Validation of the pepsinogen test method for gastric cancer screening using a follow-up study

A dual-gene panel of two fragments of methylated IRF4 and one of ZEB2 in plasma cell-free DNA for gastric cancer detection

Early detection is crucial for increasing the survival rate of gastric cancer (GC). We aimed to identify a methylated cell-free DNA (cfDNA) marker panel for detecting GC. The differentially methylated CpGs (DMCs) were selected from datasets of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The selected DMCs were validated and further selected in tissue samples (40 gastric cancer and 36 healthy white blood cell samples) and in a quarter sample volume of plasma samples (37 gastric cancer, 12 benign gastric disease, and 43 healthy individuals). The marker combination selected was then evaluated in a normal sample volume of plasma samples (35 gastric cancer, 39 control diseases, and 40 healthy individuals) using real-time methylation-specific PCR (MSP). The analysis of the results compared methods based on 2-ΔΔCt values and Ct values. In the results, 30 DMCs were selected through bioinformatics methods, and then 5 were selected for biological validation. The marker combination of two fragments of IRF4 (IRF4-1 and IRF4-2) and one of ZEB2 was selected due to its good performance. The Ct-based method was selected for its good results and practical advantages. The assay, IRF4-1 and IRF4-2 in one fluorescence channel and ZEB2 in another, obtained 74.3% sensitivity for the GC group at any stage, at 92.4% specificity. In conclusion, the panel of IRF4 and ZEB2 in plasma cfDNA demonstrates good diagnostic performance and application potential in clinical settings.

The diagnostic value of serum trefoil factor 3 and pepsinogen combination in chronic atrophic gastritis: a retrospective study based on a gastric cancer screening cohort in the community population

BACKGROUND

Chronic atrophic gastritis (CAG) is an important precursor of gastric cancer(GC), and there is currently a lack of reliable non-invasive diagnostic markers. This study aims to find a biomarker for non-invasive screening of CAG in the community.

METHODS

A total of 540 individuals were enrolled (test set = 385, validation set = 155). ROC curve analysis was used to evaluate the diagnostic significance of serum Trefoil Factor 3 (TFF3) alone or in combination with pepsinogen (PG) for CAG in the test and validation set. Furthermore, the diagnostic value of TFF3 and PG in different Helicobacter pylori (H. pylori) infection states was studied.

RESULTS

When compared with chronic superficial gastritis (CSG), the expression level of serum TFF3 in the CAG was higher (27 ng/ml vs 19.61, P < 0.001). ROC curve analysis found that the sensitivity, specificity, and area under the curve (AUC) of CAG diagnosis using serum TFF3 alone at the optimal cut-off value of 26.55 ng/ml were 0.529, 0.87, and 0.739, respectively. When TFF3 was combined with The Ratio of PGI to PGII (PGR), the AUC and specificity reached 0.755 and 0.825, respectively. TFF3 individual or combined with PGR had good predictive value, especially in the H. Pylori negative patients.

CONCLUSION

TFF3 combined with PGR can effectively predict CAG, especially in patients with H. pylori negative.

Helicobacter pylori Infection Combined with OLGA and OLGIM Staging Systems for Risk Assessment of Gastric Cancer: A Retrospective Study in Eastern China

PURPOSE

Helicobacter pylori (H. pylori) infection is a high-risk factor for gastric cancer (GC). The main aim of this study was to evaluate the effect of H. pylori on gastritis staging systems and the value of H. pylori combined with gastritis staging systems in predicting GC risk.

PATIENTS AND METHODS

This study enrolled 609 patients with gastric atrophy (GA) and 527 patients with gastric intestinal metaplasia (GIM), who were graded by the OLGA and OLGIM staging systems, respectively. Each individual underwent serum pepsinogen (PG) test, H. pylori detection and questionnaire investigation. We did a real-world retrospective follow-up survey for them in April 2022.

RESULTS

Compared with H. pylori-negative patients, H. pylori-positive patients had higher serum PGs/gastrin-17 (G-17) levels and lower PGR levels, regardless of OLGA/OLGIM stages I-II or III-IV. Furthermore, eight patients with atrophic gastritis who progressed to GC were previously in OLGA stages III-IV and OLGIM stages II-IV. The average duration of this process was 2.19±1.03 years. Logistic regression analysis indicated that PGI and H. pylori infection were independent risk factors of individuals with OLGA stages III-IV. Age and PGR were independent risk factors of patients with OLGIM stages III-IV. PGI and PGR had good clinical diagnostic values for OLGA stages III-IV and OLGIM stages III-IV, respectively.

CONCLUSION

Patients with OLGA/OLGIM stages III-IV should undergo endoscopic surveillance regardless of H. pylori infection. H. pylori-positive patients with OLGIM stage II also have a high risk of GC. H. pylori combined with PGI and PGR is helpful to evaluate the severity of chronic gastritis.

Diagnostic performances of pepsinogens and gastrin-17 for atrophic gastritis and gastric cancer in Mongolian subjects

In Mongolia, gastric cancer morbidity and mortality are high, and more than 80 percent of cases are diagnosed at an advanced stage. This study aimed to evaluate pepsinogens (PGIs) and gastrin-17 (G-17) levels and to determine the diagnostic performances for gastric cancer and chronic atrophic gastritis among Mongolian individuals. We enrolled a total of 120 subjects, including gastric cancer (40), atrophic gastritis (40), and healthy control (40), matched by age (±2) and sex. Pepsinogen I (PGI), Pepsinogen II (PGII), G-17, and H. pylori IgG levels were measured using GastroPanel ELISA kit (Biohit, Helsinki, Finland). Also, PGI to PGII ratio (PGR) was calculated. For atrophic gastritis, when the optimal cut-off value of PGI was ≤75.07 ng/ml, the sensitivity and specificity were 75% and 50%, respectively; when the optimal cut-off value of PGR was ≤6.25, sensitivity and specificity were 85% and 44.7%, respectively. For gastric cancer, when the optimal cut-off value of PGI was ≤35.25 ng/ml, the sensitivity and specificity were 47.2% and 86.8%, respectively; when the optimal cut-off value of PGR was ≤5.27, sensitivity and specificity were 75% and 60.5%, respectively. Combinations of biomarkers with risk factors could improve diagnostic accuracy (AUC for atrophic gastritis 74.8, 95% CI 64.0–85.7, p<0.001; AUC for gastric cancer 75.5, 95% CI 64.2–86.8, p<0.001). PGI, PGR biomarkers combined with the risk of age, family history of gastric cancer, and previous gastric disease could not be an alternative test for upper endoscopy but might be a supportive method which is identifying individuals at medium- and high risk of gastric cancer and precancerous lesions who may need upper endoscopy.

SFRP4 drives invasion in gastric cancer and is an early predictor of recurrence

OBJECTIVE

Gastric cancer patients generally have a poor outcome, particularly those with advanced-stage disease which is defined by the increased invasion of cancer locally and is associated with higher metastatic potential. This study aimed to identify genes that were functional in the most fundamental hallmark of cancer, namely invasion. We then wanted to assess their value as biomarkers of gastric cancer progression and recurrence.

