Non-invasive tests in gastric diseases

A pathway for detection of gastric cancer biomarkers via using a layer-by-layer coated D-shaped grinding long-period fiber grating sensor

Gastric cancer significantly contributes to global cancer mortality, often leading to inoperable stages and high recurrence rates post-surgery. Elevated levels of G-17 and G-gly have been identified as potential risk factors, particularly in patients with duodenal ulcers. This study introduces an innovative D-shaped grinding long-period fiber grating sensor (D-LLPFGs) designed for non-invasive detection of the gastrin G-17 antigen, employing a layer-by-layer chemical self-assembly to bond G-17 antibodies onto the fiber surface through hydrogen bonding. The D-LLPFGs sensor demonstrated significant spectral shifts within 1 min of antigen-antibody interaction, highlighting its rapid detection capability. At an optimized antibody concentration of 4 μg/ml, antigen testing across different concentrations (10, 12.5, 20, 50 μg/ml) showed peak changes at 12.5 μg/ml antigen, with a 1.186 nm shift and 0.503 dB loss. The sensor exhibited a wavelength sensitivity of 0.095 nm/μg/ml, indicating its high sensitivity and potential in gastric cancer classification, diagnosis, and treatment. This research concludes that the D-shaped fiber sensor is an effective and sensitive tool for detecting G-17 antigen levels, presenting a significant advancement in non-invasive gastric cancer diagnosis. Its quick response time and high sensitivity highlight its potential for broad biomedical applications, offering a new avenue for early cancer detection and improving patient prognosis. The success of this study opens the door to further exploration and implementation of fiber optic sensors in clinical settings, marking a significant step forward in the fight against gastric cancer.

Improvement of functional dyspepsia with Suaeda salsa (L.) Pall via regulating brain-gut peptide and gut microbiota structure

PURPOSE

The traditional Chinese herbal medicine Suaeda salsa (L.) Pall (S. salsa) with a digesting food effect was taken as the research object, and its chemical composition and action mechanism were explored.

METHODS

The chemical constituents of S. salsa were isolated and purified by column chromatography, and their structures were characterized by nuclear magnetic resonance. The food accumulation model in mice was established, and the changes of the aqueous extract of S. salsa in gastric emptying and intestinal propulsion rate, colonic tissue lesions, serum brain-gut peptide hormone, colonic tissue protein expression, and gut microbiota structure were compared.

RESULTS

Ten compounds were isolated from S. salsa named as naringenin (1), hesperetin (2), baicalein (3), luteolin (4), isorhamnetin (5), taxifolin (6), isorhamnetin-3-O-β-D-glucoside (7), luteolin-3'-D-glucuronide (8), luteolin-7-O-β-D-glucuronide (9), and quercetin-3-O-β-D-glucuronide (10), respectively. The aqueous extract of S. salsa can improve the pathological changes of the mice colon and intestinal peristalsis by increasing the rate of gastric emptying and intestinal propulsion. By adjusting the levels of 5-HT, CCK, NT, SS, VIP, GT-17, CHE, MTL, and ghrelin, it can upregulate the levels of c-kit, SCF, and GHRL protein, and restore the imbalanced structure of gut microbiota, further achieve the purpose of treating the syndrome of indigestion. The effect is better with the increase of dose.

CONCLUSION

S. salsa has a certain therapeutic effect on mice with the syndrome of indigestion. From the perspective of "brain-gut-gut microbiota", the mechanism of digestion and accumulation of S. salsa was discussed for the first time, which provided an experimental basis for further exploring the material basis of S. salsa.

Generation and characterization of nanobodies targeting human pepsinogens

Human pepsinogens (mainly pepsinogen I and pepsinogen II) are the major inactive precursor forms of the digestive enzyme pepsin which play a crucial role in protein digestion. The levels and ratios of human pepsinogens have demonstrated potential as diagnostic biomarkers for gastrointestinal diseases, particularly gastric cancer. Nanobodies are promising tools for the treatment and diagnosis of diseases, owing to their unique recognition properties. In this study, recombinant human pepsinogens proteins were expressed and purified as immunized antigens. We constructed a VHH phage library and identified several nanobodies via phage display bio-panning. We determined the binding potency and cross-reactivity of these nanobodies. Our study provides technical support for developing immunodiagnostic reagents targeting human pepsinogens.

Pepsinogen ratio and brachial-ankle pulse wave velocity: a cross-sectional study on their interrelationship in atherosclerosis

BACKGROUND

Existing research has established the pepsinogen ratio (PGR) as a complex biomarker, not only as an independent predictor for various gastrointestinal diseases but also in its association with atherosclerotic cardiovascular diseases. However, the precise mechanism linking changes in PGR to cardiovascular pathologies remains unclear. The objective of this study is to quantitatively elucidate the association between PGR and brachial-ankle pulse wave velocity (baPWV) as an indicator of atherosclerotic progression.

METHODS

We conducted a cross-sectional study that analyzed clinical data from 465 patients who underwent health screenings. One-way Analysis of Variance (ANOVA) identified potential risk factors affecting baPWV. Multiple logistic regression was employed to evaluate if PGR serves as an independent risk factor for elevated baPWV after accounting for these variables. Generalized additive models and smoothed curve fitting were utilized to investigate the possibility of a nonlinear association between PGR and baPWV. When such nonlinearity was found, threshold effect analysis pinpointed the inflection point in this relationship, followed by segmented correlation analyses.

RESULTS

PGR negatively correlated with both right baPWV (RbaPWV) and left baPWV (LbaPWV) after adjusting for confounders. Smoothed curve analyses revealed nonlinear relationships, with inflection points at 22.5 for RbaPWV and 22.3 for LbaPWV. For PGR values below 22.5, a significant negative correlation with RbaPWV was observed (β = - 6.3 cm/s, P < 0.001). Conversely, for PGR values above 22.5, no significant linear relationship was found (P = 0.141). Similarly, when PGR was below 22.3, a strong negative correlation with LbaPWV was detected (β = - 7.0 cm/s, P < 0.001), but such correlation was absent for higher PGR levels (P = 0.273).

CONCLUSION

The study reveals that PGR is associated with RbaPWV and LbaPWV in a nonlinear manner. Specifically, lower levels of PGR were linearly and inversely correlated with baPWV, but this relationship became nonlinear at higher PGR levels. These findings suggest that modulating PGR levels may offer a therapeutic strategy for managing atherosclerosis.

Site-specific protein biomarkers in gastric cancer: a comprehensive review of novel biomarkers and clinical applications

INTRODUCTION

Gastric cancer (GC) is the fifth most common cancer and the fourth leading cause of cancer-related death worldwide, thus representing a significant global health burden. Early detection and monitoring of GC are essential to improve patient outcomes. While traditional cancer biomarkers such as carcinoembryonic antigen, carbohydrate antigen (CA) 19-9, and CA 72-4 are widely used, their limited sensitivity and specificity necessitate the exploration of alternative biomarkers.

