Hypergastrinemia is associated with adenocarcinomas in the gastric corpus and shorter patient survival

The role of microbiota in gastric cancer: A comprehensive review

BACKGROUND

Gastric cancer (GC) continues to pose a significant global threat in terms of cancer-related fatalities. Despite notable advancements in medical research and therapies, further investigation is warranted to elucidate its underlying etiology and risk factors. Recent times have witnessed an escalated emphasis on comprehending the role of the microbiota in cancer development.

METHODS

This review briefly delves into recent developments in microbiome-related research pertaining to gastric cancer.

RESULTS

According to studies, the microbiota can influence GC growth by inciting inflammation, disrupting immunological processes, and generating harmful microbial metabolites. Furthermore, there is ongoing research into how the microbiome can impact a patient's response to chemotherapy and immunotherapy.

CONCLUSION

The utilization of the microbiome for detecting, preventing, and managing stomach cancer remains an active area of exploration.

The central role of gastrin in gastric cancer

The prevalence of gastric cancer has markedly declined, but due to the high mortality rates associated with gastric cancer, it is still a serious disease. The preferred classification of gastric cancer is according to Lauren into either the intestinal type, which has a glandular growth pattern, or the diffuse type, which does not have glandular structures. Both types have been classified as adenocarcinomas, with the latter type based on periodic acid-Schiff (PAS) positivity presumed to reflect mucin. However, the presence of mucin in the diffuse type, in contrast to neuroendocrine/enterochromaffin-like (ECL) cell markers, has not been confirmed by immunohistochemistry and in situ hybridization. The ECL cells are probably prone to becoming cancerous because they do not express E-cadherin. Gastric cancer is unique in that a bacterium, Helicobacter pylori, is thought to be its main cause. H. pylori predisposes infected individuals to cancer only after having caused oxyntic atrophy leading to gastric hypoacidity and hypergastrinemia. No single H. pylori factor has been convincingly proved to be carcinogenic. It is probable that gastrin is the pathogenetic factor for gastric cancer due to H. pylori, autoimmune gastritis, and long-term prolonged inhibition of gastric acid secretion. Hypergastrinemia induces ECL cell hyperplasia, which develops into neuroendocrine tumors (NETs) and then into neuroendocrine carcinomas in rodents, a sequence that has also been described in humans. During carcinogenesis, the tumor cells lose specific traits, requiring that sensitive methods be used to recognize their origin. Gastric cancer occurrence may hopefully be prevented by H. pylori eradication at a young age, and by the reduced use of inhibitors of acid secretion and use of a gastrin antagonist in those with previous long-term H. pylori infection and those with autoimmune gastritis.

Inflammation and Digestive Cancer

Chronic inflammation is linked to carcinogenesis, particularly in the digestive organs, i.e., the stomach, colon, and liver. The mechanism of this effect has, however, only partly been focused on. In this review, we focus on different forms of chronic hepatitis, chronic inflammatory bowel disease, and chronic gastritis, conditions predisposing individuals to the development of malignancy. Chronic inflammation may cause malignancy because (1) the cause of the chronic inflammation is itself genotoxic, (2) substances released from the inflammatory cells may be genotoxic, (3) the cell death induced by the inflammation induces a compensatory increase in proliferation with an inherent risk of mutation, (4) changes in cell composition due to inflammation may modify function, resulting in hormonal disturbances affecting cellular proliferation. The present review focuses on chronic gastritis (Helicobacter pylori or autoimmune type) since all four mechanisms may be relevant to this condition. Genotoxicity due to the hepatitis B virus is an important factor in hepatocellular cancer and viral infection can similarly be central in the etiology and malignancy of inflammatory bowel diseases. Helicobacter pylori (H. pylori) is the dominating cause of chronic gastritis and has not been shown to be genotoxic, so its carcinogenic effect is most probably due to the induction of atrophic oxyntic gastritis leading to hypergastrinemia.