DESIGN

Data from a cohort of patients profiled on cDNA expression arrays was interrogated using K-means analysis. This genomic approach classified the data based on patterns of gene expression allowing the identification of the genes most correlated with the invasion of GC. We evaluated the functional role of a key protein from this analysis in invasion and as a biomarker of recurrence after curative resection.

RESULTS

Expression of secreted frizzled-related protein 4 (SFRP4) was identified as directly proportional to gastric cancer invasion. This finding was validated in multiple, independent datasets and its functional role in invasion was also confirmed using invasion assays. A change in serum levels of SFRP4 after curative resection, when coupled with AJCC stage, can accurately predict the risk of disease recurrence after curative therapy in an assay we termed PredictR.

CONCLUSIONS

This simple ELISA-based assay can help predict recurrence of disease after curative gastric cancer surgery irrespective of adjuvant therapy. The results require further evaluation in a prospective trial but would help in the rational prescription of cancer therapies and surveillance to prevent under or over treatment of patients after curative resection.

Analysis of factors associated with recovery of the serum pepsinogen ratio after Helicobacter pylori eradication: a long-term follow-up study in Korea

Objective: Serum levels of pepsinogen (PG) are related to Helicobacter pylori-induced inflammation of the gastric mucosa. This study aimed to examine the influence of H. pylori eradication on serum PG, analyze its associated factors, and evaluate the long-term outcomes.Methods: H. pylori-positive patients who underwent gastroscopy and serum PG measurement were enrolled in a single academic hospital. After H. pylori eradication, the measurement of serum PG level was performed. Recovery of serum PG I/II ratio was defined as a PG I/II ratio after eradication of >3.0 in patients with a PG I/II ratio ≤ 3.0 before eradication. Follow-up involved serum PG measurement and gastroscopy with a rapid urease test annually.Results: In all, 327 patients were eligible for study inclusion. Compared to those before H. pylori eradication, serum PG I (74.9 vs. 44.3 ng/mL, p < .001) and PG II (25.4 vs. 9.1 ng/mL, p < .001) levels significantly decreased after successful eradication. In addition, there was a significant increase in serum PG I/II ratio after eradication (3.07 vs. 4.98, p < .001). In multivariate analyses, the following were independently associated with failed recovery of serum PG I/II ratio despite successful eradication: age ≥ 60 years (odds ratio [OR] = 0.231, 95% confidence interval [CI] = 0.084-0.629, p = .004) and severe gastric atrophy (OR = 0.156, 95% CI = 0.055-0.440, p < .001).Conclusions: Recovery of serum PG I/II ratio after H. pylori eradication may be achieved in H. pylori-infected patients aged <60 years without severe gastric atrophy.

Only serum pepsinogen I and pepsinogen I/II ratio are specific and sensitive biomarkers for screening of gastric cancer

Purpose We aimed to determine optimal cut-off points of plasma levels of ghrelin and serum levels of pepsinogen I, II, and their ratio for screening of gastric cancer (GC). Methods Blood samples were taken from 41 patients with confirmed gastric cancer along with 82 patients without malignancy. Serum levels of pepsinogen I and II, plus plasma levels of acylated ghrelin were measured using commercial ELISA kits. Results The case group had significant lower plasma levels of ghrelin, pepsinogen I, and pepsinogen I/II ratio in comparison to the control group (P<0.001). In the control group, there was significant higher serum pepsinogen I (P=0.028) and pepsinogen II (P=0.003) and lower pepsinogen I/II ratio (P=0.020) in males versus females; significantly higher serum pepsinogen II (P=0.047) and lower pepsinogen I/II ratio (P=0.030) in overweight compared to normal weight patients; and significantly lower pepsinogen I/II ratio (P=0.030) in smokers versus non-smoker. In the case group, there was only significantly lower pepsinogen I (P=0.006) in males versus females, and significantly lower plasma ghrelin (P=0.017) in overweight compared to normal weight patients. The characteristic curve analysis indicated that pepsinogen I at a cut-off of 70.95 μg/L and pepsinogen I/II ratio at cut-off of 2.99, had good sensitivity and specificity. Conclusions Just serums levels of pepsinogen I and the ratio of pepsinogen I/II can be used as biomarker to screen GC.

Prediction of Chronic Atrophic Gastritis and Gastric Neoplasms by Serum Pepsinogen Assay: A Systematic Review and Meta-Analysis of Diagnostic Test Accuracy

Serum pepsinogen assay (sPGA), which reveals serum pepsinogen (PG) I concentration and the PG I/PG II ratio, is a non-invasive test for predicting chronic atrophic gastritis (CAG) and gastric neoplasms. Although various cut-off values have been suggested, PG I ≤70 ng/mL and a PG I/PG II ratio of ≤3 have been proposed. However, previous meta-analyses reported insufficient systematic reviews and only pooled outcomes, which cannot determine the diagnostic validity of sPGA with a cut-off value of PG I ≤70 ng/mL and/or PG I/PG II ratio ≤3. We searched the core databases (MEDLINE, Cochrane Library, and Embase) from their inception to April 2018. Fourteen and 43 studies were identified and analyzed for the diagnostic performance in CAG and gastric neoplasms, respectively. Values for sensitivity, specificity, diagnostic odds ratio, and area under the curve with a cut-off value of PG I ≤70 ng/mL and PG I/PG II ratio ≤3 to diagnose CAG were 0.59, 0.89, 12, and 0.81, respectively and for diagnosis of gastric cancer (GC) these values were 0.59, 0.73, 4, and 0.7, respectively. Methodological quality and ethnicity of enrolled studies were found to be the reason for the heterogeneity in CAG diagnosis. Considering the high specificity, non-invasiveness, and easily interpretable characteristics, sPGA has potential for screening of CAG or GC.

Serum Pepsinogen as a Predictor for Gastric Cancer Death: A 16-Year Community-based Cohort Study

GOALS

The purpose of this article is to validate the long-term association between initial serum pepsinogen (PG) measurements and subsequent gastric cancer-specific deaths from a long-term longitudinal cohort.

BACKGROUND

Endoscopic surveillance can be effective and efficient in reducing gastric cancer mortality if a biomarker such as serum PG is available to identify high-risk individuals and if the biomarker also is specific to gastric cancer risk.

STUDY

Between 1995 and 1998, a gastric cancer-screening program was conducted in a high-risk population: The first stage involved PG testing, and the second stage involved upper endoscopy. The outcome was gastric cancer death, which was monitored until December 31, 2010; results were expressed as the hazard ratio (HR) and corresponding 95% confidence interval (CI) using the Cox proportional hazards regression model. Other causes of death were used as comparators.