AREAS COVERED

This review comprehensively analyzes the landscape of GC protein biomarkers identified from 2019 to 2022, with a focus on tissue, blood, urine, saliva, gastric juice, ascites, and exhaled breath as sample sources. We address the potential clinical applications of these biomarkers in early diagnosis, monitoring recurrence, and predicting survival and therapeutic response of GC patients.

EXPERT OPINION

The discovery of novel protein biomarkers holds great promise for improving the clinical management of GC. However, further validation in large, diverse cohorts is needed to establish the clinical utility of these biomarkers. Integrating these biomarkers with existing diagnostic and monitoring approaches will likely lead to improved personalized treatment plans and patient outcomes.

Development of amplified luminescent proximity homogeneous assay for quantitation of gastrin-17

A highly sensitive and convenient amplified luminescent proximity homogeneous assay (AlphaLISA) method with high throughput and automation potential was developed for quantitation of serum Gastrin-17 (G-17) levels, which can facilitate the early diagnosis of atrophic gastritis in people at high risk of gastric cancer using a non-invasive approach. In this study, donor and acceptor beads with modified carboxyl groups on the surface were directly coupled to anti-G-17 antibodies through activation was proposed for application in the development of the new AlphaLISA, which can effectively simplify the steps and shorten the reaction time to achieve faster detection. Therefore, the G-17-AlphaLISA only needs to react for 15 min to obtain good analysis results. The proposed method has a wider detection range than commercial enzyme-linked immunosorbent assay (ELISA) kits (0.12-112.8 pmol/L > 0.5-40 pmol/L). In addition, results of G-17-AlphaLISA and ELISA had good correlation and agreement (ρ = 0.936). Importantly, the developed method may be more suitable for the large-scale screening of people at high risk for gastric cancer than traditional ELISA and provides a novel solution for other biomarkers that require accurate, highly sensitive, and high throughput detection.

Assessment of Serum Pepsinogens with and without Co-Testing with Gastrin-17 in Gastric Cancer Risk Assessment-Results from the GISTAR Pilot Study

Introduction−−Serum pepsinogen tests for gastric cancer screening have been debated for decades. We assessed the performance of two pepsinogen assays with or without gastrin-17 for the detection of different precancerous lesions alone or as a composite endpoint in a Latvian cohort. Methods−−Within the intervention arm of the GISTAR population-based study, participants with abnormal pepsinogen values by ELISA or latex-agglutination tests, or abnormal gastrin-17 by ELISA and a subset of subjects with all normal biomarker values were referred for upper endoscopy with biopsies. Performance of biomarkers, corrected by verification bias, to detect five composite outcomes based on atrophy, intestinal metaplasia, dysplasia or cancer was explored. Results−−Data from 1045 subjects were analysed, of those 273 with normal biomarker results. Both pepsinogen assays showed high specificity (>93%) but poor sensitivity (range: 18.4−31.1%) that slightly improved when lesions were restricted to corpus location (40.5%) but decreased when dysplasia and prevalent cancer cases were included (23.8%). Adding gastrin-17 detection, sensitivity reached 33−45% while specificity decreased (range: 61.1−62%) and referral rate for upper endoscopy increased to 38.6%. Conclusions−−Low sensitivity of pepsinogen assays is a limiting factor for their use in population-based primary gastric cancer screening, however their high specificity could be useful for triage.

Value of GastroPanel in the diagnosis of atrophic gastritis

Analysis of serum biomarkers for the assessment of atrophic gastritis (AG), considered as precursor of the intestinal type of gastric cancer, is of growing interest. The combination of pepsinogen (PG), gastrin-17 (G17) and anti-Helicobacter pylori (H. pylori) antibody serological assays (panel test) is a non-invasive tool for the diagnosis of atrophic gastritis. However, the diagnostic reliability of this test remains uncertain. The aim of our study was to assess the diagnostic performance of the serum panel test (GastroPanel) for the diagnosis of atrophic gastritis. From dyspeptic patients, endoscopic biopsy samples (two from the gastric corpus and two from the antrum) and blood samples were collected. The determination of sPGI, sPGII, sG17 and IgG antibodies to H. pylori (H.p IgG) was performed using an enzyme-linked immunosorbent assay (GastroPanel; Biohit Oyj). Histopathology results were compared with GastroPanel values. Sixty patients were included: 35 (58.3%) females and 25 (41.66%) males; mean age 67.63±9.36 years; 45% H. pylori-positive. A total of 65% of patients had atrophic gastritis. There were no significant differences between the levels of biomarkers and localization of atrophy. The ratio PG1/PG2 was lower in patients with multifocal atrophy; the difference being close to the threshold of statistical significance. In cases of intestinal metaplasia the values of G17, PG1, PG2, H.p IgG were not statistically altered compared to those without intestinal metaplasia; only the ratio PG1/PG2 was lower in intestinal metaplasia; the difference being almost of statistical significance. Our results revealed that, GastroPanel values did not differ depending on the severity of the atrophy. Biomarkers used by GastroPanel do not have enough accuracy for use in the diagnosis of atrophy in the population studied. A low accuracy only for the ratio PG1/PG2 in patients with multifocal atrophy was found. However, our data revealed a correlation in detecting intestinal metaplasia.

A point-of-care chemiluminescence immunoassay for pepsinogen I enables large-scale community health screening

Pepsinogen I (PGI) can reflect the morphology and function of the gastric mucosa. Accordingly, the large-scale community health screening of PGI can dramatically increase the early diagnosis rate of gastric cancer. However, PGI testing can only be carried out in comprehensive hospitals and health examination centers. To ameliorate this issue, a point-of-care chemiluminescent immunoassay for PGI was developed in a fully automated miniaturized instrument. This instrument was especially developed for health check-ups in the grassroots communities; its volume of which is only 0.18 m³. Critically, the entire detection process for a single sample only requires 20 min, and the samples can be loaded continuously, making the method suitable for high-throughput analysis. The assay displayed an excellent detection limit of 0.048 ng/mL with a broad detection range of 0-200 ng/mL. Furthermore, this assay exhibited high sensitivity and specificity, had low intra- and inter-assay coefficients of variation (<10%), and was not affected after storage at 37 °C for 7 days. The assay was used to detect PGI in 95 clinical serum samples, and the results were highly correlated with those that were clinically tested (correlation coefficient, R² = 0.998). Hence, the method established in this work has great application value and can be broadly applied for the large-scale screening of gastric cancer in resource-limited areas.

