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

Argel's stemmoside C as a novel natural remedy for mice with alcohol-induced gastric ulcer based on its molecular mechanistic pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Solenostemma argel is widely distributed in Africa & Asia with traditional usage in alleviating abdominal colic, aches, & cramps. This plant is rich in phytochemicals, which must be explored for its pharmacological effects.

PURPOSE

Peptic Ulcer Disease (PUD) is the digestion of the digestive tube. PUD not only interferes with food digestion & nutrient absorption, damages one of the largest defensive barriers against pathogenic micro-organisms, but also impedes drug absorption & bioavailability, rendering the oral route, the most convenient way, ineffective. Omeprazole, one of the indispensable cost-effective proton-pump inhibitors (PPIs) extensively prescribed to control PUD, is showing growing apprehensions toward multiple drug interactions & side effects. Hence, finding a natural alternative with Omeprazole-like activity & limited side effects is a medical concern.

STUDY DESIGN

Therefore, we present Stemmoside C as a new gastroprotective phytochemical agent isolated from Solenostemma argel to be tested in upgrading doses against ethanol-induced gastric ulcers in mice compared to negative, positive, & reference Omeprazole groups.

METHODS

We carried out in-depth pharmacological & histopathological studies to determine the possible mechanistic pathway.

RESULTS

Our results showed that Stemmoside C protected the stomach against ethanol-induced gastric ulcers parallel to Omeprazole. Furthermore, the mechanistic studies revealed that Stemmoside C produced its effect using an orchestrated array of different mechanisms. Stemmoside C stimulates stomach defense by increasing COX-2, PGE-2, NO, & TFF-1 healing factors, IL-10 anti-inflammatory cytokine, & Nrf-2 & HO-1 anti-oxidant pathways. It also suppresses stomach ulceration by inhibiting leucocyte recruitment, especially neutrophils, leading to subsequent inhibition of NF-κBp65, TNF-α, IL-1β, & iNOS pro-inflammatory cytokines & JAK-1/STAT-3 inflammation-induced carcinogenicity cascade in addition to MMP-9 responsible for tissue degradation.

CONCLUSION

These findings cast light on Stemmoside C's clinical application against gastric ulcer progression, recurrence, & tumorigenicity & concurrently with chemotherapy.

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.

Albizzia chinensis (Osbeck) Merr extract YS ameliorates ethanol-induced acute gastric ulcer injury in rats by regulating NRF2 signaling pathway

BACKGROUND

Around the world, there is a high incidence of gastric ulcers. YS, an extract from the Chinese herb Albizzia chinensis (Osbeck) Merr, has potential therapeutic applications for gastrointestinal diseases. Here we elucidated the protective effect and underlying mechanism of action of YS on gastric ulcer in rats injured by ethanol.

METHODS

The ethanol-induced gastric ulcer rat model was used to assess the protective effect of YS. A pathological examination of gastric tissue was performed by H&E staining. GES-1 cells damaged by hydrogen peroxide were used to simulate oxidative damage in gastric mucosal epithelial cells. Endogenous NRF2 was knocked down using small interfering RNA. Immunoprecipitation was used to detect ubiquitination of NRF2. Co-immunoprecipitation was used to detect the NRF2-Keap1 interaction.

RESULTS

YS (10 and 30 mg/kg, i.g.) significantly reduced the ulcer index, decreased MDA level, and increased SOD and GSH levels in gastric tissues damaged by ethanol. YS promoted NRF2 translocation from cytoplasm to nucleus and enhanced the NQO1 and HO-1 expression levels in injured rat gastric tissue. In addition, YS regulated NQO1 and HO-1 via NRF2 in H2O2-induced oxidative injured GES-1 cells. Further studies on the underlying mechanism indicated that YS reduced the interaction between NRF2 and Keap1 and decreased ubiquitylation of NRF2, thereby increasing its stability and expression of downstream factors. NRF2 knockdown abolished the effect of YS on MDA and SOD in GES-1 cells treated with H2O2.

CONCLUSION

YS reduced the NRF2-Keap1 interaction, promoting NRF2 translocation into the nucleus, which increasing the transcription and translation of NQO1 and HO-1 and improved the antioxidant capacity of rat stomach.