Association between Proton Pump Inhibitor Use and Risk of Hepatocellular Carcinoma: A Korean Nationally Representative Cohort Study

(1) Background: The association between proton pump inhibitor (PPI) use and hepatocellular carcinoma (HCC) has been controversial, especially in the general population. We aimed to determine the impact of PPI on HCC risk in participants without liver cirrhosis or chronic hepatitis virus infection. (2) Methods: We assessed 406,057 participants from the Korean National Health Insurance Service database who underwent health screening from 2003 to 2006. We evaluated exposure to PPI before the index date using a standardized daily defined dose (DDD) system. The association of proton pump inhibitor use with the risk of HCC was evaluated using multivariable-adjusted Cox proportional hazards regression. (3) Results: Compared with non-users, PPI use was not associated with the HCC risk in low (<30 DDDs; aHR, 1.07; 95% CI, 0.91−1.27), intermediate (30 ≤ PPI < 60 DDDs; aHR, 0.96; 95% CI, 0.73−1.26), and high (≥60 DDDs; aHR, 0.86; 95% CI, 0.63−1.17) PPI groups in the final adjustment model. In addition, risks of cirrhosis-associated HCC and non-cirrhosis-associated HCC were not significantly associated with PPI use. The results remained consistent after excluding events that occurred within 1, 2, and 3 years to exclude pre-existing conditions that may be associated with the development of HCC. We also found no PPI-associated increase in HCC risk among the selected population, such as those with obesity, older age, and chronic liver diseases. (4) Conclusions: PPI use may not be associated with HCC risk regardless of the amount. We call for future studies conducted in other regions to generalize our findings.

Hypergastrinemia and mortality in gastric adenocarcinoma: a population-based cohort study, the HUNT study

Purpose: Hypergastrinemia increases the risk of developing proximal gastric adenocarcinoma. However, it is unclear if hypergastrinemia affects the survival in patients with gastric adenocarcinoma. This study aimed to examine the hypothesis that hypergastrinemia is associated with increased risk of mortality in patients with gastric adenocarcinoma.Materials and methods: This prospective population-based cohort study based on the Trøndelag Health Study (HUNT) included 78,962 adult individuals (≥20 years). During the baseline assessment period (1995-2008) of these participants, serum samples were collected and frozen. All participants with a newly diagnosed gastric adenocarcinoma in the cohort in 1995-2015 were identified and their gastrin levels were measured in the pre-diagnostic serum samples. Gastrin levels were analysed in relation to all-cause mortality until year 2020 using multivariable Cox regression providing hazard ratios (HRs) with 95% confidence intervals (CIs), adjusted for sex, age, body mass index (BMI), tobacco smoking, tumour stage, completeness of surgical resection, and peri-operative chemotherapy.Results: Among 172 patients with gastric adenocarcinoma, 81 (47%) had hypergastrinemia (serum gastrin >60 pmol/L) and 91 (53%) had normal gastrin level. The tumour location was proximal in 83 patients (43%) and distal in 78 (41%). Hypergastrinemia was not associated with any increased risk of all-cause mortality in all patients (adjusted HR 0.8, 95% CI 0.5-1.1), or in sub-groups of patients with proximal tumour location (HR 0.9, 95% CI 0.4-2.2) or distal tumour location (HR 0.9, 95% CI 0.5-1.7).Conclusion: This population-based cohort study indicates that hypergastrinemia may not increase the risk of mortality in patients with gastric adenocarcinoma.

Tumor Classification Should Be Based on Biology and Not Consensus: Re-Defining Tumors Based on Biology May Accelerate Progress, An Experience of Gastric Cancer

Simple Summary

Rational treatment of diseases including cancers depends on knowledge of their cause as well as their development. The present review is based upon more than 40 years’ work in clinical gastroenterology, gastric physiology, and pathology. The central role of hormones as well as local endocrine cells in cancer development has become apparent. Moreover, the classification of tumors should focus not only on the organ of origin but also on the cell of origin. All cells with the ability to divide may give rise to tumors. Based upon knowledge of the growth regulation of the cell of origin, prophylaxis and treatment may be tailored. Presently, there is hope for individual treatment of cancer patients based upon genetic analyses of tumors. However, with correct identification of the cell of origin, this may not be necessary.