HELICOBACTER PYLORI CHRONIC GASTRITIS ON PATIENTS WITH PREMALIGNANT CONDITIONS: OLGA AND OLGIM EVALUATION AND SERUM BIOMARKERS PERFORMANCE

BACKGROUND

H. pylori chronic atrophic gastritis is a premalignant lesion, and its staging, according to OLGA and OLGIM systems aims to identify patients at increased risk of developing gastric cancer and optimize their follow-up. GastroPanel®, serum biomarkers panel including pepsinogen I (PGI), pepsinogen II (PGII), Gastrin 17 (G17) and anti- H. pylori antibodies is a noninvasive test for adenocarcinoma risk assessment in chronic H. pylori gastritis patients.

OBJECTIVE

Prospective study to evaluate the concordance between OLGA and OLGIM grading systems, as well as to evaluate GastroPanel´s performance in patients with premalignant lesions secondary to H. pylori chronic gastritis in Brazil.

METHODS

Patients with H. pylori chronic gastritis with premalignant lesions confirmed by histology were recruited from the gastrointestinal clinic of a University Hospital. All participants underwent endoscopic examination with biopsies which were reported according to updated Sydney system and premalignant lesions grading systems (OLGA and OLGIM). Blood samples were collected for biomarkers serological analysis (GastroPanel®, Biohit, Helsinki, Finland). The cut off values used to define high risk patients were those recommended by the manufacturer: PGI ≤30 µm/L and PGI/PGII ≤3.

RESULTS

41 patients were recruited: 28 women, 13 men, mean age 67.3 (47-89, SD: 9.6) years. By OLGA system, were obtained: OLGA 0 (n=1), OLGA I (n=7), OLGA II (n=17), OLGA III (n=9), and OLGA IV (n=7). By OLGIM system, were obtained: OLGIM 0 (n=14), OLGIM I (n=5), OLGIM II (n=10), OLGIM III (n=10), and OLGIM IV (n=2). Regarding histological staging among patients staged as low risk (OLGA/OLGIM 0, I and II) and high risk (OLGA/OLGIM III and IV) for gastric cancer development, the concordance rate found between both classifications was 85.4%. Considering high risk patients, those patients thus included in at least one of the systems the final distribution of our sample considered 24 low-risk and 17 high-risk patients for the development of gastric cancer. To determine by GastroPanel® whether the patient would be at low or high risk of developing gastric cancer, PGI showed a sensitivity, specificity and accuracy of 0.47 (95%CI: 0.26-0.69), 0.67 (95%CI: 0.47-0.82), and 0.58 (95%CI: 0.43-0.72), respectively, while PGI/PGII showed sensitivity, specificity and accuracy of 0.06 (95%CI: 0.01-0.27), 0.83 (95%CI: 0.64-0.93) and 0.51 (95%CI: 0.36-0.66), respectively.

CONCLUSION

The histological classifications OLGA and OLGIM presented a substantial concordance rate among themselves. Simultaneous use of both histological classification systems increased the identification's rate of high-risk patients. Biomarker analysis was not effective to distinguish low to high risk patients in the studied population. Further studies are needed to validate its use in clinical practice in Brazil.

Helicobacter pylori and colorectal neoplasms: a concise review

Helicobacter pylori is the main etiological agent of all malignant tumors caused by an infectious disease. It is a major, at times dominant, factor in the pathogenesis of a large spectrum of diseases such as acute and chronic gastritis, gastric and duodenal ulcers, gastric carcinoma, and lymphoma. Epidemiological and experimental studies suggest that H. pylori chronic infection may be related to different extragastric diseases, including colorectal neoplasms. This concise review aims to explore the association of H. pylori infection with colorectal cancer and adenoma, including the recent epidemiological findings, the diagnostic methods employed to detect H. pylori and virulent factors, and the potentially involved mechanisms. Furthermore, is attempted to establish the current data integration for causal inference using the Bradford-Hill causality criteria. The weak, although global, strength of the epidemiological positive association between H. pylori infection and colonic neoplasms associated to new mechanisms postulated to explain this interaction, including intestinal dysbiosis, should stimulate future studies. Prospective confirmatory studies to establish the role of H. pylori eradication in the process of carcinogenic transformation of the colonic epithelium may define its eventual role in the treatment and prevention of colonic neoplasms.

Early detection of gastric cancer beyond endoscopy - new methods

Early detection of gastric cancer is remaining a challenge. This review summarizes current knowledge on non-invasive methods that could be used for the purpose. The role of traditional cancer markers such as CEA, CA 72-4, CA 19-9, CA 15-3, and CA 12-5 lies mainly in therapy monitoring than early detection. Most extensive studied biomarkers (pepsinogens, ABC method) are aiming at the detection of precancerous lesions with modest sensitivity for cancer. Tests based on the detection of cancer-specific methylation patterns (PanSeer), circulating proteins and mutations in circulating tumour DNA (CancerSEEK), as well as miRNA panels have demonstrated promising results bringing those closer to practice. More extensive research is required before tests based on the detection of circulating tumour cells, extracellular vesicles and cell-free RNA could reach the practice. Detection of volatile organic compounds in the human breath is a promising development; sensor technologies for this purpose could be very attractive in screening settings.

Association between serum pepsinogen and atherosclerotic cardiovascular disease

BACKGROUND AND AIM

Serum pepsinogens (PGs) are biomarkers for gastric mucosal damage and have been reported to be associated with atherosclerosis. Its correlation with atherosclerotic cardiovascular disease (ASCVD) is still unknown. This study aimed to explore the association between serum PGs and ASCVD for providing physicians with an integrative picture to make rational plans in the diagnosis and treatment of ASCVD.

METHODS AND RESULTS

The concentrations of serum PGs and their distributions between ASCVD and non-ASCVD were compared by non-parametric test, Chi-squared test and Fisher exact test. The correlation between variables was analyzed by Spearman's correlation test. The association of serum PGs with ASCVD was analyzed by the binary logistic regression and two-piecewise linear regression. A total of 8355 recruited cases were eligible for the study. The concentrations of serum PGs were significantly different between the ASCVD and non-ASCVD groups (P = 0.025, P < 0.001). The lower PGI and PGR levels were significantly correlated with a high risk of ASCVD presence after adjustment for 26 potential covariates. Moreover, there was a linear relationship between the high level of PGII and the high risk of ASCVD [adjusted OR = 1.16 (1.00, 1.37), P = 0.07]. A nonlinear relationship of PGI/PGR and ASCVD (P = 0.08/<0.001) was also revealed. The risk of ASCVD increased with a range of log PGI ≥2.13 (PGI≥131 ng/mL) [adjusted OR = 4.67 (1.00, 23.17)], and decreased with a range of log PGR ≥0.22 (1.65) [adjusted OR = 0.59 (0.48, 0.74), P < 0.001].

CONCLUSIONS

Serum PGI and PGR are nonlinearly correlated with ASCVD, while PGII is linearly correlated with ASCVD. Among all PGs, PGR may serve as a reliable biomarker for ASCVD.