RESULTS

Among participants (n=3514) aged ≥30 years, 1682 (47.9%) were screened to determine serum PG levels. After 16 years of follow-up, 14 deaths from gastric cancer were documented. Multivariate analyses adjusted for age, sex, and Helicobacter pylori serological positivity showed that PG-I <30 μg/L and PG-I <30 μg/L or PG-I/II ratio <3 were significantly associated with the risk of gastric cancer death (HR, 3.27; 95% CI, 1.11-9.61 and HR, 3.45; 95% CI, 1.18-10.12, respectively). In contrast, there were no significant associations between PG and other causes of death, including neoplastic and non-neoplastic diseases.

CONCLUSION

This long-term cohort study shows the usefulness of PG measurement as a biomarker that is specific to the risk of gastric cancer death.

The Value of Pepsinogen in GC Screening: A Systematic Review and Meta-Analysis

Background

The current gold standard for gastric cancer (GC) screening is pathology or a barium meal followed by X-ray. This is not applicable to a wide range of screening capabilities due to the lack of operability. This article used a meta-analysis to evaluate the value of pepsinogen (PG) screening for GC.

Methods

PubMed, EMbase, the Cochrane Library, CNKI, WanFang, VIP, and CBM databases were systematically searched for published studies that used serum PG to diagnose GC. Articles were searched from January 2003 to January 2018. Two reviewers independently screened the literature according to specified inclusion and exclusion criteria. The data were extracted and evaluated, and the quality of the methodologies evaluated using the QUADAS entry. The meta-analysis (MA) was performed using Meta-DiSc 1.4 software. Stata 12.0 software was used to assess publication bias.

Results

A total of 19 studies were finally included from a total of 169,009 cases. The MA showed a combined sensitivity and specificity of 0.56 (95% CI (0.53-0.59), P < 0.01) and 0.71 (95% CI (0.70-0.71), P < 0.01), respectively. The combined likelihood ratios were +LR = 2.82 (95% CI (2.06-3.86), P < 0.01) and -LR = 0.56 (95% CI (0.45-0.68), P < 0.01). The combined DOR was 5.41 (95% CI (3.64~ 8.06), P < 0.01), and the area under the SROC curve was 0.7468.

Conclusions

Serum PG provides medium levels of sensitivity and specificity for GC assessment. To be used in a clinical setting, further high-quality research must be performed and verified.

HIV related hypochlorhydria does not appear to respond to anti-retroviral therapy in Zambian adults: a case control study

INTRODUCTION

Human Immunodeficiency Virus (HIV) infection is associated with hypochlorhydria but the mechanism is unknown. The objective of this study was to determine effects of anti-retroviral therapy (ART) on gastric physiology as measured by validated markers.

METHODS

We studied HIV infected individuals who were either ART-naïve or on treatment with undetectable viral loads. We measured H.pylori IgG antibodies, pepsinogen (PG) 1 and 2 levels and fasting gastrin-17 using Biohit GastroPanel®. Gastric antral biopsies and juice were obtained for histology and pH respectively. Also included were historical data from HIV negative participants (n = 72) in a previous study, for reference.

RESULTS

We enrolled 84 HIV positive individuals with a median age 42 years (IQR 37-40 years). 55(66%) were female, 32(38%) were ART naïve, and 52(62%) were on ART. Hypochlorhydria (pH>4) was present in 48(57%) of the HIV positive and 18(25%) of the HIV negative individuals (OR 4: 95% CI 1.9-8.5, P<0.001) with no significant effect of ART (OR 0.9: 95% CI 0.3-2.3, P = 0.82). Hypochlorhydria was not associated with the serological detection of corpus atrophy using low PG 1:2 ratio (OR 2.1: 95% CI 0.5-10.2, P = 0.37) or GastroPanel® algorithm, (OR 0.7: 95% CI 0.01-60.1, P = 1.0). ART reduced the frequency of low PG 1:2 ratio (P = 0.001), but not the histological detection in the antrum of atrophy or non-atrophic gastritis.

CONCLUSION

ART use is associated with reduced serological evidence of corpus atrophy but has no effect on fasting pH, supporting earlier data that suggest that the mechanism of HIV-associated hypochlorhydria is multifactorial.

Helicobacter pylori infection and serum level of pepsinogen are associated with the risk of metachronous gastric neoplasm after endoscopic resection

BACKGROUND

Patients who have undergone endoscopic resection of early gastric cancers (EGCs) are at risk for metachronous gastric neoplasm.

AIM

To determine whether serum level of pepsinogen (PG), a marker of gastric atrophy, can determine which patients who have undergone endoscopic submucosal dissection for EGC are at risk for metachronous gastric neoplasm. We also investigated the effects of Helicobacter pylori eradication on metachronous gastric neoplasm incidence.

METHODS

We performed a retrospective study of 590 consecutive patients who underwent endoscopic submucosal dissection for EGC, from January 2008 to May 2013 at a tertiary centre in South Korea; serum levels of PG were measured at the time of endoscopic submucosal dissection and H. pylori infection status were recorded. In case of proven presence of current H. pylori infection, eradication treatment was provided. Patients underwent follow-up endoscopies at 3 months, 9 months, and each year after the procedure to detect neoplasms and were tested for H. pylori infection; serum levels of PG were measured at these time points from 442 of the patients. The main and sub-cohorts were assessed for baseline characteristics, H. pylori infection, serum level of PG, and metachronous gastric neoplasm lesions.

RESULTS

During a median follow-up period of 47.7 months, 64 patients developed metachronous gastric neoplasms. In multivariate analysis of the main cohort (n = 590), risk factors for metachronous gastric neoplasm included persistent H. pylori infection (hazard ratio [HR], 2.532; P = .022) and serum ratio of PGI:PGII of three or less at the time of endoscopic submucosal dissection (HR, 1.881; P = .018). Among patients with serum PG measurements, persistent H. pylori infection (odds ratio [OR], 4.404; P = .009) and persistent decrease in mean serum ratio of PGI:PGII to 3 or less were associated with increased risk of metachronous gastric neoplasm (OR, 2.141; P = .039).

CONCLUSIONS

In a retrospective analysis of patients who underwent endoscopic resection of EGCs, eradication of H. pylori infection reduced risk for metachronous gastric neoplasm. Serum ratio of PGI:PGII of 3 or less also increase risk of metachronous gastric neoplasm after endoscopic submucosal dissection. ClinicalTrials.gov. registry number, NCT02682446.

