Prescreening of a high-risk group for gastric cancer by serologically determined Helicobacter pylori infection and atrophic gastritis

Development and validation of a relatively accurate gastric cancer high-risk group screening scoring system in urban residents

PURPOSE

Our study aimed to develop a relatively accurate gastric cancer (GC) screening score system for urban residents and to validate the screening efficacy.

METHODS

The present study included a derivation cohort (n = 3406) and a validation cohort (n = 868) of urban residents. Applying the full-stack engineering intelligent system platform of Hualian Health Big Data of Shandong University, the clinical physical examination data of subjects were collected. Univariate and multivariate analyses were used to identify risk factors for GC, and subsequently, an optimal prediction rule was established to create three distinct scoring systems.

RESULTS

In the GC-risk scoring system I, age, plateletocrit (PCT), carcinoembryonic antigen (CEA), glucose, albumin, creatinine were independent risk factors of GC, with scores ranging from 0 to 28 and optimal cut-off was 15.5. The second scoring system consisted of age, PCT, RDW-CV, CEA, glucose, albumin, and creatinine, with scores ranging from 0 to 31. The optimal cut-off point was determined to be 15.5. The scoring system III comprise of age, sex, PCT, RDW CV, CEA, glucose, with scores ranging from 0 to 21 and optimal cut-off was 10.5. All three scoring systems demonstrated excellent discrimination for GC, achieving an AUC of 0.884, 0.89, and 0.876, respectively. In external validation, the AUC values were 0.654, 0.658, and 0.714. Notably, the GC-risk scoring system III exhibited the highest screening efficiency.

CONCLUSIONS

Urban residents benefited from the effective and verified GC-risk scoring systems, which demonstrated excellent performance in identifying individuals with an elevated risk of GC.

Novel and Effective Blood-Based miRNA Diagnostic Panel for Gastric Cancer: A Pilot Study in a Japanese Population

BACKGROUND

Gastric cancer (GC) has a high prevalence in Asian countries, and there is an unmet need for non-invasive and efficient GC screening methods. This study evaluated the diagnostic efficacy of GASTROClear, a panel of blood serum miRNAs for the detection of GC, in a Japanese population.

METHODS

We conducted a pilot cohort study, comprising 103 patients with GC and 122 healthy controls. Serum samples were prospectively collected from study participants at two Japanese hospitals using a predefined blood-processing protocol. The diagnostic performance of GASTROClear was analyzed using a receiver operating characteristic curve and cutoff. By applying a logistic regression algorithm, we evaluated the diagnostic efficacy of novel combinations of GC diagnostic biomarker panels, consisting of GASTROClear and alternative serum markers (anti-Helicobacter pylori [Hp] antibody and pepsinogen).

RESULTS

Most patients had Stage I (58%) GC and were asymptomatic (59%). The area under the curve (AUC) value for the detection of GC using GASTROClear was 0.80, with 70.9% sensitivity and 75.2% specificity. GASTROClear performed equally well within the subgroups based on age, sex, symptoms, Hp status, and tumor characteristics. We improved the diagnostic performance of GASTROClear by combining it with an anti-Hp antibody and pepsinogen. This yielded an AUC value of 0.88, with the highest specificity (86.9%) at a fixed sensitivity (70.9%).

CONCLUSIONS

GASTROClear demonstrated competent diagnostic efficacy for GC in the detection of GC in our Japanese cohort, even in the early stages of cancer and asymptomatic cases. Its combination with existing serum markers may contribute to efficient risk stratification to detect GC.

Diagnostic performance of the normal range of gastrin calculated using strict criteria based on a combination of serum markers and pathological evaluation for detecting gastritis: a retrospective study

BACKGROUND

The ABC method, which combines the pepsinogen method and anti-Helicobacter pylori antibody titers, has been used for risk screening for gastric cancer in Japan. However, it has been reported that there are cases of gastritis and carcinogenesis risk even in group A, which is considered to be a low-risk group based on the ABC method. Currently, in group A, endoscopic examination is needed to strictly discriminate "patients without gastritis" (defined as true A patients) from those "with gastritis." A simple and minimally invasive diagnostic criterion for gastritis using serological markers is desirable. In this study, we aimed to identify the normal serum gastrin concentrations in normal stomach cases based on pathological diagnosis and investigate the usefulness of serum gastrin concentrations in diagnosing gastritis.

METHODS

Patients who underwent endoscopy and blood tests at Hiroshima University Hospital were enrolled in the study and categorized into the "pathologically-evaluated group" and "endoscopically-evaluated group," according to the evaluation method of atrophic gastritis. Initially, we measured serum gastrin concentrations in the normal stomach cases in the pathologically-evaluated group and calculated the normal range of serum gastrin concentrations. We used the upper limit of this normal range of serum gastrin concentrations and performed a validation study to determine its usefulness as a diagnostic marker for distinguishing between cases of gastritis and true A in the endoscopically-evaluated group.

RESULTS

The 95th percentile of serum gastrin concentrations in pathologically-evaluated normal stomach cases was 34.12-126.03 pg/mL. Using the upper limit of this normal range of serum gastrin concentrations, the sensitivity, specificity, positive predictive value, and negative predictive value for gastritis were 52.8%, 92.6%, 97.0%, and 31.0%, respectively. Additionally, the receiver operating characteristic (ROC) curve for the endoscopically-evaluated group showed an area under the ROC curve of 0.80.

CONCLUSION

The gastrin cut-off value of 126 pg/mL has a good positive predictive value (97.0%) for detecting gastritis positing its use as a marker for cases requiring endoscopy. However, the identification of patients with gastritis having normal serum gastrin concentrations due to insufficient sensitivity remains a challenge for the future.

Controlling Gastric Cancer in a World of Heterogeneous Risk

Gastric cancer (GC) is a leading cause of global mortality but also a cancer whose footprint is highly unequal. This review aims to define global disease epidemiology, critically appraise strategies of prevention and disease attenuation, and assess how these strategies could be applied to improve outcomes from GC in a world of variable risk and disease burden. Strategies of primary prevention focus on improving the detection and eradication of the main environmental risk factor, Helicobacter pylori. In certain countries of high incidence, endoscopic or radiographic screening of the asymptomatic general population has been adopted as a means of secondary prevention. By contrast, identification and targeted surveillance of individuals with precancerous lesions (such as intestinal metaplasia) is being increasingly embraced in nations of low incidence. This review also highlights existing knowledge gaps in GC prevention as well as the role of emerging technologies for early detection and risk stratification.

Role of Occupation in Shaping Cancer Disparities

Simple Summary

The investigation of cancer disparities is of major importance. In this paper, we address this issue through the occupational point of view, trying to capture how work and its related factors impact on cancer inequalities. The data we provide may increase awareness relevant to cancer control, and stimulate further studies aimed at the identification of the occupational determinants of cancer disparities and the quantification of their role.

Abstract

Cancer occurrence is characterized globally by profound socioeconomic differences. Occupation is a fundamental component of socioeconomic status. In this review, we discuss the role of occupation as a determinant of cancer disparities. First, we address the issue of participation in cancer screening programs based on income, health insurance, occupational status and job title. Second, we review the role of occupation in contributing to disparities by acting as a mediator between cancer and (i) education and (ii) race/ethnicity. Lastly, we analyze data from a multicenter case−control study of lung cancer to calculate the mediating role of occupational exposure to diesel exhaust, silica and welding fumes in the association between education and lung cancer. By addressing the complex paths from occupation to cancer inequalities from multiple points of view, we provide evidence that occupational-related characteristics, such as income, health insurance, unemployment and hazardous exposures impinge on cancer control and outcomes. The increasing awareness of these aspects is fundamental and should lead to public health interventions to avoid inequalities rising from occupational factors.

Current and Future Perspectives in the Diagnosis and Management of Helicobacter pylori Infection

Helicobacter pylori (Hp) is a prevalent organism infecting almost half the global population. It is a significant concern, given its associated risk of gastric cancer, which is the third leading cause of cancer death globally. Infection can be asymptomatic or present with dyspeptic symptoms. It may also present with alarm symptoms in the case of progression to cancer. Diagnosis can be achieved non-invasively (breath tests, stool studies, or serology) or invasively (rapid urease test, biopsy, or culture). Treatment involves acid suppression and regimens containing several antibiotics and is guided by resistance rates. Eradication is essential, as it lowers the risk of complications and progression to cancer. Follow-up after eradication is similarly important, as the risk of cancer progression remains. There have been many recent advances in both diagnosis and treatment of Hp. In particular, biosensors may be effective diagnostic tools, and nanotechnology, vaccines, and potassium-competitive acid blockers may prove effective in enhancing eradication rates.

