Proton pump inhibitors and gastric neoplasia

Proton pump inhibitor use and the risk of metachronous gastric cancer after H. pylori eradication in patients who underwent endoscopic resection for gastric neoplasms: A population-based cohort study

BACKGROUND

The association between proton pump inhibitors (PPI) use and gastric cancer remains controversial.

AIMS

To investigate the impact of long-term PPI use on metachronous gastric cancer after Helicobacter pylori eradication in high-risk patients who underwent endoscopic resection of gastric neoplasms.

METHODS

Using the Korean National Health Insurance Services database, we identified 1836 PPI users and 12,218 non-users among patients who received H. pylori eradication therapy after endoscopic resection for gastric neoplasms between 2009 and 2014. We then compared the incidence of metachronous gastric cancer between the PPI user and non-user groups. We conducted sensitivity analysis using various time lags and propensity score-matched analysis to ensure the robustness of the results.

RESULTS

After a median follow-up of 7.3 years, the incidence of metachronous gastric cancer was significantly higher in the PPI user group than in the non-user group, with a crude hazard ratio of 6.20 (95% confidence interval, 5.78-6.65). After adjustment, PPI use was associated with the development of metachronous gastric cancer, with an adjusted hazard ratio of 5.51 (95% confidence interval, 5.12-5.92). The PPI user group was categorised into three subgroups according to the cumulative PPI dose; the increased risk of metachronous gastric cancer remained significant regardless of the PPI dose. Moreover, these results remained robust after applying various time lags and propensity score-matched analyses.

CONCLUSIONS

Long-term PPI use is associated with an increased risk of metachronous gastric cancer in patients who undergo H. pylori eradication therapy after endoscopic resection of gastric neoplasms.

Meta-analysis: Use of proton pump inhibitors and risk of gastric cancer in patients requiring gastric acid suppression

BACKGROUND

Proton-pump inhibitors (PPIs) are suspected to increase the risk of gastric cancer.

AIM

To assess the risk of gastric cancer associated with the use of PPIs.

METHODS

We systematically searched Medline/PubMed, Embase and Scopus databases (until June 1, 2022) for randomised and non-randomised studies (NRS) of the association between PPIs and gastric cancer having considered Histamine-2 receptor antagonists (H2RAs) users as controls. We chose this comparison to minimise confounding by indication, and focus on patients requiring gastric acid suppression. Two authors independently extracted study data and assessed each study's risk of bias. Maximally-adjusted relative risk (RR) estimates were extracted. Heterogeneity and small-study effect were examined, and summary estimates were calculated using random- and fixed-effect models. Stratified analyses and meta-regression were employed to explore heterogeneity. We used GRADE to evaluate the certainty of evidence.

RESULTS

Of 8375 records, 12 NRS (>6 million patients; 11,554 gastric cancers) and two randomised clinical trials (498 patients; 1 gastric cancer) fulfilled the eligibility criteria. Randomised evidence was very imprecise and provided very-low certainty evidence. Meta-analysis of six NRS providing a comprehensive adjustment for confounding (2.5 million patients; 7372 gastric cancers) did not show any association between PPIs and gastric cancer (RR_random  = 1.07, 0.97-1.19; RR_fixed  = 1.05, 0.98-1.12). The certainty of the evidence was low. No convincing evidence of dose-response, or increased risk with long-term use, was found. Lack of or minimal adjustment for confounding was associated with larger effect sizes.

CONCLUSIONS

We found no association between PPIs and gastric cancer in NRS having adequately controlled for confounding. Published studies may suffer residual confounding.

SYSTEMATIC REVIEW REGISTRATION

CRD42022335971.

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.

Clinicopathological features of gastric cancer after pancreaticoduodenectomy: reporting of three institutional cases and review of the global literature

PURPOSE

Gastric cancer after pancreaticoduodenectomy was firstly reported in 1995, and the number of reports about this topic has increased in the past years. This review aimed to elucidate the clinicopathological features of this disease.

METHODS

Data for 32 cases were obtained using literature search, and three cases in our institution were added.

RESULTS

Twenty cases were reported from Japan, and fifteen cases were from the Western countries (Germany: 1 case, France: 2 cases, USA: 12 cases). In Japanese and the Western cases, the most dominant indication for pancreaticoduodenectomy was distal bile duct cancer and pancreatic ductal adenocarcinoma, respectively. The most frequently applied procedure of pancreaticoduodenectomy was pylorus-preserving pancreatoduodenectomy with pancreaticogastrostomy and pancreaticoduodenectomy with pancreaticojejunostomy, respectively. The median length of time interval from pancreaticoduodenectomy to GC detection tended to be shorter in the Japanese cases (61.5 months vs. 115 months). Of all cases, thirteen (37.1%) patients with gastric cancer showed no abdominal symptoms, and eight were diagnosed at regular gastroscopy. Surgical gastrectomy was performed in 30 patients, and among them, concomitant pancreatectomy was performed in six patients. Four patients received reanastomosis of remnant pancreas using pancreaticojejunostomy. Twenty-two (73.3%) patients had undifferentiated carcinomas, and stage 1, 2, 3, and 4 cancer was identified in 14, six, six, and four patients, respectively. All eight patients who had received routine gastroscopy were T1N0M0 stage 1.

CONCLUSION

Gastric cancers after pancreaticoduodenectomy including newly reported Japanese cases and our institutional cases were reviewed to make Japanese studies available to a broader scientific audience. Further investigation is necessary to elucidate the most important carcinogens among the various potential local and systemic factors.

Pretreatment Levels of Chromogranin A and Neuron-specific Enolase in Patients With Gastroenteropancreatic Neuroendocrine Neoplasia

BACKGROUND/AIM

Chromogranin A (CgA) and neuron-specific enolase (NSE) are applied in the diagnosis of neuroendocrine neoplasms (NENs), especially non-functional ones. The aim of this study was to investigate the predictive values of CgA and NSE in long-term survival.

PATIENTS AND METHODS

Our retrospective analysis included 65 patients with histologically verified gastroenteropancreatic NEN between 2005 and 2019. We performed bivariate and multivariable analyses to evaluate the relationship between CgA and NSE values before histological assessment and overall survival. Distribution of time-to-event was analyzed using Kaplan-Meier survival curves and modelled by Cox regression models.

