OLGA and OLGIM stage distribution according to age and Helicobacter pylori status in the Korean population

Carbon footprint and cost reduction by endoscopic grading of gastric intestinal metaplasia using narrow-band imaging

BACKGROUND AND AIM

Gastric intestinal metaplasia (GIM) is a high-risk factor for the development of gastric cancer. Narrow-band imaging (NBI) enables endoscopic grading of GIM (EGGIM). In the era of climate change, gastrointestinal endoscopists are expected to reduce greenhouse gas emissions and medical waste. Based on the diagnostic performance of NBI endoscopy, this study measured the environmental impact and reduced cost of implementing EGGIM during gastroscopy.

METHODS

Using NBI endoscopy in 242 patients, EGGIM classification and operative link on GIM (OLGIM) staging were prospectively performed in five different areas (lesser and greater curvatures of the corpus and antrum, and the incisura angularis). We estimated the environmental impact and cost reduction of the biopsy procedures and pathological processing if EGGIM were used instead of OLGIM.

RESULTS

The diagnostic accuracy of NBI endoscopy for GIM was 93.0-97.1% depending on the gastric area. When a high EGGIM score ≥ 5 was the cut-off value for predicting OLGIM stages III-IV, the area under the curve was 0.862, sensitivity was 81.9%, and specificity was 90.4%. The reduction in the carbon footprint by EGGIM was -0.4059 kg carbon dioxide equivalents per patient, equivalent to 1 mile driven by a gasoline-powered car. The cost savings were calculated to be $47.36 per patient.

CONCLUSIONS

EGGIM is a reliable method for identifying high-risk gastric cancer patients, thereby reducing the carbon footprint and medical costs in endoscopy practice.

The prediction model of operative link on gastric intestinal metaplasia stage III-IV: A multicenter study

Purpose

Intestinal metaplasia plays a crucial role in the risk stratification of gastric cancer development. The objective of the study was to develop a prediction model for Operative Link on Gastric Intestinal Metaplasia (OLGIM) Stage III-IV.

Methods

We analyzed 7945 high-risk gastric cancer individuals from 115 hospitals who underwent questionnaires and gastroscope. The participants were assigned to either the development or validation cohort randomly. Demographics and clinical characteristics were obtained. The outcome measurement was OLGIM III-IV. Univariate logistic regression was used for feature selection and multivariate logistic analysis was performed to develop the nomogram. Area under the curves, calibration plots, decision curve and clinical impact analysis were used to assess the performance of the nomogram.

Results

4600 individuals and 3345 individuals were included in the development and validation cohort, of which 124 and 86 individuals were diagnosed with OLGIM III-IV, respectively. Parameters in the training validation cohort matched well and there was no significant difference between two cohorts. A nomogram model for predicting OLGIM Stage III-IV consisted of 4 significantly associated variables, including age, gender, PG I and G-17 (AUC 0.723 and 0.700 for the 2 cohorts). The nomogram demonstrated excellent performance in the calibration curve. Decision curve and clinical impact analysis suggested clinical benefit of the prediction model.

Conclusions

This reliable individualized nomogram might contribute to more accurate management for patients with OLGIM III-IV. Therefore, we suggest that this study be used as an incentive to promote the application.

Clinical Practice Guideline for Gastritis in Korea

Gastritis is a disease characterized by inflammation of the gastric mucosa. It is very common and has various classification systems such as the updated Sydney system. As there is a lot of evidence that Helicobacter pylori infection is associated with the development of gastric cancer and that gastric cancer can be prevented by eradication, H. pylori gastritis has been emphasized recently. The incidence rate of gastric cancer in Korea is the highest in the world, and due to the spread of screening endoscopy, atrophic gastritis and intestinal metaplasia are commonly diagnosed in the general population. However, there have been no clinical guidelines developed in Korea for these lesions. Therefore, this clinical guideline has been developed by the Korean College of Helicobacter and Upper Gastrointestinal Research for important topics that are frequently encountered in clinical situations related to gastritis. Evidence-based guidelines were developed through systematic review and de novo processes, and eight recommendations were made for eight key questions. This guideline needs to be periodically revised according to the needs of clinical practice or as important evidence about this issue is published in the future.

Risk assessment of metachronous gastric cancer development using OLGA and OLGIM systems after endoscopic submucosal dissection for early gastric cancer: a long-term follow-up study

BACKGROUND

Metachronous gastric cancer (MGC) may develop in patients undergoing curative endoscopic submucosal dissection for early gastric cancer. As gastritis and intestinal metaplasia are notable precursors to gastric cancer, we assessed MGC risk using the Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia assessment (OLGIM) systems.

METHODS

This retrospective cohort study classified the OLGA and OLGIM stages for 916 patients who had undergone endoscopic submucosal dissection for early gastric cancer between 2005 and 2015. MGC development was followed up until 2020 and risk factors were evaluated using the Cox proportional hazards regression analysis.