Serum Pepsinogen as a Biomarker for Gastric Cancer in the United States: A Nested Case-Control Study Using the PLCO Cancer Screening Trial Data

BACKGROUND

Gastric cancer lacks specific symptoms, resulting in diagnosis at later stages and high mortality. Serum pepsinogen is a biomarker for atrophic gastritis, a gastric cancer precursor, and may be useful to detect persons at increased risk of gastric cancer.

METHODS

The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial was conducted in the United States between 1993 and 2001. ELISA-based pepsinogen tests were conducted on prediagnostic serum samples of 105 PLCO participants who developed gastric cancer and 209 age, sex, and race-matched controls. Pepsinogen positive (PG+) was defined as pepsinogen I ≤ 70 μg/L and pepsinogen I/II ratio ≤3.0. Results of conditional logistic regression models, and sensitivity and specificity, of PG+ for gastric cancer are reported.

RESULTS

Gastric cancer cases were more likely to be PG+ (31.4% vs. 5.5%, P < 0.001) at baseline than controls. Compared to PG-, PG+ was associated with an 8.5-fold increased risk for gastric cancer [95% confidence interval (CI) = 3.8-19.4]. This risk remained significant after adjusting for Helicobacter pylori, family history of gastric cancer, education, smoking, and BMI (aOR, 10.6; 95% CI, 4.3-26.2). In subgroup analysis, PG+ individuals were 11-fold more like to develop non-cardia gastric cancer (OR, 11.1; 95% CI, 4.3-28.8); conversely, they were not significantly more likely to develop cardia gastric cancer (OR, 2.0; 95% CI = 0.3-14.2). PG+ status yielded low sensitivity but high specificity for both noncardia (44.3%; 93.6%) and cardia gastric cancer (5.7%; 97.2%).

CONCLUSIONS

Prediagnostic serum pepsinogen levels from a large, prospective cohort study were associated with risk of gastric cancer, particularly noncardia gastric cancer.

IMPACT

PG status may identify individuals at higher risk of noncardia gastric cancer for targeted screening or interventions. See related commentary by Zhou and Huang, p. 1257.

Lifetime incidence risk for gastric cancer in the Helicobacter pylori-infected and uninfected population in Japan: A Monte Carlo simulation study

Helicobacter pylori (H. pylori) infection is considered the leading cause of gastric cancer. Gastric cancer is currently a common cancer with high incidence and mortality rates, but it is expected that the incidence rate will gradually decrease as the H. pylori infection prevalence decreases in the future. When evaluating the effectiveness of gastric cancer prevention strategies, it is essential to note the differences in long‐term cumulative risks between H. pylori‐infected and uninfected populations, but this has not yet been precisely evaluated. In our study, we aimed to estimate the cumulative incidence risks of developing gastric cancer from birth to 85 years among H. pylori‐infected and uninfected populations by using population‐based cancer registry data and birth year‐specific H. pylori infection prevalence rates. Death from gastric cancer and other causes of death were considered in the estimations of the adjusted cumulative incidence risks stratified by sex and H. pylori infection status. After performing 5000 Monte Carlo simulations with repeated random sampling using observed cancer incidence in selected three prefectures (Fukui, Nagasaki, Yamagata) of prefectural population‐based cancer registry in Japan, the mean adjusted cumulative incidence risk for gastric cancer in the H. pylori‐infected population was 17.0% for males and 7.7% for females and 1.0% for males and 0.5% for females in the uninfected population. These results calculated with Japanese cancer registry data may be useful in considering and evaluating future prevention strategies for gastric cancer in Japan.

What's new?

Helicobacter pylori infection is considered the leading cause of gastric cancer. This study estimated the cumulative incidence risk for gastric cancer from birth to 85 years of age, stratified by H. pylori infection status, for the first time in Japan. The cumulative risk among H. pylori‐infected individuals was 17.0% in males and 7.7% in females, after adjusting for gastric cancer incidence and other causes of death. The cumulative risk in the population without H. pylori infection was low. These results offer essential information for future cost‐effectiveness and cost‐benefit analyses and new gastric cancer prevention programs in Japan.

Helicobacter pylori Eradication and Gastric Cancer Prevention

Since Warren and Marshall demonstrated Helicobacter pylori (H. pylori) as a cause of gastritis in the early 1980s, H. pylori has been associated with various gastric diseases, including gastric ulcer, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, gastric adenoma, gastric adenocarcinoma, and hyperplastic gastric polyps. H. pylori eradication therapy can treat some associated diseases, including low-grade gastric MALT lymphoma, and significantly reduce the risk of peptic ulcer recurrence or progression of atrophic gastritis and intestinal metaplasia. In East Asia, where H. pylori and gastric cancer are prevalent, several studies have been conducted to prove whether the risk of gastric cancer development is reduced through H. pylori eradication therapy. Early studies failed to show the benefits of H. pylori eradication therapy in gastric cancer prevention. However, recent studies with extended follow-up periods have reported reduced risks of gastric cancer after treatment of H. pylori infection. H. pylori eradication therapy effectively prevents gastric cancer even in patients who were treated for early gastric cancer, and can be used in treating hyperplastic gastric polyps. Herein, we reviewed current evidence supporting the benefits of H. pylori eradication therapy to help clinicians understand its impact on gastric cancer prevention and hyperplastic polyp treatment.

Risk Prediction for Gastric Cancer Using GWAS-Identifie Polymorphisms, Helicobacter pylori Infection and Lifestyle-Related Risk Factors in a Japanese Population

Simple Summary

Gastric cancer remains the major cancer in Japan and worldwide. It is expected that practical intervention strategies for prevention, such as personalized approaches based on genetic risk models, will be developed. Here, we developed and validated a risk prediction model for gastric cancer using genetic, biological, and lifestyle-related risk factors. Results showed that the combination of selected GWAS-identified SNP polymorphisms and other predictors provided high discriminatory accuracy and good calibration in both the derivation and validation studies; however, the contribution of genetic factors to risk prediction was limited. The greatest contributor to risk prediction was ABCD classification (Helicobacter pylori infection-related factor).

Abstract

Background: As part of our efforts to develop practical intervention applications for cancer prevention, we investigated a risk prediction model for gastric cancer based on genetic, biological, and lifestyle-related risk factors. Methods: We conducted two independent age- and sex-matched case–control studies, the first for model derivation (696 cases and 1392 controls) and the second (795 and 795) for external validation. Using the derivation study data, we developed a prediction model by fitting a conditional logistic regression model using the predictors age, ABCD classification defined by H. pylori infection and gastric atrophy, smoking, alcohol consumption, fruit and vegetable intake, and 3 GWAS-identified polymorphisms. Performance was assessed with regard to discrimination (area under the curve (AUC)) and calibration (calibration plots and Hosmer–Lemeshow test). Results: A combination of selected GWAS-identified polymorphisms and the other predictors provided high discriminatory accuracy and good calibration in both the derivation and validation studies, with AUCs of 0.77 (95% confidence intervals: 0.75–0.79) and 0.78 (0.77–0.81), respectively. The calibration plots of both studies stayed close to the ideal calibration line. In the validation study, the environmental model (nongenetic model) was significantly more discriminative than the inclusive model, with an AUC value of 0.80 (0.77–0.82). Conclusion: The contribution of genetic factors to risk prediction was limited, and the ABCD classification (H. pylori infection-related factor) contributes most to risk prediction of gastric cancer.