Three-dimensional combined biomarkers assay could improve diagnostic accuracy for gastric cancer

So far, stomach-specific biomarkers, gastric cancer(GC)-related environmental factors, and cancer-associated biomarkers are three major classes of serological biomarkers with GC warning potential, joint detection of which is expected to increase the diagnosis efficiency. We investigated whether the combination of serum pepsinogens(PGs), IgG anti-Helicobacter pylori (HpAb), and osteopontin (OPN) can be used as a panel for GC diagnose. Serum was collected from 365 GC patients and 729 healthy individuals,furtherly 332 cases and 332 age- and sex-matched controls were selected for the matched analysis. Serum levels were measured by ELISA. Logistic regression and receiver operator characteristic curve (ROC) were used to assess the associations of biomarkers with GC and the discriminative performance of biomarkers for GC. The area under ROC from three-dimensional combination of PGI/II-HpAb-OPN (0.826) was significantly higher than two-dimensional combination of PGI/II-HpAb (0.786, P < 0.001), PGI/II-OPN (0.787, P < 0.001), and OPN-HpAb (0.801, P = 0.006), as well as one-biomarker of PGI/II (0.735, P < 0.001), HpAb (0.737, P < 0.001) and OPN(0.713, P < 0.001), respectively. The combination of PGI/II-HpAb-OPN, yielded a sensitivity of 70.2% and specificity of 78.3% at the predicted probability of 0.493 as the optimal cutoff point. Three-dimensional combined biomarkers assay could improve diagnostic accuracy for gastric cancer.

The Prevalence of Cancer-Associated Autoantibodies in Patients with Gastric Cancer and Progressive Grades of Premalignant Lesions

Background: Serum autoantibodies against tumor-associated antigens (TAAs) are detectable in early-stage gastric cancer patients; however, the time point during cancerogenesis when they appear in circulation is still obscure.Methods: In this study, we developed a recombinant antigen microarray and analyzed the prevalence of autoantibodies against 102 TAAs in 829 gastric cancer patients and 929 healthy controls from Caucasian and Asian populations, as well as 100 patients with chronic atrophic gastritis and 775 individuals staged according to different grades of intestinal metaplasia.Results: Six antigens, including CTAG1B/CTAG2, DDX53, IGF2BP2, TP53, and MAGEA3, were predominantly reacting with sera from gastric cancer patients when compared with healthy controls, and the seroreactivity was associated with intestinal-type gastric cancer, but not with patients' Helicobacter pylori status, grade, age, gender, or stage of gastric cancer. We detected gastric cancer-associated seroreactivity in 13% of patients with advanced/severe intestinal metaplasia, which was increased in comparison with mild/moderate intestinal metaplasia (5.3%) and was comparable with that seen in early-stage gastric cancer patients (12%). Moreover, by testing serum samples taken 1 to 9 years before the clinical diagnosis of 18 incident gastric cancer cases, we detected autoantibody responses against several TAAs-SOX2, MYC, BIRC5, IGF2BP1, and MUC1.Conclusions: Our results suggest that humoral immune response against TAAs is generated already during premalignant stages.Impact: Based on the obtained results, cancer-associated autoantibodies might make a valuable contribution to the stratification of high-risk patients with premalignant lesions in the stomach through enhancing the positive predictive power of existing risk models. Cancer Epidemiol Biomarkers Prev; 26(10); 1564-74. ©2017 AACR.

Host pathogen interactions in Helicobacter pylori related gastric cancer

Helicobacter pylori (H. pylori), discovered in 1982, is a microaerophilic, spiral-shaped gram-negative bacterium that is able to colonize the human stomach. Nearly half of the world's population is infected by this pathogen. Its ability to induce gastritis, peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma has been confirmed. The susceptibility of an individual to these clinical outcomes is multifactorial and depends on H. pylori virulence, environmental factors, the genetic susceptibility of the host and the reactivity of the host immune system. Despite the host immune response, H. pylori infection can be difficult to eradicate. H. pylori is categorized as a group I carcinogen since this bacterium is responsible for the highest rate of cancer-related deaths worldwide. Early detection of cancer can be lifesaving. The 5-year survival rate for gastric cancer patients diagnosed in the early stages is nearly 90%. Gastric cancer is asymptomatic in the early stages but always progresses over time and begins to cause symptoms when untreated. In 97% of stomach cancer cases, cancer cells metastasize to other organs. H. pylori infection is responsible for nearly 60% of the intestinal-type gastric cancer cases but also influences the development of diffuse gastric cancer. The host genetic susceptibility depends on polymorphisms of genes involved in H. pylori-related inflammation and the cytokine response of gastric epithelial and immune cells. H. pylori strains differ in their ability to induce a deleterious inflammatory response. H. pylori-driven cytokines accelerate the inflammatory response and promote malignancy. Chronic H. pylori infection induces genetic instability in gastric epithelial cells and affects the DNA damage repair systems. Therefore, H. pylori infection should always be considered a pro-cancerous factor.

Pepsinogens to Distinguish Patients With Gastric Intestinal Metaplasia and Helicobacter pylori Infection Among Populations at Risk for Gastric Cancer

OBJECTIVES

The objectives of this study were to investigate the serum pepsinogen test for the prediction of OLGIM (Operative Link on Gastric Intestinal Metaplasia Assessment) stages in first-degree relatives (FDR-GC) of patients with gastric cancer (GC) and autoimmune chronic atrophic gastritis (ACAG).

METHODS

In 67 consecutive patients with ACAG, 82 FDR-GC, and 53 controls (CTRL) without gastric disease (confirmed by biopsy), serum levels of pepsinogen 1 (PG1), pepsinogen 2 (PG2), G17, and the PG1/2 ratio were assessed by enzyme-linked immunosorbent assay kit. All ACAG patients had positive antiparietal cell antibody levels, estimated by indirect immunofluorescence. Biopsies taken in duplicate from the antrum, corpus, and fundus were stained with Giemsa for Helicobacter pylori detection. Endoscopic detection of metaplasia was confirmed by histological diagnosis. Histological classification of OLGIM stages was applied by using the criteria of severity and topography of intestinal metaplasia (IM).

RESULTS

The highest discrimination capacity for distinguishing ACAG from other groups of patients was the gastrin G17 test. The lowest mean for PG1 and PG2 serum levels was found in ACAG. In multivariate analysis by age, PG1 and PG1/PG2 were independent prognostic factors for metaplasia, and PG2 also for the presence of a histological H. pylori infection. The serum PG1 level was significantly lower in individuals with IM at OLGIM stage >2 than in those with IM at OLGIM stage <2, resulting in a useful method for the prediction of OLGIM stage. With the inclusion of patient age at diagnosis in the prediction of ≥2 vs. 0-1 OLGIM stages, the receiver operating characteristic (ROC) curve at 47.9 ng/ml PG1 level reached a significant area under the curve (AUC) value (0.978, P<0.001). We also observed a slight difference in PG2 serum levels between histological H. pylori-positive and H. pylori-negative subjects (ROC AUC: 0.599).

CONCLUSIONS

This study demonstrated an important increase in gastrin G17 serum level in autoimmune gastritis. PG1 serum level corrected by patient age can be used in the management of patients at risk for GC with a high predicted probability of having an OLGIM stage ≥2. Using a cutoff of 47.9 ng/ml, PG1 testing in FDR-GC and ACAG patients had a sensitivity of 95.83% and a specificity of 93.37. Although these results could be validated in a prospective study, the known importance of higher OLGIM stages in increasing the risk of GC development supports the rationale of proposing PG1 algorithm as a diagnostic tool for the selection of high-risk FDR-GC and ACAG patients at high-risk stages for subsequent detailed endoscopic examination to detect dysplasia and asymptomatic GC. In addition, serum PG1 and PG2 levels could stratify patients based on both H. pylori infection and OLGIM risk in consideration of the increased acknowledge regarding the role of H. pylori in the progression of gastritis to GC.