RESULTS

Elevated NSE levels prior to histology were significantly associated with worse survival (HR=1.13, p=0.004) and were associated with low-differentiated NENs (r_s=0.321, p=0.0338). CgA was associated with well-differentiated tumors (r_s=0.233), but not significantly.

CONCLUSION

Pretreatment serum levels of NSE can serve as a valuable additional predictor of long-term survival in patients with NEN.

Autoimmune atrophic gastritis in systemic sclerosis

Systemic sclerosis (SSc) is a rare connective tissue disorder with a complex pathogenesis involving vascular dysfunction, small vessel proliferation as well as alterations of innate and adaptive immunity. Gastrointestinal (GI) involvement in SSc is almost universal and affects nearly 90% of the patients. Of all the GI manifestations, 30%-75% are oesophageal abnormalities, including gastro-oesophageal reflux disease, reflux oesophagitis and Barret's oesophagus. The incidence of gastric manifestations is about 22% with a common presentation of gastric antral vascular ectasia (GAVE). However, autoimmune atrophic gastritis (AIG) is not a known manifestation of SSc. Our case has a unique presentation of the coexistence of GAVE and AIG. We have conducted a thorough literature review to study a possible association of AIG and SSc and understand the pathology of SSc.

[Proton pump inhibitors and cancers: A hazardous association?]

Proton pump inhibitors, a major progress in gastro-enterology, are globally among the most widely prescribed drugs. But, due to their strong gastric acid inhibition, they can be responsible for side effects, particularly in cancer patients. They are involved in renal function impairment, bone fractures, digestive bacterial overgrowth, particularlyclostridium difficile infections, anemia and hypomagnesemia. Long term use can increase the risks of gastric, pancreatic and liver cancers. They decrease absorption of weak bases drugs, particularly tyrosine kinase inhibitors and capecitabine and are responsible for a poorer prognosis if taken concomitantly with erlotinib, gefitinib and pazopanib. Modification of cyclin dependent kinases is also possible as well as decrease of efficacy of immune check point inhibitors (microbiome modifications). Absoption and efficacy of capecitabine seem also poorer with negative prognosis effect on treatment of gastric and colon cancer. Their long term use, particularly in cancer patients, should probably be avoided.

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.

Insights into the biology and treatment strategies of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are the second most common primary pancreatic neoplasms after pancreatic ductal adenocarcinoma. PNETs present with widely various clinical manifestation and unfavorable survival rate. The recent advances in next generation sequencing have significantly increased our understanding of the molecular landscape of PNETs and help guide the development of targeted therapies. This review intends to outline a holistic picture of the tumors by discussing current understanding of clinical presentations, up-to-date treatment strategies, novel mouse models, and molecular biology of PNETs. Furthermore, we will provide insight into the future development of more effective targeted therapies that are necessary to manage PNETs.

GASTRIC FUNDIC GLAND POLYPS: CAN HISTOLOGY BE USEFUL TO PREDICT PROTON PUMP INHIBITORS USE?

BACKGROUND

Fundic gland polyps allegedly increased in frequency in recent decades, and had attracted great attention due to possible association with prolonged proton pump inhibitor therapy. Prolonged use of this drug could cause parietal cell hyperplasia, obstruction of glandular lumen and cystic dilation of the gland.

OBJECTIVE

This study aims to analyze clinical and pathological features of fundic gland polyps in patients with and without proton pump inhibitor therapy in a selected population from Brazil.

METHODS

It was selected a sample of 101 Brazilian patients (78 females and 23 males), from a five years retrospective search of the files from a private pathology laboratory. The patients had an average age of 57 years and we included patients with a histological diagnosis of fundic gland polyp. The clinical data were obtained from their files and all histological slides were reviewed and examined with hematoxylin and eosin (HE) and Giemsa.

RESULTS

Information about the use or non-use of proton pump inhibitors (PPI) was obtained in 84 patient files. In 17 cases we could not determine if PPI were used or not. Among those in which the information was available, a positive history of anti-acid therapy was observed in 63 (75.0%) patients. Parietal cell hypertrophy/hyperplasia and parietal cell protrusions were detected in most slides. Histological findings were identical in PPI users and PPI negative patients. Helicobacter pylori infection was detected in just two samples. Epithelial dysplasia or adenocarcinoma were not observed in our cases. Histopathological analysis of fundic gland polyps could not distinguish between PPI and non-PPI related cases. Parietal cell cytoplasmic protrusions, an alleged marker of prolonged acid suppression therapy, was detected in both groups.

CONCLUSION

Histological features could not discriminate anti-acid therapy related fundic glands polyps in our patients.

Adverse Effects of Proton Pump Inhibitors on Platelet Count: A Case Report and Review of the Literature

Proton pump inhibitors (PPIs) are the most effective and preferred class of drugs used to treat peptic ulcer disease, gastroesophageal reflux disease, and other diseases associated with increased production of gastric acid. PPIs in general have an excellent long-term safety profile and are well-tolerated. However, studies have shown some adverse reactions (e.g., osteoporosis, Clostridium difficile-associated diarrhea, Vitamin B12 and iron deficiency, and acute interstitial nephritis) on long-term PPI use. Thrombocytopenia attributed to use of PPIs has been described in a few case reports and a retrospective study. In this case report, we describe a case of PPI-induced thrombocytopenia. In our patient, thrombocytopenia immediately developed after the initiation of PPI on two separate occasions and resolved after its discontinuation. The strong association found in our case implies the potential role of PPI in causing this rare but serious adverse reaction. Based on this case report and the observation from other studies, a PPI-induced adverse event should be considered as a possible etiology for new-onset idiopathic thrombocytopenia.