The simplified Kyoto classification score is consistent with the ABC method of classification as a grading system for endoscopic gastritis

The ABC method combined with Helicobacter pylori antibody and serum pepsinogen is a useful predictive method for stomach cancer. Kyoto classification is a new grading system for endoscopic gastritis. However, the consistency of the Kyoto score with the ABC method remains unclear. The Kyoto classification score, which ranges from 0 to 8, is based on the following findings: atrophy, intestinal metaplasia, diffuse redness, nodularity, and enlarged folds. Furthermore, we defined a simplified Kyoto classification score as the sum of scores of just atrophy and intestinal metaplasia. The association between the Kyoto classification score and the ABC method was analyzed using the Kruskal-Wallis and Steel-Dwass tests. A total of 307 subjects were enrolled. Kyoto classification scores were similar in groups B, C, and D, while scores in group A were significantly lower than those of the other groups. The simplified Kyoto classification score showed the same stepwise increase as the classification of the ABC method. In conclusion, unlike the Kyoto classification score, the simplified Kyoto score showed the same significant stepwise increase as the classification of the ABC method.

Changes of serum pepsinogen level and ABC classification after bariatric surgery

BACKGROUND

Very few studies have explored the changes of serum pepsinogen after bariatric surgery and no research has evaluated the feasibility of ABC classification to predict gastric cancer risk after bariatric surgery.

METHODS

We enrolled 94 obese subjects that received bariatric surgery, including 41 sleeve gastrectomy (SG) and 53 Roux-en-Y gastric bypass (RYGB). The serum pepsinogen I (PGI), pepsinogen II (PGII), PGI/II ratio and seropositivity of Helicobacter pylori ( H. pylori ) were measured before and one year after surgery. Patients were classified according to ABC classification and post-operative change was evaluated.

RESULTS

Preoperatively, four (4.2%) patients were classified into high risk group (classification C and D) for gastric cancer. Significant reduction of PGI, PGII and decrease of PGI/II ratio were noted after bariatric surgery. H. pylori seropositive patients had a greater postoperative change of PGI (-38.6μg/L vs -22.1μg/L, p=0.003) and PGII (-8.0μg/L vs -2.5μg/L, p <0.001) but a less postoperative change of PGI/II ratio (-0.6 vs -2.1, p =0.04) than H. pylori seronegative patients. One year after surgery, the portion of high risk group of ABC classification for gastric cancer increased markedly from 4.2% to 23.7%.

CONCLUSION

Both of SG and RYGB resulted in significant reduction of serum PGI and PGII after bariatric surgery, and significantly influenced the ABC classification. The application of ABC classification for gastric cancer screening was limited after bariatric surgery.

Impact of the timing of Helicobacter pylori eradication on the risk of development of metachronous lesions after treatment of early gastric cancer: a population-based cohort study

BACKGROUND AND AIMS

Helicobacter pylori eradication can reduce the risk of metachronous lesions after the treatment of early gastric cancer. We aimed to analyze the impact of the timing of H pylori eradication on metachronous recurrence.

METHODS

Data of patients who underwent endoscopic resection or partial gastrectomy for early stage gastric cancer and received H pylori eradication therapy were obtained from the Korean National Health Insurance Service database. Patients were classified into 3 groups according to the timing of the prescription for H pylori eradication: preresection; within 1 year postresection; and >1 year postresection.

RESULTS

Among 19,767 patients, 7452 and 12,315 underwent endoscopic resection and surgery, respectively. The 5-year cumulative incidence of metachronous lesions after endoscopic resection was 14.0% in the preresection group, 12.3% in the within 1 year postresection group, and 16.9% in the >1 year postresection group. Surgery was performed in 1.2% of the preresection group, 1.3% of the within 1 year postresection group, and 2.9% of the >1 year postresection group. The within 1 year postresection group had a lower risk of development of metachronous lesions than the >1 year postresection group (hazard ratio [95% confidence interval]: after endoscopic resection, 0.79 [0.65-0.95]; after surgery, 0.39 [0.28-0.53]). The risk of development of metachronous lesions did not differ between the preresection and within 1 year postresection groups.

CONCLUSION

Prescription of H pylori eradication therapy within 1 year after gastric cancer treatment reduces the risk of development of metachronous gastric neoplasms compared with a late prescription of eradication therapy in patients undergoing endoscopic resection and those undergoing surgery.

Usefulness and Limitations of a Serum Screening System to Predict the Risk of Gastric Cancer

Objective The aim of the present study was to evaluate the effectiveness and limitations of a serum screening system for predicting the risk of gastric cancer. Methods Serum pepsinogen I (PG I)/pepsinogen II (PG II) and Helicobacter pylori (HP) antibody levels were measured. Subjects were classified into four groupsaccording to their serological status (the ABC classification system). The grade of atrophic gastritis was assessed endoscopically. We evaluated gastric cancer detection rates according to the ABC classification system and the endoscopic grade of atrophy. Patients Individuals who underwent esophagogastroduodenoscopy (EGD) in a health check were prospectively enrolled in the present study. Results According to the ABC classification system, the gastric cancer detection rates in groups A, B, C, and D were 0.07% (4/6,105), 0.5% (8/1,739), 0.8% (16/2,010), and 1.1% (3/281), respectively. The gastric cancer detection rates in subjects with no atrophy, closed type (C-type) atrophy, and open type (O-type) atrophy were 0% (0/4,567), 0.2% (4/2,581), and 0.9% (27/2,987), respectively. In group A (HP(-)/PG(-)), the proportions of subjects with no atrophy, C-type atrophy, and O-type atrophy were 71.2%, 22.8%, and 6.0%, respectively. In group A, the gastric cancer detection rates in subjects with no atrophy, C-type atrophy, and O-type atrophy were 0%, 0.07%, and 0.8%, respectively. Conclusion The ABC classification system is useful for predicting the risk of gastric cancer. However, this system was limited in group A, which included individuals with a high risk of developing gastric cancer. An endoscopic diagnosis of atrophy may be more effective than the ABC classification system for predicting the risk of gastric cancer.

Previous Helicobacter pylori infection-induced atrophic gastritis: A distinct disease entity in an understudied population without a history of eradication

Individuals with chronic atrophic gastritis who are negative for active H. pylori infection with no history of eradication therapy have been identified in clinical practice. By excluding false-negative and autoimmune gastritis cases, it can be surmised that most of these patients have experienced unintentional eradication of H. pylori after antibiotic treatment for other infectious disease, unreported successful eradication, or H. pylori that spontaneously disappeared. These patients are considered to have previous H. pylori infection-induced atrophic gastritis. In this work, we define these cases based on the following criteria: absence of previous H. pylori eradication; atrophic changes on endoscopy or histologic confirmation of glandular atrophy; negative for a current H. pylori infection diagnosed in the absence of proton-pump inhibitors or antibiotics; and absence of localized corpus atrophy, positivity for autoantibodies, or characteristic histologic findings suggestive of autoimmune gastritis. The risk of developing gastric cancer depends on the atrophic grade. The reported rate of developing gastric cancer is 0.31%-0.62% per year for successfully eradicated severely atrophic cases (pathophysiologically equal to unintentionally eradicated cases and unreported eradicated cases), and 0.53%-0.87% per year for spontaneously resolved cases due to severe atrophy. Therefore, for previous H. pylori infection-induced atrophic gastritis cases, we recommend endoscopic surveillance every 3 years for high-risk patients, including those with endoscopically severe atrophy or intestinal metaplasia. Because of the difficulty involved in the endoscopic diagnosis of gastric cancer in cases of previous infection, appropriate monitoring of the high-risk subgroup of this understudied population is especially important.

Gastric cancer in patients with gastric atrophy and intestinal metaplasia: A systematic review and meta-analysis

AIM

Intestinal metaplasia (IM) and gastric atrophy (GA) are precancerous lesions in the stomach. There is a large debate on natural course of these lesions and surveillance strategy in these patients. This meta-analysis was aimed to find the most appropriate follow up and the rate of progression from IM and GA to GC.

METHODS

This meta-analysis is followed and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic databases including EMBASE, PubMed, Web of Science databases, Scopus, and the Cochrane Library were searched until July 2018. Cochran's Q test and I-square (I2) test were used to examine heterogeneity across included studies. We pooled data using random-effect or fixed effect models indicated as incidence rate or proportion with 95% confidence intervals (CI). The variables of study included demographic data, endoscopy interval, follow up interval and time, GA and IM type and GC stage. Moreover, incidence rate of GC and progress rate, regress and persistence proportion in both GA and IM patients were assessed.