Scenario and future prospects of microRNAs in gastric cancer: A review

Carcinoma of the stomach is one of the major prevalent and principal causes of cancer-related deaths worldwide. Current advancement in technology has improved the understanding of the pathogenesis and pathology of gastric cancers (GC). But, high mortality rates, unfavorable prognosis and lack of clinical predictive biomarkers provide an impetus to investigate novel early diagnostic/prognostic markers and therapeutic targets for GC, which are sufficiently sensitive to GC. Current biomedical investigations have explored several budding GC biomarker by utilizing serum proteins, natural oncogenic genes during improvement in molecular technologies as microarray, and RNA/DNA-Seq. Recently, small non-coding microRNAs (miRNAs) are becoming vital regulators in oncogenesis pathways and can act as handy clinical biomarkers. The newly introduced class of biomarkers is rising as new molecules for cancer diagnosis and prognosis. For better understanding of the gastric carcinogenesis, miRNAs may help to elucidate the mechanisms of tumor growth and can help to discover novel untimely potent markers for early detection of GC. Here in this review, we summarize the recent research studies supporting the utility of miRNAs as novel early diagnostic/prognostic tools and therapeutic targets. Thus, here we introduce potential future treatment strategies for gastrointestinal (GI) cancers, which indicate the practicality and clinical applications of miRNAs in GC.

Non-invasive method for the assessment of gastric acid secretion

Methods for the measure of gastric acid secretion include invasive and non-invasive tests. The gold-standard to measure the acid output is the collection of gastric after in basal condition (Basal Acid Output, B.A.O.) and after an i.m. injection of pentagastrin (Maximal Acid Output, M.A.O.). However, direct measurement of gastric acid production is out of order in clinical practice, but many GI symptoms are claimed to be related with acid disorders and empirically cured. Hypochlorhydria is associated with precancerous conditions such as chronic atrophic gastritis (CAG). Acid measurement with non-invasive methods (pepsinogens) is supported by international guidelines.

IVTH BRAZILIAN CONSENSUS CONFERENCE ON HELICOBACTER PYLORI INFECTION

ABSTRACT Significant progress has been obtained since the III Brazilian Consensus Conference on H. pylori infection held in 2012, in Bento Gonçalves, Brazil, and justify a fourth meeting to establish updated guidelines on the current management of H. pylori infection. Therefore, the Núcleo Brasileiro para Estudo do Helicobacter pylori e Microbiota (NBEHPM), association linked to Brazilian Federation of Gastroenterology (FBG) held its fourth meeting again in Bento Gonçalves, RS, Brazil, on August 25-27, 2017. Twenty-six delegates, including gastroenterologists, endoscopists, and pathologists from the five regions of Brazil as well as one international guest from the United States, participated in the meeting. The participants were invited based on their knowledge and contribution to the study of H. pylori infection. The meeting sought to review different aspects of treatment for infection; establish a correlation between infection, dyspepsia, intestinal microbiota changes, and other disorders with a special emphasis on gastric cancer; and reassess the epidemiological and diagnostic aspects of H. pylori infection. Participants were allocated into four groups as follows: 1) Epidemiology and Diagnosis, 2) Dyspepsia, intestinal microbiota and other afections, 3) Gastric Cancer, and, 4) Treatment. Before the consensus meeting, participants received a topic to be discussed and prepared a document containing a recent literature review and statements that should be discussed and eventually modified during the face-to-face meeting. All statements were evaluated in two rounds of voting. Initially, each participant discussed the document and statements with his group for possible modifications and voting. Subsequently, during a second voting in a plenary session in the presence of all participants, the statements were voted upon and eventually modified. The participants could vote using five alternatives: 1) strongly agree; 2) partially agree; 3) undecided; 4) disagree; and 5) strongly disagree. The adopted consensus index was that 80% of the participants responded that they strongly or partially agreed with each statement. The recommendations reported are intended to provide the most current and relevant evidences to management of H. pylori infection in adult population in Brazil.

Autoimmunity and Gastric Cancer

Alterations in the immune response of patients with autoimmune diseases may predispose to malignancies, and a link between chronic autoimmune gastritis and gastric cancer has been reported in many studies. Intestinal metaplasia with dysplasia of the gastric corpus-fundus mucosa and hyperplasia of chromaffin cells, which are typical features of late-stage autoimmune gastritis, are considered precursor lesions. Autoimmune gastritis has been associated with the development of two types of gastric neoplasms: intestinal type and type I gastric carcinoid. Here, we review the association of autoimmune gastritis with gastric cancer and other autoimmune features present in gastric neoplasms.

Changes with aging in gastric biomarkers levels and in biochemical factors associated with Helicobacter pylori infection in asymptomatic Chinese population

AIM

To observe changes in gastric biomarker levels with age and effects of Helicobacter pylori (H. pylori) infection in a healthy population, and explore factors associated with gastric biomarkers.

METHODS

Three hundred and ninety-five subjects were selected and underwent physical examinations, biochemical tests, and measurement of serum pepsinogen (PG) I and II, gastrin-17 (G-17) and H. pylori antibody levels. Analyses were made by Student’s t-test, ANOVA, Pearson’s correlation and multiple linear regressions.

RESULTS

PGII levels were higher in the ≥ 65-years-old age group (P < 0.05) and PGI/PGII were lower in the ≥ 75-years-old age group (P = 0.035) compared to the 35-44-years-old age group. Levels of low-density lipoprotein cholesterol (LDL-C) were higher (P = 0.009) in H. pylori-infected subjects that were male. LDL-C levels were higher in 55-74-years-old age group (P < 0.05) for H. pylori-infected subjects and 45-64-years-old age group (P < 0.05) for non-infected subjects compared to 35-44-years-old age group. Hp-IgG level positively correlated with PGI, PGII and G-17 (P < 0.001, P < 0.001, P = 0.006), and negatively correlated with PGI/PGII (P < 0.001). Creatinine positively correlated with PGI, PGII and G-17 (P < 0.001, P < 0.001, P < 0.001). Fasting blood glucose (FBG) positively correlated with PGI/PGII and G-17 (P < 0.001, P = 0.037). Age positively correlated with PGII and G-17 (P = 0.005, P = 0.026).

CONCLUSION

PGII levels increased while PGI/PGII declined with age in a healthy population. H. pylori infection had an effect on raising LDL-C levels to increase the risk of atherosclerosis in males, especially those of elderly age. Age, H. pylori infection, levels of renal function and FBG were associated with levels of pepsinogens and gastrin.

