Rectal cell proliferation and colon cancer risk in patients with hypergastrinaemia

Long-term effect of Helicobacter pylori eradication on colorectal cancer incidences

Background

There is evidence supporting the association between Helicobacter pylori infection and colorectal cancer (CRC), but whether H. pylori eradication reduces the risk of CRC is still unknown.

Objectives

To compare the incidence of CRC in subjects who had received H. pylori eradication therapy with general population.

Design

A population-based retrospective cohort study.

Methods

This study included all H. pylori-infected subjects who had received their first course of clarithromycin-containing triple therapy in 2003-2015 in Hong Kong. We compared the observed incidences of CRC in this H. pylori eradicated cohort with the expected incidences in the age- and sex-matched general population. The standardized incidence ratio (SIR) with 95% confidence interval (CI) was computed.

Results

Among 96,572 H. pylori-eradicated subjects with a median follow-up of 9.7 years, 1417 (1.5%) developed CRC. Primary analysis showed no significant difference in the observed and expected incidences of CRC (SIR: 1.03, 95% CI: 0.97-1.09). However, when stratified according to the follow-up period, higher incidence of CRC was only observed in the first 5 years after eradication (SIR: 1.47, 95% CI: 1.39-1.55), but it was lower (SIR: 0.85, 95% CI: 0.74-0.99) than general population after 11 years. When stratified by tumor location, the observed incidence was higher for colon (SIR: 1.20, 95% CI: 1.12-1.29) but lower for rectal cancer (SIR: 0.90, 95% CI: 0.81-0.999) among H. pylori-eradicated subjects.

Conclusions

H. pylori-infected subjects appeared to have a higher incidence of CRC initially, which declined progressively to a level lower than general population 10 years after H. pylori eradication, particularly for rectal cancer.

Prevalence and predictors of colonoscopic findings in patients with autoimmune gastritis

The clinical spectrum of autoimmune gastritis is silent in the early stages of the disease and no specific symptom is related to this entity. Although gastroscopic findings of this entity are well defined, data regarding colonoscopic findings are limited. The aims of this study were to determine the prevalence of colonoscopic findings and to explore factors that might affect these findings. This is a retrospective chart review of patients with autoimmune gastritis (n=240). Data regarding colonoscopic findings, serum gastrin and chromogranin A (CgA) levels and gastric histopathological results were extracted and compared with 550 patients positive for Helicobacter pylori and gastric atrophy. Control subjects had colonoscopy and gastroscopy with biopsies. Colorectal lesions were observed in 64 (26.6%) of patients with autoimmune gastritis and 36 (6.6%) patients had colorectal lesions in the control group (p<0.001). Serum gastrin (OR: 8.59, 95% CI 1.72 to 25.07, p<0.001) and CgA levels (OR: 6.79, 95% CI 0.41 to 27.26, p<0.001) were found as factors affecting the presence of colorectal carcinoma. Serum gastrin and CgA levels were also found as predictors for the presence of colorectal adenomas. There is a higher prevalence of colorectal neoplastic lesions in patients with autoimmune gastritis. Serum gastrin and CgA levels were found to be determinants of colorectal neoplastic lesions observed in patients. In the workup of these patients, serum gastrin and CgA levels may guide physicians for the demonstration of colorectal neoplastic lesions.

Proton pump inhibitors and odds of cholangiocarcinoma: A retrospective case-control study

BACKGROUND & AIMS

Proton pump inhibitors (PPIs) have been reported to be associated with cholangitis and might possibly be carcinogenic. However, few studies have been conducted to investigate the association of PPIs with cholangiocarcinoma (CCA). Thus, a hospital-based case-control study was carried out in China to explore the association between PPIs and CCA.

METHODS

In this study, 1468 CCA cases (826 intrahepatic cholangiocarcinoma (ICC) and 642 extrahepatic cholangiocarcinoma (ECC)) were included, which were observed at Beijing Friendship Hospital, from February 2002 to October 2018. We retrospectively extracted PPI use and other possible risk factors from clinical records, followed by an investigation of the relationship with CCA via calculation of odds ratios (ORs), adjusted odds ratios (AORs), and 95% confidence intervals (CIs) using logistic regression analysis.

RESULTS

PPIs were used by 135 (9.2%) CCA cases and 173 (5.9%) controls. We found that PPI use was associated with a 1.61-fold elevated CCA odds (P < .001) (AOR = 1.61, 95% CI = 1.28-2.05; P < .001). After stratification by CCA subtypes, the AORs of PPIs were consistent for both CCA subtypes, with ORs of 1.36 (AOR = 1.36, 95% CI = 1.02-1.83; P = .003) and 1.95 (AOR = 1.95, 95% CI = 1.46-2.62; P < .001) for ICC and ECC respectively. Our results also showed that PPI use was slightly linked to the odds of CCA in a dose-dependent manner.

CONCLUSION

PPI use was correlated with a significant 61% increased odds of CCA, particularly in the ECC. However, the retrospective design and observational nature cannot establish causation. Larger scale, multi-centre prospective studies are required for further validation.

An overview of the role of interleukin-8 in colorectal cancer

Colorectal Cancer (CRC), a common malignancy, is developing globally among people. Mutagenic insults activate peripheral nucleated cells to secrete chemokines in order to cause an inflammatory state. Despite the presence of multi-retrieving factors, elevated production of minor cytokines may speed-up the sever stages of the baseline inflammation targeting normal compensatory mechanism. IL-8 is a pro-inflammatory cytokine that is believed to be up-regulated in CRC to proceed primary condition into tumor behavior via induction of proliferation, angiogenesis and metastasis. Here, we assess the role of IL-8 in every step of CRC from signaling pathway and formation to invasion and discuss around new perspective therapy that targets IL-8 to manage CRC worldwide incidence and survival rate, more precisely.

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

The use of proton pump inhibitors (PPIs) over the last 30 years has rapidly increased both in the United States and worldwide. PPIs are not only very widely used both for approved indications (peptic ulcer disease, gastroesophageal reflux disease (GERD), Helicobacter pylori eradication regimens, stress ulcer prevention), but are also one of the most frequently off-label used drugs (25–70% of total). An increasing number of patients with moderate to advanced gastroesophageal reflux disease are remaining on PPI indefinitely. Whereas numerous studies show PPIs remain effective and safe, most of these studies are <5 years of duration and little data exist for >10 years of treatment. Recently, based primarily on observational/epidemiological studies, there have been an increasing number of reports raising issues about safety and side-effects with very long-term chronic treatment. Some of these safety issues are related to the possible long-term effects of chronic hypergastrinemia, which occurs in all patients taking chronic PPIs, others are related to the hypo-/achlorhydria that frequently occurs with chronic PPI treatment, and in others the mechanisms are unclear. These issues have raised considerable controversy in large part because of lack of long-term PPI treatment data (>10–20 years). Zollinger–Ellison syndrome (ZES) is caused by ectopic secretion of gastrin from a neuroendocrine tumor resulting in severe acid hypersecretion requiring life-long antisecretory treatment with PPIs, which are the drugs of choice. Because in <30% of patients with ZES, a long-term cure is not possible, these patients have life-long hypergastrinemia and require life-long treatment with PPIs. Therefore, ZES patients have been proposed as a good model of the long-term effects of hypergastrinemia in man as well as the effects/side-effects of very long-term PPI treatment. In this article, the insights from studies on ZES into these controversial issues with pertinence to chronic PPI use in non-ZES patients is reviewed, primarily concentrating on data from the prospective long-term studies of ZES patients at NIH.

Helicobacter pylori infection and the risk of colorectal cancer: a nationwide population-based cohort study

BACKGROUND

The role of Helicobacter pylori (H. pylori) infection in the development of colorectal neoplasia has been a matter of scientific debate with controversial findings.