Abstract

Malignant tumors are a consequence of genetic changes mainly occurring during cell division, sometimes with a congenital component. Therefore, accelerated cell divisions will necessarily predispose individuals, whether due to conditions of chronic cell destruction or hormonal overstimulation. It has been postulated that two genetic hits are necessary for the development of malignancy (Knudson). The correct view is probably that the number of genetic changes needed depends on the role the mutated genes have in proliferation and growth control. Hormones should accordingly be regarded as complete carcinogens. In this review based upon experience of gastric cancer where gastrin is central in the pathogenesis, it is argued that oxyntic atrophy—and not metaplasia as postulated by Correa—is the central precancer change in gastric mucosa. Moreover, the target cell of gastrin, the enterochromaffin-like (ECL) cell, is central in gastric carcinogenesis and most probably the cell of origin of gastric carcinomas of the diffuse type according to Lauren (a classification probable in accordance with biology). The distinction between adenocarcinomas and neuroendocrine carcinomas based upon a certain percentage of cancer cells with neuroendocrine differentiation is questioned. To make progress in the treatment of cancer, a correct classification system and knowledge of the pathogenesis are necessary.

Effects of pirenzepine on vonoprazan-induced gastric acid inhibition and hypergastrinemia

BACKGROUND

Compared to proton pump inhibitors, vonoprazan exerts a greater inhibitory effect on gastric acid secretion and is useful for treating acid-related diseases, such as gastro-esophageal reflux disease. However, there is a problem that vonoprazan causes hypergastrinemia, which confers a risk of carcinoid tumor. A previous report demonstrated that pirenzepine, an M1 muscarinic receptor antagonist, enhances the acid inhibitory effects while suppressing hypergastrinemia induced by omeprazole. Here, we examined whether pirenzepine enhances the gastric acid inhibitory effects of vonoprazan without further increasing serum gastrin levels.

METHODS

Eleven healthy volunteers were subjected to 24-h intragastric pH monitoring and serum gastrin measurements on day 7 of three different regimens: pirenzepine 75 mg alone, vonoprazan 10 mg alone, and vonoprazan 10 mg plus pirenzepine 75 mg administered in a randomized crossover fashion.

RESULTS

Median pH 4 holding time ratios (range) achieved with pirenzepine 75 mg, vonoprazan 10 mg, and vonoprazan 10 mg plus pirenzepine 75 mg were 6.9% (2.4-32.8%), 88.4% (54.6-100%), and 84.2% (40.3-100%), respectively. Respective serum gastrin levels were 79 (75-210) pg/ml, 310 (110-870) pg/ml, and 170 (140-930) pg/ml. In cases with hypergastrinemia (gastrin ≥ 200 pg/ml) induced by vonoprazan 10 mg alone, concomitant treatment with pirenzepine significantly reduced serum gastrin levels from 370 to 180 pg/ml (P = 0.028).

CONCLUSION

Although pirenzepine does not enhance acid inhibition, it does improve hypergastrinemia induced by vonoprazan to some extent.

Adverse Effects Associated with Proton Pump Inhibitor Use

Proton pump inhibitors (PPIs) marked a before and after in the management of gastric acid-related disorders since their introduction to the market in 1989. Due to a novel, highly effective mechanism of action blocking the last converging step of gastric acid secretion by parietal cells and very few and mostly tolerable side effects, these drugs quickly displaced other pharmacological compounds such as H2 antagonists as the first treatment choice for peptic ulcer disease, gastroesophageal ulcers, Zollinger-Ellison syndrome, nonsteroidal anti-inflammatory drug-associated ulcers, and eradication of Helicobacter pylori, leading to an exponential increase in their prescription up to now. However, widespread PPI use has led to emerging evidence of long-term adverse effects not described previously, including increased risk of kidney, liver, and cardiovascular disease, dementia, enteroendocrine tumors of the gastrointestinal tract, susceptibility to respiratory and gastrointestinal infections, and impaired absorption of nutrients. Although the evidence published thus far has not established strong correlations, it has been relevant enough to raise new questions about PPIs' safety profile and reconsideration of their clinical indications. Hence, the aim of this review is to evaluate the association between PPI use and the risk of serious adverse effects given increasing concerns about the overuse of PPIs in the general population.

Selective Resection of Type 1 Gastric Neuroendocrine Neoplasms and the Risk of Progression in an Endoscopic Surveillance Programme

BACKGROUND

Current guidance for type 1 gastric neuroendocrine neoplasms (gNENs) recommends either resection of all visible lesions or selective resection of gNENs >10 mm. We adopt a selective strategy targeting lesions approaching 10 mm for endoscopic mucosal resection (EMR) and provide surveillance for smaller lesions.