RESULTS

Overall, 68 original articles out of 32981 citations were included in our meta-analysis. The pooled GC incidence rate in patients with GA was 1.24 (95% CI, 0.80, 1.76; I2: 83.6%) cases per 1,000 person-years. The rates of later diagnosis of IM and gastric dysplasia in patients with GA were estimated as 41.42 (95% CI, 3.11, 64.45; I2: 95.6%) and 6.23 (95% CI, 2.34, 11.46; I2: 83.0%) cases per 1,000 person-years, respectively. The pooled regressed proportion was 32.23 (95% CI, 18.07-48.02; I2: 94.0%) and the persistence proportion was 38.83 (95% CI, 20.20-59.13; I2: 97.0%) per 100 observations in GA patients. In IM studies, the pooled incidence rate of GC was 3.38 (95% CI, 2.13, 4.85; I2: 93.4%) cases per 1,000 person-years. The progressed rate to dysplasia in IM patient was estimated to be 12.51 (95% CI, 5.45, 22.03; I2: 95.1%) cases per 1,000 person-years. The pooled regressed proportion was 31.83 (95% CI, 25.48-38.51; I2: 91.0%) and the persistence proportion was 43.46 (95% CI, 32.52-54.71; I2: 96.0%) per 100 observations in IM patients.

CONCLUSION

Overall, the incidence of GC in patients with IM and GA are low but there is heterogeneity in data with the highest rate in Asian, males with those with incomplete IM. There is probability of regression or persistence without progression in patients with IM and GA who receive appropriate management.

Prevention of gastric cancer by Helicobacter pylori eradication: A review from Japan

Japan introduced a Helicobacter pylori eradication therapy strategy in 2013, with the aim of decreasing the number of gastric cancer‐related death, the number of new cases of gastric cancer, and associated medical costs. Five years have passed since then, but no reduction in the annual number of gastric cancer has been observed. In addition, it was suggested that the number of deaths due to gastric cancer could be reduced to 30,000 a year by 2020, but the annual death toll in 2017 remained at more than 45,000. Based on the above evidence, it was examined whether it was possible to reach the target value based on the data from the last 5 years. The number of deaths per year in 2020 is predicted to be more than 40,000, which is clearly different from the target value. Logically, the effect of the strategy might appear by 2023. However, there is a possibility that the risk of gastric cancer may increase in some populations due to the influence of proton pump inhibitors and dysbiosis in the gastric microbiome. To solve these problems, combined therapy with PPIs and aspirin for patients after H pylori eradication should be considered.

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.

Helicobacter pylori infection, atrophic gastritis, and risk of pancreatic cancer: A population-based cohort study in a large Japanese population: the JPHC Study

Helicobacter pylori (H. pylori), an established risk factor for gastric cancer, is suggested to also play a role in the development of pancreatic cancer; however, the association remains inconclusive. We examined this association among Japanese men and women. H. pylori and atrophic gastritis (AG) status were determined serologically, using blood sample collected during health checkups. A total of 20,116 subjects enrolled in the Japan Public Health Center-based Prospective Study Cohort II with available data on H. pylori seropositivity (anti-H. pylori) and AG were followed until the end of 2010. Cox proportional hazards models were used to calculate the hazard ratios (HR) and 95% confidence intervals (CI), using the information from the baseline survey. During 320,470 person-years of follow-up, 119 cases of pancreatic cancer were identified. No statically significant increase or decrease in pancreatic cancer risk was observed for H. pylori and AG status, independently or in combination. In a multivariable-adjusted model, we observed a non-significant decrease in the risk among those who had AG but were anti-H. pylori seronegative (HR 0.57, 95% CI 0.31–1.03). In a stratified analysis, we observed a statistically significant increased risk of pancreatic cancer for AG+ (HR 3.64, 95% CI 1.37–9.66), and AG+/anti-H. pylori− or AG+/anti-H. pylori+ (HR 5.21, 95% CI 1.14–23.87) among current smokers. Non-smokers in all categories of AG and anti-H. pylori showed a non-statistical decrease in the risk. There was no statistically significant interaction between H. pylori infection, AG status, and smoking status. Our findings suggest H. pylori seropositivity and AG, individually or in combination, are not associated with the risk of pancreatic cancer in a general Japanese population. Among current smokers, pancreatic cancer risk increased with AG, regardless of H. pylori infection status.

Grading of Atrophic Gastritis is Useful for Risk Stratification in Endoscopic Screening for Gastric Cancer

OBJECTIVES

In order to screen for gastric cancer effectively, its interval should be set according to the risk. This study aimed to determine whether risk stratification is possible using the data obtained from medical examination or endoscopic findings.

METHODS

First, subjects who underwent both cancer screening and medical examination from 2009 to 2015 and underwent cancer screening once more by 2016 were studied. Data such as the lipid profile and history of smoking obtained during the medical examination, and the grade of atrophy and presence of peptic ulcers were studied using multivariate analysis. Next, subjects who underwent cancer screening twice or more between 2009 and 2015 with or without medical examinations were studied to analyze any correlation between the grade of atrophy and cancer occurrence using univariate analysis. In both studies, the status of Helicobacter pylori (HP) infection was determined.

RESULTS

In the multivariate analysis, 9378 subjects were included. Aging, advanced atrophy, presence of ulcers, and uric acid levels were identified as risk factors. Among subjects who underwent successful HP eradication therapy, advanced atrophy and aging were observed to be crucial risk factors. In the univariate analysis, there were 12,941 subjects. Gastric cancer occurred more frequently in the more severe atrophy group (P < 0.001). The annual rate of cancer occurrence in the most severe atrophy group was 0.31%, which was approximately thrice as that in the less atrophy group.

CONCLUSIONS

Risk stratification was possible based on endoscopic examination alone. The interval should be set depending on each case.

Risk factors for atrophic gastritis in the Japanese young and middle-aged: a study using double-contrast upper gastrointestinal barium X-ray radiography

PURPOSE

To identify risk factors for atrophic gastritis in Japanese young and middle-age subjects by double-contrast upper gastrointestinal barium X-ray radiography (UGI-XR).

MATERIALS AND METHODS

We included 351 consecutive Japanese subjects (158 males, 193 females; age 25-49 years, mean 44 years) seen between October 2014 and March 2016. All underwent serum Helicobacter pylori (Hp) antibody- and UGI-XR examinations. Two radiologists independently recorded their UGI-XR findings of atrophic gastritis (AG). Interobserver agreement was assessed by calculating the kappa (κ) coefficient. Univariate and multivariate analyses were performed to investigate the association between AG and the subjects' gender, smoking habit, alcohol intake, body mass index, and Hp infection.

RESULTS

AG was diagnosed in 85 subjects (24%) on UGI-XR images; interobserver agreement was good (κ = 0.745). By univariate analysis, the male gender and a high serum Hp titer (IgG ≥ 10 U/ml) were significantly association with AG (p < 0.05). Multivariate analysis revealed that a high serum Hp titer was the only independent, significant factor (p < 0.05). The odds ratio for a high serum Hp titer was 128 (95% CI, 54.8-498.4).

CONCLUSION

Our UGI-XR study indicated that Hp infection was significantly associated with AG in Japanese young and middle-aged subjects.

Gastric Cancer Screening by Combined Determination of Serum Helicobacter pylori Antibody and Pepsinogen Concentrations: ABC Method for Gastric Cancer Screening

Objective:

Gastroscopy combined with gastric mucosa biopsies is currently regarded as a gold standard for diagnosis of gastric cancer. However, its application is restricted in clinical practice due to its invasive property. A new noninvasive population screening process combining the assay of anti-Helicobacter pylori antibody and serum pepsinogen (PG) (ABC method) is adopted to recognize the high-risk patients for further endoscopy examination, avoiding the unnecessary gastroscopy for most population and saving the cost consumption for mass screening annually. Nevertheless, controversies exist for the grouping of ABC method and the intervals of gastroscopy surveillance for each group. In this review, we summarized these popular concerned topics for providing useful references to the healthcare practitioner in clinical practice.

Data Sources:

The PubMed databases were systematically searched from the inception dates to November 22, 2017, using the keywords “Helicobacter pylori,” “Pepsinogens,” and “Stomach Neoplasms.”

Study Selection:

Original articles and reviews on the topics were selected.

Results:

Anti-H. pylori antibody and serum PG concentration showed significant changes under the different status of H. pylori infection and the progression of atrophic gastritis, which can be used for risk stratification of gastric cancer in clinic. In addition, anti-H. pylori antibody titer can be used for further risk stratification of gastric cancer contributing to determine better endoscopy surveillance interval.