Gastric adenocarcinoma screening and prevention in the era of new biomarker and endoscopic technologies: a cost-effectiveness analysis

OBJECTIVE

To estimate the cost-effectiveness of noncardia gastric adenocarcinoma (NCGA) screening strategies based on new biomarker and endoscopic technologies.

DESIGN

Using an intestinal-type NCGA microsimulation model, we evaluated the following one-time screening strategies for US men: (1) serum pepsinogen to detect gastric atrophy (with endoscopic follow-up of positive screen results), (2) endoscopic screening to detect dysplasia and asymptomatic cancer (with endoscopic mucosal resection (EMR) treatment for detected lesions) and (3) Helicobacter pylori screening and treatment. Screening performance, treatment effectiveness, cancer and cost data were based on published literature and databases. Subgroups included current, former and never smokers. Outcomes included lifetime cancer risk and incremental cost-effectiveness ratios (ICERs), expressed as cost per quality-adjusted-life-year (QALY) gained.

RESULTS

Screening the general population at age 50 years reduced the lifetime intestinal-type NCGA risk (0.24%) by 26.4% with serum pepsinogen screening, 21.2% with endoscopy and EMR and 0.2% with H. pylori screening/treatment. Targeting current smokers reduced the lifetime risk (0.35%) by 30.8%, 25.5%, and 0.1%, respectively. For all subgroups, serum pepsinogen screening was more effective and more cost-effective than all other strategies, although its ICER varied from $76,000/QALY (current smokers) to $105,400/QALY (general population). Results were sensitive to H. pylori prevalence, screen age and serum pepsinogen test sensitivity. Probabilistic sensitivity analysis found that at a $100,000/QALY willingness-to-pay threshold, the probability that serum pepsinogen screening was preferred was 0.97 for current smokers.

CONCLUSIONS

Although not warranted for the general population, targeting high-risk smokers for serum pepsinogen screening may be a cost-effective strategy to reduce intestinal-type NCGA mortality.

First-line eradication for Helicobacter pylori-positive gastritis by esomeprazole-based triple therapy is influenced by CYP2C19 genotype

AIM: To evaluate the effect of first line esomeprazole (EPZ)-based triple therapy on Helicobacter pylori (H. pylori) eradication.

METHODS: A total of 80 Japanese patients with gastritis who were diagnosed as positive for H. pylori infection by endoscopic biopsy-based or ¹³C-urea breath tests were included in this study. The average age of the patients was 57.2 years (male/female, 42/38). These patients were treated by first-line eradication therapy with EPZ 40 mg/d, amoxicillin 1500 mg/d, and clarithromycin 400 mg/d for 7 d. All drugs were given twice per day. Correlations between H. pylori eradication, CYP2C19 genotype, and serum pepsinogen (PG) level were analyzed. This study was registered with the UMIN Clinical Trials Registry (UMIN000009642).

RESULTS: The H. pylori eradication rates by EPZ-based triple therapy evaluated by intention-to-treat and per protocol were 67.5% and 68.4%, respectively, which were similar to triple therapies with other first-generation proton pump inhibitors (PPIs). The eradication rates in three different CYP2C19 genotypes, described as extensive metabolizer (EM), intermediate metabolizer, and poor metabolizer, were 52.2%, 72.1%, and 84.6%, respectively. The H. pylori eradication rate was significantly lower in EM than non-EM (P < 0.05). The serum PG I level and PG I/II ratio were significantly increased after eradication of H. pylori (P < 0.01), suggesting that gastric atrophy was improved by H. pylori eradication. Thus, first-line eradication by EPZ-based triple therapy for patients with H. pylori-positive gastritis was influenced by CYP2C19 genotype, and the eradication rate was on the same level with other first-generation PPIs in the Japanese population.

CONCLUSION: The results from this study suggest that there is no advantage to EPZ-based triple therapy on H. pylori eradication compared to other first-generation PPIs.

Long noncoding RNAs as potential biomarkers in gastric cancer: Opportunities and challenges

Gastric cancer (GC) is a major threat to human health, and its prognosis is poor due to the lack of appropriate biomarkers. LncRNAs are a group of non-protein-coding RNAs that regulate gene expression at the transcriptional or posttranscriptional level. LncRNAs play essential roles in GC initiation and development in the same way as oncogenes or tumour suppressor genes. Recent investigations have revealed that lncRNAs are often aberrantly expressed in GC; are involved in cell proliferation, apoptosis, migration and invasion; and correlate with the malignant phenotype of GC. LncRNAs, especially the lncRNAs present in the blood and gastric juice, show potential value as biomarkers for the diagnosis of GC or for determining disease prognosis. However, there are still many challenges to be faced before lncRNAs can be used in clinical applications. In this review, we summarise lncRNAs as the potential biomarkers for GC and the current challenges associated with the clinical application.

Significance of Serum Pepsinogens as a Biomarker for Gastric Cancer and Atrophic Gastritis Screening: A Systematic Review and Meta-Analysis

BACKGROUND

Human pepsinogens are considered promising serological biomarkers for the screening of atrophic gastritis (AG) and gastric cancer (GC). However, there has been controversy in the literature with respect to the validity of serum pepsinogen (SPG) for the detection of GC and AG. Consequently, we conducted a systematic review and meta-analysis to assess the diagnostic accuracy of SPG in GC and AG detection.

METHODS

We searched PubMed, Embase, and the Chinese National Knowledge Infrastructure (CNKI) for correlative original studies published up to September 30, 2014. The summary sensitivity, specificity, positive diagnostic likelihood ratio (DLR+), negative diagnostic likelihood ratio (DLR-), area under the summary receiver operating characteristic curve (AUC) and diagnostic odds ratio (DOR) were used to evaluate SPG in GC and AG screening based on bivariate random effects models. The inter-study heterogeneity was evaluated by the I2 statistics and publication bias was assessed using Begg and Mazumdar's test. Meta-regression and subgroup analyses were performed to explore study heterogeneity.