AIMS

This study examined the association between H. pylori infection and colorectal cancer (CRC) in a nationwide population-based Chinese cohort study.

METHODS

A total of approximately 3936 individuals with newly diagnosed H. pylori infection (the H. pylori-infected cohort) and 15 744 age- and sex-matched patients with diagnoses absence of H. pylori infection (the comparison cohort) from 2000 to 2005 were identified from Taiwan's National Health Insurance Research Database. The Kaplan-Meier method was used for measuring the cumulative incidence of CRC in each cohort. Cox proportional hazards models were used to compute hazard ratios (HRs) and accompanying 95% confidence intervals (CIs) for the estimation of the association between H. pylori infection and CRC.

RESULTS

The cumulative incidence of CRC was higher in H. pylori-infected cohort than that in the comparison cohort (log-rank test, P < 0.001). After adjustment for potential confounders, H. pylori infection was associated with a significantly increased risk of CRC (adjusted HR 1.87; 95% CI 1.37-2.57). In addition, the HR of CRC appeared to increase with increasing frequency of clinical visits for H. pylori infection.

CONCLUSIONS

Our study demonstrated that H. pylori infection was associated with an increased risk of CRC, which warrants confirmation and exploration of the underlying biologic mechanisms by future studies.

Helicobacter pylori infection coexisting with intestinal metaplasia is not associated with colorectal neoplasms

Introduction

Colorectal cancer is one of the most common cancers and is a major cause of morbidity and mortality in the world and our country. Studies have indicated that there might be a relationship between Helicobacter pylori (Hp) and colorectal neoplasia (CN), although others have not found any relationship.

Aim

To determine whether there is a potential relationship between Hp and CN in our patients.

Material and methods

A total of 314 patients, aged 16–86 years, who underwent gastroscopy and colonoscopy at our department between 2015 and 2017 were evaluated retrospectively. The age, gender, endoscopy results, presence of Hp, complete blood count (CBC), vitamin B₁₂, folic acid, C-reactive protein (CRP), and sedimentation levels of the patients were examined.

Results

CBC, ferritin, vitamin B₁₂, and CRP measurements did not show statistical significance in terms of the presence of Hp (p > 0.05). Folate values of Hp-positive patients were significantly lower than Hp-negative patients (p = 0.007; p < 0.01). No significant relationship was detected between Hp and colon cancer (p > 0.05). Adenomatous polyps were not related to Hp (p > 0.05). Correlation between intestinal metaplasia (IM) and adenomatous polyps was insignificant. There was no statistically significant difference between colon and gastric pathology results.

Conclusions

In our study, no significant relationship was noted between Hp and CN. A few studies have been conducted in our country, and our results are consistent with some of these studies while it is contradictory to others. Large populational multicentre studies are needed in order to identify the relationship between Hp and CN.

Review: Diagnostic accuracy of PCR-based detection tests for Helicobacter Pylori in stool samples

BACKGROUND

Although different methods have been established to detect Helicobacter pylori (H. pylori) infection, identifying infected patients is an ongoing challenge. The aim of this meta-analysis was to provide pooled diagnostic accuracy measures for stool PCR test in the diagnosis of H. pylori infection.

METHODS

In this study, a systematic review and meta-analysis were carried out on various sources, including MEDLINE, Web of Sciences, and the Cochrane Library from April 1, 1999, to May 1, 2016. This meta-analysis adheres to the guidelines provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses report (PRISMA Statement). The clinical value of DNA stool PCR test was based on the pooled false positive, false negative, true positive, and true negative of different genes.

RESULTS

Twenty-six of 328 studies identified met the eligibility criteria. Stool PCR test had a performance of 71% (95% CI: 68-73) sensitivity, 96% (95% CI: 94-97) specificity, and 65.6 (95% CI: 30.2-142.5) diagnostic odds ratio (DOR) in diagnosis of H. pylori. The DOR of genes which showed the highest performance of stool PCR tests was as follows: 23S rRNA 152.5 (95% CI: 55.5-418.9), 16S rRNA 67.9 (95%CI: 6.4-714.3), and glmM 68.1 (95%CI: 20.1-231.7).

CONCLUSIONS

The sensitivity and specificity of stool PCR test are relatively in the same spectrum of other diagnostic methods for the detection of H. pylori infection. In descending order of significance, the most diagnostic candidate genes using PCR detection were 23S rRNA, 16S rRNA, and glmM. PCR for 23S rRNA gene which has the highest performance could be applicable to detect H. pylori infection.

Prediagnostic Helicobacter pylori Antibodies and Colorectal Cancer Risk in an Elderly, Caucasian Population

BACKGROUND

Study results on overall seroprevalence of Helicobacter pylori and colorectal cancer risk have been inconsistent. However, one study found positive associations with antibodies to specific H. pylori proteins. To follow up on those findings, we assessed associations of 15 H. pylori specific proteins with colorectal cancer incidence in the prospective Cancer Prevention Study-II Nutrition Cohort.

MATERIALS AND METHODS

Participants in this nested case-control study included 392 cases and 774 controls who were predominantly elderly (median age at blood draw: 71 years) and Caucasian (98%). Seroreactivity against 15 H. pylori proteins was assessed by fluorescent bead-based multiplex serology and associations with colorectal cancer were estimated using conditional logistic regression.

RESULTS

Helicobacter pylori serostatus was not associated with colorectal cancer incidence (odds ratio (OR), 1.17, 95% confidence interval (95% CI), 0.91-1.50). Among individual antigens, GroEl serostatus was associated with colorectal cancer risk (OR, 1.32, 95% CI: 1.03-1.70), whereas CagM was associated with colon cancer risk only (OR, 1.35, 95% CI: 1.01-1.80). No dose-response relationships were observed for any of the antigens, including GroEl and CagM.

CONCLUSIONS

The results of our study do not support an association between H. pylori infection and colorectal cancer risk in this elderly, mostly Caucasian population.

Comparison of biomarker expression between proximal and distal colorectal adenomas: The Tennessee-Indiana Adenoma Recurrence Study

It is unclear if proximal and distal traditional adenomas present with differences in molecular events which contribute to cancer heterogeneity by tumor anatomical subsite. Participants from a colonoscopy-based study (n = 380) were divided into subgroups based on the location of their most advanced adenoma: proximal, distal, or "equivalent both sides." Eight biomarkers in the most advanced adenomas were evaluated by immunohistochemistry (Ki-67, COX-2, TGFβRII, EGFR, β-catenin, cyclin D1, c-Myc) or TUNEL (apoptosis). After an adjustment for pathological features, there were no significant differences between proximal and distal adenomas for any biomarker. Conversely, expression levels did vary by other features, such as their size, villous component, and synchronousness. Large adenomas had higher expression levels of Ki-67(P < 0.001), TGFβRII (P < 0.0001), c-Myc (P < 0.001), and cyclin D1 (P < 0.001) in comparison to small adenomas, and tubulovillous/villous adenomas also were more likely to have similar higher expression levels in comparison to tubular adenomas. Adenoma location is not a major determinant of the expression of these biomarkers outside of other pathological features. This study suggests similarly important roles of Wnt/β-catenin and TGF-β pathways in carcinogenesis in both the proximal and distal colorectum. © 2016 Wiley Periodicals, Inc.