Chromogranin A as circulating marker for diagnosis and management of neuroendocrine neoplasms: more flaws than fame

Owing to the heterogeneity of neuroendocrine neoplasms (NENs), the availability of reliable circulating markers is critical for improving diagnostics, prognostic stratification, follow-up and definition of treatment strategy. This review is focused on chromogranin A (CgA), a hydrophilic glycoprotein present in large dense core vesicles of neuroendocrine cells. Despite being long identified as the most useful NEN-related circulating marker, clinical application of CgA is controversial. CgA assays still lack standardization, thus hampering not only clinical management but also the comparison between different analyses. In the diagnostic setting, clinical utility of CgA is limited as hampered by (a) the variety of oncological and non-oncological conditions affecting marker levels, which impairs specificity; (b) the fact that 30-50% of NENs show normal CgA, which impairs sensitivity. Regarding the prognostic phase, there is prospective evidence which demonstrates that advanced NENs secreting CgA have poorer outcome, as compared with those showing non-elevated marker levels. Although the identification of cut-offs allowing a proper risk stratification of CgA-secreting patients has not been performed, this represents the most important clinical application of the marker. By contrast, based on prospective studies, the trend of elevated circulating CgA does not represent a valid indicator of morphological evolution and has therefore no utility for the follow-up phase. Ultimately, current knowledge about the role of the marker for the definition of treatment strategy is poor and is limited by the small number of available studies, their prevalent retrospective nature and the absence of control groups of untreated subjects.

Sporadic Fundic Gland Polyps and Gastric Acid Suppression Level

BACKGROUND

Fundic gland polyps (FGPs) are a common endoscopic finding and are known to be associated with proton pump inhibitors (PPIs) use. It is not known if their prevalence is affected by gastric acidity levels. This study aimed to assess whether there is a correlation between FGPs and gastric acidity levels as identified on 24-hour ambulatory impedance-pH studies in patients on PPI therapy.

METHODS

We performed a review of 402 consecutive patients who take at least once daily PPI and underwent esophagogastroduodenoscopy with combined impedance-pH studies in the same setting (time and place) between January 2010 and December 2014. Patients were classified into 2 groups based on the presence or absence of biopsy-confirmed FGPs during endoscopy.

RESULTS

Of the 402 patients, 30 (7%) had FGPs. One of these polyps was found with low-grade dysplasia. There was no significant difference of the distributions of the [H⁺] in the FGPs versus the nonpolyp groups (P = 0.741). There was no significant difference between the 2 groups regarding PPI dose frequency regimens (once and twice) (P = 0.074). However, we found weak ordinal association with PPI duration (P = 0.01) (Spearman = 0.1).

CONCLUSIONS

FGPs are common endoscopic lesions. Incidence of dysplasia in FGPs is not only rare, but also of unknown clinical significance. Although they seem to be associated with PPIs, the mechanism remains unclear, as we found no correlation between the presence of FGPs and gastric acid control or PPI dose. Future studies would be useful to elucidate an alternate mechanism.

Gastric outlet obstruction secondary to a pedunculated hyperplastic polyp with early malignant changes

Hyperplastic polyps are the most common polypoidal lesions of the stomach showing a varied presentation. They may be asymptomatic; however, occasionally they can cause anaemia and gastric outlet obstruction. Malignant transformation is a serious complication associated with such polyps. We present the case of an elderly woman who complained of epigastric pain and intermittent vomiting. Oesophagogastroduodenoscopy (OGDS) showed a large pedunculated polyp along the lesser curvature of the stomach, 4 cm from the gastro-oesophageal junction, extending into the first part of the duodenum that caused gastric outlet obstruction. Computed tomography reported a soft-tissue mass arising from the incisura and extending through the pylorus into the duodenum (D1 and proximal D2). An endoscopic polypectomy was performed, and histopathological examination reported evidence of early gastric carcinoma. She underwent regular endoscopic follow-up with biopsies performed over 2 years, and the last follow-up showed mild-to-moderate dysplasia at the previous excision site. She underwent a planned laparoscopic wedge resection, and histopathological examination confirmed the presence of a hyperplastic polyp showing low-grade dysplasia.

Proton pump inhibitors: Risks of long-term use

Proton pump inhibitors are among the most commonly prescribed classes of drugs, and their use is increasing, in particular for long-term treatment, often being over-prescribed and used for inappropriate conditions. In recent years, considerable attention has been directed towards a wide range of adverse effects, and even when a potential underlying biological mechanism is plausible, the clinical evidence of the adverse effect is often weak. Several long-term side effects have been investigated ranging from interaction with other drugs, increased risk of infection, reduced intestinal absorption of vitamins and minerals, and more recently kidney damage and dementia. The most recent literature regarding these adverse effects and their association with long-term proton pump inhibitor treatment is reviewed, and the mechanisms through which these possible complications might develop are discussed.

The Safety of Appropriate Use of Over-the-Counter Proton Pump Inhibitors: An Evidence-Based Review and Delphi Consensus

The availability of over-the-counter (OTC) proton pump inhibitors (PPIs) for the short-term (2 weeks) management of frequent heartburn (≥2 days/week) has increased markedly, yet evidence-based recommendations have not been developed. A panel of nine international experts in gastroesophageal reflux disease developed consensus statements regarding the risks and benefits of OTC PPIs using a modified Delphi process. Consensus (based on ≥80% approval) was reached through multiple rounds of remote voting and a final round of live voting. To identify relevant data, the available literature was searched and summarized. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system terminology was used to rate the quality of evidence and strength of recommendations; consensus was based on ≥2/3 agreement. After 4 rounds of review, consensus was achieved for 18 statements. Notably, the available data did not directly reflect OTC use, but instead, prescription use; therefore, extrapolations to the OTC setting were often necessary. This limitation is regrettable, but it justifies performing this exercise to provide evidence-based expert opinion on a widely used class of drugs. The panel determined that using OTC PPIs according to label instructions is unlikely to mask the symptoms of esophageal or gastric cancer or adversely impact the natural history of related precursor conditions. OTC PPIs are not expected to substantially affect micronutrient absorption or bone mineral density or cause community-acquired pneumonia, Clostridium difficile infection, or cardiovascular adverse events. However, OTC PPI use may be associated with slightly increased risks for infectious diarrhea, certain idiosyncratic reactions, and cirrhosis-related spontaneous bacterial peritonitis. The available evidence does not suggest that OTC PPI use consistent with label instructions is associated with substantial health risks. To minimize potential risks, healthcare professionals and consumers must actively participate in decision making when managing reflux-related symptoms in the self-care setting.