RESULTS

During a median follow-up of 94 months, MGC developed in 120 subjects. OLGA stages II ~ IV were significantly associated with increased MGC risk (hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.05-3.19; HR 2.31, 95% CI 1.22-4.38; HR 2.36, 95% CI 1.16-4.78) in multivariable analysis, even after adjusting for the well-known positive predictor of Helicobacter pylori eradication. OLGIM stages II ~ IV also showed significant association (HR 2.86, 95% CI 1.29-6.54; HR 2.94, 95% CI 1.34-6.95; HR 3.64, 95% CI 1.60-8.29). 5-year cumulative incidence increased with each stage. Helicobacter pylori-eradicated patients with OLGIM stages 0 ~ II had significantly less MGC than non-eradicated patients (4.5% vs 11.8%, p = 0.022), which was not observed with OLGIM stages III ~ IV.

CONCLUSIONS

High OLGA and OLGIM stages are independent risk factors for metachronous gastric cancer, with the OLGIM staging system being a better predictor. Patients with OLGIM stages 0 ~ II are a subgroup that may benefit more from Helicobacter pylori eradication.

Chinese integrated guideline on the management of gastric precancerous conditions and lesions

The standardized diagnosis and management of gastric precancerous conditions and lesions are important to prevent gastric cancer. This guideline, created by 5 traditional Chinese medicine and Western medicine associations, based on the current morbidity and diagnosis and treatment of gastric precancerous conditions and lesions, provides specific key points and strategies for diagnosis and treatment in the following five aspects: definition and epidemiology, diagnosis and stage, surveillance, treatment and efficacy evaluation. It is hoped that these aspects, assessed by integrating Western medicine and traditional Chinese medicine and involving multidisciplinary participation, will play a guiding role in clinical diagnosis and treatment and achieve effective secondary prevention of gastric cancer.

Endoscopic scoring system for gastric atrophy and intestinal metaplasia: correlation with OLGA and OLGIM staging: a single-center prospective pilot study in Korea

BACKGROUND/AIMS

We aimed to develop an endoscopic scoring system to evaluate gastric atrophy and intestinal metaplasia using narrow-band imaging (NBI) and near focus mode (NFM) to compare endoscopic scores with the Operative link for gastritis assessment (OLGA) and the Operative link for gastric intestinal metaplasia assessment (OLGIM).

METHODS

A total of 51 patients who underwent diagnostic esophagogastroduodenoscopy were prospectively enrolled and endoscopic scoring using NBI and NFM was performed. Four areas (the lesser and greater curvatures of the antrum and the lesser and greater curvature side of the corpus) were observed and biopsies were taken. The degree of atrophy was scored from 0 to 2 according to the Kimura-Takemoto classification. The degree of intestinal metaplasia was scored from 0 to 4 according to the location and the extent of the intestinal metaplasia.

RESULTS

The correlation coefficient for atrophy between the endoscopic and histologic scores was 0.70 (95% CI: 0.52-0.81 p < .001) and for intestinal metaplasia, it was 0.75 (95% CI: 0.60-0.85; p < .001). For atrophic gastritis, an endoscopic score >1 correlated with OLGA stage III and IV with a sensitivity, specificity, positive predictive value, negative predictive value, and agreement of 88, 74, 75, 87, and 80.4%, respectively, and for intestinal metaplasia, an endoscopic score >1 correlated with high OLGIM stage III and IV with 100, 59, 69, 100, and 78.4%, respectively.

CONCLUSIONS

Endoscopic scoring for gastric atrophy and intestinal metaplasia using NBI-NFM likely correlates with histologic staging in Korea, a high-risk region for gastric cancer.

The OLGA-OLGIM staging and the interobserver agreement for gastritis and preneoplastic lesion screening: a cross-sectional study

Stomach cancer (SC) incidence and mortality are relevant public health issues worldwide. In Colombia, screening for preneoplastic lesions (PNL) and the presence of H. pylori is not routinely performed. Therefore, the aim of this study was to evaluate OLGA-OLGIM staging and the interobserver agreement in gastritis and preneoplastic lesions in patients with gastroduodenal symptoms from Colombia. A cross-sectional study was conducted in 272 patients with gastroduodenal symptoms. Gastric biopsies were taken following the Updated Sydney System with the OLGA-OLGIM classification, and the results were evaluated by two pathologists. Chronic gastritis and PNL were reported in 76% and 24% of the patients, respectively. Furthermore, 25% of the patients with PNL displayed gastric atrophy (GA) and 75% intestinal metaplasia (IM). Agreement in the histopathological reading for IM was good, whereas for OLGA was variable, and for the H. pylori quantity was poor. OLGA-OLGIM stages 0-II were the most frequent (96%), while stage III (4%) and SC (4%) were the least frequent. Age and coffee consumption were associated with a higher prevalence of PNL. This work determined that 4% of the population is at high risk of developing SC and would benefit from follow-up studies. Reinforcement of training programs to improve the agreement in histopathology readings is required.