RESULTS

In total, 31 studies involving 1,520 GC patients and 2,265 AG patients were included in the meta-analysis. The summary sensitivity, specificity, DLR+, DLR-, AUC and DOR for GC screening using SPG were 0.69 (95% CI: 0.60-0.76), 0.73 (95% CI: 0.62-0.82), 2.57 (95% CI: 1.82-3.62), and 0.43 (95% CI: 0.34-0.54), 0.76 (95% CI: 0.72-0.80) and 6.01 (95% CI: 3.69-9.79), respectively. For AG screening, the summary sensitivity, specificity, DLR+, DLR-, AUC and DOR were 0.69 (95% CI: 0.55-0.80), 0.88 (95% CI: 0.77-0.94), 5.80 (95% CI: 3.06-10.99), and 0.35 (95% CI: 0.24-0.51), 0.85 (95% CI: 0.82-0.88) and 16.50 (95% CI: 8.18-33.28), respectively. In subgroup analysis, the use of combination of concentration of PGI and the ratio of PGI:PGII as measurement of SPG for GC screening yielded sensitivity of 0.70 (95% CI: 0.66-0.75), specificity of 0.79 (95% CI: 0.79-0.80), DOR of 6.92 (95% CI: 4.36-11.00), and AUC of 0.78 (95% CI: 0.72-0.81), while the use of concentration of PGI yielded sensitivity of 0.55 (95% CI: 0.51-0.60), specificity of 0.79 (95% CI: 0.76-0.82), DOR of 6.88 (95% CI: 2.30-20.60), and AUC of 0.77 (95% CI: 0.73-0.92). For AG screening, the use of ratio of PGI:PGII as measurement of SPG yielded sensitivity of 0.69 (95% CI: 0.52-0.83), specificity of 0.84 (95% CI: 0.68-0.93), DOR of 11.51 (95% CI: 6.14-21.56), and AUC of 0.83 (95% CI: 0.80-0.86), the use of combination of concentration of PGI and the ratio of PGI:PGII yield sensitivity of 0.79 (95% CI: 0.72-0.85), specificity of 0.89 (95% CI: 0.85-0.93), DOR of 24.64 (95% CI: 6.95-87.37), and AUC of 0.87 (95% CI: 0.81-0.92), concurrently, the use of concentration of PGI yield sensitivity of 0.46 (95% CI: 0.38-0.54), specificity of 0.93 (95% CI: 0.91-0.95), DOR of 19.86 (95% CI: 0.86-456.91), and AUC of 0.86 (95% CI: 0.52-1.00).

CONCLUSION

SPG has great potential as a noninvasive, population-based screening tool in GC and AG screening. In addition, given the potential publication bias and high heterogeneity of the included studies, further high quality studies are required in the future.

Emerging blood-based biomarkers for detection of gastric cancer

Early detection and efficient monitoring of tumor dynamics are prerequisites for reducing disease burden and mortality, and for improving the management of patients with gastric cancer (GC). Blood-based biomarker assays for the detection of early-stage GC could be of great relevance both for population-wide or risk group-based screening programs, while circulating biomarkers that reflect the genetic make-up and dynamics of the tumor would allow monitoring of treatment efficacy, predict recurrences and assess the genetic heterogeneity of the tumor. Recent research to identify blood-based biomarkers of GC has resulted in the identification of a wide variety of cancer-associated molecules, including various proteins, autoantibodies against tumor associated antigens, cell-free DNA fragments, mRNAs and various non-coding RNAs, circulating tumor cells and cancer-derived extracellular vesicles. Each type of these biomarkers provides different information on the disease status, has different advantages and disadvantages, and distinct clinical usefulness. In the current review, we summarize the recent developments in blood-based GC biomarker discovery, discuss the origin of various types of biomarkers and their clinical usefulness and the technological challenges in the development of biomarker assays for clinical use.

Implementation of gastric cancer screening - the global experience

Gastric cancer (GC) is still an important global healthcare problem, and in absolute figures it is going to remain at the present level in foreseeable future. In general, survival of patients with GC is poor mainly due to advanced-stage diagnosis. Early-stage GC can be cured by endoscopic resection or less invasive surgical treatment. Unfortunately, there is no appropriate screening strategy available for global application. This article provides a description of established national and regional GC screening programs and the screening modalities used. This review also summarizes current approaches to develop cancer-screening biomarkers. Although candidates with initial promising results have been suggested, moving discovery into clinical practice is still a major challenge. Well-designed biomarker studies, with systematic validation steps, are needed to decrease the burden of this fatal disease.

Gastric cancer: prevention, screening and early diagnosis

Gastric cancer continues to be an important healthcare problem from a global perspective. Most of the cases in the Western world are diagnosed at late stages when the treatment is largely ineffective. Helicobacter pylori (H. pylori) infection is a well-established carcinogen for gastric cancer. While lifestyle factors are important, the efficacy of interventions in their modification, as in the use of antioxidant supplements, is unconvincing. No organized screening programs can be found outside Asia (Japan and South Korea). Although several screening approaches have been proposed, including indirect atrophy detection by measuring pepsinogen in the circulation, none of them have so far been implemented, and more study data is required to justify any implementation. Mass eradication of H. pylori in high-risk areas tends to be cost-effective, but its adverse effects and resistance remain a concern. Searches for new screening biomarkers, including microRNA and cancer-autoantibody panels, as well as detection of volatile organic compounds in the breath, are in progress. Endoscopy with a proper biopsy follow-up remains the standard for early detection of cancer and related premalignant lesions. At the same time, new advanced high-resolution endoscopic technologies are showing promising results with respect to diagnosing mucosal lesions visually and targeting each biopsy. New histological risk stratifications (classifications), including OLGA and OLGIM, have recently been developed. This review addresses the current means for gastric cancer primary and secondary prevention, the available and emerging methods for screening, and new developments in endoscopic detection of early lesions of the stomach.

Current issues and future perspectives of gastric cancer screening

Gastric cancer remains the second leading cause of cancer death worldwide. About half of the incidence of gastric cancer is observed in East Asian countries, which show a higher mortality than other countries. The effectiveness of 3 new gastric cancer screening techniques, namely, upper gastrointestinal endoscopy, serological testing, and “screen and treat” method were extensively reviewed. Moreover, the phases of development for cancer screening were analyzed on the basis of the biomarker development road map. Several observational studies have reported the effectiveness of endoscopic screening in reducing mortality from gastric cancer. On the other hand, serologic testing has mainly been used for targeting the high-risk group for gastric cancer. To date, the effectiveness of new techniques for gastric cancer screening has remained limited. However, endoscopic screening is presently in the last trial phase of development before their introduction to population-based screening. To effectively introduce new techniques for gastric cancer screening in a community, incidence and mortality reduction from gastric cancer must be initially and thoroughly evaluated by conducting reliable studies. In addition to effectiveness evaluation, the balance of benefits and harms must be carefully assessed before introducing these new techniques for population-based screening.

Meta-analysis on validity of serum pepsinogen measurement for mass screening of gastric carcinoma in the high-risk population

AIM: To assess the validity of measurement of serum pepsinogen as a screening test for gastric carcinoma in the high-risk population.