OBJECTIVES

This study aimed to describe the incidence of type 1 gNENs requiring endoscopic/surgical resection and the risk of disease progression (both considered significant disease) on endoscopic surveillance. The secondary objective was to assess the risk factors for disease progression during surveillance and the incidence of gastric dysplasia/adenoma/adenocarcinoma.

METHODS

We collected consecutive patients with type 1 gNENs and obtained demographic and clinical data through the electronic patient record.

RESULTS

In our cohort of 57 patients, 12 patients had EMR at index gastroscopy; 7 patients had surgery (4: large/multiple gNENs and 3: nodal metastases) (5.2% [3/57] risk of nodal metastases); and a patient with nodal and liver metastases (1.8% [1/57] risk of distant metastases). The prevalence of gastric adenocarcinoma in our study was 3.5% with an incidence rate of 9.59 per 1,000 persons per year. For patients undergoing surveillance, 29.5% (13/44) of patients progressed requiring resection. Serum gastrin was significantly higher in patients who progressed to resection (p value = 0.023).

CONCLUSION

We concluded that up to a third of patients with type 1 gNENs have significant disease requiring resection. Hence, endoscopic surveillance and resect strategy would benefit patients.

Hypergastrinemia is associated with an increased risk of gastric adenocarcinoma with proximal location: A prospective population-based nested case-control study

The incidence of proximal gastric adenocarcinoma is increasing among younger adults. Rodent models have shown that hypergastrinemia causes carcinogenesis in the proximal stomach. The aim of our study was therefore to assess if hypergastrinemia was associated with an increased risk of developing gastric adenocarcinoma also in humans. A prospective population‐based nested case‐control study within the Nord‐Trøndelag Health Study (HUNT) cohort, Norway, was used to assess this association. Serum was collected from 78 962 participants in 1995 to 1997 and 2006 to 2008. In the cohort, 181 incident gastric adenocarcinoma cases were identified from the Norwegian Cancer and Patient Registries through 2015 and matched with 359 controls. The risk of gastric adenocarcinoma was compared between participants with prediagnostic hypergastrinemia (>60 pmol/L) and normal serum gastrin (≤60 pmol/L). Logistic regression provided odds ratios (ORs) with 95% confidence intervals (CIs), adjusted for body mass index, tobacco smoking and comorbidity. Hypergastrinemia was associated with increased risk of gastric adenocarcinoma overall (OR 2.2, 95% CI 1.4‐3.4) and in particular for gastric adenocarcinoma with proximal location (OR 6.1, 95% CI 2.7‐13.8), but not with gastric adenocarcinoma with distal location (OR 1.7, 95% CI 0.9‐3.4). Moreover, hypergastrinemia was associated with an increased risk of gastric adenocarcinoma of intestinal histological type (OR 3.8, 95% CI 1.8‐7.9), but not for diffuse histological type (OR 1.6, 95% CI 0.7‐3.7). In conclusion, hypergastrinemia was associated with an increased risk of proximal and intestinal type gastric adenocarcinoma.

What's new?

The incidence of proximal gastric adenocarcinoma has been reported to increase among younger adults in Western countries. Rodent models have shown that serum gastrin levels above the normal range cause carcinogenesis in the proximal stomach. In this first prospective population‐based study on the association between hypergastrinemia and gastric adenocarcinoma, the risk of gastric adenocarcinoma in the proximal stomach, but not in the distal stomach, was markedly increased in hypergastrinemic individuals. The finding supports the hypothesis that hypergastrinemia mediates the development of gastric adenocarcinoma in the proximal stomach, where mucosal proliferation is stimulated by gastrin.

Proton pump inhibitors and risk of liver cancer and mortality in patients with chronic liver disease: a systematic review and meta-analysis

BACKGROUND

Epidemiological studies investigating the use of proton pump inhibitors (PPI) on the risk of liver cancer and/or mortality among persons with chronic liver disease (CLD) have reported conflicting results. We conducted a systematic review and meta-analysis to determine the impact of PPI use on liver cancer and/or death among patients with CLD.

METHODS

The core databases including MEDLINE, EMBASE, and Cochrane library were searched through January 2020. We included studies, evaluating the association between PPIs and liver cancer or mortality among patients with CLD including randomized controlled, nonrandomized controlled, and observational studies. We used inverse-variance random-effects models to estimate the pooled relative risk (RR) and 95% confidence interval (CI) for liver cancer or mortality.

