The central role of gastrin in gastric cancer

The central role of gastrin in Helicobacter pylori gastric carcinogenesis

Gastric cancer is still a prevalent and lethal cancer. Gastric hypoacidity and gastritis have long been recognized in the pathogenesis. The identification of Helicobacter(H.) pylori as the main cause of gastritis leading to peptic ulcer disease and gastric cancer was a breakthrough. H. pylori was the first bacterium accepted as a carcinogen. The mechanism was not found before H. pylori was shown to predispose to cancer only after having induced oxyntic atrophy incriminating reduced killing of microorganisms and/or secondary hypergastrinemia. H. pylori has an uncertain carcinogenic role in cardia cancer, making microbes more unlikely. Gastrin has a trophic effect on the oxyntic mucosa, particularly on the enterochromaffin like cell carrying the gastrin receptor. Every condition with long-term hypergastrinemia in whatever species predisposes to gastric neoplasia. All observations on gastric neoplasia connected to H. pylori gastritis (the protective effect of duodenal ulcer, increased risk with oxyntic atrophy and preserved risk after loss of H. pylori in complete oxyntic atrophy) may be explained by gastrin. The role of gastrin in gastric carcinogenesis is also reflected by autoimmune gastritis and profound long-term gastric acid inhibition.

Effective endoscopic management of gastric neoplastic complications in patients with autoimmune gastritis: results of a monocentric study of 88 patients

Background

We evaluated the efficacy of endoscopic treatment (ET) for gastric neoplastic complications of autoimmune gastritis (AIG). We also assessed the safety of ET and the risk factors for the occurrence of neuroendocrine tumors (NETs) and gastric adenocarcinoma (GA).

Methods

This was a retrospective, single-center, observational study. All patients diagnosed with AIG between 1987 and 2019 and had at least 1 upper endoscopy available were included.

Results

The study population comprised 88 patients (68.2% female). The median follow up was 5 years (range 1-28). A total of 132 NETs were diagnosed in 39/88 patients (44.3%) (median age 50.0 years, range 27.0-85.0 years). The mean lesion size was 7.1 mm (range 1-30); there were 80 G1 NETs and 52 G2 NETs. Among the 132 lesions, 86.3% (114/132) were endoscopically resected, mostly by endoscopic mucosal resection (105/114, 92.1%), without complications. Only 1 patient underwent surgery. Twelve patients (13.6%) (7 females; median age, 76.0 years; range, 53.0-90.0 years) presented with GA. Of these, 66.7% (8/12) needed surgery, while 4 patients underwent exclusive endoscopic resection. Only 2 patients presented with NETs and GA (2.8%). Patients who presented with NETs were significantly younger at AIG diagnosis than patients with GA: 52.0 (18.0-85.0) vs. 67.0 (44.0-81.0) years (P=0.008). Patients who presented with GA were significantly older than those who presented with NETs: 76.0 (53.0-90.0) vs. 50.0 (27.0-85.0) years (P<0.001).

Conclusion

ET of NETs for AIG is effective and safe. GA is rarer, occurs in significantly older patients, and usually requires surgery.

Predictors for the Development of Hypergastrinemia in Maintenance Treatment for Mild Gastroesophageal Reflux Disease Using a Half-dose Proton Pump Inhibitor

Background/Aims

Serum gastrin levels may be elevated following proton pump inhibitor (PPI) therapy. We aim to elucidate the predictors for the development of hypergastrinemia in maintenance treatment for mild gastroesophageal reflux disease (GERD) using a half-dose PPI.

Methods

This study analyzed data from a prospective randomized trial to compare continuous versus on-demand maintenance treatment modalities in patients with mild GERD. Age, sex, body mass index, Helicobacter pylori infection, serum gastrin levels, pepsinogen (PG) I/II ratios, total days of PPI intake, and weight-based PPI dosage (mg/kg) were evaluated.

Results

Data from 293 patients who completed a randomized trial were analyzed (continuous group, n = 147 vs on-demand group, n = 146). In univariate analysis, age (P < 0.001), H. pylori infection (P = 0.012), baseline gastrin levels (P < 0.001), and baseline PG ratios (P = 0.016) significantly correlated with post-treatment gastrin levels. In multivariate analysis, age, baseline gastrin levels, and baseline PG ratios were independently associated with final serum gastrin levels. In univariate analysis, age (P = 0.018), H. pylori infection (P = 0.028), baseline gastrin levels (P = 0.011), and baseline PG ratios (P = 0.031) significantly correlated with the development of hypergastrinemia. In multivariate analysis, age, baseline gastrin levels, and baseline PG ratios were independently associated with the development of hypergastrinemia.

Conclusion

Old age, high baseline serum gastrin levels, and low baseline PG ratios are significant predictors of the development of hypergastrinemia in maintenance treatment for mild GERD using a half-dose PPI.

Eradication of Helicobacter pylori by a potassium-competitive acid blocker alone?