Helicobacter pylori infection, chronic corpus atrophic gastritis and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: A nested case-control study

The association between H. pylori infection and pancreatic cancer risk remains controversial. We conducted a nested case-control study with 448 pancreatic cancer cases and their individually matched control subjects, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, to determine whether there was an altered pancreatic cancer risk associated with H. pylori infection and chronic corpus atrophic gastritis. Conditional logistic regression models were applied to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs), adjusted for matching factors and other potential confounders. Our results showed that pancreatic cancer risk was neither associated with H. pylori seropositivity (OR = 0.96; 95% CI: 0.70, 1.31) nor CagA seropositivity (OR = 1.07; 95% CI: 0.77, 1.48). We also did not find any excess risk among individuals seropositive for H. pylori but seronegative for CagA, compared with the group seronegative for both antibodies (OR = 0.94; 95% CI: 0.63, 1.38). However, we found that chronic corpus atrophic gastritis was non-significantly associated with an increased pancreatic cancer risk (OR = 1.35; 95% CI: 0.77, 2.37), and although based on small numbers, the excess risk was particularly marked among individuals seronegative for both H. pylori and CagA (OR = 5.66; 95% CI: 1.59, 20.19, p value for interaction < 0.01). Our findings provided evidence supporting the null association between H. pylori infection and pancreatic cancer risk in western European populations. However, the suggested association between chronic corpus atrophic gastritis and pancreatic cancer risk warrants independent verification in future studies, and, if confirmed, further studies on the underlying mechanisms.

Silencing of ATP4B of ATPase H+/K+ Transporting Beta Subunit by Intragenic Epigenetic Alteration in Human Gastric Cancer Cells

The ATPase H+/K+ Transporting Beta Subunit (ATP4B) encodes the β subunit of the gastric H+, K+-ATPase, which controls gastric acid secretion and is therefore a target for acid reduction. Downregulation of ATP4B was recently observed in human gastric cancer (GC) without known mechanisms. In the present study, we demonstrated that ATP4B expression was decreased in human GC tissues and cell lines associated with DNA hypermethylation and histone hypoacetylation of histone H3 lysine 9 at its intragenic region close to the transcriptional start site. The expression of ATP4B was restored in GC cell lines by treatment with the DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (5-AZA), or histone deacetylase inhibitor, trichostatin A (TSA), with further enhancement by combined treatment with both drugs. In contrast, 5-AZA had no effect on ATP4B expression in human hepatocellular carcinoma (HCC) and pancreatic cancer cell lines, in which ATP4B was silenced and accompanied by intragenic methylation. Chromatin immunoprecipitation (ChIP) showed that, in BGC823 GC cells, histone H3 lysine 9 acetylation (H3K9ac) was enhanced in the intragenic region of ATP4B upon TSA treatment, whereas 5-AZA showed a minimal effect. Additionally, ATP4B expression enhanced the inhibitory effects of chemotherapeutic mediation docetaxel on GC cell growth. Thus, as opposed to HCC and pancreatic cancer cells, the silencing of ATP4B in GC cells is attributable to the interplay between intragenic DNA methylation and histone acetylation of ATP4B, the restoration of which is associated with a favorable anticancer effect of docetaxel. These results have implications for targeting epigenetic alteration at the intragenic region of ATP4B in GC cells to benefit diagnosis and treatment of GC.

Does long-term profound inhibition of gastric acid secretion increase the risk of ECL cell-derived tumors in man?

OBJECTIVE

Since the description of ECL cell-derived tumors in rodents after long-term profound acid inhibition inducing hypergastrinemia, there has been concern that proton pump inhibitors (PPIs) could also do that in man. The recent description of a Spanish family with gastric ECL cell tumors at the age of about 30 years secondary to a defect in the proton pump due to mutation in the ATP4A gene clearly shows that hypergastrinemia alone also is sufficient to induce ECL cell neoplasia in man. The present review aims to evaluate the risk of gastric neoplasia secondary to gastric acid inhibition.

METHODS

Literature (MEDLINE) was searched for the role of the ECL cell in gastric carcinogenesis in animals and man in general and particularly secondary to long-term inhibition of acid secretion.

RESULTS

An important proportion of patients treated with PPI develops hypergastrinemia causing ECL cell hyperplasia and the first descriptions of ECL cell carcinoids secondary to PPI have been reported. The role of the ECL cell has hitherto been under estimated in gastric carcinogenesis in man where for instance the signet ring cell type of gastric carcinoma seems to originate from the ECL cell.

CONCLUSIONS

The first two of three steps in rodent ECL cell carcinogenesis (hyperplasia, carcinoid, and carcinoma) secondary to PPI dosing, have been described for man. It is every reason to believe that the final step, gastric carcinoma, will develop also in man. Clinical decisions should be based not only on so-called evidence based medicine, but also on physiological knowledge and animal studies.

Safety of proton pump inhibitors and risk of gastric cancers: review of literature and pathophysiological mechanisms

INTRODUCTION

Despite being an overall safe drug, several long-term adverse effects are associated with proton pump inhibitors (PPIs). The link between PPI use and gastric neuroendocrine tumors (NETs), gastric adenocarcinomas and Barrett's esophagus progression gastric cancers has been investigated due to PPI-induced hypergastrinemia.

AREAS COVERED

The pathophysiological mechanisms underlying PPI exposure and gastric NETs, gastric adenocarcinomas and Barrett's esophagus progression are discussed. The quality of randomized control studies, cohort studies and case reports investigating the link between gastric cancers and PPIs are examined. Recommendations for clinicians are provided.

EXPERT OPINION

PPIs cause a hypergastrinemic state, increasing enterochromaffin-like cell dysplasia and risk of gastric NET development, increasing gastritis severity in the context of Helicobacter pylori infection, and progression of carcinogenesis in a certain predisposed subset of Barrett's esophagus patients. There are case reports of PPI-induced gastric NETs and adenocarcinomas as consequences of these effects. In pernicious anemia and chronic gastritis, clinicians should be aware of potential increased risk of gastric NET development with chronic PPI use in these patients. Eradication status of H. pylori prior to commencing long-term PPI therapy should be established to reduce the risk of severe atrophic gastritis and development of gastric dysplasia.

Systematic review: the effects of long-term proton pump inhibitor use on serum gastrin levels and gastric histology

BACKGROUND

Proton pump inhibitors (PPIs) have a well-established safety profile. However, concerns have been raised about a potential relationship between PPI-induced hypergastrinaemia and the development of enterochromaffin-like (ECL) cell hyperplasia, neuroendocrine tumours and gastric cancer during long-term therapy.

AIM

To review the effects of long-term PPI use on serum gastrin levels and gastric histopathology.

METHODS

A systematic literature search was conducted in PubMed on 21 April 2015 to identify studies reporting the effects of long-term (defined as >3 years) PPI use on gastrin levels and gastric histopathology.