Current Evidence for a Paradigm Shift in Gastric Cancer Prevention From Endoscopic Screening to Helicobacter pylori Eradication in Korea

Gastric cancer is prevalent in Korea and ranked as the third most common cancer in 2019, followed by lung and thyroid cancers. The National Cancer Screening Program (NCSP) for gastric cancer has been implemented in adults aged ≥40 since 1999 and involves endoscopic screening every 2 years. The beneficial effects of the current NCSP on early cancer detection, cost-effectiveness, and mortality reduction are evident. However, the screening program results in a large socioeconomic burden and the consumption of medical resources, as it focuses solely on secondary prevention (early detection) rather than primary prevention of cancer. Helicobacter pylori is defined as a group I carcinogen by the International Agency for Research on Cancer. Hence, its eradication has been suggested as an important primary gastric cancer prevention strategy. Well-designed randomized controlled trials involving high-risk groups (post-endoscopic resection of early gastric cancer and family history of gastric cancer) and long-term follow-up studies in the general population have provided high-quality evidence regarding the effects of H. pylori eradication on gastric cancer prevention. In this review, we discussed the evidences for a possible modification of the current gastric cancer secondary prevention strategy by introducing primary prevention through H. pylori eradication. Areas for future research to optimize primary prevention strategies were also suggested.

Association of serum pepsinogen with degree of gastric mucosal atrophy in an asymptomatic population

BACKGROUND

Atrophic gastritis is a precancerous lesion of the stomach. It has been reported that pepsinogen (PG) can reflect the morphology and function of the gastric mucosa, and it is therefore used as a marker for the early diagnosis of atrophic gastritis.

AIM

To evaluate the diagnostic value of serum PG for degree of gastric mucosal atrophy in asymptomatic Chinese upon physical examination.

METHODS

Medical data were collected from subjects who underwent transnasal gastroscopy between October 2016 and October 2018. For each study subject, serum PG levels and presence of Helicobacter pylori (H. pylori) infection were investigated. Pathology was evaluated using the Operative Link for Gastritis Assessment (OLGA) classification and Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) systems. All statistical analyses were carried out using SPSS statistical software.

RESULTS

A total of 2256 subjects were enrolled and 1922 cases were finally included in the study. Based on the OLGA grading system, the levels of PGI were slightly decreased, while those of PGII were slightly increased. The PGI/PGII ratio (PGR) was reduced with increasing atrophy. The association between PG and OLGA grading was higher compared with that between PG and the OLGIM grading system. Compared with the OLGA-0 group, a statistically significant difference was observed in the mean age of OLGA-I, III, and IV groups (P < 0.05). In the H. pylori-positive subjects, the PGR levels were notably lower in the OLGA-I, II, and III groups compared with the OLGA-0 group (P < 0.05). H. pylori-positive subjects exhibited significantly higher PGI and PGII serum levels and a significantly lower PGR compared with H. pylori-negative patients in different OLGA groups (P < 0.05).

CONCLUSION

Serum PG levels may represent a non-invasive screening marker for gastric mucosal atrophy in asymptomatic subjects.

Gastric Cancer in BRCA1 Germline Mutation Carriers: Results of Endoscopic Screening and Molecular Analysis of Tumor Tissues

INTRODUCTION

There is some evidence suggesting a link between BRCA1/2 germline mutations and increased risk of gastric cancer.

METHODS

Endoscopic screening for stomach malignancies was performed in 120 BRCA1 mutation carriers in order to evaluate the probability of detecting the tumor disease.

RESULTS

No instances of gastric cancer were revealed at the first visit. The analysis of atrophic changes performed by OLGA (Operative Link for Gastritis Assessment) criteria revealed that OLGA stages I-IV alterations were observed in 26 of 41 (63%) subjects aged >50 years as compared to 29 of 79 (37%) in younger subjects (p = 0.007, χ2 test). One BRCA1 mutation carrier developed gastric cancer 4 years after the first visit for endoscopic examination. We performed next-generation sequencing analysis for this tumor and additional 4 archival gastric cancers obtained from BRCA1/2 mutation carriers. Somatic loss of the remaining BRCA1/2 allele was observed in 3 out of 5 tumors analyzed; all of these carcinomas, but none of the malignancies with the retained BRCA1/2 copy, showed chromosomal instability.

CONCLUSION

Taken together, these data justify further studies on the relationships between the BRCA1/2 and gastric cancer.