AIMS

Helicobacter pylori (H. pylori), the dominating cause of gastric cancer, most often infects children initiating inflammation in the antral part and spreads orally to the oxyntic mucosa. Traditionally, eradication of H. pylori has been based upon a combination of antibiotics together with a proton pump inhibitor (PPI) to reduce gastric destruction of the antibiotics. Recently it has been shown that the more efficient inhibitors of acid secretion, the potassium-competitive acid blockers (PCABs) in combination with amoxicillin alone gave highly sufficient H. pylori eradication.

METHODS

To further elucidate the importance of gastric acidity we studied the literature for the connection between gastric acidity and the presence of H. pylori.

RESULTS

It is well-known that H. pylori is dependent of some acidity in the surroundings to neutralize NH3 produced by its urease, explaining the loss of H. pylori in total oxyntic atrophy. With adequate dosing PCABs can induce almost complete anacidity for 24-h which probably is necessary for H. pylori eradication. Even a short period with hypergastrinemia may induce mutations in the target cell of gastrin, the enterochromaffin-like (ECL) cell which may contribute to the relatively short interval between H. pylori eradication and gastric cancer in the users of profound acid inhibitors.

CONCLUSION

The use of PCABs alone dosed sufficiently seems promising for H. pylori eradication, but a combination with a gastrin antagonist would be preferable.

Identification of gastric cancer biomarkers through in-silico analysis of microarray based datasets

Gastric cancer is among the most prevalent cancers worldwide including in Pakistan. Late diagnosis of gastric cancer leads to reduced survival. The present study aimed to investigate biomarkers for early diagnosis and prognosis of gastric cancer. For this purpose, the ten microarray-based gene expression datasets (GSE54129, GSE79973, GSE161533, GSE103236, GSE33651, GSE19826, GSE118916, GSE112369, GSE13911, and GSE81948) were retrieved from GEO database and analyzed by GEO2R to identify differentially expressed genes. Datasets were arranged in subsets of different dataset combinations to identify common DEGs. The gene ontology and functional pathway enrichment analysis of common DEGs was performed by DAVID tool. Pan-cancer analysis was conducted by UALCAN database. Survival analysis of common DEGs was done by Kaplan-Meier plotter. A total of 71 common DEGs were identified in different combinations of datasets. Among them, only 5 DEGs namely ATP4B, ATP4A, CCKBR, KCNJ15, and KCNJ16 were detected to be common in all the datasets. The GO and pathway analysis represented that the identified DEGs are involved in gastric acid secretion and collecting duct acid secretion pathways. Further expression validation of these five genes using three additional datasets (GSE31811, GSE26899, and GSE26272) confirmed their differential expression in gastric cancer samples. The pan-cancer analysis also revealed aberrant expression of DEGs in various cancers. The survival analysis showed the association of these 5 DEGs with poor survival of gastric cancer patients. To conclude, this study revealed a panel of 5 genes, which can be employed as diagnostic and prognostic biomarkers of gastric cancer patients.

CiteSpace-based visual analysis on transcutaneous electrical acupoint stimulation of clinical randomized controlled trial studies and its mechanism on perioperative disorders

To systematically present an overview of randomized controlled trials on transcutaneous electrical acupoint stimulation (TEAS) using bibliometric methods, and describe the role and mechanisms of TEAS in most prevalent diseases. Relevant literature was searched in China National Knowledge Infrastructure, Wanfang Data, VIP, SinoMed, PubMed, and Web of Science. The literature was imported and screened into NoteExpress, screened according to inclusion and exclusion criteria, and analyzed using Excel and CiteSpace 6.3R1 software. A total of 1296 documents were included. The number of publications increased annually after 2012. Junlu Wang was the most prolific author. The main research institutions were Peking University, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Shuguang Hospital, and Tongde Hospital of Zhejiang Province. The research hotspots in this field include perioperative care, cancer, pain management, and stroke, primarily focusing on analgesia, immune enhancement, antihypertension, and reduction of gastrointestinal disorders. The main regulatory mechanisms of TEAS include the control of inflammation, oxidative stress, and regulation of the autonomic nervous system. TEAS is most widely used in the elderly, with PC6, ST36, and LI4 being the most frequently studied acupoints in clinical randomized controlled trials. The concept of accelerated rehabilitation is gradually being applied to TEAS, representing an emerging trend for future development. Clinical research on TEAS is rapidly developing, with a focus on applications in cancer and perioperative care. Future research should expand collaboration and conduct high-level clinical and mechanistic studies, which will contribute to the development of standardized protocols and clinical practice.

