background mucosa, and magnifying narrow-band imaging depicted a uniformly long, narrow, and elliptical marginal crypt epithelium with an unclear microvascular pattern. Histopathological findings revealed hyperplastic changes of the foveolar epithelium, and parietal cell protrusions and oxyntic gland dilatations were observed in the fundic glands, without any intestinal metaplasia. The rate of acid-reducing drug use was significantly higher in patients with MWFL than in those without (100% [13/13] vs. 53.7% [88/164], p<0.001).

Conclusions:

The present study indicated a relationship between the presence and endoscopic features of MWFL and history of acidreducing drug use.