Conclusions:

The early detection and diagnosis of gastric cancer benefit from the risk stratification, but the cutoff values for H. pylori antibody and serum PG concentration require further modification.

Expression of KK-LC-1, a cancer/testis antigen, at non-tumour sites of the stomach carrying a tumour

Kita-Kyushu lung cancer antigen-1 (KK-LC-1) is a cancer/testis antigen (CTA) and predominant target for cancer immunotherapy. Our previous study indicated that KK-LC-1 was expressed in 82% of gastric cancers, and also in 79% of early stage of gastric cancers, with a correlation to Helicobacter pylori (H. pylori) infection. In addition, we found that KK-LC-1 was occasionally expressed at non-tumour sites of stomachs carrying tumours. Here, we investigated the characteristics of KK-LC-1 expression at non-tumour sites and the clinical utility of these phenomena. The gene expression of KK-LC-1 was detected at the non-tumour sites including pyloric glands. The most detectable corpus/gland subset had a KK-LC-1 expression rate of 77% in the pyloric gland of the lower corpus where H. pylori preferentially exists. KK-LC-1 expression rates were 67% or 32% with or without intestinal metaplasia, which also induced by H. pylori, respectively. Consequently, KK-LC-1 would be detected at the pre-cancerous condition of the stomach, and may be a useful marker to predict gastric cancer.

Preliminary study of automatic gastric cancer risk classification from photofluorography

AIM

To perform automatic gastric cancer risk classification using photofluorography for realizing effective mass screening as a preliminary study.

METHODS

We used data for 2100 subjects including X-ray images, pepsinogen I and II levels, PGI/PGII ratio, Helicobacter pylori (H. pylori) antibody, H. pylori eradication history and interview sheets. We performed two-stage classification with our system. In the first stage, H. pylori infection status classification was performed, and H. pylori-infected subjects were automatically detected. In the second stage, we performed atrophic level classification to validate the effectiveness of our system.

RESULTS

Sensitivity, specificity and Youden index (YI) of H. pylori infection status classification were 0.884, 0.895 and 0.779, respectively, in the first stage. In the second stage, sensitivity, specificity and YI of atrophic level classification for H. pylori-infected subjects were 0.777, 0.824 and 0.601, respectively.

CONCLUSION

Although further improvements of the system are needed, experimental results indicated the effectiveness of machine learning techniques for estimation of gastric cancer risk.

Serum pepsinogen 1 and anti-Helicobacter pylori IgG antibodies as predictors of gastric cancer risk in Finnish males

BACKGROUND

Serum pepsinogen 1 (SPG1) and anti-Helicobacter pylori serology have been used for gastric risk stratification in Asia.

AIM

To assess utility of these markers in a Western population.

METHODS

SPG1 measurements were available for 21 895 Finnish male smokers in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. We used Cox proportional hazards models adjusted for potential confounders to estimate gastric cancer hazard ratios (HR) and 95% confidence intervals (95% CI) for low SPG1 (<25 μg/L). In a subset (n = 3555) with anti-H. pylori serology, these markers jointly defined the following: Group A (H. pylori[-], SPG1[normal]; reference group), Group B (H. pylori[+], SPG1[normal]), Group C (H. pylori[+], SPG1[low]) and Group D (H. pylori[-], SPG1[low]). Odds ratios (ORs) and 95% CI were calculated using multivariate logistic regression.

RESULTS

There were 329 gastric cancers diagnosed an average of 13.9 years after baseline. Pre-diagnostic low SPG1 was significantly associated with increased gastric cancer risk (HR 2.68, 95% CI 1.99-3.61). Among subjects with both SPG1 and H. pylori serology, groups B, C and D had increased gastric cancer ORs (95% CI) of 1.79 (1.21-2.64), 3.85 (2.36-6.28) and 6.35 (2.20-18.34), respectively. CagA seropositives had significantly higher ORs than CagA seronegatives within group B (P_{heterogeneity}  = 0.01). For groups B and C, repeat SPG1 level at 3 years did not further stratify gastric cancer risk.

CONCLUSIONS

Low SPG1 was associated with increased gastric cancer risk in our large Finnish cohort. A single measurement of SPG1 along with H. pylori whole cell and CagA serology provides potentially useful prediction of gastric cancer risk.

Serum Pepsinogens and Helicobacter Pylori are not Associated with Esophageal Squamous Cell Carcinoma in a High-Risk Area in China

Aims and background

The role of serum pepsinogen level and Helicobacter pylori infection in esophageal carcinoma remains controversial. It may be a risk or protective factor, or without association with esophageal carcinoma. We prospectively examined associations between serum pepsinogen status, H pylori infection and the risk of esophageal squamous cell carcinoma in the Chinese population.

Methods

In the present study, 1501 subjects from a community-based general population of Northern China were included. The incidence of esophageal carcinoma among the subjects was registered during a 15-year follow-up period by annual home visit, and the risks of low serum pepsinogen level and H pylori infection in the development of ESCC were evaluated using logistic regression.

Results

The total accumulated incidence of ESCC in the cohort was 666/100,000 during the 15-year follow-up. Notably, all the cases were verified to be ESCC. Logistic regression analysis showed that age ≥60 (OR = 9.67; 95% CI, 2.797–33.423) was the only risk factor for esophageal squamous cell carcinoma in the population. There was no significant association between sex, H pylori infection, pepsinogen level (PG I ≤70 ng/ml alone, PG I/II ratio ≤3 alone, or PG I ≤70 ng/ml and PG I/II ratio ≤3) and esophageal squamous cell carcinoma.

Conclusions

In this prospective study, neither H pylori infection nor abnormal pepsinogen status had a predictive role for the development of esophageal squamous cell carcinoma in the rural population of China.

Estimation of lifetime cumulative incidence and mortality risk of gastric cancer

Objective

To estimate cumulative incidence and mortality risk for gastric cancer by risk category.

Methods

Risk was classified into four types according to the presence/absence of Helicobacter pylori infection and chronic atrophic gastritis: in order of lowest to highest risk, Group A: H. pylori(−) and atrophic gastritis(−); Group B: H. pylori(+) and atrophic gastritis(−); Group C:H. pylori(+) and atrophic gastritis(+); and, Group D: H. pylori(−) and atrophic gastritis(+). We used vital statistics for the crude all-cause and crude gastric cancer mortality rates in 2011 and data from population-based cancer registries (the Monitoring of Cancer Incidence in Japan) for gastric cancer incidence in 2011. For relative risk and prevalence, we used the results of a meta-analysis integrating previous studies and data from the Japan Public Health Center-based Prospective Study for the Next Generation, respectively (baseline survey 2011–16). We calculated the crude incidence and mortality rates and estimated the cumulative risk using a life-table method.

Results

The estimated lifetime cumulative incidence risk was 11.4% for men and 5.7% for women. The estimated risk for Groups A, B, C and D was 2.4%, 10.8%, 26.7% and 35.5% for men, and 1.2%, 5.5%, 13.5% and 18.0% for women, respectively. Similarly, the estimated lifetime cumulative mortality risk was 3.9% for men and 1.8% for women. The estimated risk of mortality for Groups A, B, C and D was 0.8%, 3.6%, 9.0% and 12.0% for men, and 0.4%, 1.7%, 4.2% and 5.7% for women, respectively.

Conclusions

Our results may be useful for designing individually tailored prevention programs.

Changing trends in the prevalence of H. pylori infection in Japan (1908-2003): a systematic review and meta-regression analysis of 170,752 individuals

Changing trends in the prevalence of H. pylori infection in the general population over time are thought to be the main driving force behind the declining gastric cancer mortality in Japan. However, whether the prevalence of H. pylori infection itself shows a birth-cohort pattern needs to be corroborated. We performed a systematic review of studies that reported the prevalence of H. pylori infection among Japanese individuals. Meta-regression was conducted in the framework of a generalized additive mixed model (GAMM) to account for heterogeneity in the prevalence of H. pylori infection as a function of birth year. The prevalence of H. pylori infection confirmed a clear birth cohort pattern: the predicted prevalence (%, 95% CI) was 60.9 (56.3–65.4), 65.9 (63.9–67.9), 67.4 (66.0–68.7), 64.1 (63.1–65.1), 59.1 (58.2–60.0), 49.1 (49.0–49.2), 34.9 (34.0–35.8), 24.6 (23.5–25.8), 15.6 (14.0–17.3), and 6.6 (4.8–8.9) among those who were born in the year 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990, and 2000, respectively. The present study demonstrated a clear birth-cohort pattern of H. pylori infection in the Japanese population. The decreased prevalence of H. pylori infection in successive generations should be weighed in future gastric cancer control programs.