Proton Pump Inhibitors and Cancer Risk: A Comprehensive Review of Epidemiological and Mechanistic Evidence

Background: Proton pump inhibitors (PPIs) are commonly prescribed long-acting drugs used to treat acid reflux, gastroesophageal reflux disease (GERD), and peptic ulcers. Recently, concerns have been raised about their safety, particularly due to the association between long-term PPI use and cancer development. Multiple comprehensive studies have consistently suggested a noteworthy link between prolonged PPI usage and an increased risk of developing gastric, esophageal, colorectal, and pancreatic cancers, yet the precise underlying mechanism remains elusive. Methods: First, we review the extensive body of research that investigates the intricate relationship between cancer and PPIs. Then, we predict PPI toxicity using the prodrug structures with the ProTox-II webserver. Finally, we predict the relative risk of cancer for each PPI, using PubMed citation counts of each drug and keywords related to cancer. Results: Our review indicates that prolonged PPI use (exceeding three months) is significantly associated with an elevated risk of cancer, while shorter-term usage (less than three months) appears to pose a comparatively lower risk. Our review encompasses various proposed mechanisms, such as pH and microbiome alterations, vitamin and mineral malabsorption, hypergastrinemia, and enterochromaffin-like cell proliferation, while ProTox-II also suggests aryl hydrocarbon receptor binding. Potentially, the PubMed citations count suggests that the PPIs omeprazole and lansoprazole are more associated with cancer than pantoprazole and esomeprazole. In comparison, the H2R blocker, famotidine, is potentially less associated with cancer than PPIs, and may serve as a safer alternative treatment for periods beyond 3 months. Conclusions: Despite the well-established cancer risk associated with PPIs, it is notable that these medications continue to be widely prescribed for periods longer than 3 months. Thus, it is of paramount importance for clinicians and patients to thoughtfully evaluate the potential risks and benefits of long-term PPI usage and explore alternative treatments before making informed decisions regarding their medical management.

Neuroendocrine mechanism of gastric acid secretion: Historical perspectives and recent developments in physiology and pharmacology

The physiology of gastric acid secretion is one of the earliest subjects in medical literature and has been continuously studied since 1833. Starting with the notion that neural stimulation alone drives acid secretion, progress in understanding the physiology and pathophysiology of this process has led to the development of therapeutic strategies for patients with acid-related diseases. For instance, understanding the physiology of parietal cells led to the developments of histamine 2 receptor blockers, proton pump inhibitors (PPIs), and recently, potassium-competitive acid blockers. Furthermore, understanding the physiology and pathophysiology of gastrin has led to the development of gastrin/CCK2 receptor (CCK2 R) antagonists. The need for refinement of existing drugs in patients have led to second and third generation drugs with better efficacy at blocking acid secretion. Further understanding of the mechanism of acid secretion by gene targeting in mice has enabled us to dissect the unique role for each regulator to leverage and justify the development of new targeted therapeutics for acid-related disorders. Further research on the mechanism of stimulation of gastric acid secretion and the physiological significances of gastric acidity in gut microbiome is needed in the future.

Adverse Effects Associated with Long-Term Use of Proton Pump Inhibitors

Proton Pump Inhibitors are used widely to manage many gastric acid-related conditions such as gastroesophageal disease, gastritis, esophagitis, Barrett's esophagus, Zollinger-Ellison syndrome, peptic ulcer disease, nonsteroidal anti-inflammatory drug-associated ulcers, and Helicobacter pylori eradication, around the globe. This review article focuses on adverse effects associated with the long-term use of proton pump inhibitors. Various observational studies, clinical trials, and meta-analyses have established the adverse effects associated with the long-term use of proton pump inhibitors including renal disorders (acute interstitial nephritis, acute kidney injury, chronic kidney disease, and end-stage renal disease), cardiovascular risks (major adverse cardiovascular events, myocardial infarction, stent thrombosis, and stroke), fractures, infections (Clostridium difficile infection, community-acquired pneumonia, and Coronavirus disease 2019), micronutrient deficiencies (hypomagnesemia, anemia, vitamin B12 deficiency, hypocalcemia, hypokalemia), hypergastrinemia, cancers (gastric cancer, pancreatic cancer, colorectal cancer, hepatic cancer), hepatic encephalopathy, and dementia. Clinicians including prescribers and pharmacists should be aware of the adverse effects of taking proton pump inhibitors for an extended period of time. In addition, the patients taking proton pump inhibitors for long-term should be monitored for the listed adverse effects. The American Gastroenterological association recommends a few non-pharmacological measures and the use of histamine 2 blockers to lessen gastrointestinal symptoms of gastroesophageal reflex disease and the utilization of proton pump inhibitors treatment if there is a definitive indication. Additionally, the American Gastroenterological association's Best Practice Advice statements emphasize deprescribing when there is no clear indication for proton pump inhibitors therapy.