The serum pepsinogen levels for risk assessment of gastric neoplasms: New proposal from a case-control study in Korea

To decrease the gastric cancer related mortality rate, endoscopic screening is widely performed in Korea. However, a precise method for identifying those at a high risk of gastric neoplasms has not been established. This study aims to evaluate serum pepsinogen (PG) levels for risk assessment of gastric neoplasms. Between August 2014 and March 2016, a total of 398 subjects, including 87 with gastric neoplasms, were enrolled in this study. On the basis of the serum PG I/II ratio, the enrolled subjects were classified into 4 groups: group A, PG I/II ratio >4; group B, >3 and ≤4; group C, >2 and ≤3; group D, ≤2. Compared with group A, a stepwise increase in the risk of gastric neoplasm was observed from group B [odds ratio (OR) = 9.9, 95% confidence interval (95% CI) = 4.0-24.4] to group C (OR = 20.9, 95% CI = 8.7-50.5) to group D (OR = 37.3, 95% CI = 14.3-97.4). The optimal cutoff value of the serum PG I/II ratio for predicting gastric neoplasms was 4.5, with a sensitivity of 97.7% and a specificity of 57.6%. A decrease in the serum PG I/II ratio was strongly associated with an increased risk of gastric neoplasms. The serum PG I/II ratio can be used to identify those at a high risk of gastric neoplasms in Korean population.

幽门螺杆菌根除治疗在胃癌预防中的现状及前景

幽门螺杆菌(Helicobacter pylori, H. pylori)与胃癌(gastric cancer, GC)发生发展密切相关, 根除H. pylori可降低GC发生率. 经济学分析表明, 在高危人群中根除治疗H. pylori作为预防GC的策略是成本效益较好的. 即使在GC低风险人群中, H. pylori筛查和治疗也能使上消化道其他非恶性疾病获益. 然而, 广泛开展H. pylori根除治疗可能带来其他问题, 包括抗生素耐药增加和与H. pylori负相关疾病(如胃食管反流病、Barrett食管、哮喘和肥胖等)的患病率升高. 本文将结合近年最新研究, 就上述问题展开论述, 进一步提出H. pylori根除治疗预防GC所面临的挑战以及将来可能的进展方向.

Population screening and treatment of Helicobacter pylori infection

Helicobacter pylori is an important human pathogen, associated with a substantial burden from both malignant and non-malignant diseases. The bacterium is classed as a human carcinogen, being strongly linked with gastric cancer, the third most common cause of cancer death worldwide and is also associated with common conditions such as dyspepsia and peptic ulcer. Eradication of H. pylori reduces the incidence of gastric cancer and peptic ulcer, as well as the prevalence and costs of managing dyspepsia. Economic analyses suggest that eradication of H. pylori as a means of controlling gastric cancer is cost-effective in high-risk populations. Even in populations at low risk of gastric cancer, there might be other benefits arising from screening and treatment, owing to the effects on non-malignant upper gastrointestinal diseases. However, public health authorities have been slow to consider the benefits of population-based screening and treatment as a means of reducing the morbidity and mortality associated with the infection. There are also concerns about widespread use of eradication therapy, including antimicrobial resistance and a rise in the prevalence of diseases that are negatively associated with H. pylori, such as GERD, Barrett oesophagus, asthma and obesity. This Review summarizes these issues.

Evaluation of Pepsinogen I as a Biomarker of Drug-induced Gastric Mucosal Injury in Cynomolgus Monkeys

Gastric mucosal injury is frequently observed in nonclinical studies of nonhuman primates. Because microscopic evaluation of stomach is generally a terminal procedure, our objective was to determine whether serum pepsinogen I (PG I) could serve as a noninvasive biomarker for detection of gastric mucosal injury in monkey. Serum PG I was measured using a commercial human immunoassay in cynomolgus monkeys ( n = 166) prior to dosing and/or terminally in 11 studies of up to 1 month duration. Mean ( SD) PG I values (ug/L) for monkeys with ( n = 59) and without ( n = 100) gastric mucosal degeneration were 101 (215) and 28 (12.6), respectively. For monkeys with baseline and terminal PG I data, mean ( SD) fold change (ratio of terminal to baseline PG I) for monkeys with ( n = 57) and without ( n = 76) glandular degeneration were 4.1 (11.3) and 1 (0.28). Receiver operating characteristic area under the curve (AUC) data demonstrated moderate diagnostic accuracy for serum PG I for glandular degeneration, AUC ( SE) 0.789 (0.04), with improved diagnostic accuracy as a fold change of baseline, AUC ( SE) 0.816 (0.04), consistent with the large interindividual but low intraindividual variability of serum PG I values in control monkeys. These data demonstrate that serum PG I is a useful biomarker of drug-induced gastric mucosal injury in the cynomolgus monkey.

Combination of OipA, BabA, and SabA as candidate biomarkers for predicting Helicobacter pylori-related gastric cancer

Helicobacter pylori (H. pylori ) infection is a major cause of chronic gastritis and is highly related to duodenal ulcer (DU) and gastric cancer (GC). To identify H. pylori-related GC biomarkers with high seropositivity in GC patients, differences in levels of protein expression between H. pylori from GC and DU patients were analyzed by isobaric tag for relative and absolute quantitation (iTRAQ). In total, 99 proteins showed increased expression (>1.5-fold) in GC patients compared to DU patients, and 40 of these proteins were categorized by KEGG pathway. The four human disease-related adhesin identified, AlpA, OipA, BabA, and SabA, were potential GC-related antigens, with a higher seropositivity in GC patients (n = 76) than in non-GC patients (n = 100). Discrimination between GC and non-GC patients was improved using multiple antigens, with an odds ratio of 9.16 (95% CI, 2.99-28.07; p < 0.0001) for three antigens recognized. The optimized combination of OipA, BabA, and SabA gave a 77.3% correct prediction rate. A GC-related protein microarray was further developed using these antigens. The combination of OipA, BabA, and SabA showed significant improvement in the diagnostic accuracy and the protein microarray containing above antigens should provide a rapid and convenient diagnosis of H. pylori-associated GC.

Pepsinogen-II 100 bp ins/del gene polymorphism and its elevated circulating levels are associated with gastric cancer, particularly with Helicobacter pylori infection and intestinal metaplasia

BACKGROUND

Polymorphism in the gene of pepsinogen-II (PG-II) and its serum level are effective biomarkers for terminal differentiation of gastric mucosa into gastritis, intestinal metaplasia (IM), and gastric cancer (GC) in relationship to Helicobacter pylori infection.

METHODS

Genotyping of the PG-II 100 bp insertion/deletion (ins/del) polymorphism was performed in patients with GC (n = 192) and age- and gender-matched H. pylori-associated dyspepsia (n = 180) and healthy subjects (HS, n = 240) by PCR. IgG anti-H. pylori (in all subjects) and serum PG-II levels were estimated in 145 patients each with GC and dyspepsia and in 65 healthy controls (HC) using ELISA (Biohit Oyj, Finland).