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.

Association between Gastric Cancer Risk and Serum Helicobacter pylori Antibody Titers

Background/Aims

It is difficult to confirm the accurate cutoff value to diagnose Helicobacter pylori (Hp) infection using commercial serology kits. It is reported that there were many cases with present/past infection that even the serum Hp-IgG antibody (HpAb) titers were below the cutoff value (e.g., 10 U/mL for E-Plate®), suggesting that we might overlook many gastric cancer (GC). We investigated an association between gastric cancer risk and serum Helicobacter pylori antibody titers.

Methods

We conducted a primary screening between 2014 and 2015. We performed gastroendoscopy if HpAb titers were ≥3.0 U/mL (i.e., more than measurable limit, E-Plate). These patients were divided into two groups: HpAb = 3.0–9.9 U/mL (“negative-high” group) and HpAb ≥ 10 U/mL; cutoff value (“over-10 U/mL” group). Hp infection status was investigated, and the number of GC patients was counted.

Results

Among the 3321 subjects in the primary screening, 56.9% (1891/3321) showed HpAb titers ≥3.0 U/mL; 1314 patients underwent gastroendoscopy. Ten were GC. 421 patients were “negative-high” group; two were GC. After evaluating 381 patients for Hp infection, 22.6%/60.6% was with present/past infection among the “negative-high” group.

Conclusion

We also found a correlation between HpAb titers and Hp infection status. “Negative-high” group has a risk of GC.

Factors Related to Upper Gastrointestinal Symptom Generation in 2275 Helicobacter pylori Seroprevalent Adults

BACKGROUND AND AIM

Upper gastrointestinal (UGI) symptoms are common; however, the role of Helicobacter pylori and gastric corpus atrophy in the generation of these symptoms is controversial. The aim of this study was to determine the risk factors for UGI symptoms in adults in an endemic area of H. pylori infection.

METHODS

Korean adults who completed questionnaires on the day of serum anti-H. pylori IgG and pepsinogen (PG) assays before UGI endoscopy were included. Gastric corpus atrophy was based on the criteria of a serum PG I/II ratio <3.0 and a PG I <70 ng/ml.

RESULTS

Of the 2275 included subjects, 723 (31.8%) had at least one UGI symptom. A total of 374 (16.4%) subjects had multiple symptoms without significant correlations between the symptoms (λ < 0.2). The H. pylori serology assay was positive in 1382 (60.7%) subjects, and gastric corpus atrophy was present in 291 (12.8%). Neither H. pylori seropositivity (p = 0.077) nor gastric corpus atrophy (p = 0.138) was related to the presence of UGI symptoms. Female gender and smoking were independent risk factors for heartburn and upper abdominal pain (all p < 0.001). Furthermore, female gender was the only independent risk factor for multiple UGI symptoms (p < 0.001), globus sensation (p < 0.001), early satiety (p < 0.001), epigastric soreness (p = 0.001), and chest discomfort (p = 0.003).

CONCLUSIONS

In an H. pylori seroprevalent population, female gender is the most common risk factor followed by smoking for UGI symptom generation. Neither H. pylori seropositivity nor gastric corpus atrophy is an independent risk factor for UGI symptom generation.

Correlation Between Expression of the Cancer/Testis Antigen KK-LC-1 and Helicobacter pylori Infection in Gastric Cancer

BACKGROUND/AIM

Our previous study indicated that Kita-kyushu lung cancer antigen-1 (KK-LC-1) is a cancer/testis antigen (CTA) expressed in 82% of gastric cancer cases. Here, we investigated the relationship between KK-LC-1 expression and Helicobacter pylori infection in Japanese patients with gastric cancer.

PATIENTS AND METHODS

We examined CTA expression in 25 surgical gastric cancer specimens and anti-H. pylori IgGs in the serum of each patient.

RESULTS

KK-LC-1 was expressed in 80% of tumor samples, markedly higher than melanoma antigen gene (MAGE)-A1, MAGE-A3, MAGE-A4, synovial sarcoma, X breakpoint 4 (SSX4) and New York esophageal squamous cell carcinoma-1 (NY-ESO-1). Anti-H. pylori IgG titers from the KK-LC-1-positive patients were significantly higher (67.5±7.6) than those from KK-LC-1-negative patients (15.8±7.5, p<0.01) although there were no significant differences between patients positive and negative for MAGE-A1, -A3 and-A4, SSX4 and NY-ESO-1.

CONCLUSION

As far as we are aware, this is the first report of a correlation between a carcinogen and CTA expression in clinical samples. KK-LC-1 was frequently expressed in gastric cancer caused by H. pylori infection. The risk diagnosis for gastric cancer might be more accurate if KK-LC-1 expression status were also considered.

Cutoff Pepsinogen Level for Predicting Unintendedly Eradicated Cases of Helicobacter pylori Infection in Subjects with Seemingly Normal Pepsinogen Levels

BACKGROUNDS/AIMS

In the ABC method, which is a method for risk stratification of gastric cancer using serum anti-Helicobacter pylori antibody and pepsinogen (PG) test, subjects with normal PG and seronegative for H. pylori are named as "Group A" and are regarded as having a low risk of gastric cancer. These "Group A" subjects include unintentionally eradicated cases at relatively high risk, and this study aimed to identify these subjects.

METHODS

Of the 109 subjects, 76 were classified as uninfected Group A subjects with negative histologic H. pylori infection and no histologic and endoscopic atrophy, and 33 subjects were classified serologically as Group A after successful eradication, which are serologically equal to the unintendedly eradicated cases in Group A. The usefulness of measuring PG levels to detect post-eradication cases was validated by using a receiver operating characteristic (ROC) curve analysis.

RESULTS

The area under the ROC curve for PGI level was 0.736 ± 0.06 (p < 0.01; cutoff value, 37.0 ng/mL; sensitivity, 77.6%; specificity, 72.7%), and that for the PGI/II ratio was 0.660 ± 0.06 (p < 0.01; cutoff value, 5.1; sensitivity, 84.2%; specificity, 43.4%).

CONCLUSION

PGI levels of ≤37 ng/mL and PGI/II ratios of ≤5.1 effectively identified unintendedly eradicated cases in Group A.

Helicobacter Pylori infection detection from gastric X-ray images based on feature fusion and decision fusion

In this paper, a fully automatic method for detection of Helicobacter pylori (H. pylori) infection is presented with the aim of constructing a computer-aided diagnosis (CAD) system. In order to realize a CAD system with good performance for detection of H. pylori infection, we focus on the following characteristic of stomach X-ray examination. The accuracy of X-ray examination differs depending on the symptom of H. pylori infection that is focused on and the position from which X-ray images are taken. Therefore, doctors have to comprehensively assess the symptoms and positions. In order to introduce the idea of doctors' assessment into the CAD system, we newly propose a method for detection of H. pylori infection based on the combined use of feature fusion and decision fusion. As a feature fusion scheme, we adopt Multiple Kernel Learning (MKL). Since MKL can combine several features with determination of their weights, it can represent the differences in symptoms. By constructing an MKL classifier for each position, we can obtain several detection results. Furthermore, we introduce confidence-based decision fusion, which can consider the relationship between the classifier's performance and the detection results. Consequently, accurate detection of H. pylori infection becomes possible by the proposed method. Experimental results obtained by applying the proposed method to real X-ray images show that our method has good performance, close to the results of detection by specialists, and indicate that the realization of a CAD system for determining the risk of H. pylori infection is possible.

Receiver operating characteristic analysis of prediction for gastric cancer development using serum pepsinogen and Helicobacter pylori antibody tests

BACKGROUND

Chronic Helicobacter pylori infection plays a central role in the development of gastric cancer as shown by biological and epidemiological studies. The H. pylori antibody and serum pepsinogen (PG) tests have been anticipated to predict gastric cancer development.