Prescriptive Appropriateness: Inhospital Adherence to Proton Pump Inhibitors Deprescription Flow Chart

The prescriptive appropriateness of Proton Pump Inhibitors (PPIs) in polypharmacy is controversial. PPIs are often overprescribed and the risk of prescribing errors and adverse drug reactions increases for each additional drug added to therapy. Hence, guided deprescription should be considered and easily implementable in ward practice. This observational prospective study evaluated the implementation of a validated PPIs deprescription flow chart to real-life internal ward activity through the presence of a clinical pharmacologist as an enhancing additional factor by assessment of inhospital prescriber's adherence to the proposed flow chart. Patients' demographics and prescribing trends of PPIs prescriptions were analyzed by descriptive statistics. The final analysis of data included ninety-eight patients (forty-nine male and forty-nine female), aging 75.6 ± 10.6 years; 55.1% of patients had home-PPIs prescriptions, while 44.9% received inhospital-PPIs prescriptions. Evaluation of prescriber's adherence to the flow chart revealed that the percentage of patients with a prescriptive/deprescriptive pathway conforming to that of the flow chart was 70.4%, with low symptomatologic recurrences. The clinical pharmacologists' presence and influence in ward activity may have contributed to this finding, since continuous training of the prescribing physicians is deemed a success-related factor in the deprescribing strategy. Multidisciplinary management of PPIs deprescription protocols shows high adherence by prescribers in real-life hospital settings and low recurrence events.

Successful Lifetime/Long-Term Medical Treatment of Acid Hypersecretion in Zollinger-Ellison Syndrome (ZES): Myth or Fact? Insights from an Analysis of Results of NIH Long-Term Prospective Studies of ZES

Analysis of the efficacy/pharmacology of long-term/lifetime medical treatment of acid hypersecretion in a large cohort of ZES patients in a prospective study. This study includes the results from all 303 patients with established ZES who were prospectively followed and received acid antisecretory treatment with either H2Rs or PPIs, with antisecretory doses individually titrated by the results of regular gastric acid testing. The study includes patients treated for short-term periods (<5 yrs), patients treated long-term (>5 yrs), and patients with lifetime treatment (30%) followed for up to 48 years (mean 14 yrs). Long-term/lifelong acid antisecretory treatment with H2Rs/PPIs can be successfully carried out in all patients with both uncomplicated and complicated ZES (i.e., with MEN1/ZES, previous Billroth 2, severe GERD). This is only possible if drug doses are individually set by assessing acid secretory control to establish proven criteria, with regular reassessments and readjustments. Frequent dose changes both upward and downward are needed, as well as regulation of the dosing frequency, and there is a primary reliance on the use of PPIs. Prognostic factors predicting patients with PPI dose changes are identified, which need to be studied prospectively to develop a useful predictive algorithm that could be clinically useful for tailored long-term/lifetime therapy in these patients.

Current management of gastro-oesophageal reflux disease-treatment costs, safety profile, and effectiveness: a narrative review

Background

The purpose of this study was to review the current management of gastro-oesophageal reflux disease (GORD), including treatment costs, safety profile and effectiveness.

Methods

A literature review was performed of randomized-controlled trials, systematic reviews, Cochrane reports and National/Societal guidelines of the medical, endoscopic and surgical management of GORD. Proton pump inhibitor (PPI) prescribing patterns and expenditure were reviewed in different countries, including Australia, Canada, New Zealand, UK and USA.

Results

Proton pump inhibitors (PPIs) are primarily indicated for control of GORD, Helicobacter pylori eradication (combined with antibiotics), preventing NSAID-induced gastrointestinal bleeding and treating peptic ulcer disease. There is widespread overprescribing of PPIs in Western and Eastern nations in terms of indication and duration, with substantial expense for national health providers. Despite a favourable short-term safety profile, there are observational associations of adverse effects with long-term PPIs. These include nutrient malabsorption, enteric infections and cardiovascular events. The prevalence of PPI use makes their long-term safety profile clinically relevant. Cost-benefit, symptom control and quality-of-life outcomes favour laparoscopic fundoplication rather than chronic PPI treatment. Laparoscopic fundoplication in long-term management of PPI-responsive GORD is supported by SAGES, NICE and ACG, and PPI-refractory GORD by AGA and SAGES guidelines. The importance of establishing a definitive diagnosis prior to invasive management is emphasized, especially in PPI-refractory heartburn.