METHODS: We searched the databases including PubMed, EMBASE, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wan Fang Data, VIP Journal Integration Platform and China Biology Medicine disc (CBM disc) for diagnostic tests using the serum pepsinogen test with pathological biopsy or X-ray examination (golden criteria) before January 2013. Two reviewers in-dependently screened the literature according to the inclusion and exclusion criteria, extracted the data, and assessed the methodological quality of the included studies according to quality assessment of diagnostic accuracy studies (QUADAS) items. The Meta-DiSc software (version 1.4) was used to conduct pooling on sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. Heterogeneity test was performed and the summary receiver operating characteristic curve was plotted for calculating the area under the curve (AUC).

RESULTS: A total of 15 studies involving 184600 subjects were included. The results of meta-analysis showed that specificity, sensitivity, positive likelihood ratio, negative likelihood ratio and diagnostic ratio were 0.55 (95%CI: 0.51-0.58), 0.67 (95%CI: 0.67-0.68), 2.23 (95%CI: 1.71-2.92), 0.58 (95%CI: 0.46-0.73), and 4.33 (95%CI: 3.17-5.92), respectively. The AUC of the summary receiver operating characteristic curve was 0.73.

CONCLUSION: Current evidence shows that serum pepsinogen has a low sensitivity and a low specificity in the diagnosis of gastric carcinoma, and its diagnostic efficiency is medium.

Temporal changes in serum biomarkers and risk for progression of gastric precancerous lesions: a longitudinal study

Effectively managing precancerous lesions is crucial to reducing the gastric cancer (GC) burden. We evaluated associations of temporal changes in multiple serological markers (pepsinogen I [PGI], PGII, PGI/II ratio, gastrin-17 and anti-Helicobacter pylori IgG) with risk for progression of gastric precancerous lesions. From 1997 to 2011, repeated esophagogastroduodenoscopies with gastric mucosal biopsies and blood sample collections were conducted on 2,039 participants (5,070 person-visits) in the Zhuanghe Gastric Diseases Screening Program, Liaoning, China. Serum biomarkers were measured using ELISA, and gastric biopsies were evaluated using standardized histologic criteria. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using generalized estimating equations for correlated binary outcomes. The ORs for progression of gastric conditions comparing those whose serum PGI, PGII, and anti-H. pylori IgG levels increased ≥ 50% relative to those whose decreased ≥ 50% were, respectively 1.67 (CI, 1.22-2.28), 1.80 (CI, 1.40-2.33) and 1.93 (CI, 1.48-2.52). The OR for those whose PGI/II ratio decreased ≥ 50% relative to those whose increased ≥ 50% was 1.40 (CI, 1.08-1.81), and for those whose PGII and anti-H. pylori IgG levels both increased ≥ 50% relative to those whose levels both decreased ≥ 50% the OR was 3.18 (CI, 2.05-4.93). Changes in gastrin-17 were not statistically significantly associated with progression. These findings suggest that temporal changes in serum PGI, PGII, PGI/II ratio, and anti-H. pylori IgG levels (especially PGII and anti-H. pylori IgG combined) may be useful for assessing and managing risk for progression of gastric precancerous lesions.

Serum trefoil factor 3 is a promising non-invasive biomarker for gastric cancer screening: a monocentric cohort study in China

BACKGROUND

The search for better non-invasive biomarkers for gastric cancer remains ongoing. We investigated the predictive power of serum trefoil factor (TFF) levels as biomarkers for gastric cancer in comparison with the pepsinogen (PG) test.

METHODS

Patients with gastric cancer, chronic atrophic gastritis (CAG) or chronic non-atrophic gastritis (CNAG), and healthy people were recruited. Serum concentrations of TFFs, PG I, and PG II, as well as the presence of antibodies against Helicobacter pylori, were measured by enzyme-linked immunosorbent assays (ELISA). Receiver operating characteristics (ROC) were used to compare the predictive powers of the selected factors.

RESULTS

The serum concentrations of TFF1, TFF2, and TFF3 in the control groups were significantly lower than those in the gastric cancer group with the exception of TFF2 which was elevated in CAG. The area under the ROC curve for TFF3 was greater than that for the PG I/II ratio (0.81 vs 0.78). TFF3 also had a significantly higher predictive power for distinguishing gastric cancer than the PG test (odds ratio: 10.33 vs 2.57). Moreover, combining the serum TFF3 and PG tests for gastric cancer had better predictive power than either alone.

CONCLUSIONS

Serum TFF3 may be a better predictor of gastric cancer than the PG test, while the combined testing of serum PG and TFF3 could further improve the efficacy of gastric cancer screening.

Significant association between serum interleukin-6 and Helicobacter pylori antibody levels among H. pylori-positive Japanese adults

Background. Interleukin-6 (IL-6) is a multifunctional cytokine produced by many types of cells. Inflammation plays a key role in the pathogenesis of atherosclerosis that is an underlying cause of coronary heart disease (CHD). Since the 1990s, some studies have shown an association between H. pylori infection and CHD, which may be mediated by inflammation. Therefore, this study aimed to evaluate the association between serum anti-H. pylori IgG levels and serum IL-6 levels in H. pylori-infected adults. Methods. We enrolled 158 subjects who visited a clinic located in an urban area to be tested for H. pylori infection, using the ¹³C-urea breath test, and who were found to be infected and subsequently received eradication. Results. The geometric mean serum IL-6 level was 1.78 pg/mL for men, 1.57 pg/mL for women, and 1.64 pg/mL overall. Logarithms of serum IL-6 levels were positively correlated with logarithms of serum H. pylori IgG levels (r = 0.24, P = 0.002). In multiple linear regression analysis adjusting for sex and age, the serum IL-6 level was still significantly associated with the IgG level in all subjects (β = 0.18, P = 0.012). Conclusion. Higher H. pylori IgG levels were significantly associated with higher serum IL-6 levels among H. pylori-infected individuals.

Helicobacter pylori: clinical management

PURPOSE OF REVIEW

Progress continues in our understanding of the role of Helicobacter pylori infection in gastroduodenal as well as extragastric disorders. This review gives an overview on selected areas of the H. pylori infection and their clinical implications.

RECENT FINDINGS

Indications for therapy have been extended and now include idiopathic thrombocytopenic purpura, iron deficiency anemia, and vitamin B12 deficiency. New data are presented on the role of H. pylori in neurodegenerative disorders and in the metabolic syndrome. H. pylori is associated with a (small) increase in the risk for colorectal adenoma and colon cancer. The biggest challenge is the selection of new therapies and treatment strategies because of the increasing failure of standard triple therapies. The best option in high clarithromycin resistance areas is bismuth-based quadruple therapy. Probiotic bacteria and yeasts reduce adverse effects of standard H. pylori eradication regimens. In gastric cancer prevention, screening programs based on the serological detection of preneoplastic conditions may prove useful.

SUMMARY

New algorithms for preventing H. pylori-induced disease and eradicating the organism should be individualized.

Identification of gastric cancer risk markers that are informative in individuals with past H. pylori infection

BACKGROUND

Epigenomic damage induced by Helicobacter pylori infection is accumulated in gastric mucosae before the development of malignancy. In individuals without current H. pylori infection, DNA methylation levels of specific CpG islands (CGIs) are associated with gastric cancer risk. Because risk estimation in individuals with past infection is clinically important, we here aimed to identify the risk markers that reflect epigenomic damage induced by H. pylori infection, and that are informative in these individuals.