Pre-existing Helicobacter pylori serum IgG enhances the vibriocidal antibody response to CVD 103-HgR live oral cholera vaccine in Malian adults

Accumulating evidence indicates that persistent Helicobacter pylori gastric infection influences immune responses to oral enteric vaccines. We studied the association between pre-existing H. pylori serum IgG and serum pepsinogens levels (PGs) as markers of gastric inflammation and the immune response to single-dose live oral cholera vaccine CVD 103-HgR in Malian adults. Baseline sera obtained during a phase 2 safety/immunogenicity clinical trial of cholera vaccine CVD 103-HgR among 93 healthy Malian adults were tested for H. pylori IgG antibodies and PGI and PGII levels using enzyme linked immunosorbent assays. Overall 74/93 (80%) vaccine recipients were H. pylori IgG seropositive at baseline. Vibriocidal antibody seroconversion (≥ fourfold increase 14 days following administration of CVD 103-HgR compared to baseline) among vaccine recipients was 56%. However, vibriocidal antibody seroconversion was markedly higher among H. pylori seropositives than seronegatives 64% vs. 26% (p = 0.004); adjusted relative risk: 2.20 (95% confidence intervals 1.00–4.80; p = 0.049). Among H. pylori seropositive vaccine recipients, there were no significant associations between PGI, PGII and PGI:PGII levels and vibriocidal seroconversion. The enhanced seroconversion to oral cholera vaccine CVD 103-HgR among H. pylori seropositive African adults provides further evidence of the immunomodulating impact of H. pylori on oral vaccine immunogenicity.

Pepsinogen Serology and Gastritis OLGA Staging in Mucosal Atrophy Assessment: A Cross-Sectional Study Involving East China Endoscopy Population

The histological gastric stage (OLGA) plays an important role in evaluating gastric atrophy, a symptom which suggests a risk of gastric cancer (GC). However, gastroscopy is an invasive examination, which has limited application in populations undergoing physical examination. Serum pepsinogen (PG) and gastin-17 (G-17) levels are noninvasive indexes which are recommended when screening for GC. We aim to explore the correlation between PG/G-17 and OLGA stage, in order to provide reliable indexes for GC screening. The study included 453 asymptomatic individuals from East China undergoing physical examination, who then underwent endoscopy including collection of biopsy samples. Assays for serum PG, G-17, and Helicobacter pylori (Hp) were performed. Atrophy of gastric mucosa was graded according to OLGA for each individual. 453 participants, average age 52.46 ± 10.30 years, 253 male and 200 female, were included. In the asymptomatic physical examination population, serum PGI, PGII, and PGR levels decreased with increasing OLGA scores. PGI and PGR were inversely correlated with increasing OLGA stage in both Hp-positive and Hp-negative groups. The levels of serum PGI, PGII, and G-17 in the Hp-positive group were higher than those in the Hp-negative group; conversely, the PGR levels were lower. Furthermore, OLGA scores increased with age in the Hp-positive group. In conclusion, there is a significant correlation between OLGA stage and serum PG in populations from East China undergoing physical examination. Serum PG and G-17 combined with Hp test plays an important role in evaluating gastric atrophy.

Biopsy strategies for endoscopic screening of pre-malignant gastric lesions

Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) were adopted to evaluate gastric risk stratification in five biopsy samples. This study aimed to evaluate the degree of gastric atrophy (GA) and intestinal metaplasia (IM) in five locations to detect a more representative biopsy sample in gastric cancer (GC) screening. Our study enrolled 368 patients and 5 biopsy pieces were acquired from them. Gastric risk stratification was calculated by OLGA and OLGIM staging system. The results revealed that the IM score in the incisura angularis was higher than that in the larger and lesser curvature of corpus mucosa (p = 0.037 and p = 0.030, respectively) and the IM score in the lesser curvature of antrum mucosa was higher than that in the incisura angularis mucosa (p = 0.018). IM is more frequently observed in the angulus region than in the lesser curvature of corpus in the mild degree (p = 0.004) and mild IM lesions in the lesser curvature of antrum were more frequently observed than in the incisura angularis mucosa (p = 0.004), Four biopsy pieces protocol (larger curvature and lesser curvature of the antrum, lesser curvature of the corpus and angulus) demonstrated accurate consistency (97.83% and 98.37%, respectively) with a Kendall’s tau-b of higher than 0.990, along with low misdiagnosis rates of OLGA and OLGIM (III + IV) (9.76% and 5.00%, respectively). Three biopsy pieces protocol (lesser curvature of the antrum and corpus, angulus biopsy) in OLGA and OLGIM staging system was close to the standard protocol (five biopsy specimens) with a consistency of 94.84% and 94.29% and has a Kendall’s tau-b higher than 0.950 and diagnostic omission rates of 9.76% and 5.00%, respectively, which was exactly the same with the four biopsy pieces protocol. Furthermore, it had the second-highest Youden index (0.902 and 0.950, respectively) and area under the ROC curve (0.992 and 0.996, respectively) for the screening of high-risk GC by OLGA and OLGIM stages. Thus, we recommended the angulus and the lesser curvature of antrum as a conventional biopsy and three biopsy pieces for further GC risk screening.