RESULTS

Eleven studies including 173,894 patients were selected. In three studies, individuals with CLD who used PPIs had a 67% greater risk of developing hepatocellular carcinoma (HCC) compared to nonusers (RR, 1.67; 95% CI, 1.12-2.50; I² = 92%). Combining data from the eight studies relating PPI to overall mortality, we observed a 57% increased risk of mortality in PPI users with CLD compared to CLD nonusers (RR: 1.57; 95% CI, 1.24-1.99; I² = 69%).

CONCLUSION

PPI use was associated with an increased risk of HCC and mortality in patients with CLD suggesting that PPI prescriptions in patients with CLD should be considered carefully.

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.

Gastric Corpus Mucosal Hyperplasia and Neuroendocrine Cell Hyperplasia, but not Spasmolytic Polypeptide-Expressing Metaplasia, Is Prevented by a Gastrin Receptor Antagonist in H+/K+ATPase Beta Subunit Knockout Mice

Proton pump inhibitor use is associated with an increased risk of gastric cancer, which may be mediated by hypergastrinemia. Spasmolytic polypeptide-expression metaplasia (SPEM) has been proposed as a precursor of gastric cancer. We have examined the effects of the gastrin receptor antagonist netazepide (NTZ) or vehicle on the gastric corpus mucosa of H⁺/K⁺ATPase beta subunit knockout (KO) and wild-type (WT) mice. The gastric corpus was evaluated by histopathology, immunohistochemistry (IHC), in situ hybridization (ISH) and whole-genome gene expression analysis, focusing on markers of SPEM and neuroendocrine (NE) cells. KO mice had pronounced hypertrophy, intra- and submucosal cysts and extensive expression of SPEM and NE cell markers in the gastric corpus, but not in the antrum. Numerous SPEM-related genes were upregulated in KO mice compared to WT mice. NTZ reduced hypertrophia, cysts, inflammation and NE hyperplasia. However, NTZ neither affected expression of SPEM markers nor of SPEM-related genes. In conclusion, NTZ prevented mucosal hypertrophy, cyst formation and NE cell hyperplasia but did not affect SPEM. The presence of SPEM seems unrelated to the changes caused by hypergastrinemia in this animal model.

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.

Gastric cancer and gastrin: on the interaction of Helicobacter pylori gastritis and acid inhibitory induced hypergastrinemia

Gastric cancer, a disease with a reduced frequency for decades, now appears to be on the rise again in young Americans. The epidemiology of gastric cancer differs between tumors in the cardia and those of the more distal parts of the stomach. The tumors are divided into the intestinal type showing glandular growth pattern and the diffuse type with a different pattern. The latter often expresses neuroendocrine and more specifically ECL-cell markers suggesting that they originate from the ECL cell, the target cell for the antral hormone, gastrin. Helicobacter pylori gastritis is accepted as the major cause of gastric cancer, but only after having induced oxyntic atrophy which reduces gastric acid secretion and thus induces hypoacidity leading to hypergastrinemia. Long-term hypergastrinemia is known to induce malignant neoplasia in the stomach of animals as well as man. Recently treatment with proton pump inhibitor after Helicobacter pylori eradication in patients with gastroesophageal reflux disease, has been reported to predispose to gastric cancer. Since profound acid inhibition is a well-known cause of gastric neoplasia, it is to be expected that Helicobacter pylori infection and profound acid inhibition has an additive or possibly potentiating effect on the development of gastric cancer.

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.

Proton pump inhibitor and histamine-2 receptor antagonist use and risk of liver cancer in two population-based studies

BACKGROUND

Proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) are commonly used. PPIs have been shown to promote liver cancer in rats; however, only one study has examined the association in humans.

AIMS

To investigate PPIs and H2RAs and risk of primary liver cancer in two large independent study populations.

METHODS

We conducted a nested case-control study within the Primary Care Clinical Informatics Unit (PCCIU) database in which up to five controls were matched to cases with primary liver cancer, recorded by General Practitioners. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for associations with prescribed PPIs and H2RAs were calculated using conditional logistic regression. We also conducted a prospective cohort study within the UK Biobank using self-reported medication use and cancer-registry recorded primary liver cancer. Hazard ratios (HRs) and 95% CIs were calculated using Cox regression.