Conclusions

We examined evidence-based guidelines for PPI prescribing and deprescribing in primary care and hospital settings and the need for PPI stewardship and education of health professionals. This narrative review presents the advantages and disadvantages of surgical, endoscopic and medical management of GORD, which may assist in shared decision making and treatment choice in individual patients.This paper was presented (GS020) at the 88th RACS Annual Scientific Conference, 6-10 May, 2019.

Use of proton pump inhibitors for the risk of gastric cancer

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Does Chronic Use of High Dose Proton Pump Inhibitors Increase Risk for Pancreatic Cancer?

OBJECTIVES

To analyze whether use of proton pump inhibitors increase the risk for pancreatic cancer in a mouse model and human clinical cohorts.

METHODS

p48-Cre/LSL-KrasG12D mice that develop precancerous pancreatic intraepithelial neoplasia (PanINs) were treated with low- or high-dose proton pump inhibitors (PPIs) orally for 1 and 4 months. The mechanism for the cholecystokinin receptor 2 (CCK-2R) activation was investigated in vitro. Two resources were employed to analyze the risk of pancreatic cancer in human subjects with PPI use.

RESULTS

Serum gastrin levels were increased 8-fold (P < 0.0001) in mice treated with chronic high-dose PPIs, and this change correlated with an increase (P = 0.02) in PanIN grade and the development of microinvasive cancer. The CCK-2R expression was regulated by microRNA-148a in the p48-Cre/LSL-KrasG12D mice pancreas and in human pancreatic cancer cells in vitro. Proton pump inhibitor consumption in human subjects was correlated with pancreatic cancer risk (odds ratio, 1.54). A validation analysis conducted using the large-scale United Kingdom Biobank database confirmed the correlation (odds ratio, 1.9; P = 0.00761) of pancreatic cancer risk with PPI exposure.

CONCLUSIONS

This investigation revealed in both murine models and human subjects, PPI use is correlated with a risk for development of pancreatic cancer.

Assessment of the Potential of Sarcandra glabra (Thunb.) Nakai. in Treating Ethanol-Induced Gastric Ulcer in Rats Based on Metabolomics and Network Analysis

Gastric ulcer (GU) is one of the most commonly diagnosed diseases worldwide, threatening human health and seriously affecting quality of life. Reports have shown that the Chinese herbal medicine Sarcandra glabra (Thunb.) Nakai (SGN) can treat GU. However, its pharmacological effects deserve further validation; in addition, its mechanism of action is unclear. An acute gastric ulcer (AGU) rat model induced by alcohol was used to evaluate the gastroprotective effect of SGN by analysis of the histopathological changes in stomach tissue and related cytokine levels; the potential mechanisms of action of SGN were investigated via serum metabolomics and network pharmacology. Differential metabolites of rat serum were identified by metabolomics and the metabolic pathways of the identified metabolites were enriched via MetaboAnalyst. Furthermore, the critical ingredients and candidate targets of SGN anti-AGU were elucidated. A compound-reaction-enzyme-gene network was established using Cytoscape version 3.8.2 based on integrated analysis of metabolomics and network pharmacology. Finally, molecular docking was applied to verify the acquired key targets. The results showed that SGN exerted a certain gastroprotective effect via multiple pathways and targets. The effects of SGN were mainly caused by the key active ingredients isofraxidin, rosmarinic, and caffeic acid, which regulate hub targets, such as PTGS2, MAPK1, and KDR, which maintain the homeostasis of related metabolites. Signal pathways involved energy metabolism as well as immune and amino acid metabolism. Overall, the multi-omics techniques were proven to be promising tools in illuminating the mechanism of action of SGN in protecting against diseases. This integrated strategy provides a basis for further research and clinical application of SGN.

A study for every second day administration of vonoprazan for maintenance treatment of erosive GERD (ESD von GERD): a multicenter randomized cross-over study

BACKGROUND

Vonoprazan is a potassium competitive acid blocker used to treat erosive gastroesophageal reflux disease (GERD) with stronger, more stable acid-suppressing effects than proton pump inhibitors (PPIs). This study clarified the usefulness and superiority of vonoprazan administered every second day over PPIs in the maintenance therapy of erosive GERD.