Gastric cancer prevention targeted on risk assessment: Gastritis OLGA staging

Gastric cancer (GC) ranks among the most lethal epithelial malignancies, and its striking mortality rate prompts a global prevention strategy. Helicobacter pylori (H. pylori) gastritis is the main GC promoter, and the 2014 Global Kyoto conference recognized H. pylori gastritis as a (treatable) infectious disease. It is therefore plausible that any large-scale intervention for H. pylori eradication would result in cleansing the world of the fifth cause of cancer-related death. Atrophic gastritis is the cancerization field in which GCs (both intestinal and diffuse histotypes) mainly develop. Discontinuing the inflammatory cascade triggered by H. pylori is tantamount to preventing GC. For patients (still infected or eradicated) who have already developed gastric atrophy, the severity/topography of the atrophic changes correlates with their cancer risk. Gastritis OLGA (Operative Link for Gastritis Assessment) staging consistently ranks the atrophy-associated cancer risk, providing a solid clinical/biological rationale for establishing patient-specific surveillance programs. By combining primary and secondary prevention strategies, gastric cancer is a preventable disease.

Gastritis staging in the endoscopic follow-up for the secondary prevention of gastric cancer: a 5-year prospective study of 1755 patients

OBJECTIVE

Operative link on gastritis assessment (OLGA) staging for gastritis ranks the risk for gastric cancer (GC) in progressive stages (0-IV). This prospective study aimed at quantifying the cancer risk associated with each gastritis stage.

DESIGN

A cohort of 1755 consecutive patients with dyspepsia underwent initial (T-0) oesophagogastroduodenoscopy with mapped gastric biopsies, OLGA staging and assessment of Helicobacter pylori infection. Patients were followed for 55 months (median); patients with stages II III and IV underwent a second endoscopy/restaging (T-1), and those with stages 0 and I were followed clinically and through in-depth clinical and record checking. Endpoints were OLGA stage at T-1 and development of gastric epithelial neoplasia.

RESULTS

At T-0, 77.6% of patients had stage 0, 14.4% stage I, 5.1% stage II, 2.1% stage III and 0.85% stage IV. H. pylori infection was detected in 603 patients at T-0 and successfully eradicated in 602 of them; 220 had a documented history of H. pylori eradication; and 932 were H. pylori naïve-negative. Incident neoplastic lesions (prevalence=0.4%; low-grade intraepithelial neoplasia (IEN)=4; high-grade IEN=1; GC=2) developed exclusively in patients with stages III-IV. The risk for epithelial neoplasia was null in patients at stages 0, I and II (95% CI 0 to 0.4), 36.5 per 1000 person-years in patients at stage III (95% CI 13.7 to 97.4) and 63.1 per 1000 person-years in patients at stage IV (95% CI 20.3 to 195.6).

CONCLUSIONS

This prospective study confirms that OLGA staging reliably predicts the risk for development of gastric epithelial neoplasia. Although no neoplastic lesions arose in H. pylori-naïve patients, the H. pylori eradication in subjects with advanced stages (III-IV) did not abolish the risk for neoplastic progression.

Rate and predictive factors of Helicobacter pylori recurrence: Analysis of a screening cohort

BACKGROUND/AIM

The aim of the study was to identify the recurrence rate of Helicobacter pylori after successful eradication in an endemic area and investigate baseline and clinical factors related to the recurrence.

PATIENTS AND METHODS

H. pylori infected patients from a screening cohort of National Cancer Center between 2007 and 2012 were enrolled in the study. A total of 647 patients who were confirmed to be successfully eradicated were annually followed by screening endoscopy and rapid urease test. Median follow-up interval was 42 months. Annual recurrence rate of H. pylori was identified. Demographics, clinical factors, and endoscopic findings were compared between H. pylori recurrence group and persistently eradicated group (control group).

RESULTS

H. pylori recurrence was observed in 21 (3.25%) patients. Its annual recurrence rate was 0.91% (1.1% in males and 0.59% in females). Mean age was higher in the recurrence group than that in the control group (55.9 vs 50.7, P = 0.006). Median follow-up was shorter in the recurrence group than that in the control group (34 vs. 42.5 months, P = 0.031). In multivariate analysis, OR for H. pylori recurrence was 1.08 per each increase in age (P = 0.012). Adjusted ORs for H. pylori recurrence were 0.20 (95% CI: 0.06-0.69) and 0.25 (95% CI: 0.08-0.76) in age groups of 50-59 years and less than 50 years, respectively, compared to the group aged 60 years or older.