METHODS

We determined the predictive sensitivity and specificity of gastric cancer development using these tests. Receiver operating characteristic analysis was performed, and areas under the curve were estimated. The predictive sensitivity and specificity of gastric cancer development were compared among single tests and combined methods using serum pepsinogen and H. pylori antibody tests.

RESULTS

From a large-scale population-based cohort of over 100,000 subjects followed between 1990 and 2004, 497 gastric cancer subjects and 497 matched healthy controls were chosen. The predictive sensitivity and specificity were low in all single tests and combination methods. The highest predictive sensitivity and specificity were obtained for the serum PG I/II ratio. The optimal PG I/II cut-off values were 2.5 and 3.0. At a PG I/II cut-off value of 3.0, the sensitivity was 86.9% and the specificity was 39.8%. Even if three biomarkers were combined, the sensitivity was 97.2% and the specificity was 21.1% when the cut-off values were 3.0 for PG I/II, 70 ng/mL for PG I, and 10.0 U/mL for H. pylori antibody.

CONCLUSIONS

The predictive accuracy of gastric cancer development was low with the serum pepsinogen and H. pylori antibody tests even if these tests were combined. To adopt these biomarkers for gastric cancer screening, a high specificity is required. When these tests are adopted for gastric cancer screening, they should be carefully interpreted with a clear understanding of their limitations.

Precancerous histopathologic lesions of upper gastrointestinal tract among dyspeptic patients upon endoscopic evaluations

PURPOSE

Gastric cancer is one of the most important causes of morbidity and mortality worldwide which is influenced by different risk factors. This study aimed to investigate the effects of various factors associated with precancerous lesions among dyspeptic patients.

METHODS

Among dyspeptic patients admitted to gastrointestinal clinics in Ilam city, west of Iran, 1123 were investigated during 2008 to 2011. All patients were evaluated by endoscopy and their biopsy samples were examined for histological differentiations and their pathology reports were classified according to Sydney criteria.

RESULTS

One thousand out of 1123 admitted dyspeptic patients were finally analyzed. The mean age of participants was 48 years (ranged 21-84 years), and 64.8% of patients were male. The frequency of patients with atrophy, metaplasia, or both was 14.4%, adenocarcinoma 1.2%, and polyp hyperplasia 0.7%, respectively. The highest frequency was related to those with chronic gastritis accompanied by Helicobacter pylori infection with a figure of 80.8%. The frequency of precancerous lesions among smokers compared to non-smokers was higher significantly (p < 0.03). Though non-significant, BMI was associated with the higher risk of premalignant lesions among dyspeptic patients by an increasing manner.

CONCLUSION

Chronic gastritis accompanied with H. pylori infection was revealed as the most prevalent variable among dyspeptic patients. Also, higher BMI compared to normal and smokers compared to non-smokers were more involved by precancerous lesions.

Combination of Helicobacter pylori Antibody and Serum Pepsinogen as a Good Predictive Tool of Gastric Cancer Incidence: 20-Year Prospective Data From the Hisayama Study

BACKGROUND

There is little information regarding whether the combination of Helicobacter pylori (H. pylori) antibody and serum pepsinogen (sPG), which is a marker of the degree of atrophic gastritis, has a discriminatory ability for detecting incident gastric cancer. We examined this issue in a long-term prospective cohort study of a Japanese population.

METHODS

A total of 2446 Japanese community-dwelling individuals aged ≥40 years were stratified into four groups according to baseline H. pylori serological status and sPG: Group A (H. pylori[-], sPG[-]), Group B (H. pylori[+], sPG[-]), Group C (H. pylori[+], sPG[+]), and Group D (H. pylori[-], sPG[+]), and participants were followed up prospectively for 20 years.

RESULTS

During the follow-up, 123 subjects developed gastric cancer. Compared with that in Group A, the cumulative incidence of gastric cancer was significantly increased in Groups B, C, and D, whereas no significant difference was found between Groups C and D. The multivariable-adjusted risk of gastric cancer was significantly increased in Group B (hazard ratio [HR], 4.08; 95% confidence interval [CI], 1.62-10.28) and in Groups C and D combined (HR 11.1; 95% CI, 4.45-27.46). When the multivariable model with H. pylori antibody was changed into that with the combination of H. pylori antibody and sPG, the C statistics for developing gastric cancer increased significantly (0.773 vs 0.732, P = 0.005), and the continuous net reclassification improvement value was 0.591 (P < 0.001).

CONCLUSIONS

Our findings suggest that the combination of H. pylori antibody and sPG is a useful tool for predicting the development of gastric cancer.

Endoscopic gastritis, serum pepsinogen assay, and Helicobacter pylori infection

Endoscopic findings of the background gastric mucosa are important in the Helicobacter pylori-seroprevalent population. It is strongly correlated not only with the risk of gastric cancer, but also with the excretion ability of gastric mucosa cells. In noninfected subjects, common endoscopic findings are regular arrangement of collecting venules, chronic superficial gastritis, and erosive gastritis. In cases of active H. pylori infection, nodularity on the antrum, hemorrhagic spots on the fundus, and thickened gastric folds are common endoscopic findings. The secreting ability of the gastric mucosa cells is usually intact in both noninfected and actively infected stomachs, and the intragastric condition becomes hyperacidic upon inflammation. Increased serum pepsinogen II concentration correlates well with active H. pylori infection, and also indicates an increased risk of diffuse-type gastric cancer. In chronic inactive H. pylori infection, metaplastic gastritis and atrophic gastritis extending from the antrum (closed-type chronic atrophic gastritis) toward the corpus (open-type chronic atrophic gastritis) are common endoscopic findings. The intragastric environment is hypoacidic and the risk of intestinal-type gastric cancer is increased in such conditions. Furthermore, there is a decrease in serum pepsinogen I concentration when the secreting ability of the gastric mucosa cells is damaged. Serologic and endoscopic changes that occur upon H. pylori infection are important findings for estimating the secreting ability of the gastric mucosa cells, and could be applied for the secondary prevention of gastric cancer.

Evaluation of the diagnostic value of 64 simultaneously measured autoantibodies for early detection of gastric cancer

Autoantibodies against tumor-associated antigens (TAAs) have been suggested as biomarkers for early detection of gastric cancer. However, studies that systematically assess the diagnostic performance of a large number of autoantibodies are rare. Here, we used bead-based multiplex serology to simultaneously measure autoantibody responses against 64 candidate TAAs in serum samples from 329 gastric cancer patients, 321 healthy controls and 124 participants with other diseases of the upper digestive tract. At 98% specificity, sensitivities for the 64 tested autoantibodies ranged from 0–12% in the training set and a combination of autoantibodies against five TAAs (MAGEA4 + CTAG1 + TP53 + ERBB2_C + SDCCAG8) was able to detect 32% of the gastric cancer patients at a specificity of 87% in the validation set. Sensitivities for early and late stage gastric cancers were similar, while chronic atrophic gastritis, a precursor lesion of gastric cancer, was not detectable. However, the 5-marker combination also detected 26% of the esophageal cancer patients. In conclusion, the tested autoantibodies and combinations alone did not reach sufficient sensitivity for gastric cancer screening. Nevertheless, some autoantibodies, such as anti-MAGEA4, anti-CTAG1 or anti-TP53 and their combinations could possibly contribute to the development of cancer early detection tests (not necessarily restricted to gastric cancer) when being combined with other markers.

Low Incidence of Synchronous or Metachronous Tumors after Endoscopic Submucosal Dissection for Early Gastric Cancer with Undifferentiated Histology

Background

Gastric cancer with undifferentiated histology has different clinicopathologic characteristics compared to differentiated type gastric cancer. We aimed to compare the risk of synchronous or metachronous tumors after curative resection of early gastric cancer (EGC) via endoscopic submucosal dissection (ESD), according to the histologic differentiation of the primary lesion.

Methods

Clinicopathological data of patients with initial-onset EGC curatively resected via ESD between January 2007 and November 2014 in a single institution were reviewed. We analyzed the incidence of synchronous or metachronous tumors after ESD with special reference to the differentiation status of the primary lesion.