METHODS

This is a prospective, multicenter, open-label, two-period randomized cross-over study. Patients were randomized to either the vonoprazan-lansoprazole (VP-LZ) group, who were given vonoprazan 10 mg for the first 4 weeks and then lansoprazole 15 mg for the next 4 weeks both administered once every second day, or the lansoprazole-vonoprazan (LZ-VP) group, who were treated in reverse. GERD symptoms were compared using symptom diaries, the frequency scale for symptoms of GERD (FSSG), and the gastrointestinal symptom rating scale (GSRS).

RESULTS

We enrolled 122 patients between December 2017 and May 2019. Symptoms were well controlled in vonoprazan administration and lansoprazole administration were 93.6% and 82.1%, respectively, with a significant difference on McNemar's test (P = 0.003). During the second 4 weeks, 94.4% and 76.7% of patients in the VP-LZ and LZ-VP groups, respectively, were well controlled following for ≥ 6 consecutive days a week (P = 0.009). During the first 4 weeks, 96.7% and 80.0% of patients were well controlled with < 1 weekly in the VP-LZ and LZ-VP groups, respectively, during the first 4 weeks (P = 0.007). GERD symptoms, assessed via FSSG and GSRS, significantly decreased with vonoprazan administration once every second day.

CONCLUSIONS

Vonoprazan administered once every second day could be an effective alternative to PPIs in the maintenance treatment of erosive GERD (UMIN000030393).

Predictive Factors for Resistant Disease with Medical/Radiologic/Liver-Directed Anti-Tumor Treatments in Patients with Advanced Pancreatic Neuroendocrine Neoplasms: Recent Advances and Controversies

Simple Summary

Tumor resistance, both primary and acquired, is leading to increased complexity in the nonsurgical treatment of patients with advanced panNENs, which would be greatly helped by reliable prognostic/predictive factors. The importance in identifying resistance is being contributed to by the increased array of possible treatments available for treating resistant advanced disease; the variable clinical course as well as response to any given treatment approach of patients within one staging or grading system, the advances in imaging which are providing increasing promising results/parameters that correlate with grading/outcome/resistance, the increased understanding of the molecular pathogenesis providing promising prognostic markers, all of which can contribute to selecting the best treatment to overcome resistance disease. Several factors have been identified that have prognostic/predictive value for identifying development resistant disease and affecting overall survival (OS)/PFS with various nonsurgical treatments of patients with advanced panNENs. Prognostic factors identified for patients with advanced panNENs for both OS/PFSs include various clinically-related factors (clinical, laboratory/biological markers, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors. Particularly important prognostic factors for the different treatment modalities studies are the recent grading systems. Most prognostic factors for each treatment modality for OS/PFS are not specific for a given treatment option. These advances have generated several controversies and new unanswered questions, particularly those related to their possible role in predicting the possible sequence of different anti-tumor treatments in patients with different presentations. Each of these areas is reviewed in this paper.

Abstract

Purpose: Recent advances in the diagnosis, management and nonsurgical treatment of patients with advanced pancreatic neuroendocrine neoplasms (panNENs) have led to an emerging need for sensitive and useful prognostic factors for predicting responses/survival. Areas covered: The predictive value of a number of reported prognostic factors including clinically-related factors (clinical/laboratory/imaging/treatment-related factors), pathological factors (histological/classification/grading), and molecular factors, on therapeutic outcomes of anti-tumor medical therapies with molecular targeting agents (everolimus/sunitinib/somatostatin analogues), chemotherapy, radiological therapy with peptide receptor radionuclide therapy, or liver-directed therapies (embolization/chemoembolization/radio-embolization (SIRTs)) are reviewed. Recent findings in each of these areas, as well as remaining controversies and uncertainties, are discussed in detail, particularly from the viewpoint of treatment sequencing. Conclusions: The recent increase in the number of available therapeutic agents for the nonsurgical treatment of patients with advanced panNENs have raised the importance of prognostic factors predictive for therapeutic outcomes of each treatment option. The establishment of sensitive and useful prognostic markers will have a significant impact on optimal treatment selection, as well as in tailoring the therapeutic sequence, and for maximizing the survival benefit of each individual patient. In the paper, the progress in this area, as well as the controversies/uncertainties, are reviewed.