RESULTS

In the PCCIU case-control analysis, 434 liver cancer cases were matched to 2103 controls. In the UK Biobank cohort, 182 of 475 768 participants developed liver cancer. In both, ever use of PPIs was associated with increased liver cancer risk (adjusted OR 1.80, 95% CI 1.34, 2.41 and adjusted HR 1.99, 95% CI 1.34, 2.94 respectively). There was little evidence of association with H2RA use (adjusted OR 1.21, 95% CI 0.84, 1.76 and adjusted HR 1.70, 95% CI 0.82, 3.53 respectively).

CONCLUSIONS

We found some evidence that PPI use was associated with liver cancer. Whether this association is causal or reflects residual confounding or reverse causation requires additional research.

Serum gastrin and cholecystokinin are associated with subsequent development of gastric cancer in a prospective cohort of Finnish smokers

Background

Gastrin, which induces gastric acid secretion, and a structurally similar hormone, cholecystokinin (CCK)-a potent acid inhibitor, may each play a role in gastric cancer. However, few studies have investigated this hypothesis in humans. We therefore investigated whether serum gastrin or CCK concentrations at baseline were associated with the incidence of gastric non-cardia adenocarcinomas (GNCA), oesophagogastric junctional adenocarcinomas (EGJA) or gastric carcinoid tumours over 24 years of follow-up in a study nested within the all-male Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study of Finnish smokers.

Methods

Totals of 283 incident GNCA, 96 EGJA and 10 gastric carcinoid cases, and 778 matched controls, were included in our analysis. Gastrin and CCK were measured using specific radioimmunoassays. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated by multivariable logistic regression with adjustment for all known or suspected confounding factors, including Helicobacter pylori seropositivity.

Results

Those with high gastrin (Q4 vs Q1), had an increased risk of GNCA (fully adjusted OR: 1.92; 95% CI: 1.21, 3.05) and gastric carcinoids, though the small number of carcinoid cases meant the fully adjusted model was unstable (age-adjusted continuous model OR: 4.67; 95% CI: 2.67, 8.15). CCK was associated with risk of GNCA only for those in Q3 relative to Q1 (OR: 0.56; 95% CI: 0.33, 0.96), and no significant trend was observed.

Conclusions

Our data suggest that high serum concentrations of gastrin may be associated independently with an increased risk of gastric cancer; the role of CCK in cancer risk is less clear.

Not only stem cells, but also mature cells, particularly neuroendocrine cells, may develop into tumours: time for a paradigm shift

Stem cells are considered the origin of neoplasms in general, and malignant tumours in particular, and the stage at which the stem cells stop their differentiation determines the degree of malignancy. However, there is increasing evidence supporting an alternative paradigm. Tumours may develop by dedifferentiation from mature cells able to proliferate. Studies of gastric carcinogenesis demonstrate that mature neuroendocrine (NE) cells upon long-term overstimulation may develop through stages of hyperplasia, dysplasia, and rather benign tumours, into highly malignant carcinomas. Dedifferentiation of cells may change the histological appearance and impede the identification of the cellular origin, as seen with gastric carcinomas, which in many cases are dedifferentiated neuroendocrine tumours. Finding the cell of origin is important to identify risk factors for cancer, prevent tumour development, and tailor treatment. In the present review, we focus not only on gastric tumours, but also evaluate the role of neuroendocrine cells in tumourigenesis in two other foregut-derived organs, the lungs and the pancreas, as well as in the midgut-derived small intestine.

Comparison of effect of an increased dosage of vonoprazan versus vonoprazan plus lafutidine on gastric acid inhibition and serum gastrin

BACKGROUND

Vonoprazan, a novel potassium-competitive acid blocker, elicits potent acid inhibition and hypergastrinemia at a dose of 20 mg. Its recommended maintenance dose for gastro-esophageal reflux disease is 10 mg, which is sometimes insufficient for preventing nocturnal acid breakthrough (NAB). Concomitant use of a histamine 2 receptor antagonist (H₂RA) is effective for NAB. However, further acid inhibition by addition of H2RA has concern of hypergastrinemia again. Lafutidine (H2RA) is known to stimulate somatostatin release.

AIMS

The aim of this study is to compare the levels of acid inhibition and serum gastrin attained by addition of lafutidine to vonoprazan 10 mg with levels after a dose increase of vonoprazan from 10 to 20 mg.