RESULTS

A total of 16 studies (1920 patients) met the inclusion criteria. During long-term PPI therapy, mean gastrin levels rose to one to three times the upper limit of the normal range (~100 pg/mL), and an increased prevalence of ECL cell hyperplasia was observed (+7.8-52.0%). Helicobacter pylori-positive patients had a significantly increased risk of developing ECL linear/micronodular hyperplasia compared with H. pylori-negative patients [OR: 2.45 (95% CI: 1.47-4.10), P = 0.0006]; however, no evidence of neoplastic changes was found. The risk of corpus atrophy was markedly higher in H. pylori-positive patients than in H. pylori-negative patients [OR: 11.45 (95% CI: 6.25-20.99), P < 0.00001]. Not a single case of gastric adenocarcinoma was found.

CONCLUSIONS

Long-term PPI therapy induced moderate hypergastrinaemia in most patients and an increased prevalence of ECL cell hyperplasia. H. pylori-positive patients receiving long-term PPI therapy were exposed to a higher risk of corpus atrophy than H. pylori-negative patients. No neuroendocrine tumours or gastric cancers were found.

Two distinct etiologies of gastric cardia adenocarcinoma: interactions among pH, Helicobacter pylori, and bile acids

Gastric cancer can be classified as cardia and non-cardia subtypes according to the anatomic site. Although the gastric cancer incidence has decreased steadily in several countries over the past 50 years, the incidence of cardia cancers and esophageal adenocarcinoma (EAC) continue to increase. The etiological factors involved in the development of both cardia cancers and EACs are associated with high animal fat intake, which causes severe obesity. Central obesity plays roles in cardiac-type mucosa lengthening and partial hiatus hernia development. There are two distinct etiologies of cardia cancer subtypes: one associated with gastroesophageal reflux (GER), which predominantly occurs in patients without Helicobacter pylori (H. pylori) infection and resembles EAC, and the other associated with H. pylori atrophic gastritis, which resembles non-cardia cancer. The former can be developed in the environment of high volume duodenal content reflux, including bile acids and a higher acid production in H. pylori-negative patients. N-nitroso compounds, which are generated from the refluxate that includes a large volume of bile acids and are stabilized in the stomach (which has high levels of gastric acid), play a pivotal role in this carcinogenesis. The latter can be associated with the changing colonization of H. pylori from the distal to the proximal stomach with atrophic gastritis because a high concentration of soluble bile acids in an environment of low acid production is likely to act as a bactericide or chemorepellent for H. pylori in the distal stomach. The manuscript introduces new insights in causative factors of adenocarcinoma of the cardia about the role of bile acids in gastro-esophageal refluxate based upon robust evidences supporting interactions among pH, H. pylori, and bile acids.

Systems biology analysis of omeprazole therapy in cirrhosis demonstrates significant shifts in gut microbiota composition and function

Proton pump inhibitors (PPI) have been associated with infectious complications in cirrhosis, but their impact on distal gut microbiota composition and function is unclear. We aimed to evaluate changes in stool microbiota composition and function in patients with cirrhosis and healthy controls after omeprazole therapy. Both 15 compensated cirrhotic patients and 15 age-matched controls underwent serum gastrin measurement, stool microbiota profiling with multitagged pyrosequencing, and urinary metabolic profiling with NMR spectroscopy to assess microbial cometabolites before/after a 14-day course of 40 mg/day omeprazole under constant diet conditions. Results before (pre) and after PPI were compared in both groups, compared with baseline by systems biology techniques. Adherence was >95% without changes in diet or MELD (model for end-stage liver disease) score during the study. Serum gastrin concentrations significantly increased after PPI in cirrhosis (pre 38.3 ± 35.8 vs. 115.6 ± 79.3 pg/ml P < 0.0001) and controls (pre 29.9 ± 14.5 vs. 116.0 ± 74.0 pg/ml, P = 0.001). A significant microbiota change was seen in both controls and cirrhosis after omeprazole (QIIME P < 0.0001). Relative Streptococcaceae abundance, normally abundant in saliva, significantly increased postomeprazole in controls (1 vs. 5%) and cirrhosis (0 vs. 9%) and was correlated with serum gastrin levels (r = 0.4, P = 0.005). We found significantly reduced hippurate in cirrhosis vs. controls both pre- and postomeprazole and increased lactate in both groups post vs. preomeprazole, whereas dimethylamine (DMA) decreased in cirrhosis only. On correlation network analysis, significant changes in linkages of bacteria with metabolites (hippurate/DMA/lactate) were found postomeprazole, compared with pre-PPI in cirrhosis patients. In conclusion, omeprazole is associated with a microbiota shift and functional change in the distal gut in patients with compensated cirrhosis that could set the stage for bacterial overgrowth.

Potential mechanism of corpus-predominant gastritis after PPI therapy in Helicobacter pylori-positive patients with GERD

The long-term use of proton pump inhibitors (PPIs) exacerbates corpus atrophic gastritis in patients with Helicobacter pylori (H. pylori) infection. To identify a potential mechanism for this change, we discuss interactions between pH, bile acids, and H. pylori. Duodenogastric reflux, which includes bile, occurs in healthy individuals, and bile reflux is increased in patients with gastroesophageal reflux disease (GERD). Diluted human plasma and bile acids have been found to be significant chemoattractants and chemorepellents, respectively, for the bacillus H. pylori. Although only taurine conjugates, with a pKa of 1.8-1.9, are soluble in an acidic environment, glycine conjugates, with a pKa of 4.3-5.2, as well as taurine-conjugated bile acids are soluble in the presence of PPI therapy. Thus, the soluble bile acid concentrations in the gastric contents of patients with GERD after continuous PPI therapy are considerably higher than that in those with intact acid production. In the distal stomach, the high concentration of soluble bile acids is likely to act as a bactericide or chemorepellent for H. pylori. In contrast, the mucous layer in the proximal stomach has an optimal bile concentration that forms chemotactic gradients with plasma components required to direct H. pylori to the epithelial surface. H. pylori may then colonize in the stomach body rather than in the pyloric antrum, which may explain the occurrence of corpus-predominant gastritis after PPI therapy in H. pylori-positive patients with GERD.