Long-Term Proton Pump Inhibitor-Acid Suppressive Treatment Can Cause Vitamin B12 Deficiency in Zollinger-Ellison Syndrome (ZES) Patients

Whether the long-term treatment of patients with proton pump inhibitors (PPIs) with different diseases [GERD, Zollinger-Ellison syndrome (ZES), etc.] can result in vitamin B12 (VB12) deficiency is controversial. In this study, in 175 patients undergoing long-term ZES treatment with anti-acid therapies, drug-induced control acid secretory rates were correlated with the presence/absence of VB12 deficiency, determined by assessing serum VB12 levels, measurements of VB12 body stores (blood methylmalonic acid (MMA) and total homocysteine[tHYC]), and other features of ZES. After a mean of 10.2 yrs. of any acid treatment (5.6 yrs. with PPIs), 21% had VB12 deficiency with significantly lower serum and body VB12 levels (p < 0.0001). The presence of VB12 deficiency did not correlate with any feature of ZES but was associated with a 12-fold lower acid control rate, a 2-fold higher acid control pH (6.4 vs. 3.7), and acid control secretory rates below those required for the activation of pepsin (pH > 3.5). Over a 5-yr period, the patients with VB12 deficiency had a higher rate of achlorhydria (73% vs. 24%) and a lower rate of normal acid secretion (0% vs. 49%). In conclusion, in ZES patients, chronic long-term PPI treatment results in marked acid hyposecretion, resulting in decreased serum VB12 levels and decreased VB12-body stores, which can result in VB12 deficiency.

Autoimmune Gastritis and Hypochlorhydria: Known Concepts from a New Perspective

Autoimmune atrophic gastritis is an immune-mediated disease resulting in autoimmune destruction of the specialized acid-producing gastric parietal cells. As a consequence, in autoimmune atrophic gastritis, gastric acid secretion is irreversibly impaired, and the resulting hypochlorhydria leads to the main clinical manifestations and is linked, directly or indirectly, to the long-term neoplastic complications of this disease. In the last few years, autoimmune atrophic gastritis has gained growing interest leading to the acquisition of new knowledge on different aspects of this disorder. Although reliable serological biomarkers are available and gastrointestinal endoscopy techniques have substantially evolved, the diagnosis of autoimmune atrophic gastritis is still affected by a considerable delay and relies on histopathological assessment of gastric biopsies. One of the reasons for the diagnostic delay is that the clinical presentations of autoimmune atrophic gastritis giving rise to clinical suspicion are very different, ranging from hematological to neurological-psychiatric up to gastrointestinal and less commonly to gynecological-obstetric symptoms or signs. Therefore, patients with autoimmune atrophic gastritis often seek advice from physicians of other medical specialties than gastroenterologists, thus underlining the need for increased awareness of this disease in a broad medical and scientific community.

Clinicopathological Characteristics and Risk Factors of Young-Onset Gastric Carcinoma: A Systematic Review and Meta-analysis

INTRODUCTION

The characteristics of gastric carcinoma in young individuals differ from that in older individuals. We conducted a systematic review and meta-analysis to explore the clinicopathological features and risk factors associated with young-onset (younger than 50 years) gastric carcinoma.

METHODS

We searched for studies published between January 1, 1990, and September 1, 2023, on patients with young-onset gastric carcinoma in PubMed, EMBASE, Web of Science, and MEDLINE to explore clinicopathological characteristics among this specific patient group. Extracted information included the proportion of patients with symptoms or family history of gastric cancer, tumor location, and histological features such as Lauren or World Health Organization histological classification and degree of differentiation. Additional analyses were conducted on risk factors such as positive family history, Helicobacter pylori infection, or high-risk nutritional or behavioral factors. The estimates were derived using random or fixed-effect models and included subgroup analyses based on different sex and age groups. This study was registered in PROSPERO (CRD42023466131).

RESULTS

We identified 5,696 records, 1,292 were included in the quality assessment stage. Finally, 84 studies from 18 countries or regions including 89,447 patients with young-onset gastric carcinoma were included. Young-onset gastric carcinoma has slight female predominance (53.7%, 95% confidence interval [CI]: 51.6-55.7%), with most having symptoms (87.0%, 95% CI: 82.4%-91.7%). Family history was reported in 12.1% (95% CI: 9.5%-14.7%). H. pylori infection was detected in 60.0% of cases (95% CI: 47.1%-72.8%). Most of these carcinomas were in the non-cardia region (89.6%, 95% CI: 82.4%-96.8%), exhibiting Lauren diffuse-type histology (71.1%, 95% CI: 66.8%-75.3%) and poor/undifferentiated features (81.9%, 95% CI%: 79.7-84.2%). A positive family history of gastric cancer was the most important risk factor associated with the development of gastric carcinoma in young individuals (pooled odds ratios 4.0, 95% CI: 2.8-5.2), followed by H. pylori infection (odds ratio 2.3; 95% CI: 1.4-3.2) and dietary and other lifestyle risk factors.

DISCUSSION

Young-onset gastric carcinoma exhibits specific clinicopathological characteristics, with positive family history being the most important risk factor. Most of the patients were symptomatic at diagnosis. These findings could help to inform future strategies for the early detection of gastric carcinoma among young individuals.