Combination of Triple Therapy and Chronic PPI Use May Decrease Risk of Colonic Adenomatous Polyps in Helicobacter pylori Infection

Aim. The aim of the paper is to determine association between H. pylori and colonic adenomatous polyps and to explore whether treatment or chronic PPI use can mitigate this risk. Methods. This case-control study included 943 patients who had H. pylori testing and underwent colonoscopy. Presence of polyps was the outcome of interest, whereas age, sex, race, H. pylori infection, triple therapy, and chronic PPI use were independent variables. Multivariate regression analysis was used to calculate odds ratios at 95% confidence intervals. This study was approved by the New York Medical College Institutional Review Board. Results. H. pylori was associated with increased odds of colonic adenomatous polyps (adjusted OR 1.43, 95% CI 1.04–1.77), with stronger association among patients older than 50 (OR 1.65, 95% CI 1.18–2.33). Triple therapy (OR 0.69, 95% CI 0.44–1.07) or chronic PPI use (OR 0.69, 95% CI 0.43–1.09) decreased odds of polyp formation. Analysis revealed a statistically significant reduction in patients who received both triple therapy and chronic PPI, lowering the odds by 60% (adjusted OR 0.43, 95% CI 0.27–0.67). Conclusion. There is increased risk of colonic adenomatous polyps among H. pylori-infected patients. Triple therapy or chronic PPI use may mitigate this risk, with further reduction when these two interventions are combined.

The association of H. pylori and colorectal adenoma: does it exist in the US Hispanic population?

BACKGROUND

Although data on the association between colorectal adenomas and Helicobacter pylori (H. pylori) exists in White and Black patients, there is no data on this association in a US Hispanic population. Our aim was to study the association of adenoma detection and biopsy proven H. pylori infection in a cohort of US Hispanics.

METHODS

Data were collected from Nassau University Medical Center, a 530-bed tertiary care teaching hospital in East Meadow, New York. Patients who underwent both an esophagogastroduodenoscopy (EGD) and colonoscopy from July 2009 to March 2011 were pulled from an electronic database. A total of 1,737 patients completed colonoscopies during this time with 95 excluded: 17 inflammatory bowel disease, 12 malignancy, 22 prior history of colorectal adenoma, and 44 incomplete. Among the colonoscopies, 799 patients had EGD's performed prior to colonoscopies that were eligible for our study.

RESULTS

H. pylori prevalence was highest in Hispanics 40.9%, followed by Blacks 29.1% (OR 0.59, 95% CI: 0.42-0.84), then Whites 7.9% (OR 0.12, 95% CI: 0.06-0.24). The adenoma detection rate was significantly higher in Whites 23.2% and Blacks 21.8% compared to Hispanics 14.5%, P=0.0002 respectively. Smoking and alcohol were lower in the H. pylori group, 18.6% (n=44) vs. 26.1% (n=147) for smoking (P=0.02) and 14.4% (n=34) vs. 19% (n=107) for alcohol (P=0.12), respectively. There was no evidence in the Hispanics for an association between adenoma detection and H. pylori infection. Furthermore size, location, and multiple polyps did not differ between the two groups.

CONCLUSIONS

While data has shown an association between H. pylori and colorectal adenomas, we did not find this in our Hispanic population. With the growing population of Hispanics in the U.S, large scale studies are needed to conclusively characterize the role of H. pylori infection in colorectal adenoma and adenocarcinoma in this group of patients.

Circulating gastrin concentrations in patients at increased risk of developing colorectal carcinoma

BACKGROUND AND AIM

An increase in circulating concentrations of gastrin or gastrin precursors such as progastrin and glycine-extended gastrin has been proposed to promote the development of colorectal carcinomas (CRC). The aim of this study was to investigate whether or not circulating gastrin concentrations were increased in patients with an increased risk of developing CRC.

METHOD

Patients were divided according to their risk into the five following groups: familial adenomatous polyposis (n = 20), hereditary non-polyposis colorectal cancer (n = 53), cluster of common colorectal cancers (n = 13), personal history and/or family history of adenomatous polyps or CRC (n = 150) and controls (n = 42). Radioimmunoassay with four region-specific gastrin antisera was used to measure progastrin, glycine-extended gastrin (gastrin-gly), amidated gastrin (gastrin-amide), and total gastrin in peripheral blood taken at the time of colonoscopy.

RESULTS

Compared with the control group, familial adenomatous polyposis patients had significantly higher median values of total gastrin (29.8 pM vs 16.9 pM, P = 0.003) and gastrin-amide (17.1 pM vs 12.0 pM, P = 0.015). Patients with a personal or family history of adenomatous polyps or CRC also had higher circulating concentrations of total gastrin (21.8 pM) compared with controls (P < 0.05), while patients from all groups who presented with an adenomatous polyp on the day of colonoscopy had higher concentrations of total gastrin, progastrin, and gastrin-amide than patients without polyps.

CONCLUSION

Concentrations of gastrin precursors are increased in particular groups with an increased risk of developing CRC.

Helicobacter pylori but not gastrin is associated with the development of colonic neoplasms

Recent studies have suggested that Helicobacter pylori (H. pylori) constitutes a risk for the development of colonic neoplasia. Hypergastrinemia can be induced by H. pylori infection, and gastrin can act as putative promoter of colorectal carcinogenesis. Aim of our study was to assess whether H. pylori infection and/or increased serum gastrin levels are associated with the occurrence of colonic neoplasms. For this, we reviewed prospectively collected data of 377 patients with a minimum age of 50 years who underwent colonoscopy. H. pylori and CagA status were determined by serology. Serum gastrin levels were measured in fasting state by commercially available assay. In H. pylori infected patients (n = 138; 36.6%), the overall prevalence of colonic neoplasms was more frequent compared to H. pylori negative patients (n = 239; 63.4%) (OR = 2.73, 95% CI: 1.76-4.24). H. pylori infection occurred more frequently in patients with hyperplastic polyps (OR = 2.66, 95% CI: 1.23-5.74) and adenomas presenting with low grade intraepithelial neoplasia (IEN) (OR = 1.85, 95% CI: 1.14-2.99). Attributable risk for adenomas with high grade IEN and colorectal adenocarcinoma (n = 14) was not assessed due to the low number of cases. The expression of CagA was also associated with an increased risk for colonic neoplasms (OR = 2.25, 95% CI: 1.29-3.94). Hypergastrinemia did not increase the risk for any colonic neoplasms and there was no difference in basal serum gastrin levels between H. pylori positive and negative patients. In conclusion, H. pylori infection, including CagA expression is associated with an increased risk for the development of colonic neoplasm.

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.

Association of helicobacter pylori infection and colon cancer

BACKGROUND

Gastrin has been shown to exert carcinogenic effect to the epithelium of the colon. This study examines whether hypergastrinemia and H. pylori infection -especially infection by the CagA+ strain- are statistically associated with colorectal cancer and examine possible correlations with the colorectal cancer stage and lymph node metastasis.

METHODS

In this prospective case-control study, fasting serum samples from 93 consecutive patients with colorectal cancer treated in a university surgical clinic were preoperatively collected and serum levels of gastrin were measured. A group of 20 age matched hernia patients were used as controls. The pathology report of the specimens was documented and statistical analysis of the data where performed with the spss 17 statistical suite.

RESULTS

H. pylori IgG antibodies was reported in 66/93 (71%) in the colorectal cancer group and 13/20 patients in the control group (65%), the difference having non-statistical significance (P = n.s). The prevalence of cagA protein expression in the anti- H. pylori IgG+ patients were higher in the colorectal cancer group (56% positivity), when compared to the control group (38,4% positivity) but the difference was not of statistical significance (P = n.s). The mean levels of serum gastrin levels in the two groups did not significantly differ (Ca group 51.1 ± 36.6 pg/mL vs Control 49.8 ± 17.6 P = n.s.). Patients with lymph node metastasis had higher serum gastrin levels than patients without metastasis and this difference was statistically significant. (53.6 vs 41.06 pg/mL P = 0.025).