RESULTS

Five alleles were amplified by PCR: allele 5 (510 bp), allele 4 (480 bp), allele 3 (450 bp), allele 2 (400 bp), and allele 1 (shorter allele, 310 bp). Allele 1 carriage was infrequent, and serum PG-II level was higher among patients with GC than in HC [OR 0.43 (95 % CI, 0.29-0.85), p < 0.001 and mean ± SD; 17.53 ± 12.60 vs. 12.77 ± 7.53 µg/l, p = 0.005, respectively], particularly in the presence of H. pylori [OR 0.42 (0.25-0.71), p = 0.001 and 18.78 ± 12.63 vs. 13.97 ± 8.14, p = 0.034]. However, allele 1 carriage and PG-II levels were comparable among patients with GC and dyspepsia. Patients with IM also carried allele 1 infrequently and had higher levels of PG-II than those without [OR 0.5 (0.29-0.85), p = 0.011 and 20.07 ± 14.22 vs. 16.61 ± 12.08, p = 0.048].

CONCLUSIONS

Carriage of the shorter allele of the PG-II 100 bp ins/del polymorphism and elevated levels of PG-II are associated with GC, particularly with H. pylori infection and IM.

A 2015 survey of established or potential epigenetic biomarkers for the accurate detection of human cancers

Context The silencing or activation of cancer-associated genes by epigenetic mechanisms can ultimately lead to the clonal expansion of cancer cells. Objective The aim of this review is to summarize all relevant epigenetic biomarkers that have been proposed to date for the diagnosis of some prevalent human cancers. Methods A Medline search for the terms epigenetic biomarkers, human cancers, DNA methylation, histone modifications and microRNAs was performed. Results One hundred fifty-seven relevant publications were found and reviewed. Conclusion To date, a significant number of potential epigenetic cancer biomarkers of human cancer have been investigated, and some have advanced to clinical implementation.

Emerging roles of non-coding RNAs in gastric cancer: Pathogenesis and clinical implications

Gastric cancer is a leading cause of cancer-related deaths. However, the mechanisms underlying gastric carcinogenesis remain largely unclear. The association of non-coding RNAs (ncRNAs) with cancer has been widely studied during the past decade. In general, ncRNAs have been classified as small ncRNAs, including microRNAs (miRNAs), and long non-coding RNAs (lncRNAs). Emerging evidence shows that miRNAs and lncRNAs play key roles in the formation and progression of many cancers. In this review, we focus on the regulation of miRNAs and lncRNAs in gastric cancer. miRNAs and lncRNAs appear to be involved in gastric tumor growth, invasion, and metastasis and in establishment of the gastric tumor microenvironment through various mechanisms. Furthermore, we also discuss the possibilities of establishing miRNAs and lncRNAs as potential biomarkers and therapeutic targets for gastric cancer. Taken together, we summarize the emerging roles of ncRNAs in gastric cancer development and their possible clinical significance.

Method evaluation of pepsinogen I/II assay based on chemiluminescent immunoassays and comparison with other test methods

BACKGROUND

Serum pepsinogen (PG) I and the PG I/PG II ratio have been used for atrophic gastritis (AG) diagnosis for decades. Low levels of PG I and/or PG I/PG II are closely related to AG and predict the risk of gastric cancer. We evaluated the performance of the chemiluminescent immunoassay-based Architect Pepsinogen I/II assay.

METHODS

The evaluation consisted of determination of the precision, linearity, limit of blank (LoB), limit of detection (LoD) and method comparison with Eiken and Biohit assays.

RESULTS

The total CVs were below 5% for both PG I and PG II. Acceptable linearity was observed for PG I and PG II in their respective reportable ranges. The PG I LoB was 0.317ng/mL and the PG II LoB was 0.418ng/mL, and LoDs were 0.412ng/mL and 0.497ng/mL, respectively. Correlation analysis indicated that results of the Architect assay were comparable to those of the Eiken and Biohit assays, but the three methods lead to different estimations of the cancer risk.

CONCLUSION

The overall analytical performance of Architect Pepsinogen I/II assay is acceptable for the detection of patients with suspected AG. The categorization results of gastric cancer risk showed some difference among test methods suggesting the need for harmonization among the methods from vendors.

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.

Gastric Cancer Risk in Patients with Helicobacter pylori Infection and Following Its Eradication

As Helicobacter pylori is a first-class carcinogen, eradication of the infection would be expected to be a beneficial measure for the (primary) prevention of gastric cancer. Given the natural history of gastric cancer, it is plausible that eradication before gastric atrophy sets in offers the best chance for cancer risk reduction. The beneficial effects of eradication may, nevertheless, still be achievable in more advanced disease. The reversibility of inflammatory lesions has been supported by undeniable evidence; the regression of mucosal atrophy/metaplasia has also been confirmed by several recent histologic studies.

Serum Indicators Reflecting Gastric Function May Also Correlate with Other Extragastric Diseases

Aim. Serological indicators of organ function can reveal intrinsic links between different organs. The present study aimed to determine the correlations of serum indicators for gastric and extragastric function. Methods. A total of 823 individuals were enrolled. Data on indicators reflecting blood lipids, blood glucose, indexes of stomach, kidney, liver, and thyroid function, and H. pylori IgG antibody level were collected. Results. As creatine (Cr) levels increased, PGI (pepsinogen I), PGII concentrations, and PGI/II ratio increased monotonically from 79.7 to 105.15 µg/L, 6.5 to 8.4 µg/L, and 11.97 to 12.27, respectively (P < 0.05). As thyroid peroxidase antibody (TPOAb) levels increased, PGI level decreased from 100.85 to 84 µg/L (P < 0.05) and as thyroid stimulating hormone (TSH) increased, PGI/II ratio increased monotonically from 11.54 to 12.68 (P < 0.05). As triglyceride (TG) levels increased, gastrin 17 (G17) concentrations increased monotonically from 1.73 to 2.7 pmol/L (P < 0.05). As serum glucose and glycated hemoglobin (HbA1C) increased, PGI/II concentrations increased monotonically from 11.98 to 12.67 and 9.7 to 13.54 (P < 0.05), respectively. Conclusions. Serum PG and G17 levels were associated with blood glucose and lipids, kidney function, and thyroid function but not with liver function. Serum indicators reflecting gastric function may correlate not only with primary diseases, but also with other extragastric diseases.