Review article: the investigation and management of gastric neuroendocrine tumours

BACKGROUND

Gastric carcinoids (GCs) or neuroendocrine tumours (NETs) are increasingly identified at endoscopy, and account for 0.6-2% of all gastric polyps identified. The SEER database in the US has demonstrated a rising incidence of gastric NETs amongst all NETs; from 2.2% between 1950 and 1969 to 6.0% between 2000 and 2007.

AIM

To review the literature and assist clinicians in managing patients with GCs.

METHODS

A literature search was conducted through MEDLINE using search terms: gastric, carcinoid, neuroendocrine tumour, therapy, endoscopy, mucosal resection, submucosal dissection. Relevant articles were identified through manual review. The reference lists of these articles were reviewed to include further appropriate articles.

RESULTS

There are three types of GCs with important epidemiological, pathophysiological, histological and endoscopic differences that affect prognosis and management. Type 1 and 2 GCs develop in the context of hypergastrinaemia that originates from achlorhydria in atrophic gastritis and a gastrinoma, respectively. Type 3 GCs occur sporadically and independent of gastrin. The histological type, grade and Ki67 index are used to determine prognosis and direct clinical management. Type 1 GCs >1 cm in size and type 2 GCs should be assessed for invasion beyond the submucosa with EUS prior to endoscopic resection with EMR or ESD. Type 3 GCs should be managed as per recommendations for gastric adenocarcinoma. The treatment of advanced disease is multimodal.

CONCLUSIONS

Patients with gastric carcinoids should be discussed in a specialist neuroendocrine tumour multidisciplinary meeting to ensure all treatment options are explored in localised and advanced disease. Areas of controversy exist that need further research.

Helminth co-infection in Helicobacter pylori infected INS-GAS mice attenuates gastric premalignant lesions of epithelial dysplasia and glandular atrophy and preserves colonization resistance of the stomach to lower bowel microbiota

Higher prevalence of helminth infections in Helicobacter pylori infected children was suggested to potentially lower the life-time risk for gastric adenocarcinoma. In rodent models, helminth co-infection does not reduce Helicobacter-induced inflammation but delays progression of pre-malignant gastric lesions. Because gastric cancer in INS-GAS mice is promoted by intestinal microflora, the impact of Heligmosomoides polygyrus co-infection on H. pylori-associated gastric lesions and microflora were evaluated. Male INS-GAS mice co-infected with H. pylori and H. polygyrus for 5 months were assessed for gastrointestinal lesions, inflammation-related mRNA expression, FoxP3(+) cells, epithelial proliferation, and gastric colonization with H. pylori and Altered Schaedler Flora. Despite similar gastric inflammation and high levels of proinflammatory mRNA, helminth co-infection increased FoxP3(+) cells in the corpus and reduced H. pylori-associated gastric atrophy (p < 0.04), dysplasia (p < 0.02) and prevented H. pylori-induced changes in the gastric flora (p < 0.05). This is the first evidence of helminth infection reducing H. pylori-induced gastric lesions while inhibiting changes in gastric flora, consistent with prior observations that gastric colonization with enteric microbiota accelerated gastric lesions in INS-GAS mice. Identifying how helminths reduce gastric premalignant lesions and impact bacterial colonization of the H. pylori infected stomach could lead to new treatment strategies to inhibit progression from chronic gastritis to cancer in humans.

Recombinogenic activity of Pantoprazole(®) in somatic cells of Drosophila melanogaster

Pantoprazole^® is one of the leading proton pump inhibitors (PPIs) used in the treatment of a variety of diseases related to the upper gastrointestinal tract. However, studies have shown an increased risk of developing gastric cancer, intestinal metaplasia and hyperplasia of endocrine cells with prolonged use. In the present study, the somatic mutation and recombination test (SMART) was employed to determine the mutagenic effects of Pantoprazole on Drosophila melanogaster. Repeated treatments with Pantoprazole were performed on 72-hour larvae of the standard (ST) and high bioactivation (HB) crosses at concentrations of 2.5, 5.0, and 10.0 μM. In addition, doxorubicin (DXR) was administered at 0.4 mM, as a positive control. When administered to ST descendants, total number of spots were statistically significant at 2.5 and 5.0 μM concentrations. For HB descendants, a significant increase in the total number of spots was observed among the marked transheterozygous (MH) flies. Through analysis of balancer heterozygous (BH) descendants, recombinogenic effects were observed at all concentrations in descendants of the HB cross. In view of these experimental conditions and results, it was concluded that Pantoprazole is associated with recombinogenic effects in Drosophila melanogaster.

Dietary factors modulate Helicobacter-associated gastric cancer in rodent models

Since its discovery in 1982, the global importance of Helicobacter pylori-induced disease, particularly in developing countries, remains high. The use of rodent models, particularly mice, and the unanticipated usefulness of the gerbil to study H. pylori pathogenesis have been used extensively to study the interactions of the host, the pathogen, and the environmental conditions influencing the outcome of persistent H. pylori infection. Dietary factors in humans are increasingly recognized as being important factors in modulating progression and severity of H. pylori-induced gastric cancer. Studies using rodent models to verify and help explain mechanisms whereby various dietary ingredients impact disease outcome should continue to be extremely productive.

Safety of long-term PPI therapy

Proton pump inhibitors have become the mainstay of medical treatment of acid-related disorders. Long-term use is becoming increasingly common, in some cases without a proper indication. A large number of mainly observational studies on a very wide range of possible associations have been published in the past decade and are critically reviewed in this article and the existing evidence is evaluated and translated into possible clinical consequences. Based on the existing evidence the benefits of PPI treatment seem to outweigh potential risks in the large majority of patients especially if PPI use is based on a relevant indication. The concern for complications should primarily be directed at elderly, malnourished with significant co-morbidity. In this population an increased risk for enteric infections, fractures and nutritional deficiencies might have clinical consequences and should lead to a careful evaluation of the indication for PPI treatment.

Indications and safety of proton pump inhibitor drug use in patients with cancer

INTRODUCTION

Although the exact prevalence of proton pump inhibitor (PPI) use in cancer patients is not known, it is generally perceived to be widespread. PPIs are generally well tolerated and carry an excellent safety profile. However, increasing and longer term PPI use has raised concerns about the risk of pneumonia, bone fractures and enteric infections, and a possible interaction with clopidogrel that could increase the risk of cardiovascular events.