CONCLUSION

H. pylori recurrence rate in Korea is very low after successful eradication. Advanced age is at increased risk for H. pylori recurrence. Thus, H. pylori treatment for patients who are under 60 years of age is more effective, leading to maintenance of successful eradication status.

Assessment of Gastritis and Gastric Cancer Risk in the Chilean Population Using the OLGA System

Gastric cancer (GC) is the first cancer-related cause of death in Chile; however, no plan for GC early detection has been implemented in this country. The OLGA system characterizes gastritis from stages 0 to IV according to the risk of developing GC based on H. pylori infection, atrophy, metaplasia and GC. In this study, the performance of the OLGA system was evaluated in 485 Chilean patients receiving routine endoscopy to improve the detection of early GC or preneoplastic lesions. The results showed that OLGA scores, atrophy, metaplasia and GC increased significantly with age (p < 0.001). Conversely, H. pylori infection was higher in younger groups (p < 0.05). All gastric lesions were more frequent in men than women. The majority of patients with atrophy also had metaplasia (99%, p < 0.0001). Patients with H. pylori infection had more gastric atrophy and metaplasia than those without infection (p < 0.05). Of the 485 patients, 21 (4.3%) had GC, being 2.3 times more frequent among men than women and about 2/3 (14) were in OLGA stage ≥2. In addition, 19 (90%) GC patients had atrophy and 18 (85%) had metaplasia (p < 0.001). In conclusion, the OLGA system facilitated the evaluation of GC precursor lesions particularly in patients with an OLGA score > 2 between 45 and 56 years old, because this group showed atrophy and intestinal metaplasia more frequently. Therefore, biennial endoscopic surveillance of patients with an OLGA >2 can be an important health policy in Chile for diagnosing GC in its early stages and reducing mortality over the next two decades.

OLGA Gastritis Staging for the Prediction of Gastric Cancer Risk: A Long-term Follow-up Study of 7436 Patients

OBJECTIVES

Gastritis OLGA-staging ranks the risk for gastric cancer (GC) in progressive stages (0-IV). This long-term follow-up study quantifies the GC risk associated with each OLGA stage.

METHODS

Consecutive patients (7436) underwent esophagogastroscopy (T-0), with mapped gastric biopsies, OLGA staging, and H. pylori status assessment. Patients with neoplastic lesion (invasive or non-invasive) at the index endoscopy (and/or within 12 months) were excluded. All patients were followed-up (T-1) by combining different sources of clinical/pathological information (Regional Registries of: (i) esophagogastroduodenoscopies; (ii) pathology reports; (iii) cancer, (iv) mortality). The endpoint was histologically documented development of gastric epithelial neoplasia.

RESULTS

At T-0, the patients' distribution by OLGA stage was: Stage 0 = 80.8%; Stage I = 12.6%; Stage II = 4.3%; Stage III = 2.0%; Stage IV = 0.3%; H. pylori infection was detected in 25.9% of patients. At the end of the follow-up (mean/median = 6.3/6.6 years), 28 incident neoplasia were documented (overall prevalence = 0.60 per 10³/person-years; low-grade intraepithelial neoplasia = 17/28; high-grade intraepithelial neoplasia = 4/28; GC = 7/28). By OLGA stage at the enrollment, the rate of incident neoplasia was: Stage 0 = 1 case; rate/10³ person-years = 0.03; 95%CI: 0.004-0.19; Stage I = 2 cases; rate/10³ person-years = 0.34; 95%CI: 0.09-1.36; Stage II = 3 cases; rate/10³ person-years = 1.48; 95%CI: 0.48-4.58; Stage III = 17 cases; rate/10³ person-years = 19.1; 95%CI: 11.9-30.7; Stage IV = 5 cases; rate/10³ person-years = 41.2; 95%CI: 17.2-99.3. Multivariate analysis including gender, age, H. pylori status, and OLGA stage at enrollment only disclosed OLGA stage as predictor of neoplastic progression (OLGA stage III: HR = 712.4, 95%CI = 92.543-5484.5; OLGA stage IV: HR = 1450.7, 95%CI = 166.7-12626.0).

CONCLUSIONS

Among 7436 patients, OLGA stages at the enrollment correlated significantly with different risk for gastric neoplasia. Based on the obtained results, gastritis staging is a critical adjunct in endoscopy follow-up protocols aimed at GC secondary prevention.