METHODS

Thirteen healthy volunteers underwent 24-h intragastric pH monitoring and serum gastrin measurements on day 7 of three different regimens: vonoprazan 10 mg, vonoprazan 10 mg plus lafutidine 10 mg, and vonoprazan 20 mg.

RESULTS

Median pH 4 holding time ratios (range) by vonoprazan 10 mg, vonoprazan 10 mg plus lafutidine 10 mg, and vonoprazan 20 mg were 82% (47-88%), 88% (76-93%), and 99% (95-100%) while those at nighttime from 10 p.m. to 8 a.m. were 94% (29-100%), 100% (95-100%), and 100%, respectively. The incidences of NAB with vonoprazan 10 mg, vonoprazan plus lafutidine, and vonoprazan 20 mg were 38, 8, and 0%, respectively. Respective serum gastrin levels were 420 (173-508), 323 (196-521), and 504 (400-812) pg/ml.

CONCLUSION

Addition of lafutidine 10 mg to vonoprazan 10 mg achieved sufficient acid inhibition, especially at nighttime, without further increase of serum gastrin levels.

Expression of the Cholecystokinin-B Receptor in Neoplastic Gastric Cells

Gastric cancer is an important disease due to its high mortality. Despite the decline in frequency, most cases are discovered late in its course, and most of the cancer patients die within a few years of diagnosis. In addition to Helicobacter pylori gastritis, gastrin is considered an important factor in the development of this disease, and thus, cholecystokinin-B receptor (CCKBR) becomes of interest. The aim of our study was to explore whether CCKBR is expressed in stomach cancers. Thirty-seven tumors from 19 men and 18 women diagnosed with either adenocarcinoma or neuroendocrine neoplasm (NENs) were included in this study. The tumors were classified into 29 adenocarcinomas and eight NENs. Immunohistochemistry with antibodies against chromogranin A (CgA), synaptophysin and CCKBR, and in situ hybridization with probes against CgA, CCKBR and histidine decarboxylase were used to further explore these tumors. Thirty-three (89%) of the tumors expressed CCKBR protein, whereas only 20 (54%) of all tumors expressed CCKBR mRNA. Of the 20 tumors expressing CCKBR mRNA, eight were NENs and 12 were adenocarcinoma. The highest amount of CCKBR was expressed in NEN. Interestingly, a high degree of co-expression of CCKBR and CgA was observed when the two markers were examined together with in situ hybridization. In conclusion, we found that all eight NENs expressed CCKBR and neuroendocrine markers in a majority of tumor cells. The same markers were also expressed in a proportion of adenocarcinomas supporting the view that gastrin is important in the development of gastric cancer.

Gastrin and Gastric Cancer

Gastric cancer is the third leading cause of cancer-related mortality worldwide. Despite progress in understanding its development, challenges with treatment remain. Gastrin, a peptide hormone, is trophic for normal gastrointestinal epithelium. Gastrin also has been shown to play an important role in the stimulation of growth of several gastrointestinal cancers including gastric cancer. We sought to review the role of gastrin and its pathway in gastric cancer and its potential as a therapeutic target in the management of gastric cancer. In the normal adult stomach, gastrin is synthesized in the G cells of the antrum; however, gastrin expression also is found in many gastric adenocarcinomas of the stomach corpus. Gastrin's actions are mediated through the G-protein-coupled receptor cholecystokinin-B (CCK-B) on parietal and enterochromaffin cells of the gastric body. Gastrin blood levels are increased in subjects with type A atrophic gastritis and in those taking high doses of daily proton pump inhibitors for acid reflux disease. In experimental models, proton pump inhibitor-induced hypergastrinemia and infection with Helicobacter pylori increase the risk of gastric cancer. Understanding the gastrin:CCK-B signaling pathway has led to therapeutic strategies to treat gastric cancer by either targeting the CCK-B receptor with small-molecule antagonists or targeting the peptide with immune-based therapies. In this review, we discuss the role of gastrin in gastric adenocarcinoma, and strategies to block its effects to treat those with unresectable gastric cancer.