AREAS COVERED

We conducted a PubMed search of English language articles addressing the safety and adverse events associated with PPI use with particular emphasis in cancer patients.

EXPERT OPINION

PPIs, frequently used in cancer patients, are generally well tolerated and carry an excellent safety profile. PPI-induced acid suppression may increase the risk of Clostridium difficile or other enteric infections, nutritional deficiencies and community acquired pneumonia, all particularly important in cancer patients. The indications for PPI use in cancer patients should be carefully reviewed prior to use.

Hormonal Effects on Nodular GAVE

Gastric antral vascular ectasia (GAVE) and its nodular antral gastropathy (NAG) variant is a unique lesion associated with hypergastrinemic hormonal alterations that may be compounded by concurrent proton pump inhibitor (PPI) therapy. The use of octreotide as a somatostatin analogue and its role in the down regulation of variousenteric hormones has been well documented however its use in the management of NAG has not been widely reported. We herein present a case where octreotide induced gastrin down-regulation as well as PPI cessation facilitated NAG resolution.

Effect of short-term proton pump inhibitor treatment and its discontinuation on chromogranin A in healthy subjects

CONTEXT

Chromogranin A (CgA) is used as a generic tumor marker for neuroendocrine tumors. Proton pump inhibitors (PPI) are known to increase CgA, but it is not clear to what extent, and there is little information on how long PPI need to be discontinued before the effect of PPI has disappeared. Furthermore, is it not known whether this PPI effect is dependent on the CgA assay used.

OBJECTIVE

The aim of the study was to determine the effect of 7-d treatment with a PPI and its discontinuation on CgA in serum and plasma comparing four CgA assays.

DESIGN AND PARTICIPANTS

Seventeen healthy subjects took lansoprazole 30 mg at bedtime for 7 d, and blood samples for CgA were obtained at baseline, d 7 of PPI use, and 1, 2, 4, and 7 d after discontinuation of the PPI. In all samples, CgA was measured using the following assays: Alpco (serum and plasma), Cis-Bio (serum and plasma), DAKO, and Cis-Bio radioisotope assay.

RESULTS

When using the same assay, CgA was higher in plasma than in serum. Treatment with a PPI for 1 wk resulted in a significant (about 2.5-fold) increase in CgA with significant interindividual variation. After discontinuation of PPI, serum CgA gradually declined, with a half-life of 4-5 d.

CONCLUSION

Short-term PPI use results in a significant increase of CgA in serum and plasma, an effect that is largely independent of the assay used. PPI need to be discontinued for 2 wk to fully eliminate their effect on CgA. This effect of PPI needs to be considered when interpreting results of CgA measurements.

[Massive fundic gland polyposis caused by chronic proton pump inhibitor therapy]

We report two cases of a massive fundic gland polyposis associated with protracted proton pump inhibitor (PPI) therapy. Both patients were females aged 51. On repeated endoscopy, the number of fundic gland polyps was increasing steeply, and they resulted in a passage disorder. In the first case, the enormous number of polyps made endoscopic removal impossible, so the patient was treated by total gastrectomy. Although our case is the second one reported in the world, we would like to draw the attention to this rare complication of long lasting PPI therapy.

Limitations of Chromogranin A in clinical practice

CONTEXT

Usefulness of circulating Chromogranin A (CgA) for the diagnosis of neuroendocrine tumors (NEN) is controversial. The aim of the present study was to assess the actual role of this marker as diagnostic tool.

METHODS

Serum blood samples were obtained from 42 subjects affected with NEN, 120 subjects affected with non-endocrine neoplasias (non-NEN) and 100 non-neoplastic subjects affected with benign nodular goitre (NNG). Determination of CgA was performed by means of immunoradiometric assay.

RESULTS

The CgA levels among NEN-patients were not significantly different from NNG and non-NEN subjects. The Receiver operating characteristic (ROC) curves analysis failed to identify a feasible cut-off value for the differential diagnosis between NEN and the other conditions.

CONCLUSION

Serum CgA is not helpful for the first-line diagnosis of NEN.

Effects of Helicobacter pylori infection and long-term proton pump inhibitor use on enterochromaffin-like cells

BACKGROUND

Excessive release of gastrin leads to hypertrophy and hyperplasia of enterochromaffin-like cells (ECL) and prolonged stimulation of these cells causes functional impairment. The purpose of this study was to investigate the effect of Helicobacter pylori (H. pylori) infection and long-term proton pump inhibitors (PPI) use on ECL cells.

METHODS

Fifteen patients who underwent endoscopy because of dyspeptic symptoms were enrolled in the present study. Biopsies were taken from corpus and antrum and existence of H. pylori was investigated with culture, cytology and CLOtest. The patients were divided into 3 groups. Group-A: H. pylori-negative, never treated previously with PPI; Group-B: H. pylori-positive, never treated previously with PPI; and group-C: H. pylori-negative and continuously treated with PPI for more than 6 months before the subject recruitment period. The features of ECL cell in oxyntic glands were examined with electron microscopy on biopsy specimens.

RESULTS

ECL cells were completely normal in Group A. In group B, moderate hyperplasia and vacuolization was seen in ECL cells. In group C, ECL cell hyperplasia was observed and vacuoles with greater amounts of granules in enlarged vesicles were found more intensely in cytoplasm.

CONCLUSION

The use of PPI for a long period of time and presence of H. pylori infection are risk factors for ECL hyperplasia.

Divergent trends for gastric cancer incidence by anatomical subsite in US adults

BACKGROUND AND AIM

Age-specific analyses of non-cardia gastric cancer incidence reveal divergent trends among US whites: rates are declining in individuals aged 40 years and older but rising in younger persons. To investigate this heterogeneity further, incidence trends were evaluated by anatomical subsite.

METHODS

Gastric cancer incidence data for 1976-2007 were obtained from the US National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program and the US Centers for Disease Control and Prevention's National Program of Cancer Registries (NPCR). Incidence rates and estimated annual percentage change were calculated by age group (25-39, 40-59 and 60-84 years), race/ethnicity and subsite.