Dietary n-3 and n-6 polyunsaturated fatty acids, the FADS gene, and the risk of gastric cancer in a Korean population

n-3 polyunsaturated fatty acids (PUFAs) and n-6 PUFAs are reported to have immunomodulatory effects, but few studies have examined these functions. Thus, we examined whether dietary n-3 and n-6 PUFAs are associated with the risk of gastric cancer and further investigated whether fatty acid desaturases 1 and 2 (FADS1 and FADS2) modify this association. In a case-control study, 1,464 participants (402 cases and 1,062 controls) were enrolled. A semi-quantitative food frequency questionnaire was utilized to measure dietary PUFA intake. Genotyping was performed using the Axiom® Exome 319 Array. Multivariable logistic models were established after adjusting for confounding variables. The risk of gastric cancer was significantly decreased among participants who had the highest tertile intake of docosahexaenoic acid (DHA), an n-3 PUFA, even after adjusting for covariates [odds ratios (OR) = 0.72, 95% confidence intervals (95% CIs) = 0.53-0.99]. However, no significant interaction according to FADS1 rs174546 or FADS2 rs174583 was observed. In conclusion, we observed a significant inverse association between dietary DHA and the risk of gastric cancer but found that FADS1 rs174546 and FADS2 rs174583 did not modify the association between dietary n-3 or n-6 PUFAs and gastric cancer risk.

Atrophic and Metaplastic Progression in the Background Mucosa of Patients with Gastric Adenoma

BACKGROUND

In patients with adenoma, assessing premalignant changes in the surrounding mucosa is important for surveillance. This study evaluated atrophic and metaplastic progression in the background mucosa of adenoma or early gastric cancer (EGC) cases.

METHODS

Among 146 consecutive patients who underwent endoscopic resection for intestinal-type gastric neoplasia, the adenoma group included 56 patients with low-grade dysplasia and the ECG group included 90 patients with high-grade dysplasia or invasive carcinoma. For histology, 3 paired biopsies were obtained from the antrum, corpus lesser curvature (CLC), and corpus greater curvature (CGC). Serological atrophy was determined based on pepsinogen A (PGA), progastricsin (PGC), gastrin-17, and total ghrelin levels. Topographic progression of atrophy and/or metaplasia was staged using the operative link on gastritis assessment (OLGA) and operative link on gastric intestinal metaplasia assessment (OLGIM) systems.

RESULTS

Rates of moderate-to-marked histological atrophy/metaplasia in patients with adenoma were 52.7%/78.2% at the antrum (vs. 58.8%/76.4% in EGC group), 63.5%/75.0% at the CLC (vs. 60.2%/69.7% in EGC group), and 10.9%/17.9% at the CGC (vs. 5.6%/7.8% in EGC group). Serological atrophy indicated by PGA and PGC occurred in 23.2% and 15.6% of cases in the adenoma and ECG groups, respectively (p = 0.25). Mean serum gastrin-17 concentrations of the adenoma group and EGC group were 10.4 and 9.0 pmol/L, respectively (p = 0.54). Mean serum total ghrelin levels were 216.6 and 209.5 pg/mL, respectively (p = 0.71). Additionally, between group rates of stage III-IV OLGA and OLGIM were similar (25.9% vs. 25.0%, p = 0.90; 41.8% vs. 44.9%, p = 0.71, respectively).

CONCLUSIONS

Atrophic and metaplastic progression is extensive and severe in gastric adenoma patients. A surveillance strategy for metachronous tumors should be applied similarly for patients with adenoma or EGC.

Helicobacter pylori infection is an independent risk factor for colonic adenomatous neoplasms

PURPOSE

Helicobacter pylori infection is considered to have a positive association with colorectal neoplasms. In this study, we evaluated the association between H. pylori infection and colorectal adenomas, based on the characteristics of these adenomas in Korea, where the prevalence of H. pylori infection is high and the incidence of colorectal cancer continues to increase.

METHODS

The study cohort consisted of 4,466 subjects who underwent colonoscopy and esophagogastroduodenoscopy during screening (1,245 colorectal adenomas vs. 3,221 polyp-free controls). We compared the rate of H. pylori infection between patients with adenoma and polyp-free control cases, using multivariable logistic regression analysis.

RESULTS

The overall rate of positive H. pylori infection was higher in adenoma cases than in polyp-free control cases (55.0 vs. 48.5%, p < 0.001). The odds ratio (OR) of positive H. pylori infection in patients with adenoma compared to polyp-free controls was 1.28 (95% CI 1.11-1.47). The positive association of H. pylori infection with colorectal adenomas was more prominent in advanced adenomas (OR 1.84, 95% CI 1.25-2.70) and multiple adenomas (OR 1.72, 95% CI 1.26-2.35). Based on the location of these adenomas, the OR was significant only in patients with colonic adenomas (OR 1.31, 95% CI 1.13-1.52) and not in those with rectal adenoma (OR 0.85, 95% CI 0.58-1.24).

CONCLUSION

Helicobacter pylori infection is an independent risk factor for colonic adenomas, especially in cases of advanced or multiple adenomas, but not for rectal adenomas.