CONCLUSIONS

Although the serum gastrin levels were not statistically different between the TNM stages of our patient cohort, our data found that serum gastrin levels were significantly higher in patients with lymph node metastasis. Whether gastrin is implicated in the ability of cancer cells to metastasize to the lymph nodes merits further research.

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.

Elevated risk of colorectal adenoma with Helicobacter pylori-related chronic gastritis: a population-based case-control study

This study investigated correlations between Helicobacter pylori infection or chronic atrophic gastritis (CAG) and risk of colorectal adenoma in a population-based case-control study. Subjects comprised asymptomatic, middle-aged, male Japanese factory workers who participated in an annual health check-up program, including cancer screening with colonoscopy. We selected 239 colorectal adenoma cases based on histological evaluation and 239 age-matched adenoma-free controls, and evaluated colorectal adenoma risk according to stage of H. pylori-related chronic gastritis as determined by serum tests for H. pylori antibody titer and pepsinogen. Subjects with colorectal adenoma were more likely to be smokers and have hypercholesterolemia. H. pylori infection was a risk factor for adenoma as a whole (crude odds ratio [OR]: 2.26, 95% confidence interval [CI]: 1.44-3.55). Analysis of distal adenoma cases showed that adenoma risk was significantly increased in the presence of H. pylori infection, but there was no further increase in risk with CAG. In contrast, proximal adenoma risk increased stepwise with the presence and progression of H. pylori-related chronic gastritis and showed a maximal and significant increase with CAG (crude OR: 4.51, 95% CI: 1.43-14.2). Subjects with more extensive and severe gastritis showed still higher risk not only for proximal but also for distal adenoma. H. pylori-related chronic gastritis is likely to be involved in the development of colorectal neoplasms, and its progression appears to increase the risk, particularly for proximal adenomas. Knowing the H. pylori-related chronic gastritis stage will probably be useful for evaluation of risk for colorectal neoplasia.

Colorectal cancer risk in relation to use of acid suppressive medications

PURPOSE

Acid suppressants are commonly prescribed medications. Laboratory studies suggest a mechanism by which they could increase colorectal cancer (CRC) risk. A few epidemiologic studies have investigated acid suppressant use and CRC risk; none has documented an overall association. We sought to investigate whether acid suppressants are associated with CRC risk.

METHODS

We conducted a case-control study among members of an integrated healthcare delivery system in Washington State. Cases (N = 641) were diagnosed with CRC between 2000 and 2003; controls (N = 641) were randomly selected from enrollees and matched to cases on age, sex, and length of enrollment. We used conditional logistic regression to estimate the odds ratios (ORs) and 95% confidence intervals (CI) for CRC associated with the use of any acid suppressive medication, proton pump inhibitors (PPIs) only, histamine receptor antagonists (H2 blockers) only, or both PPIs and H2 blockers in relation to the use of neither PPIs nor H2 blockers.

RESULTS

Use of PPIs exclusively was modestly associated with an increased risk of CRC, however this finding was consistent with chance and based on a small number of patients exposed (OR = 1.7; 95%CI = 0.8, 4.0). H2 blocker use alone was not related to CRC risk (OR = 0.8; 95%CI = 0.6, 1.1).

CONCLUSIONS

PPI use may be modestly associated with CRC risk; further research should be conducted in populations with long-term PPI use.

CCK2 receptor expression transforms non-tumorigenic human NCM356 colonic epithelial cells into tumor forming cells

Expression of gastrin and cholecystokinin 2 (CCK(2)) receptor splice variants (CCK(2)R and CCK(2i4sv)R) are upregulated in human colonic adenomas where they are thought to contribute to tumor growth and progression. To determine the effects of ectopic CCK(2) receptor variant expression on colonic epithelial cell growth in vitro and in vivo, we employed the non-tumorigenic colonic epithelial cell line, NCM356. Receptor expression was induced using a retroviral expression vector containing cDNAs for either CCK(2i4sv)R or CCK(2)R. RT-PCR and intracellular Ca(2+) ([Ca(2+)](i)) imaging of RIE/CCK(2)R cells treated with conditioned media (CM) from NCM356 revealed that NCM356 cells express gastrin mRNA and secrete endogenous, biologically active peptide. NCM356 cells expressing either CCK(2)R or CCK(2i4sv)R (71 and 81 fmol/mg, respectively) grew faster in vitro, and exhibited an increase in basal levels of phosphorylated ERK (pERK), compared with vector. CCK(2) receptor selective antagonist, YM022, partially inhibited the growth of both receptor-expressing NCM356 cells, but not the control cells. Inhibitors of mitogen activated protein kinase pathway (MEK/ERK) or protein kinase C (PKC) isozymes partially inhibited the elevated levels of basal pERK and in vitro growth of receptor-expressing cells. Vector-NCM356 cells did not form tumors in nude mice, whereas, either CCK(2) receptor-expressing cells formed large tumors. Autocrine activation CCK(2) receptor variants are sufficient to increase in vitro growth and tumorigenicity of non-transformed NCM356 colon epithelial cells through a pathway involving PKC and the MEK/ERK axis. These findings support the hypothesis that expression of gastrin and its receptors in human colonic adenomas contributes to tumor growth and progression.

Long-term safety concerns with proton pump inhibitors

Proton pump inhibitors (PPIs) are among the most widely prescribed medications worldwide. Their use has resulted in dramatic improvements in treatment of peptic ulcer disease and gastroesophageal reflux disease. Despite an acceptable safety profile, mounting data demonstrate concerns about the long-term use of PPIs. To provide a comprehensive review regarding the concerns of long-term PPI use, a literature search was performed to identify pertinent original and review articles. Despite study shortcomings, the collective body of information overwhelmingly suggests an increased risk of infectious complications and nutritional deficiencies. Data regarding any increased risk in gastric or colon malignancy are less convincing. PPIs have revolutionized the management and complications of acid-related disorders with a high margin of safety; however, with the data available, efforts to reduce the dosing of or discontinue the use of PPIs must be reassessed frequently.

Gastrin, Helicobacter pylori, and colorectal adenomas

BACKGROUND & AIMS

Hypergastrinemia and Helicobacter pylori (Hp) infection have been associated with an increased risk for colorectal neoplasia in some studies. However, data from large prospective studies of both associations are lacking. The aim of this study was to evaluate whether serum gastrin levels and/or infection with Hp are associated with the subsequent development of colorectal adenomas.

METHODS

Subjects (all with a history of adenoma formation) were drawn from 2 previously completed adenoma chemoprevention trials. Participants underwent clearing colonoscopy at baseline with follow-up colonoscopy 1 and 4 years after enrollment. We used commercially available assays on fasting blood specimens to measure serum gastrin levels and Hp serologies 1 year after randomization. Risk ratios for adenoma and advanced adenoma development during the subsequent 3 years were computed by generalized linear regression.

RESULTS

Of the 1794 subjects randomized in the 2 trials, 685 had available serum and were included in the analyses. Gastrin levels were significantly higher in the 239 subjects with Hp titers indicating infection (mean, 88.3 pg/mL) than in those not infected (mean, 73.9 pg/mL; P < .001). In fully adjusted models, gastrin levels were not associated with incident adenoma development (risk ratio [RR], 1.10; 95% confidence interval [CI], 0.78-1.54) or advanced adenoma formation (RR, 0.82; 95% CI, 0.33-2.03). A positive Hp serology was associated with a decreased risk for adenoma formation (RR, 0.76; 95% CI, 0.60-0.96).

CONCLUSIONS

Neither hypergastrinemia nor serologic evidence of Hp infection were associated with an increased risk for recurrent adenoma development. These results do not support the notion that gastrin promotes colorectal carcinogenesis, at least at the stage of adenoma development.