Time to Classify Tumours of the Stomach and the Kidneys According to Cell of Origin

Malignant tumours are traditionally classified according to their organ of origin and whether they are of epithelial (carcinomas) or mesenchymal (sarcomas) origin. By histological appearance the site of origin may often be confirmed. Using same treatment for tumours from the same organ is rational only when there is no principal heterogeneity between the tumours of that organ. Organ tumour heterogeneity is typical for the lungs with small cell and non-small cell tumours, for the kidneys where clear cell renal carcinoma (CCRCC) is the dominating type among other subgroups, and in the stomach with adenocarcinomas of intestinal and diffuse types. In addition, a separate type of neuroendocrine tumours (NETs) is found in most organs. Every cell type able to divide may develop into a tumour, and the different subtypes most often reflect different cell origin. In this article the focus is on the cells of origin in tumours arising in the stomach and kidneys and the close relationship between normal neuroendocrine cells and NETs. Furthermore, that the erythropoietin producing cell may be the cell of origin of CCRCC (a cancer with many similarities to NETs), and that gastric carcinomas of diffuse type may originate from the ECL cell, whereas the endodermal stem cell most probably gives rise to cancers of intestinal type.

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.

Use of Proton Pump Inhibitors vs Histamine 2 Receptor Antagonists for the Risk of Gastric Cancer: Population-Based Cohort Study

INTRODUCTION

Proton pump inhibitors (PPIs) are commonly prescribed medications. Long-term use of PPIs has been suspected to have a provocative effect on gastric cancer. This study was to determine the association between PPI vs histamine 2 receptor antagonist (H2RA) use and the risk of gastric cancer in a region where the risk of this malignancy is high.

METHODS

A population-based cohort study using the Korean National Health Insurance Services Database. The participants with first prescription of PPIs and H2RA with normal esophagogastroduodenoscopy finding from 2004 through 2015 were collected. Among them, 50% of participants were systematic stratified randomly sampled. There were 122,118 users of PPIs or H2RAs who use medication more than cumulative defined daily dose of 180 days. The users were followed up from long-term use threshold until gastric cancer, death from non-gastric cancer cause, gastric surgery, or study end (December 2017).

RESULTS

After calculating propensity score weights, we included 39,799 PPI and 38,967 H2RA users. Among the new PPI and H2RA users, we identified 411 cases of incident gastric cancer from 182,643 person-years of follow-up observation and 397 cases from 178,846 person-years of follow-up observation, respectively. Compared with H2RA users, PPI users did not experience significantly different gastric cancer incidence (adjusted hazard ratio, 1.01; 95% confidence interval, 0.88-1.16; P = 0.89). Sensitivity analyses confirmed that gastric cancer incidence did not differ between PPI and H2RA users.

DISCUSSION

In this large study, long-term treatment with PPIs vs H2RAs did not show higher risk of gastric cancer even in a high-risk region.

Total gastrectomy for severe proton pump inhibitor-induced hypomagnesemia in a MEN1/Zollinger Ellison syndrome patient

We report here the first case of life-threatening hypomagnesemia in a Zollinger-Ellison syndrome patient with multiple endocrine neoplasia type 1 (MEN1) syndrome. The severe symptomatic hypomagnesemia proved to be due to proton pump inhibitors (PPIs), but withdrawal of PPIs led to early severe peptic complications despite a substitution by histamine H2-receptor antagonist therapy. Simultaneous management of life-threatening hypomagnesemia, severe gastric acid hypersecretion and MEN1-associated gastrinomas was complex. A total gastrectomy was performed in order to definitely preclude the use of PPIs in this frail patient who was not eligible for curative pancreatoduodenal resection.

Towards Understanding of Gastric Cancer Based upon Physiological Role of Gastrin and ECL Cells

Simple Summary

Generally, we know that cancers represent genetic changes in tumour cells, but we most often do not know the causes of cancers or how they develop. Our knowledge of the regulation of gastric acid secretion is well known, with the gastric hormone gastrin maintaining gastric acidity by stimulation of the enterochromaffin-like (ECL) cell to release histamine, which subsequently augments acid secretion. Furthermore, it seems to be a general principle that stimulation of function (which, for the ECL cell, is release of histamine) in a parallel way stimulates the proliferation of the same cell. Long-term hyperstimulation of cell division predisposes to genetic changes and, thus, development of tumours. All conditions with reduced gastric acidity result in an increased risk of gastric tumours due to elevated gastrin in order to restore gastric acidity. It is probable that Helicobacter pylori infection (the most important cause of gastric cancer), as well as drugs inhibiting gastric acid secretion induce gastric cancer in the long-term, due to an elevation of gastrin caused by reduced gastric acidity. Gastric carcinomas have been shown to express ECL cell markers, further strengthening this relationship.