Chronic gastritis

Prevalence of chronic gastritis has markedly declined in developed populations during the past decades. However, chronic gastritis is still one of the most common serious pandemic infections with such severe killing sequelae as peptic ulcer or gastric cancer. Globally, on average, even more than half of people may have a chronic gastritis at present. Helicobacter pylori infection in childhood is the main cause of chronic gastritis, which microbial origin is the key for the understanding of the bizarre epidemiology and course of the disease. A life-long and aggressive inflammation in gastritis results in destruction (atrophic gastritis) of stomach mucosa with time (years and decades). The progressive worsening of atrophic gastritis results subsequently in dysfunctions of stomach mucosa. Atrophic gastritis will finally end up in a permanently acid-free stomach in the most extreme cases. Severe atrophic gastritis and acid-free stomach are the highest independent risk conditions for gastric cancer known so far. In addition to the risks of malignancy and peptic ulcer, acid-free stomach and severe forms of atrophic gastritis may associate with failures in absorption of essential vitamins, like vitamin B12, micronutrients (like iron, calcium, magnesium and zinc), diet and medicines.

Individual risk stratification of gastric cancer: evolving concepts and their impact on clinical practice

Gastric cancer (GC) is the third leading cause of cancer-related death worldwide and it mostly develops in long-standing inflammatory conditions, and Helicobacter pylori-gastritis, in particular. Despite the increasing understanding of both the phenotypic alterations and the molecular mechanisms occurring during GC multi-step carcinogenesis, no reliable biomarker is available to be reliably implemented into GC secondary prevention strategies. Multidisciplinary diagnostic approaches integrating endoscopy, serology, histology and molecular profiling currently appears as the most appropriate approach for patients' stratification into different GC risk classes.

A comprehensive evaluation of fasting serum gastrin-17 as a predictor of diseased stomach in Chinese population

BACKGROUND AND AIM

Fasting serum gastrin-17 (FsG17) is considered as a noninvasive biomarker reflecting the structure and functional status of gastric mucosa, but its clinical utility remains unclear. This study aimed to evaluate FsG17 comprehensively: establish the ranges and cut-off points of FsG17 levels in different gastric diseases, identify their influencing factors, and investigate the accuracy of FsG17 for identifying diseased stomach.

METHODS

The study included 4064 participants from Northern China between 2008 and 2013. FsG17 and serum Helicobacter pylori IgG antibody levels were measured by enzyme-linked immunosorbent assay. Diagnostic accuracy was assessed by receiver operator characteristic curves. Multivariate logistic regression analysis was performed to determine the best predictors of gastric histopathological conditions.

RESULTS

Median FsG17 levels in healthy, non-atrophic, atrophic, and cancerous stomachs were 1.8, 4.0, 3.8, and 6.1 pmol/l, respectively. Age, smoking status, alcohol consumption, H. pylori infection, and predominant lesion site were factors that affected FsG17 levels. The optimal cut-off values for FsG17 were 3.0 pmol/l (sensitivity of 59.3% and specificity of 67.3%) for discriminating between healthy stomach and diseased stomach and 10.7 pmol/l (sensitivity of 37% and specificity of 83.7%) for discriminating between cancerous stomach and cancer-free stomach; the screening accuracy was higher (sensitivity of 50.0% and specificity of 83.0%) for gastric cancer in the corpus. Multivariate analysis showed that FsG17, gender, age, and H. pylori infection were independent predictors of cancerous stomach.

CONCLUSION

With the progression from health stomach to malignancy, FsG17 levels significantly increased and were influenced by other factors. FsG17 combined with age, gender, and H. pylori infection could distinguish between cancerous stomach and cancer-free stomach. The results will enhance our understanding of the potential clinical utility of FsG17.

MicroRNAs as potential biomarkers for gastric cancer

Gastric cancer is the fourth most common cancer in the world and the second leading cause of cancer-related death. More than 80% of diagnoses occur at the middle to late stage of the disease, highlighting an urgent need for novel biomarkers detectable at earlier stages. Recently, aberrantly expressed microRNAs (miRNAs) have received a great deal of attention as potential sensitive and accurate biomarkers for cancer diagnosis and prognosis. This review summarizes the current knowledge about potential miRNA biomarkers for gastric cancer that have been reported in the publicly available literature between 2008 and 2013. Available evidence indicates that aberrantly expressed miRNAs in gastric cancer correlate with tumorigenesis, tumor proliferation, distant metastasis and invasion. Furthermore, tissue and cancer types can be classified using miRNA expression profiles and next-generation sequencing. As miRNAs in plasma/serum are well protected from RNases, they remain stable under harsh conditions. Thus, potential functions of these circulating miRNAs can be deduced and may implicate their diagnostic value in cancer detection. Circulating miRNAs, as well as tissue miRNAs, may allow for the detection of gastric cancer at an early stage, prediction of prognosis, and monitoring of recurrence and/or lymph node metastasis. Taken together, the data suggest that the participation of miRNAs in biomarker development will enhance the sensitivity and specificity of diagnostic and prognostic tests for gastric cancer.

Circulating mitochondrial DNA level, a noninvasive biomarker for the early detection of gastric cancer

BACKGROUND

Gastric cancer represents a major health burden worldwide and is often diagnosed at an advanced stage. Biomarkers for screening and prevention of gastric cancer are missing. Changes in peripheral blood mitochondrial DNA (mtDNA) have emerged as a potential preventive/diagnosis biomarker for cancer risk. We aimed to determine whether peripheral leukocytes mtDNA levels are associated with stages of the gastric carcinogenesis cascade.

METHODS

We measured mtDNA by quantitative real-time PCR assay in peripheral leukocytes of 28 patients with non-atrophic gastritis (NAG), 74 patients with gastric cancer, and 48 matched asymptomatic controls. In parallel, the serologic level of IL8 was determined.

RESULTS

Mean mtDNA level was higher in patients with gastric cancer (P = 0.0095) than in controls, with values >8.46 significantly associated with gastric cancer (OR, 3.93). Three ranges of mtDNA values were identified: interval I, <2.0; interval II, 2.0-20; and interval III, >20. Interval I included mainly NAG cases, and few gastric cancer samples and interval III corresponded almost exclusively to patients with gastric cancer. All controls fell in interval II, together with some NAG and gastric cancer cases. IL8 levels were significantly higher in patients with gastric cancer (P < 0.05), with levels >50 pg/mL observed exclusively in patients with gastric cancer, allowing to distinguish them within interval II. We validated mtDNA results in a second cohort of patients, confirming that mtDNA was significantly higher in gastric cancer than in patients with preneoplasia.

CONCLUSIONS

Circulating levels of mtDNA and IL8 constitute a potential biomarker for the early detection of gastric cancer.

IMPACT

Our findings lead us to propose a new noninvasive method to detect patients with gastric cancer risk.