Long-term use of proton pump inhibitors does not affect the frequency, growth, or histologic characteristics of colon adenomas

BACKGROUND

The clinical significance of the trophic effects of long-term proton pump inhibitors (PPI)-related hypergastrinemia on colon polyps remains unknown.

AIM

To study the frequency, growth, and histology of colon polyps in patients on chronic PPI therapy (cases), compared to those not receiving acid suppression (controls).

METHODS

Medical records of 2868 consecutive patients who underwent two or more colonoscopies, performed 3 or more months apart were reviewed. Cases (116) that used PPIs between the two colonoscopies were then compared to controls (194).

RESULTS

Demographics and risk factors for colon cancer were comparable between the two groups. At baseline the mean frequency and size of adenomatous polyps were similar in cases and controls (P > 0.05) and at follow-up, these were 0.89 and 1.18 (P > 0.05; 95% CI of -0.08 to 0.66) and 4.09 mm and 4.00 mm (P > 0.05; 95% CI -2.29 to 2.11), respectively with no significant change. However, control group had a higher mean frequency and size of hyperplastic polyps at baseline as well as at follow-up colonoscopy (P < 0.05).

CONCLUSIONS

The long-term use of PPI does not influence the frequency, growth, or histology of adenomatous polyps, but is associated with a reduction in both baseline and interval development of hyperplastic polyps.

Proton pump inhibitor use and risk of colorectal cancer: a population-based, case-control study

BACKGROUND & AIMS

Use of proton pump inhibitors (PPIs) has been associated with elevated levels of serum gastrin. Because hypergastrinemia increases colorectal mucosa proliferation and has been associated with risk of colorectal cancer (CRC) in human beings, we conducted a large population-based study in Denmark to assess whether PPI use is associated with CRC risk.

METHODS

We conducted the study in North Jutland County, Denmark. From the County Hospital Discharge Registry we identified incident cases of CRC during the period 1989-2005. Using risk set sampling we selected approximately 10 controls from the Danish Civil Registration System, with matching for sex and birth year. PPI use was ascertained in the Prescription Database of North Jutland (and so recorded before CRC diagnosis) and analyzed with conditional logistic regression adjusted for multiple covariates.

RESULTS

We identified 5589 cases of CRC which were compared with 55,890 controls. In a comparison of ever to never or rare users (< or =30 pills during observation period), no evidence was observed of increased risk (adjusted odds ratio [OR], 1.11; 95% confidence interval [CI], 0.97-1.27). When we compared the most intense users of PPI (more than every other day) with never or rare users, we found that no increased cancer risk was shown in either short-term users (adjusted OR, 1.07; 95% CI, 0.86-1.34) or long-term users (>7 years; adjusted OR = 1.09; 95% CI, 0.58-2.06).

CONCLUSIONS

The use of PPIs in clinical practice does not measurably increase the risk of CRC.

Chronic proton pump inhibitor therapy and the risk of colorectal cancer

BACKGROUND & AIMS

Chronic acid suppression by proton pump inhibitor therapy can lead to hypergastrinemia. Because existing evidence suggested an association between hypergastrinemia and colorectal cancer, we examined whether long-term proton pump inhibitor use is associated with an increased risk of colorectal cancer in a population-representative cohort.

METHODS

We conducted a nested case-control study among patients 50 years of age and older and with > or =5 years of colorectal cancer-free initial follow-up in the General Practice Research Database (1987-2002) from the United Kingdom. Cases consisted of all patients with an incident diagnosis of colorectal cancer. Using incidence density sampling, up to 10 controls were matched with each case on practice site and both duration and calendar time of follow-up before the index date. The primary exposure of interest was > or =5 years of cumulative proton pump inhibitor therapy. We assessed the presence of duration-response and dose-response effects.

RESULTS

We identified 4432 incident colorectal cancer cases and 44,292 controls. The adjusted odds ratio for > or =5 years of proton pump inhibitor exposure was 1.1 (95% confidence interval, 0.7-1.9). Among high-dose proton pump inhibitor users (ie, > or =1.5 defined daily doses/day), there was a nonstatistically significant trend toward an increased risk with increasing duration of use (test for trend, P = .2). However, patients with pernicious anemia were not at increased risk for colorectal cancer (adjusted odds ratio, 0.9; 95% confidence interval, 0.6-1.3).

CONCLUSIONS

Long-term proton pump inhibitor therapy at a regular dose is not associated with a significantly increased risk of colorectal cancer.

Consequences of long-term proton pump blockade: insights from studies of patients with gastrinomas

Proton pump inhibitors are being increasingly used and for longer periods of time, especially in patients with gastroesophageal reflux disease. Each of these trends has led to numerous studies and reviews of the potential risk-benefit ratio of the long-term use of proton pump inhibitors. Both long-term effects of hypergastrinaemia due to the profound acid suppression caused by proton pump inhibitors as well as the effects of hypo-/achlorhydria per se have been raised and studied. Potential areas of concern that have been raised in the long-term use of proton pump inhibitors, which could alter this risk-benefit ratio include: gastric carcinoid formation; the development of rebound acid hypersecretion when proton pump inhibitor treatment is stopped; the development of tolerance; increased oxyntic gastritis in H. pylori patients and the possibility of increasing the risk of gastric cancer; the possible stimulation of growth of non-gastric tumours due to hypergastrinaemia; and the possible effect of the hypo/achlorhydria on nutrient absorption, particularly iron and vitamin B12. Because few patients with idiopathic gastro-oesophageal reflux disease/peptic ulcer disease have been treated long-term (i.e., >10 years), there is little known to address the above areas of potential concern. Most patients with gastrinomas with Zollinger-Ellison syndrome have life-long hypergastrinaemia, require continuous proton pump inhibitors treatment and a number of studies report results of >5-10 years of tratment and follow-up. Therefore, an analysis of Zollinger-Ellison syndrome patients can provide important insights into some of the safety concerns raised above. In this paper, results from studies of Zollinger-Ellison syndrome patients and other recent studies dealing with the safety concerns above, are briefly reviewed.

The effect of jaundice on the generation of anti-gastrin antibodies in G17DT immunized patients with advanced pancreatic cancer

AIM

The aim of this study was to determine the ability of G17DT to generate anti-gastrin antibodies in jaundiced patients with biliary obstruction due to advanced pancreatic cancer.

METHODS

G17DT was administered to 41 patients with advanced pancreatic adenocarcinoma by intramuscular (i.m.) injection at a dose of 250mcg at weeks 0, 1 and 3 of the study.

RESULTS

Thirty-five of 41 patients participating in the study were categorized as responders in terms of their gastrin-17 antibody response. There was no correlation between the maximum G17 antibody response and the bilirubin level at either week 0 or week 12. The median survival of patients from the time of the first injection of G17DT was 204 days with 25% of patients surviving for <or=97 days and 25% of patients surviving for >or=305 days.

CONCLUSION

This study shows that G17DT administered to jaundiced patients with advanced pancreatic cancer is immunogenic and well tolerated.

Helicobacter pylori infection increases the risk of colorectal adenoma and adenocarcinoma, especially in women

BACKGROUND

Recent reports suggest that Helicobacter pylori infection can potentially increase the risk of colorectal cancer. The purpose of this study was to assess the association between H. pylori infection and the risk of colorectal adenoma and adenocarcinoma, and to evaluate any differences on the basis of sex.

METHODS

The subjects were 669 (40- to 80-year-old) patients who underwent both barium enema examination and total colonoscopy, and who were evaluated for H. pylori infection by (13)C-urea breath test, urease test, or histological diagnosis of biopsied gastric specimens. There were 142 H. pylori-negative and 527-positive patients. The odds ratios (ORs) for H. pylori-positive patients with colorectal adenoma and adenocarcinoma, and for tumor patients with either adenoma or adenocarcinoma were calculated.