RESULTS

Based on data from the nine oldest SEER registries (covering ~10% of the US population), rates for all non-cardia subsites decreased in whites and blacks, except for corpus cancer, which increased between 1976 and 2007 with estimated annual percentage changes of 1.0% (95% CI 0.1% to 1.9%) for whites and 3.5% (95% CI 1.8% to 5.2%) for blacks. In contrast, rates for all non-cardia subsites including corpus cancer declined among other races. In combined data from NPCR and SEER registries (covering 89% of the US population), corpus cancer significantly increased between 1999 and 2007 among younger and middle-aged whites; in ethnic-specific analyses, rates significantly increased among the same age groups in non-Hispanic whites and were stable among Hispanic whites. Age-specific rates for all subsites declined or were stable in this period among blacks and other races.

CONCLUSIONS

Long- and short-term incidence trends for gastric cancers indicate a shifting distribution by anatomical subsite. Corpus cancer may have distinctive aetiology and changing risk factor exposures, warranting further investigation.

Toxicology and toxicokinetics of oral pantoprazole in neonatal and juvenile dogs

BACKGROUND

Pantoprazole is an irreversible inhibitor of H(+) /K(+) adenosine triphosphatase proton pump. This study encompassed the period of postnatal stomach development to determine whether immature animals are uniquely sensitive to progression of PPI-induced enterochromaffin-like cell hyperplasia.

METHODS

Pantoprazole was administered to beagle dogs at 3, 10, or 30 mg/kg/day (10/sex/group) from PND 1 for 13 weeks, subsets of animals had a 13-week recovery period. Clinical signs, body weights, growth, clinical chemistry, and neurobehavioral endpoints were assessed. Selected organs were weighed and histologically examined.

RESULTS

There were no effects on body weights, growth, landmarks of physical and reproductive development, or sensory and neurobehavioral function. Cholesterol and triglyceride levels were increased at 10 and 30 mg/kg/day, but resolved during the recovery period. Stomach weight was increased at all doses, but after recovery the differences in stomach weights resolved for females although male stomach weights remained slightly increased. Pantoprazole-related microscopic findings in the stomach consisted of increased mucosal height, glandular necrosis, and glandular dilation at all doses; and ECL cell hyperplasia, parietal cell vacuolation, and atrophy of chief cells are noted at 10 and/or 30 mg/kg/day. There was a partial recovery of these microscopic changes indicated by a decreased incidence and/or severity of increased mucosal height, glandular necrosis, ECL cell hyperplasia, and chief cell atrophy, and complete resolution of other microscopic observations.

CONCLUSION

Pantoprazole administered to beagles from PND 1 for 13 weeks resulted in findings similar to those in adult dogs and juvenile dogs, which showed no increase in severity or progression of ECL hyperplasia.

[Current diagnostic procedure on neuroendocrine differentiation of prostate cancer]

Chromogranin A (CgA) is considered as a major specific neuroendocrine tumor marker. It belongs to the secretogranin family, which is present in the gastrointestinal tract, respiratory system, endocrine glands and in a group of endocrine cells such us pancreas and thyroid. Serum levels of CgA could reflect the neuroendocrine activity and could be used when evaluating advance prostate carcinoma. Moreover, there are also several factors that may increase the serum level of CgA: treatment with proton-pump inhibitors or H2-receptor blockers, chronic atrophic gastritis, rheumatoid arthritis, liver and renal failure. Another method to evaluate NE differentiation is scintigraphy with the 111In-labeled somatostatin analogue (DTPA-D-Phe)-octrotide, (Octreoscan). This method takes advantage of the overexpression of type II somatostatin receptors on the cell surface of NE tumors. With this technique the presence of NE differentiation can be detected both at the primary (prostate) and the metastatic sites. A more specific system to detect NE cell activity is obtained by analyzing CgA gene expression in prostate tissue by a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR).

Gastric histology in children treated with proton pump inhibitors long term, with emphasis on enterochromaffin cell-like hyperplasia

BACKGROUND

There are longstanding concerns that carcinoid tumours or atrophic gastritis might develop in children receiving proton pump inhibitors (PPIs) long term. In children, this has not been studied using stains sensitive and specific for enterochromaffin-like (ECL) cells.

AIM

To evaluate gastric biopsies for ECL hyperplasia or gastric atrophy, in children treated long-term with PPIs.

METHODS

Synaptophysin and chromogranin immunostaining, biopsies read anonymised, blinded. Endocrine cell numbers graded according to Rindi and Solcia.

RESULTS

Of 130 children with gastro-oesophageal reflux disease (GERD), 65 had sequential gastric biopsies, starting at median 8.2 years (<1 to 17). Of the 65, 83% had GERD-predisposing conditions, mostly neurological impairment or repaired oesophageal atresia. Four hundred and fifty-eight tissue blocks (208 antrum, 250 body) were available from a mean of 5.8 endoscopies (2-14). Of 82 gastric body biopsies in 40 patients with ECL hyperplasia, 67 had grade 1 hyperplasia, 15 grade 2. Of the 40, nine had ECL hyperplasia before PPI use; all nine had received H2-receptor antagonists. Median duration of PPI use was 3.17 years in patients with ECL hyperplasia, 2.20 years in those without (P=0.16). Helicobacter pylori was present in four patients; two had ECL hyperplasia. PPI duration was >3 years in 24 patients. In nine patients who received H2-receptor antagonists, changes were present before PPI use. No patient had atrophic gastritis.

CONCLUSIONS

A high percentage of children (61%) receiving long-term PPI continuously for up to 10.8 years (median 2.84 years) develop minor degrees of ECL hyperplasia. This has no known clinical significance. Children on PPIs for this duration do not appear to develop atrophic gastritis or carcinoid tumours.

Adverse effects of long-term proton pump inhibitor therapy

Proton pump inhibitors have an excellent safety profile and have become one of the most commonly prescribed class of drugs in primary and specialty care. Long-term, sometimes lifetime, use is becoming increasingly common, often without appropriate indications. This paper is a detailed review of the current evidence on this important topic, focusing on the potential adverse effects of long-term proton pump inhibitor use that have generated the greatest concern: B12 deficiency; iron deficiency; hypomagnesemia; increased susceptibility to pneumonia, enteric infections, and fractures; hypergastrinemia and cancer; drug interactions; and birth defects. We explain the pathophysiological mechanisms that may underlie each of these relationships, review the existing evidence, and discuss implications for clinical management. The benefits of proton pump inhibitor use outweigh its risks in most patients. Elderly, malnourished, immune-compromised, chronically ill, and osteoporotic patients theoretically could be at increased risk from long-term therapy.