Results

Of 1,560 patients with EGC who underwent curative resection via ESD, 1,447 had differentiated type cancers, and 113 had undifferentiated type cancers. The cumulative incidence of metachronous or synchronous tumor after ESD was higher in the differentiated cancer group than in the undifferentiated cancer group (P = 0.008). Incidence of metachronous or synchronous tumor was 4.8% and 1.2% per person-year in the differentiated and undifferentiated cancer groups, respectively. The Cox proportional hazard model revealed that undifferentiated cancers were associated with a low risk of synchronous or metachronous tumors after adjusting for confounding variables (hazard ratio [95% confidence interval] = 0.287 [0.090–0.918]).

Conclusions

The rate of synchronous or metachronous tumors after curative ESD was significantly lower for undifferentiated cancers compare to differentiated cancers. These findings suggest that ESD should be actively considered as a possible treatment for undifferentiated type EGCs.

The new modified ABCD method for gastric neoplasm screening

BACKGROUND

The ABCD screening method was developed for risk stratification of gastric cancer. It is unclear whether the ABCD method can predict the risk of gastric neoplasms, including gastric adenomas, as observed for gastric cancer. We aimed to devise a modified ABCD method for predicting gastric neoplasms.

METHODS

We reviewed 562 patients who had undergone upper gastrointestinal tract endoscopy and whose serum IgG anti-Helicobacter pylori antibody, gastrin, and pepsinogen (PG) I and PG II data were available. Patients were classified into the following four groups: H. pylori antibody negative and normal PG level (group A), H. pylori antibody positive and normal PG level (group B), H. pylori antibody positive and low PG level (group C), and H. pylori antibody negative and low PG level (group D).

RESULTS

The PG I/PG II ratio was lower in patients with gastric neoplasms than in patients without these lesions (gastric adenoma vs gastric cancer vs no neoplasm, 3.7 ± 2.0 vs 3.8 ± 1.8 vs 4.9 ± 2.1, P < 0.001). The optimal cutoff values of the PG I/PG II ratio for predicting gastric neoplasms were 3.1 for H. pylori antibody negative patients and 4.1 for H. pylori antibody positive patients. A higher group grade was associated with a significantly higher proportion of gastric neoplasms [odds ratio (95 % confidence interval), group A, reference; group B, 1.783 (1.007-3.156); group C, 3.807 (2.382-6.085); and group D, 5.862 (2.427-14.155)].

CONCLUSIONS

The modified ABCD method using two different cutoff values according to the H. pylori antibody status was useful for predicting the presence of gastric neoplasms. This method might be a supplementary screening tool for both gastric adenoma and gastric cancer. However, further studies will be required to provide a definitive conclusion.

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.

Screening of gastric cancer in Asia

In North-Eastern Asian countries, where incidence and mortality of gastric cancer remain very high, population-based gastric cancer screenings have been conducted under governmental subsidy in Japan and Korea. Reduction of gastric cancer mortality by the screening was documented in Japan, but the Japanese gastric cancer screening with the X-ray photofluorography is criticized for its high cost and a low uptake rate. Although the Korean program seems to achieve a high-rate of uptake with increasing use of endoscopy, the work load is substantial. In the meantime, more attention in the world turns to primary prevention through eradication of Helicobacter pylori. Indeed, fairly large-scale studies to examine the feasibility of mass-eradication to prevent gastric cancer are underway in China and Taiwan. In the future, gastric cancer screening should incorporate 'screen to treat' of H. pylori infection at younger age followed by endoscopic surveillance for subjects at risk.

Helicobacter pylori Antibody Titer and Gastric Cancer Screening

The "ABC method" is a serum gastric cancer screening method, and the subjects were divided based on H. pylori serology and atrophic gastritis as detected by serum pepsinogen (PG): Group A [H. pylori (-) PG (-)], Group B [H. pylori (+) PG (-)], Group C [H. pylori (+) PG (+)], and Group D [H. pylori (-) PG (+)]. The risk of gastric cancer is highest in Group D, followed by Groups C, B, and A. Groups B, C, and D are advised to undergo endoscopy, and the recommended surveillance is every three years, every two years, and annually, respectively. In this report, the reported results with respect to further risk stratification by anti-H. pylori antibody titer in each subgroup are reviewed: (1) high-negative antibody titer subjects in Group A, representing posteradicated individuals with high risk for intestinal-type cancer; (2) high-positive antibody titer subjects in Group B, representing active inflammation with high risk for diffuse-type cancer; and (3) low-positive antibody titer subjects in Group C, representing advanced atrophy with increased risk for intestinal-type cancer. In these subjects, careful follow-up with intervals of surveillance of every three years in (1), every two years in (2), and annually in (3) should be considered.

Prediction of the 10-year probability of gastric cancer occurrence in the Japanese population: the JPHC study cohort II

Gastric cancer is a particularly important issue in Japan, where incidence rates are among the highest observed. In this work, we provide a risk prediction model allowing the estimation of the 10-year cumulative probability of gastric cancer occurrence. The study population consisted of 19,028 individuals from the Japanese Public Health Center cohort II who were followed-up from 1993 to 2009. A parametric survival model was used to assess the impact on the probability of gastric cancer of clinical and lifestyle-related risk factors in combination with serum anti-Helicobacter pylori antibody titres and pepsinogen I and pepsinogen II levels. Based on the resulting model, cumulative probability estimates were calculated and a simple risk scoring system was developed. A total of 412 cases of gastric cancer occurred during 270,854 person-years of follow-up. The final model included (besides the biological markers) age, gender, smoking status, family history of gastric cancer and consumption of highly salted food. The developed prediction model showed good predictive performance in terms of discrimination (optimism-corrected c-index: 0.768) and calibration (Nam and d'Agostino's χ(2) test: 14.78; p values = 0.06). Estimates of the 10-year probability of gastric cancer occurrence ranged from 0.04% (0.02, 0.1) to 14.87% (8.96, 24.14) for men and from 0.03% (0.02, 0.07) to 4.91% (2.71, 8.81) for women. In conclusion, we developed a risk prediction model for gastric cancer that combines clinical and biological markers. It might prompt individuals to modify their lifestyle habits, attend regular check-up visits or participate in screening programmes.

Serologically Determined Gastric Mucosal Condition Is a Predictive Factor for Osteoporosis in Japanese Men

BACKGROUND

There are few reports about the influence of Helicobacter pylori infection and/or atrophic gastritis on bone conditions in Japan.

AIMS

To assess whether the combination of serologically determined Helicobacter pylori infection and atrophic gastritis is available as a biomarker for bone conditions.

METHODS

We studied 230 men in their 50s and 60s. Helicobacter pylori infection was determined using serum antibody to this bacterium. Atrophic gastritis was diagnosed on the basis of the serum pepsinogen I and II criteria. The characteristics of the participants' bone were measured at the radius using an ultrasonic bone densitometry system. The risks of low trabecular bone density, low elastic modulus of trabecular bone, and low cortical thickness among subjects who were positive for Helicobacter pylori infection and/or atrophic gastritis relative to those who were not were calculated.

RESULTS

Helicobacter pylori infection significantly increased the risk of low trabecular bone density (odds ratio 1.83, 95 % confidence interval 1.04-3.21, P = 0.03). Atrophic gastritis significantly increased the risk of low trabecular bone density (2.22, 1.17-4.22, 0.01). Compared with anti-Helicobacter pylori antibody (-) and atrophic gastritis (-) subjects, anti-Helicobacter pylori antibody (+) and atrophic gastritis (+) subjects were a significant high-risk group for low trabecular bone density (2.65, 1.27-5.55, 0.01).

CONCLUSIONS

A serological diagnosis of Helicobacter pylori infection and atrophic gastritis, which is utilized for risk assessment of gastric cancer, was suggested to be useful for risk assessment of osteoporosis.

Determination of whether screening tests for chronic atrophic gastritis really has a positive predictive value

Intestinal‑type gastric adenocarcinomas are preceded by precancerous lesions, which begin with chronic atrophic gastritis. Over the last few years, multiple serological screening techniques have been performed and commercialized for the diagnosis of chronic atrophic gastritis. In the present study, 123 patients were recruited at the International Cancer Institute 'G. Pascale' Foundation (Naples, Italy) to test commercial kits for the serological determination of chronic atrophic gastritis, supported by histological analysis, according to the International Group of Gastroenterologists 'Operative Link for Gastritis Assessment Staging System'. The results revealed a significant discrepancy between serological screening and histological evaluation in 10.6% of patients, which highlighted the dubious positive predictive value of commercial serological screening kits.