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 anti-Helicobacter pylori immunoglobulin G titer correlates with grade of histological gastritis, mucosal bacterial density, and levels of serum biomarkers

OBJECTIVE. Clinical implications of serum anti-Helicobacter pylori immunoglobulin G (IgG) titer were unclear. This study investigated the associations of serum anti-H. pylori IgG titer with grade of histological gastritis, mucosal bacterial density and levels of serum biomarkers, including pepsinogen (PG) I, PGII, PGI/II ratio and gastrin-17. MATERIAL AND METHODS. Study participants were from a screening program in northern China. Serum anti-H. pylori IgG measurements were available for 5922 patients with superficial gastritis. Serum anti-H. pylori IgG titer and serum biomarkers were measured using ELISA, and gastric biopsies were evaluated using standardized criteria. RESULTS. In patients with mild, moderate or severe superficial gastritis, the mean serum anti-H. pylori IgG titers were 17.3, 33.4 and 54.4 EIU (p for trend < 0.0001), respectively. As mucosal H. pylori density score increased from 0 to 3, the mean serum anti-H. pylori IgG titers also increased from 24.7 to 44.8 EIU (p for trend < 0.0001). Serum anti-H. pylori IgG titer was associated positively with serum PGI, PGII and gastrin-17 concentrations and negatively with PGI/II ratio, and the association was the strongest for PGII. The mean PGII concentration of the patients in the highest quartile of IgG titer was twice the mean concentration of the patients in the lowest quartile (17.2 vs. 8.6 EIU, p < 0.0001). CONCLUSIONS. Our results suggest that serum anti-H. pylori IgG titer was associated positively with grade of histological gastritis, mucosal bacterial density and concentrations of serum PGI, PGII and gastrin-17, and negatively with PGI/II ratio.

Proton pump inhibitor for non-erosive reflux disease: A meta-analysis

AIM: To evaluate the efficacy, safety and influential factors of proton pump inhibitor (PPI) treatment for non-erosive reflux disease (NERD).

METHODS: PubMed, MEDLINE, EMBASE and the Cochrane Library were searched up to April 2013 to identify eligible randomized controlled trials (RCTs) that probed into the efficacy, safety and influential factors of PPI treatment for NERD. The rates of symptomatic relief and adverse events were measured as the outcomes. After RCT selection, assessment and data collection, the pooled RRs and 95%CI were calculated. This meta-analysis was performed using the Stata 12.0 software (Stata Corporation, College Station, Texas, United States). The level of evidence was estimated by the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS: Seventeen RCTs including 6072 patients met the inclusion criteria. The results of the meta-analysis showed that PPI treatment was significantly superior to H₂ receptor antagonists (H₂RA) treatment (RR = 1.629, 95%CI: 1.422-1.867, P = 0.000) and placebo (RR = 1.903, 95%CI: 1.573-2.302, P = 0.000) for the symptomatic relief of NERD. However, there were no obvious differences between PPI and H₂RA (RR = 0.928, 95%CI: 0.776-1.110, P = 0.414) or PPI and the placebo (RR = 1.000, 95%CI: 0.896-1.116, P = 0.997) regarding the rate of adverse events. The overall rate of symptomatic relief of PPI against NERD was 51.4% (95%CI: 0.433-0.595, P = 0.000), and relief was influenced by hiatal hernia (P = 0.030). The adverse rate of PPI against NERD was 21.0% (95%CI: 0.152-0.208, P = 0.000), and was affected by hiatal hernia (P = 0.081) and drinking (P = 0.053).

CONCLUSION: PPI overmatched H₂RA on symptomatic relief rate but not on adverse rate for NERD. Its relief rate and adverse rate were influenced by hiatal hernia and drinking.

Promoter hypermethylation of BCL6B gene is a potential plasma DNA biomarker for gastric cancer

We previously showed that BCL6B acts as a tumor suppressor in gastric cancer and up to 66% gastric cancer patients have promoter hypermethylation in tumor tissues. We aimed to evaluate the feasibility of detecting BCL6B methylation in plasma DNA as a potential biomarker for gastric cancer. Hypermethylation of the CpG islands in BCL6B promoter was detected in 42.5% (17/40) plasma DNA samples from gastric cancer patients, while no methylation was found in the plasma DNA of healthy controls (p < 0.001). BCL6B methylation may serve as a novel potential non-invasive plasma biomarker for the detection of gastric cancer.

Serologic autoantibodies as diagnostic cancer biomarkers--a review

Current diagnostic techniques used for the early detection of cancers are successful but subject to detection bias. A recent focus lies in the development of more accurate diagnostic tools. An increase in serologic autoantibody levels has been shown to precede the development of cancer disease symptoms. Therefore, autoantibody levels in patient blood serum have been proposed as diagnostic biomarkers for early-stage diagnosis of cancers. Their clinical application has, however, been hindered by low sensitivity, specificity, and low predictive value scores. These scores have been shown to improve when panels of multiple diagnostic autoantibody biomarkers are used. A five-marker biomarker panel has been shown to increase the sensitivity of prostate cancer diagnosis to 95% as compared with 12.2% for prostate-specific antigen alone. New potential biomarker panels were also discovered for lung, colon, and stomach cancer diagnosis with sensitivity of 76%, 65.4%, and 50.8%, respectively. Studies in breast and liver cancer, however, seem to favor single markers, namely α-2-HS-glycoprotein and des-γ-carboxyprothrombin with sensitivities of 79% and 89% for the early detection of the cancers. The aim of this review is to discuss the relevance of autoantibodies in cancer diagnosis and to outline the current methodologies used in the detection of autoantibodies. The review concludes with a discussion of the autoantibodies currently used in the diagnosis of cancers of the prostate, breast, lung, colon, stomach, and liver. A discussion of the potential future use of autoantibodies as diagnostic cancer biomarkers is also included in this review.

Multiple infections and cancer: implications in epidemiology

Approximately 18% of the global cancer burden has been attributed to infectious agents, with estimates ranging from 7% in developed countries to about 22% in developing countries. Chronic infections caused by the hepatitis B and C viruses, human papilloma viruses (HPV), and Helicobacter pylori (H. pylori) are reported to be responsible for approximately 15% of all human cancers. Interestingly, although many of the infectious agents that have been associated with cancer--such as HPV, Epstein-Barr virus (EBV), and H. pylori--are highly prevalent in the world, most infected individuals do not develop cancer but remain lifelong carriers. Malignancies associated with infectious agents may result from prolonged latency as a result of chronic infections. Pathogenic infections are necessary but are not sufficient for cancer initiation or progression. Cancer initiation may require additional cofactors, including secondary infections. Therefore, in patients with chronic infection with one agent, secondary co-infection with another agent may serve as an important co-factor that may cause cancer initiation and progression. Additionally, opportunistic co-infections could significantly inhibit response to cancer treatment and increase cancer mortality. Co-infections are relatively common in areas with a high prevalence of infectious agents, especially in developing countries. These co-infections can cause an imbalance in the host immune system by affecting persistence of and susceptibility to malignant infections. Several articles have been published that focus on infectious agents and cancer. In this article, we discuss the role of infectious agents in malignancies, highlight the role of multiple/co-infections in cancer etiology, and review implications for cancer epidemiology.