RESULTS

Among the H. pylori-negative patients, there were 52 patients without tumor, 63 with adenoma, 27 with adenocarcinoma, and 90 with tumor. Among the H. pylori-positive patients, there were 136, 264, 127, and 391 patients respectively. Pooling all subjects, those infected with H. pylori had a significantly increased OR for adenoma, adenocarcinoma, or tumor, compared to H. pylori-free patients (OR, 1.60, 1.80, and 1.66, respectively). For female H. pylori-positive subjects, the risk of having adenocarcinoma or tumor was significantly higher than that for their H. pylori-free counterparts, while for male H. pylori-positive and -negative subjects, there was no such significant difference.

CONCLUSIONS

The results therefore suggest that, in patients aged 40-80 years, H. pylori infection increased the risk of colorectal adenoma and adenocarcinoma, with significantly higher risks for female patients.

Long-term omeprazole and esomeprazole treatment does not significantly increase gastric epithelial cell proliferation and epithelial growth factor receptor expression and has no effect on apoptosis and p53 expression

AIM: To study the effect of proton pump inhibitor (PPI) treatment on patients with reflux esophagitis and its in vivo effect on apoptosis, p53- and epidermal growth factor receptor (EGFR) expression.

METHODS: After informed consent was obtained, gastric biopsies of the antrum were taken from patients with reflux oesophagitis prior to and after 6 mo of 20 mg omeprazole (n = 14) or 40 mg esomeprazole (n = 12) therapy. Patients did not take any other medications known to affect the gastric mucosa. All patients were Helicobacter pylori negative as confirmed by rapid urease test and histology, respectively. Cell proliferation, apoptosis, EGFR, and p53 expression were measured by immunohistochemical techniques. At least 600 glandular epithelial cells were encountered and results were expressed as percentage of total cells counted. Was considered statistically significant.

RESULTS: Although there was a trend towards increase of cell proliferation and EGFR expression both in omeprazole and esomeprazole treated group, the difference was not statistically significant. Neither apoptosis nor p53 expression was affected.

CONCLUSION: Long-term PPI treatment does not significantly increase gastric epithelial cell proliferation and EGFR expression and has no effect on apoptosis and p53 expression.

Signaling pathways associated with colonic mucosa hyperproliferation in mice overexpressing gastrin precursors

MTI/G-Gly mice and hGAS mice, overexpressing glycine-extended gastrin (G-Gly) and progastrin, respectively, display colonic mucosa hyperplasia, hyperproliferation, and an increased susceptibility to intestinal neoplasia. Here, we have used these transgenic mice to analyze in vivo the modulation of intracellular signaling pathways that may be responsible for the proliferative effects of gastrin precursors. The expression, activation, and localization of signaling and cell-to-cell adhesion molecules were studied using immunofluorescence and Western blot techniques on colonic tissues derived from MTI/G-Gly, hGAS, or wild-type FVB/N mice. These analyses revealed an up-regulation of Src tyrosine kinase and related signaling pathways [phosphatidyl inositol 3'-kinase (PI3K)/Akt, Janus-activated kinase (JAK) 2, signal transducer and activator of transcription (STAT) 3, and extracellular-signal regulated kinases (ERK)] in both MTI/G-Gly and hGAS mice compared with the wild-type control animals as well as an overexpression of transforming growth factor-alpha (TGF-alpha). In contrast, overexpression of the gastrin precursors did not affect the activation status of STAT1 nor the expression and the distribution of adhesion proteins (focal adhesion kinase, cadherins, and catenins). We report for the first time that the transition from a normal colonic epithelium to a hyperproliferative epithelium in MTI/G-Gly and hGAS mice may be a consequence of the up-regulation of Src, PI3K/Akt, JAK2, STAT3, ERKs, and TGF-alpha. Deregulation of cell adhesion, a late event in tumor progression, does not occur in these transgenic models.

Differences in plasma gastrin, CEA, and CA 19-9 concentration in patients with proximal and distal colorectal cancer

AIM

We investigated whether there are differences in plasma gastrin, as compared with carcinoembryonic antigen (CEA) and cancer antigen (CA) 19-9 between patients with proximal and distal colorectal cancer. Gastrin concentration has also been analyzed, dependent on the tumor stage, in order to evaluate the possible prognostic role of this measurement.

METHODS

In 50 patients with colon cancer-fasting gastrin, CA 19-9 and CEA levels were evaluated.

RESULTS

Mean plasma-gastrin level in patients with distal tumor yielded 105.31 +/- 12.5 microU/L and was significantly higher than in patients with the proximal tumor site (42.2 +/- 3.1 microU/L) as well as in controls (p < 0.001). No significant difference was observed between mean plasma gastrin in patients with proximal tumors and the control group. The mean CEA plasma level was significantly higher (p < 0.01) in patients with distal tumors (9.1 +/- 1.1 ng/mL) than in those with proximal tumors (1.48 +/- 0.1 ng/mL). Similarly, the mean CA 19-9 plasma level was significantly higher (p < 0.01) in patients with distal tumor (19.9 +/- 2.1 U/mL) than in those with proximal tumor: 1.8 +/- 0.2 U/mL. The mean gastrin plasma, CA 19-9, and CEA level was significantly higher in group of Duke's stage C and D as compared to A and B.

CONCLUSION

We speculate that observed differences in gastrin concentration in patients with distal and proximal tumors may contribute to the distinct pathogenesis and biological properties of those cancers. The significance of gastrin as a marker for diagnostic or prognostic purposes in colorectal cancer requires further study.

Detection of anti-HAV antibody with dot immunogold filtration assay

AIM: To establish a rapid, sensitive and specific immunogold assay for detection of hepatitis A virus infection.

METHODS: Rabbit monoclonal antibodies to anti-human IgM and IgG (Dako) were dotted on a nitrocellulose membrane (NCM) respectively to capture the human sera IgM and IgG. Then the captured antibodies would conjugate to HAV antigen, which was revealed by mouse anti-HAV IgG conjugated to gold particles. Final results were assessed by blind method.

RESULTS: Sera from 96 patients with acute hepatitis were used for our study. Compared with well-recognized standard (Abbott Laboratory, USA), the sensitivity and specificity of IgM-DIGFA (self-made) were 91.3% (42/46) and 96.0% (48/50), and those of IgM-ELISA (Kehua, Shanghai) were 97.8% (45/46) and 100.0% (50/50). The identical results were produced from the study with reagents at different conditions, and the study was repeated in 15 negative sera and 10 positive sera. The serum anti-HAV IgG was tested with DIGFA at the same time. In comparison with ELISA, the sensitivity and specificity of DIGFA for IgG anti-HAV were 87.2% (41/47) and 91.8% (45/49), respectively.

CONCLUSION: This assay can detect anti-HAV IgM and IgG simultaneously, and be done within 3 min. The simplicity, rapidity and specificity of the assay were useful for screening and epidemiological study.

Gastric autoimmune disorders in patients with chronic hepatitis C before, during and after interferon-alpha therapy

AIM: To explore the prevalence of autoimmune gastritis in chronic hepatitis C virus (HCV) patients and the influence of a-interferon (IFN) treatment on autoimmune gastritis.

METHODS: We performed a prospective study on 189 patients with positive anti-HCV and viral RNA enrolled in a 12-month IFN protocol. We evaluated: a) the baseline prevalence of autoimmune gastritis, b) the impact of IFN treatment on development of biochemical signs of autoimmune gastritis (at 3, 6 and 12 mo), c) the evolution after IFN withdrawal (12 mo) in terms of anti-gastric-parietal-cell antibodies (APCA), gastrin, anti-thyroid, and anti-non-organ-specific antibodies.