Gastrin and Gastric Cancer

Gastric cancer although occurring in reduced frequency is still an important disease, partly because of the bad prognosis when occurring in western countries. This decline in occurrence may mainly be due to the reduced prevalence of Helicobacter pylori (Hp) infection, which is the most important cause of gastric cancer. There exist many different pathological classifications of gastric carcinomas, but the most useful seems to be the one by Lauren into intestinal and diffuse types since these types seldom transform into the other and also have different epidemiology. During the nearly 30 years that have passed since the groundbreaking description of Hp as the cause of gastritis and gastric cancer, a continuous search for the mechanism by which Hp infection causes gastric cancer has been done. Interestingly, it is mainly atrophic gastritis of the oxyntic mucosa that predisposes to gastric cancer possibly by inducing hypoacidity and hypergastrinemia. There are many arguments in favor of an important role of gastrin and its target cell, the enterochromaffin-like cell, in gastric carcinogenesis. The role of gastrin in gastric carcinogenesis implies caution in the long-term treatment with inhibitors of gastric acid secretion inducing secondary hypergastrinemia, in a common disease like gastroesophageal reflux disease.

The gastrin receptor antagonist netazepide (YF476) in patients with type 1 gastric enterochromaffin-like cell neuroendocrine tumours: review of long-term treatment

OBJECTIVE

Netazepide (YF476) is a recently developed, orally active gastrin receptor antagonist that, in short trials in patients with type 1 gastric enterochromaffin-like cell neuroendocrine tumours, has been shown to induce a significant reduction in the number and size of tumours as well as serum chromogranin A (CgA). The aim of this review is to evaluate the long-term effect and safety of netazepide.

PATIENTS AND METHODS

Five patients previously treated with netazepide in an open-label trial were offered continuous treatment with netazepide 25 mg once daily. Upper endoscopy was performed every 6 months. The tumours were counted and measured, and tissue samples were obtained from the flat corpus mucosa. Enterochromaffin-like cell hyperplasia was classified according to Solcia and colleagues and volume density of CgA immunoreactive (IR) cells was calculated. Fasting serum CgA and fasting serum gastrin were measured every 3 months.

RESULTS

All tumours regressed completely in three of five patients; time until total disappearance was 3, 9 and 12 months. In the other two patients, the number of tumours was reduced from 13 to 5 and from 14 to 3. Serum CgA showed a rapid and sustained decrease (P<0.001). The mean reduction in serum CgA was 4.1±0.5 nmol/l. Similarly, volume density of CgA IR cells in the flat corpus mucosa decreased (P<0.001), with the mean change being 2.0±0.4%. Serum gastrin and volume density of gastrin IR cells in the antral part of the stomach remained unchanged (P=0.2 and 0.7, respectively).

CONCLUSION

Long-term administration of netazepide is effective and safe.

Helicobacter pylori and gastric acid: an intimate and reciprocal relationship

Helicobacter pylori (Hp) is the main cause of gastritis, peptic ulcer disease and gastric cancer. There are still unanswered questions related to the interaction between Hp and man, like what determines the susceptibility for the initial infection and the mechanisms for the carcinogenic effect. The initial infection seems to require a temporal gastric hypoacidity. For Hp to survive in the gastric mucous layer, some acidity is necessary. Hp itself is probably not directly carcinogenic. Only when inducing oxyntic mucosal inflammation and atrophy with hypoacidity, Hp predisposes for gastric cancer. Gastrin most likely plays a central role in the Hp pathogenesis of duodenal ulcer and gastric cancer.

Gastroscopic features and serum gastrin in schizophrenics taking long-term medication

AIM: To investigate the gastroscopic features and serum gastrin in schizophrenics taking long-term medication.

METHODS: Sixty schizophrenics with digestive diseases treated at our hospital were divided randomly and equally into two groups according to medication course (group A: < 0.5 year; group C (> 1 year). Diabetes or high blood pressure patients taking long-term medication were included as controls (group B). All patients underwent painless gastroscopy and examination of fasting serum gastrin.

RESULTS: The rates of bile reflux gastritis and gastric stasis were significantly higher in group C (34.37% and 30.21%, respectively) than in groups A and B (P < 0.05). The level of serum gastrin was significantly lower in group C than in groups A and B (78.43 pg/mL ± 10.68 pg/mL vs 88.72 pg/mL ± 11.35 pg/mL, 90.14 pg/mL ± 9.57 pg/mL; P < 0.05).

CONCLUSION: Schizophrenics taking long-term medication tend to develop bile reflux gastritis, gastric stasis and lowered serum gastrin.