Abstract

The stomach is an ideal organ to study because the gastric juice kills most of the swallowed microbes and, thus, creates rather similar milieu among individuals. Combined with a rather easy access to gastric juice, gastric physiology was among the first areas to be studied. During the last century, a rather complete understanding of the regulation of gastric acidity was obtained, establishing the central role of gastrin and the histamine producing enterochromaffin-like (ECL) cell. Similarly, the close connection between regulation of function and proliferation became evident, and, furthermore, that chronic overstimulation of a cell with the ability to proliferate, results in tumour formation. The ECL cell has long been acknowledged to give rise to neuroendocrine tumours (NETs), but not to play any role in carcinogenesis of gastric adenocarcinomas. However, when examining human gastric adenocarcinomas with the best methods presently available (immunohistochemistry with increased sensitivity and in-situ hybridization), it became clear that many of these cancers expressed neuroendocrine markers, suggesting that some of these tumours were of neuroendocrine, and more specifically, ECL cell origin. Thus, the ECL cell and its main regulator, gastrin, are central in human gastric carcinogenesis, which make new possibilities in prevention, prophylaxis, and treatment of this cancer.

Three Cases of Diffuse, Intense Stomach Uptake on DOTATATE PET

Incidental tracer uptake on DOTATATE PET is increasingly encountered in clinical practice. We describe 3 patients with suspected or known neuroendocrine tumor who were found to have diffuse and intense stomach uptake on DOTATATE PET. All patients underwent esophagogastroduodenoscopy and/or endoscopic ultrasound; the cause of the stomach uptake was attributed to proton-pump inhibitor use, chronic gastritis, and gastrinoma, respectively. These 3 cases highlight that diffuse and intense stomach DOTATATE uptake can be a benign finding probably attributed to proton-pump inhibitor use, chronic gastritis, or gastrinoma.

Proton pump inhibitors: misconceptions and proper prescribing practice

PURPOSE OF REVIEW

The current review summarizes and attempts to place in proper perspective the past year's literature regarding purported adverse effects of proton pump inhibitors (PPIs).

RECENT FINDINGS

Although generally considered safe, physicians are inundated with retrospective database-driven epidemiologic studies, and meta-analyses on the same studies, claiming a panoply of serious adverse effects associated with long-term use of PPIs. The quality of the evidence underlying most of these associations is very low and cannot ascribe cause and effect. Nonetheless, these reports have stoked fears, in both prescribers and patients. As a result, patients are being harmed. Physicians are not prescribing PPIs when medically indicated and patients are stopping PPIs without consulting their caregivers. It is reassuring that a cross-sectional analysis of data from the National Ambulatory Medical Care Survey as well as a double-blinded, placebo-controlled trial report no safety concerns with PPIs, other than a possible small association with enteric infection.

SUMMARY

Most of the publicized serious putative adverse effects attributed to PPIs have been debunked in more recent and properly designed studies. Nevertheless, PPIs should be prescribed for valid indications and, when prescribed long-term, they should be used at the lowest effective dose and their ongoing need periodically assessed.

Long-term use of proton pump inhibitors as a risk factor for various adverse manifestations

The long-term use of proton pump inhibitors (PPIs) can lead to increased gastric pH, hypochlorhydria and in some cases to achlorhydria when compared to other acid-suppressing agents like histamine-2 (H2) receptor blockers and antacids. These consequences by the use of long-term PPIs may lead to significant vitamin (B₁₂ and C) and mineral (iron, calcium and magnesium) deficiencies which needs gastric acid for their absorption and bioavailability. Long-term use of PPIs by the pregnant patients may impose a potential risk of congenital malformations. Various studies have recommended the life style modifications and antacid use as first choice among pregnant womens by preserving PPIs (omeprazole as a safe choice of PPI) for severe conditions of gastroesophageal reflux disease. The long-term acid suppression by PPIs can also lead to enteric, respiratory and urinary tract infections. The hypochlorhydria by chronic PPIs use may induce hypergastrinemia, which ultimately mediates the gastric polyps, gastric carcinoids and gastric cancer. The concomitant use of PPIs with antiplatelet drugs like clopidogrel can impose the patients to major adverse cardiac events. This review has enlisted the comprehensive information regarding the adverse effects induced by long-term use of PPIs and their possible relations. Considerable studies like case-control, randomized trials, cohort studies and meta-analysis were reported in supporting these adverse effects. The clinicians and patients should be cautious about these effects so that they can avoid the serious outcomes. PPIs should be avoided for long-term use mainly in older adults unless there is a proper indication.