RESULTS: APCA positivity and 3-fold gastrin levels were detected in 3 (1.6%) and 9 (5%) patients, respectively, at baseline, in 25 (13%) and 31 (16%) patients at the end of treatment (both P < 0.001, vs baseline), and in 7 (4%) and 14 (7%) patients 12 mo after withdrawal (P = 0.002 and P = 0.01 respectively, vs baseline; P = not significant vs end of treatment). The development of autoimmune gastritis was strictly associated with the presence of autoimmune thyroiditis (P = 0.0001), no relationship was found with other markers of autoimmunity.

CONCLUSION: In HCV patients, IFN frequently precipitates latent autoimmune gastritis, particularly in females. Following our 12-month protocol, the phenomenon generally regressed. Since APCA positivity and high gastrin levels are associated with the presence of antithyroid antibodies, development of autoimmune thyroiditis during IFN treatment may provide a surrogate preliminary indicator of possible autoimmune gastritis to limit the need for invasive examinations.

Involvement of cholecystokinin/gastrin-related peptides and their receptors in clinical gastrointestinal disorders

In this paper the possible roles of cholecystokinin (CCK), gastrin, or gastrin-related peptides and their receptors in human gastrointestinal diseases are reviewed. For CCK/CCK(A) receptors (CCK(A)-R), the evidence for their proposed involvement in diseases caused by impaired CCK release or CCK(A)-R mutations, pancreatic disorders (acute/chronic pancreatitis), gastrointestinal motility disorders (gallbladder disease, irritable bowel syndrome), pancreatic tumor growth and satiety disorders, is briefly reviewed. The evidence that has established the involvement of gastrin/CCK(B)-R in mediating the action of hypergastrinaemic disorders, mediating hypergastrinaemic effects on the gastric mucosa (ECL hyperplasia, carcinoids, parietal cell mass), and acid-peptic diseases, is reviewed. The evidence for their possible involvement in mediating growth of gastric and pancreatic tumours and possible involvement of gastrin-related peptides in colon cancers, is reviewed briefly.

Potential role of endocrine gastrin in the colonic adenoma carcinoma sequence

The role of hyper-gastrinaemia in the incidence of colonic cancer remains to be clarified. The aim of this study was to determine whether cholecystokinin-2 (CCK-2) receptor expression predicts the sensitivity of human colonic adenomas to the proliferative effects of serum hyper-gastrinaemia. Gene expression of the classical (74 kDa) CCK-2 receptor in human colonic adenoma specimens and cell lines, was quantified by real-time PCR. Western blotting, using a CCK-2 receptor antiserum, confirmed protein expression. A transformed human colonic adenoma was grown in SCID mice, with hyper-gastrinaemia induced by proton pump inhibitors. CCK-2 receptor blockade was achieved by using neutralising antiserum. Both human colonic adenoma cell lines and biopsies expressed CCK-2 receptor mRNA at levels comparable with CCK-2 receptor transfected fibroblasts and oxyntic mucosa. Western blotting confirmed immunoreactive CCK-2 receptor bands localised to 45, 74 and 82.5 kDa. Omeprazole and lansoprazole-induced hyper-gastrinaemia (resulting in serum gastrin levels of 34.0 and 153.0 pM, respectively) significantly increased the weight of the human adenoma grafts (43% (P=0.016) and 70% (P=0.014), respectively). The effect of hypergastrinaemia on tumour growth was reversed by use of antiserum directed against the CCK-2 receptor. Hyper-gastrinaemia may promote proliferation of human colonic adenomas that express CCK-2 receptor isoforms.

Short term infusion of glycine-extended gastrin(17) stimulates both proliferation and formation of aberrant crypt foci in rat colonic mucosa

Evidence is accumulating that gastrin precursors may act as growth factors for the colonic mucosa in vivo and for colorectal carcinoma cell lines in vitro. The effect of short term administration of synthetic gastrins on the colonic mucosa in vivo, however, has not been reported. The aim of our study was to determine whether continuous systemic infusion of glycine-extended gastrin(17) stimulated proliferation and accelerated carcinogenesis in the colorectal mucosa. A significant increase in colonic mucosal proliferation as assessed by metaphase index was seen in the caecum (23%, p < 0.02) and distal colon (27%, p < 0.001), but not the rectum, after treatment of intact rats with glycine-extended gastrin(17) for 1 week using implanted miniosmotic pumps. Defunctioning of the rectum reduced both the proliferative index and crypt height of the rectal mucosa of untreated rats. Treatment of rectally defunctioned animals with glycine-extended gastrin(17) for either 1 or 4 weeks resulted in a significant increase in both the proliferative index (40% and 93%, respectively) and crypt height (11% and 19%, respectively) of the rectal mucosa. The total number of aberrant crypt foci in intact rats treated with the procarcinogen azoxymethane plus glycine-extended gastrin(17) was increased by 48% compared to the value in controls treated with azoxymethane only (p = 0.01). We conclude that short term administration of glycine-extended gastrin(17) to mature rats not only has a proliferative effect upon colonic mucosa, but also increases the number of aberrant crypt foci formed in the colorectal mucosa after treatment with azoxymethane. Glycine-extended gastrin(17) could thus potentially act as a promoter of carcinogenesis.

Effect of long-term, continuous versus alternate-day omeprazole therapy on serum gastrin in patients treated for reflux esophagitis

BACKGROUND

Proton pump inhibitors have been proven to have a major role in the management of peptic diseases, especially the long-term control of reflux esophagitis. The potent inhibitory effect of omeprazole on gastric acid secretion is frequently associated with hypergastrinemia, and gastrin and its intermediates have been reported to promote gastrointestinal cellular functions and cell growth. Experimental data suggest that gastrin may affect the proliferation of colon cells and some other cancer cells. However, so far the direct role of gastrin in tumorigenesis is unclear. Although most clinical studies on long-term treatment with omeprazole or other proton pump inhibitors do not report serious adverse effects, the issue of prolonged hypergastrinemia and tissue growth is unsettled, and many clinicians are reluctant to recommend long-term use of omeprazole or of other proton pump inhibitors.

STUDY

We examined the effect of long-term omeprazole treatment on serum gastrin levels in patients with reflux esophagitis when given either 20 mg daily (group 1) or on alternate days (group 2). During the follow-up period, clinical remission was monitored and maintained in all patients in group 1 and in the majority of patients in group 2.

RESULTS

The mean serum gastrin level was significantly elevated in group 1 (mean +/- SE, 159 +/- 23.6 pg/mL; range, 45-620 pg/mL; n = 31) as compared with the alternate-day treatment group (group 2) (66 +/- 4.8 pg/mL; range, 37-115 pg/mL; n = 21) (p < 0.005). In controls, serum gastrin levels showed similar values to those found in group 2 (54 +/- 4.3 pg/mL; range, 27-94 pg/mL; n = 20). Fourteen patients (45%) in group 1 had serum gastric ranging from 140 to 620 pg/mL, and 8 (25%) had a 6-fold or greater increase in serum gastrin. The follow-up treatment period ranged between 3 and 60 months (mean +/- SE, 16.1 +/- 2.1 months) for group 1 and 3-36 months (9.7 +/- 1.4 months) for group 2. Upon multivariate adjustment for age and duration of treatment, a significantly lower mean serum gastrin level was observed in the alternate-day group as compared with the daily treated group.

CONCLUSION

Alternate-day, long-term treatment with omeprazole may be adequate to maintain remission in patients with reflux esophagitis. This regimen can assure serum gastrin levels within the normal range, thus reducing the potential risk of prolonged, sustained hypergastrinemia and profound hypochlorhydria.