METHODS

Gastric mucosae were obtained from 55 gastric cancer patients (GC-Pt) (21 with current infection and 34 with past infection) and 55 healthy volunteers (HV) (7 never-infected, 21 with current infection, and 27 with past infection). Hypermethylated CGIs were searched for by methylated DNA immunoprecipitation-CGI microarray, and methylation levels were analyzed by quantitative methylation-specific polymerase chain reaction (PCR).

RESULTS

By microarray analysis of a pool of three samples from GC-Pt with past infection and another pool of samples from HV with past infection, 15 hypermethylated CGIs in the former pool were isolated. Seven of them had significantly higher methylation levels in GC-Pt with past infection (n = 10) than in HV with past infection (n = 10) (P < 0.001). In a validation cohort (21 GC-Pt with past infection and 14 HV with past infection), the seven new markers had large areas under the receiver-operating characteristic curves (0.78-0.84) and high odds ratios (12.7-36.0) compared with two currently available markers (0.60-0.65, 5.0-5.7).

CONCLUSIONS

We identified seven novel gastric cancer risk markers that are highly informative in individuals with past infection.

Serological assessment of gastric mucosal atrophy in gastric cancer

Background

Non-invasive tools for gastric cancer screening and diagnosis are lacking. Serological testing with the detection of pepsinogen 1 (PG1), pepsinogen 2 (PG2) and gastrin 17 (G17) offers the possibility to detect preneoplastic gastric mucosal conditions. Aim of this study was to assess the performance of these serological tests in the presence of gastric neoplasia.

Methods

Histological and serological samples of 118 patients with gastric cancer have been assessed for tumor specific characteristics (Laurén type, localisation), degree of mucosal abnormalities (intestinal metaplasia, atrophy) and serological parameters (PG1, PG2, PG1/2-ratio, G17, H. pylori IgG, CagA status). Association of the general factors to the different serological values have been statistically analyzed.

Results

Patients with intestinal type gastric cancer had lower PG1 levels and a lower PG1/2-ratio compared to those with diffuse type cancer (p = 0.003). The serum levels of PG2 itself and G17 were not significantly altered. H. pylori infection in general had no influence on the levels of PG1, PG2 and G17 in the serum of gastric cancer patients. There was a trend towards lower PG1 levels in case of positive CagA-status (p = 0.058). The degree of both intestinal metaplasia and atrophy correlated inversely with serum levels for PG1 and the PG1/2-ratio (p < 0.01). Laurén-specific analysis revealed that this is only true for intestinal type tumors. Univariate ANOVA revealed atrophy and CagA-status as the only independent factors for low PG1 and a low PG1/2-ratio.

Conclusions

Glandular atrophy and a positive CagA status are determinant factors for decreased pepsinogen 1 levels in the serum of patients with gastric cancer. The serological assessment of gastric atrophy by analysis of serum pepsinogen is only adequate for patients with intestinal type cancer.

Serum pepsinogen test for early detection of gastric cancer in a European country

AIM

To estimate the adherence of Western individuals to serum pepsinogen (PG) test and its accuracy in the detection of gastric cancer followed by upper gastrointestinal endoscopy.

METHODS

Individuals from the northern region of Portugal, aged between 40 and 79 years, were invited to participate in a blood collection for the determination of serum PG values by ELISA method (Biohit kits). Participants were classified into two groups: positive (PG I ≤70 ng/ml and PG I/ PGII ≤3) and negative (all others). All participants with a positive test and a consecutive random sample of participants with a negative test were subjected to endoscopy with biopsy. All the participants (positive or negative) subjected to endoscopy were followed up over 5 years.

RESULTS

From a total of 13 118 participants, 5326 were men (41%) with a median age of 60 years, and 446 (3.4%) had a positive test. Of these, 274 (61%) were subjected to endoscopy. We observed six gastric cancers, five intestinal and one diffuse type, and three early gastric cancers, representing one cancer per approximately 2200 PG tests or one cancer per 74 positive tests. From these 240 participants with a negative test, three patients with gastric cancer were diagnosed during follow-up (an estimated negative predictive value of 99%). In this study, the PG test showed an estimated sensitivity, specificity, positive predictive value, and negative predictive value of 67, 47, 2, and 99%, respectively.

CONCLUSION

Inhabitants of this high-risk region showed good adherence rate to a gastric cancer detection program based on a PG test followed by upper gastrointestinal endoscopy implemented for the first time. Accuracy estimates were similar to those in Japanese reports, indicating that this methodology could also be used effectively in Western countries with high rates of gastric cancer. Further formal cost-effective studies are however needed.

Low serum pepsinogen I and pepsinogen I/II ratio and Helicobacter pylori infection are associated with increased risk of gastric cancer: 14-year follow up result in a rural Chinese community

The correlation between low serum PG level and H. pylori infection with the development of gastric cancer has caused considerable concerns all over the world. Some authors exclaimed that gastric cancer developed only in patients infected with H. pylori, whereas the other had different findings. In this study, 1,501 adult local residents with determined serum PG levels and anti H. pylori IgG status were followed for 14 years for the development of gastric cancer in a rural community with high risk of gastric cancer in Hebei Province, China. The results showed the accumulated gastric cancer incidence in the subjects with abnormal PG level and those with H. pylori infection were all significantly higher than that in the corresponding normal controls (53.9‰ vs. 12.7‰, p < 0.05 and 23.1‰ vs. 5.93‰, p < 0.05). The highest gastric cancer incidence was seen in the subjects with both abnormal serum PG and positive H. pylori (56.0‰), and followed by the subjects with abnormal PG and negative H. pylori (47.6‰) and those with normal serum PG and positive H. pylori (18.4‰). The abnormal serum PG level (OR 3.029) and H. pylori infection (OR 4.345) were all risk factors for the development of gastric cancer. The results suggested that the subjects with abnormal serum PG level and/or positive H. pylori infection in the rural area of China were all high risk population for gastric carcinoma and the subjects with both abnormal serum PG and positive H. pylori infection were at especially high risk for the development of gastric carcinoma.

Clinical aspects of gastric cancer and Helicobacter pylori--screening, prevention, and treatment

Gastric cancer still represents a global health care burden, and in the absence of strategies implemented for early detection, the disease continues to have a dismal prognosis. Patients presenting with clinical manifestations of gastric cancer have limited options for cure. Thus, early detection and prevention play a key role in the fight against gastric cancer. Serologic-based test methods have the potential to detect a subset of patients at high risk of gastric cancer that require a close clinical and endoscopic follow-up. More data have been produced to support Helicobacter pylori eradication as an efficient strategy to prevent gastric cancer. Treatment options for patients with an advanced disease are still limited, but the introduction of new agents opens a more optimistic perspective for the future.