Proton Pump Inhibitor Use, Hypergastrinemia, and Gastric Carcinoids-What Is the Relationship?

Neuroendocrine tumors (NETs) throughout the body are the focus of much current interest. Most occur in the gastrointestinal tract and have shown a major increase in incidence over the past 30 years, roughly paralleling the world-wide increase in the use of proton pump inhibitor (PPI) drugs. The greatest rise has occurred in gastric carcinoids (g-NETs) arising from enterochromaffin-like (ECL) cells. These tumors are long known to occur in auto-immune chronic atrophic gastritis (CAG) and Zollinger-Ellison syndrome (ZES), with or without multiple endocrine neoplasia type-1 (MEN-1), but the incidences of these conditions do not appear to have increased over the same time period. Common to these disease states is persistent hypergastrinemia, generally accepted as causing g-NETs in CAG and ZES, and postulated as having similar tumorigenic effects in PPI users. In efforts to study the increase in their occurrence, g-NETs have been classified in a number of discussed ways into different grades that differ in their incidence and apparent pathogenesis. Based on a large amount of experimental data, tumorigenesis is mediated by gastrin’s effects on the CCK2R-receptor on ECL-cells that in turn leads to hyperplasia, dysplasia, and finally neoplasia. However, in all three conditions, the extent of response of ECL-cells to gastrin is modified by a number of genetic influences and other underlying risk factors, and by the duration of exposure to the hormonal influence. Data relating to trophic effects of hypergastrinemia due to PPI use in humans are reviewed and, in an attached Appendix A, all 11 reports of g-NETs that occurred in long-term PPI users in the absence of CAG or ZES are summarized. Mention of additional suspected cases reported elsewhere are also listed. Furthermore, the risk in humans may be affected by the presence of underlying conditions or genetic factors, including their PPI-metabolizer phenotype, with slow metabolizers likely at increased risk. Other problems in estimating the true incidence of g-NETs are discussed, relating to non-reporting of small tumors and failure of the Surveillance, Epidemiology, and End Results Program (SEER) and other databases, to capture small tumors or those not accorded a T1 rating. Overall, it appears likely that the true incidence of g-NETs may be seriously underestimated: the possibility that hypergastrinemia also affects tumorigenesis in additional gastrointestinal sites or in tumors in other organ systems is briefly examined. Overall, the risk of developing a g-NET appears greatest in patients who are more than 10 years on drug and on higher doses: those affected by chronic H. pylori gastritis and/or consequent gastric atrophy may also be at increased risk. While the overall risk of g-NETs induced by PPI therapy is undoubtedly low, it is real: this necessitates caution in using PPI therapy for long periods of time, particularly when initiated in young subjects.

Phenotypes Associated With MEN1 Syndrome: A Focus on Genotype-Phenotype Correlations

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant inherited tumor syndrome, associated with parathyroid, pituitary, and gastro-entero-pancreatic (GEP) neuroendocrine tumors (NETs). MEN1 is usually consequent to different germline and somatic mutations of the MEN1 tumor suppressor gene, although phenocopies have also been reported. This review analyzed main biomedical databases searching for reports on MEN1 gene mutations and focused on aggressive and aberrant clinical manifestations to investigate the potential genotype-phenotype correlation. Despite efforts made by several groups, this link remains elusive to date and evidence that aggressive or aberrant clinical phenotypes may be related to specific mutations has been provided by case reports and small groups of MEN1 patients or families. In such context, a higher risk of aggressive tumor phenotypes has been described in relation to frameshift and non-sense mutations, and predominantly associated with aggressive GEP NETs, particularly pancreatic NETs. In our experience a novel heterozygous missense mutation at c.836C>A in exon 6 was noticed in a MEN1 patient operated for macro-prolactinoma, who progressively developed recurrent parathyroid adenomas, expanding gastrinomas and, long after the first MEN1 manifestation, a neuroendocrine uterine carcinoma. In conclusion, proof of genotype-phenotype correlation is limited but current evidence hints at the need for long-term interdisciplinary surveillance in patients with aggressive phenotypes and genetically confirmed MEN1.