Gastrin, CCK, signaling, and cancer

Gastrin, produced by G cells in the gastric antrum, has been identified as the circulating hormone responsible for stimulation of acid secretion from the parietal cell. Gastrin also acts as a potent cell-growth factor that has been implicated in a variety of normal and abnormal biological processes including maintenance of the gastric mucosa, proliferation of enterochromaffin-like cells, and neoplastic transformation. Here, we review the models used to study the effects of gastrin on cell proliferation in vivo and in vitro with respect to mechanisms by which this hormone might influence normal and cancerous cell growth. Specifically, human and animal models of hypergastrinemia and hypogastrinemia have been described in vivo, and several cells that express cholecystokinin (CCK)B/gastrin receptors have been used for analysis of intracellular signaling pathways initiated by biologically active amidated gastrins. The binding of gastrin or CCK to their common cognate receptor triggers the activation of multiple signal transduction pathways that relay the mitogenic signal to the nucleus and promote cell proliferation. A rapid increase in the synthesis of lipid-derived second messengers with subsequent activation of protein phosphorylation cascades, including mitogen-activated protein kinase, is an important early response to these signaling peptides. Gastrin and CCK also induce rapid Rho-dependent actin remodeling and coordinate tyrosine phosphorylation of cellular proteins including the non-receptor tyrosine kinases p125fak and Src and the adaptor proteins p130cas and paxillin. This article reviews recent advances in defining the role of gastrin and CCK in the control of cell proliferation in normal and cancer cells and in dissecting the signal transduction pathways that mediate the proliferative responses induced by these hormonal GI peptides in a variety of normal and cancer cell model systems.

Plasma levels of progastrin but not amidated gastrin or glycine extended gastrin are elevated in patients with colorectal carcinoma

BACKGROUND

The relationship between plasma gastrin levels and colorectal cancer is controversial. When confounding factors which increase plasma gastrin levels are taken into account, it has been shown that gastrin levels are not elevated in patients with colorectal cancer. However, these studies only measured amidated gastrin. Total gastrin (which includes unprocessed, partially processed, and mature forms of gastrin) has been shown to be elevated in patients with colorectal cancer.

AIMS

The aim of this study was to determine whether fasting plasma levels of progastrin, amidated gastrin, or glycine extended gastrin are elevated in patients with colorectal cancer or colorectal polyps compared with controls.

METHODS

Progastrin, amidated gastrin, and glycine extended gastrin were estimated by radioimmunoassay using the following antibodies: L289, 109-21, and L2. Blood samples were analysed for Helicobacter pylori by an enzyme linked immunosorbent assay.

RESULTS

Median progastrin levels were significantly higher in the cancer group (27.5 pmol/l) than in the polyp (< or =15 pmol/l) or control (< or =15 pmol/l) group (p=0.0001 There was no difference in median levels of amidated gastrin between groups. Median levels of amidated gastrin were significantly higher in H pylori positive patients (19 pmol/l) than in H pylori negative patients (8 pmol/l) (p=0.0022). Median plasma progastrin levels were significantly higher for moderately dysplastic polyps (38 pmol/l) compared with mildly dysplastic (15 pmol/l) and severely dysplastic (15 pmol/l) polyps (p=0.05).

CONCLUSIONS

Plasma levels of progastrin, but not amidated gastrin or glycine extended gastrin, are significantly elevated in patients with colorectal cancer compared with those with colorectal polyps or controls, irrespective of their H pylori status. We conclude that measuring plasma progastrin levels in patients with colorectal cancer is warranted.

Gastrin and gastrin receptor activation: an early event in the adenoma-carcinoma sequence

BACKGROUND AND AIMS

Gastrin and the cholecystokinin type B/gastrin receptor (CCKBR) have been shown to be expressed in colorectal adenocarcinoma. Both exogenous and autocrine gastrin have been demonstrated to stimulate growth of colorectal cancer but it is not known if gastrin affects the growth of colonic polyps. The purpose of this study was to determine if gastrin and CCKBR are expressed in human colonic polyps and to determine at which stage of progression this occurs.

METHODS

A range of human colonic polyps was assessed for gastrin and CCKBR gene and protein expression.

RESULTS

Normal colonic mucosa did not express gastrin or CCKBR. Gastrin and CCKBR reverse transcription-polymerase chain reaction products were detected and verified by specific hybridisation with an oligo probe on Southern blots. Gastrin and CCKBR were expressed in 78% and 81% of polyps, respectively. Both genes were coexpressed in 97% of cases. Immunohistochemistry identified progastrin in 91%, glycine extended gastrin 17 in 80%, and amidated gastrin 17 in only 47% of polyps. CCKBR was present in 96% of polyps. Expression of gastrin and CCKBR was seen in all histological types and sizes of polyps.

CONCLUSIONS

This study is the first to show widespread expression of both gastrin and its receptor in colorectal polyps. Their activation occurs early in the adenoma-carcinoma sequence. Gastrin may promote progression through the adenoma-carcinoma sequence.

Review article: gastrin and colorectal cancer

The polypeptide hormone gastrin was identified nearly a hundred years ago and its role in the regulation of acid secretion is well established. Gastrin also acts as a growth factor and is trophic for the normal gastric oxyntic mucosa. This growth promoting action has led to the extensive investigation of its role in carcinogenesis, in particular colorectal neoplasia. The relationship between gastrin and colorectal adenocarcinoma has been subject to controversy, however the findings from several recent studies have resulted in a clearer understanding of the mechanism of action of gastrin in this is common cancer. The majority of colorectal cancers produce their own gastrin, which may act in an autocrine manner. The tumour cells also express gastrin/CCKB receptors (and/or a combination of isoforms) which mediate the proliferative action. This locally produced gastrin gives rise to a small increase in systemic gastrin levels. Autocrine gastrin may also have a role in tumour development, as expression occurs early in the adenoma-carcinoma sequence. In addition, several studies using animal models have shown that systemic hypergastrinaemia promotes the proliferation of both normal and neoplastic colonic epithelium. Hyperproliferative colonic epithelium in the presence of hypergastrinaemia has been recorded in humans and a well-designed epidemiological study has demonstrated an increased incidence of colorectal cancer. Gastrin is a potential therapeutic target in the treatment of colorectal cancer and several approaches have been assessed. Receptor antagonists and antisecretory agents have been demonstrated to be ineffectual. Novel methods of inhibition, including the use of anti-gastrin antibodies, are currently being evaluated.

Overexpression of glycine-extended gastrin in transgenic mice results in increased colonic proliferation

Gastrin is a peptide hormone involved in the growth of both normal and malignant gastrointestinal tissue. Recent studies suggest that the glycine-extended biosynthetic intermediates mediate many of these trophic effects, but the in vivo relevance of glycine-extended gastrin (G-Gly) has not been tested. We have generated mice (MTI/G-GLY) that overexpress progastrin truncated at glycine-72 to evaluate the trophic effects of G-Gly in an in vivo model. MTI/G-GLY mice have elevated serum and colonic mucosal levels of G-Gly compared with wild-type mice. MTI/G-GLY mice had a 43% increase in colonic mucosal thickness and a 41% increase in the percentage of goblet cells per crypt. MTI/G-GLY mice exhibited increased colonic proliferation compared with wild-type controls, with an expansion of the proliferative zone into the upper third of the colonic crypts. Continuous infusion of G-Gly into gastrin-deficient mice for two weeks also resulted in elevated G-Gly levels, a 10% increase in colonic mucosal thickness, and an 81% increase in colonic proliferation when compared with gastrin-deficient mice that received saline alone. To our knowledge, these studies demonstrate for the first time that G-Gly's contribute to colonic mucosal proliferation in vivo.