[Helicobacter pylori gastritis: assessment of OLGA and OLGIM staging systems]

Helicobacter pylori (H pylori) gastritis presents a risk of cancer related to atrophy and intestinal metaplasia. Two recent classifications OLGA (Operative Link on Gastritis Assessment) and OLGIM (Operative Link on Gastritic Intestinal Metaplasia assessment) have been proposed to identify high-risk forms (stages III and IV). The aim of this study is to evaluate the OLGA and OLGIM staging systems in H pylori gastritis. A descriptive study of 100 cases of chronic H pylori gastritis was performed. The revaluation of Sydney System parameters of atrophy and intestinal metaplasia, of gastric antrum and corpus, allowed identifying respectively the stages of OLGA and OLGIM systems. The progressive risk of our H pylori gastritis was 6% according to OLGA staging and 7% according to OLGIM staging. Significant correlation was revealed between age and OLGA staging. High-risk gastritis according to OLGIM staging was significantly associated with moderate to severe atrophy. High-risk forms according to OLGA staging were associated in 80% of the cases to intestinal metaplasia. OLGA and OLGIM systems showed a highly significant positive correlation between them with a mismatch at 5% for H pylori gastritis. The OLGA and OLGIM staging systems in addition to Sydney System, allow selection of high risk forms of chronic gastritis requiring accurate observation.

Operative link on gastritis assessment stage is an appropriate predictor of early gastric cancer

AIM

To assess the predictive value of Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) stages in gastric cancer.

METHODS

A prospective study was conducted with 71 patients with early gastric cancer (EGC) and 156 patients with non-EGC. All patients underwent endoscopic examination and systematic biopsy. Outcome measures were assessed and compared, including the Japanese endoscopic gastric atrophy (EGA) classification method and the modified OLGA method as well as the modified OLGIM method. Helicobacter pylori (H. pylori) status was determined for all study participants. Stepwise logistic regression modeling was performed to analyze correlations between EGC and the EGA, OLGA and OLGIM methods.

RESULTS

For patients with EGC and patients with non-EGC, the proportions of moderate-to-severe EGA cases were 64.8% and 44.9%, respectively (P = 0.005), the proportions of OLGA stages III-IV cases were 52.1% and 22.4%, respectively (P < 0.001), and the proportions of OLGIM stages III-IV cases were 42.3% and 19.9%, respectively (P < 0.001). OLGA stage and OLGIM stage were significantly related to EGA classification; specifically, logistic regression modeling showed significant correlations between EGC and moderate-to-severe EGA (OR = 1.95, 95% CI: 1.06-3.58, P = 0.031) and OLGA stages III-IV (OR = 3.14, 95%CI: 1.71-5.81, P < 0.001), but no significant correlation between EGC and OLGIM stages III-IV (P = 0.781). H. pylori infection rate was significantly higher in patients with moderate-to-severe EGA (75.0% vs 54.1%, P = 0.001) or OLGA/OLGIM stages III-IV (OLGA: 83.6% vs 55.8%, P < 0.001; OLGIM: 83.6% vs 57.8%, P < 0.001).

CONCLUSION

OLGA classification is optimal for EGC screening. A surveillance program including OLGA stage and H. pylori infection status may facilitate early detection of gastric cancer.

Tobacco smoking and intestinal metaplasia: Systematic review and meta-analysis

BACKGROUND

The evaluation of specific risk factors for early endpoints in the gastric carcinogenesis pathway may further contribute to the understanding of gastric cancer aetiology.

AIMS

To quantify the relation between smoking and intestinal metaplasia through systematic review and meta-analysis.

METHODS

Articles providing data on the association between smoking and intestinal metaplasia were identified in PubMed(®), Scopus(®) and Web of Science™, searched until April 2014, and through backward citation tracking. Summary odds ratio estimates and 95% confidence intervals were computed using the DerSimonian and Laird method. Heterogeneity was quantitatively assessed using the I(2) statistic.

RESULTS

A total of 32 articles were included in this systematic review and 19 provided data for meta-analysis. Smoking was defined as ever vs. never (crude estimates, six studies, summary odds ratio=1.54, 95% confidence interval: 1.12-2.12, I(2)=67.4%; adjusted estimates, seven studies, summary odds ratio=1.26, 95% confidence interval: 0.98-1.61, I(2)=65.0%) and current vs. non-smokers (crude estimates, seven studies, summary odds ratio=1.27, 95% confidence interval: 0.88-1.84, I(2)=73.4%; adjusted estimates, two studies, summary odds ratio 1.49, 95% confidence interval: 0.99-2.25, I(2)=0.0%).

CONCLUSION

The weak and non-statistically significant association found through meta-analysis of the available evidence does not confirm smoking as an independent risk factor for intestinal metaplasia.