High Risk Of Gastric Cancer Research Articles

Decline of gastric cancer mortality in common variable immunodeficiency in the years 2018-2022.

In patients with Common Variable Immunodeficiency, malignancy has been reported as the leading cause of death in adults, with a high risk of B-cell lymphomas and gastric cancer. We conducted a five-year prospective study aiming to update the incidence and mortality of gastric cancer and the incidence of gastric precancerous lesions in 512 CVID patients who underwent a total of 400 upper gastrointestinal endoscopies. In the pre-pandemic period, 0.58 endoscopies were performed per patient/year and in the COVID-19 period, 0.39 endoscopies were performed per patient/year. Histology revealed areas with precancerous lesions in about a third of patients. Patients who had more than one gastroscopy during the study period were more likely to have precancerous lesions. Two patients received a diagnosis of gastric cancer in the absence of Helicobacter pylori infection. The overall prevalence of Helicobacter pylori infection in biopsy specimens was 19.8% and related only to active gastritis. Among patients who had repeated gastroscopies, about 20% progressed to precancerous lesions, mostly independent of Helicobacter pylori. While gastric cancer accounted for one in five deaths from CVID in our previous survey, no gastric cancer deaths were recorded in the past five years, likely consistent with the decline in stomach cancer mortality observed in the general population. However, during the COVID-19 pandemic, cancer screening has been delayed. Whether such a delay or true decline could be the reason for the lack of gastric cancer detection seen in CVID may become clear in the coming years. Due to the high incidence of precancerous lesions, we cannot rely on observed and predicted trends in gastric cancer mortality and strongly recommend tailored surveillance programs.

Analysis of gastrin-17 and its related influencing factors in physical examination results.

To analyze the difference of serum gastrin-17 (G17) level in healthy people with different sex, age, and body mass index (BMI), to explore the correlation between G17 and pepsinogen, and to study the influences of Helicobacter pylori (H. pylori) infection and various inflammatory factors on G17 secretion level. A total of 531 subjects who received physical examination in our center from April 2019 to December 2019 were enrolled in the study. All subjects were tested for G17, pepsinogen I (PGI), pepsinogen II (PGII), PGI/PGII ratio (PGR), H. pylori, serum amyloid A (SAA), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The difference of G17 secretion in different subjects and its correlation with PG were analyzed to investigate H. pylori infection and expound the effects of inflammatory indicators on G17. There was no significant difference in G17 secretion level in people with different sex, age and BMI (p > .05). G17 positively correlated with PGI and PGII, but negatively correlated with PGR. The G17 level of H. pylori-positive subjects was 10.16 ± 12.84, and prominently higher than that of H. pylori-negative subjects (3.27 ± 6.65). SAA and H. pylori infection were the greater risk factors for G17 abnormality among various indicators. CRP and ESR had no effect on G17 abnormality. G17 secretion is closely related to PG and H. pylori. Combined screening contributes to early screening of gastrointestinal diseases in normal people or groups at high risk for gastric cancer, but the influence of inflammatory indicators on G17 should be excluded to improve the reliability of the results.

Multidimensional Analysis of a Cell-Free DNA Whole Methylome Sequencing Assay for Early Detection of Gastric Cancer: Protocol for an Observational Case-Control Study.

Commonly used noninvasive serological indicators serve as a step before endoscope diagnosis and help identify the high-risk gastric cancer (GC) population. However, they are associated with high false positives and high false negatives. Alternative noninvasive approaches, such as cancer-related features in cell-free DNA (cfDNA) fragments, have been gradually identified and play essential roles in early cancer detection. The integrated analysis of multiple cfDNA features has enhanced detection sensitivity compared to individual features. This study aimed to develop and validate an assay based on assessing genomic-scale methylation and fragmentation profiles of plasma cfDNA for early cancer detection, thereby facilitating the early diagnosis of GC. The primary objective is to evaluate the overall specificity and sensitivity of the assay in predicting GC within the entire cohort, and subsequently within each clinical stage of GC. The secondary objective involved investigating the specificity and sensitivity of the assay in combination with possible serological indicators. This is an observational case-control study. Blood samples will be prospectively collected before gastroscopy from 180 patients with GC and 180 nonmalignant control subjects (healthy or with benign gastric diseases). Cases and controls will be randomly divided into a training and a testing data set at a ratio of 2:1. Plasma cfDNA will be isolated and extracted, followed by bisulfite-free low-depth whole methylome sequencing. A multidimensional model named Thorough Epigenetic Marker Integration Solution (THEMIS) will be constructed in the training data set. The model includes features such as the methylated fragment ratio, chromosomal aneuploidy of featured fragments, fragment size index, and fragment end motif. The performance of the model in distinguishing between patients with cancer and noncancer controls will then be evaluated in the testing data set. Furthermore, GC-related biomarkers, such as pepsinogen, gastrin-17, and Helicobacter pylori, will be measured for each patient, and their predictive accuracy will be assessed both independently and in combination with the THEMIS model. Recruitment began in November 2022 and will be ended in April 2024. As of August 2022,250 patients have been enrolled. The final data analysis is anticipated to be completed by September 2024. This is the first registered case-control study designed to investigate a stacked ensemble model integrating several cfDNA features generated from a bisulfite-free whole methylome sequencing assay. These features include methylation patterns, fragmentation profiles, and chromosomal copy number changes, with the aim of identifying the GC population. This study will determine whether multidimensional analysis of cfDNA will prove to be an effective strategy for distinguishing patients with GC from nonmalignant individuals within the Chinese population. We anticipate the THEMIS model will complement the standard-of-care screening and aid in identifying high-risk patients for further diagnosis. ClinicalTrial.gov NCT05668910; https://www.clinicaltrials.gov/study/NCT05668910. DERR1-10.2196/48247.

Gastric precancerous lesions:occurrence, development factors, and treatment.

Patients with gastric precancerous lesions (GPL) have a higher risk of gastric cancer (GC). However, the transformation of GPL into GC is an ongoing process that takes several years. At present, several factors including H.Pylori (Hp), flora imbalance, inflammatory factors, genetic variations, Claudin-4, gastric stem cells, solute carrier family member 26 (SLC26A9), bile reflux, exosomes, and miR-30a plays a considerable role in the transformation of GPL into GC. Moreover, timely intervention in the event of GPL can reduce the risk of GC. In clinical practice, GPL is mainly treated with endoscopy, acid suppression therapy, Hp eradication, a cyclooxygenase-2 inhibitor, aspirin, and diet. Currently, the use of traditional Chinese medicine (TCM) or combination with western medication to remove Hp and the use of TCM to treat GPL are common in Asia, particularly China, and have also demonstrated excellent clinical efficacy. This review thoroughly discussed the combining of TCM and Western therapy for the treatment of precancerous lesions as conditions allow. Consequently, this review also focuses on the causes of the development and progression of GPL, as well as its current treatment. This may help us understand GPL and related treatment.

Impact of interaction between interleukin-6 gene polymorphism and Helicobacter pylori infection on susceptibility to gastric cancer.

This study aimed to evaluate the association between four single nucleotide polymorphisms (SNPs) of the interleukin-6 (IL-6) gene and gastric cancer (GC), and impact of interaction between IL-6 SNPs and Helicobacter pylori (H. pylori ) infection on susceptibility to GC. Logistic regression was used to test the relationships between four SNPs of IL-6 gene and GC susceptibility. A generalized multifactor dimensionality reduction (GMDR) model was employed to assess the interaction effect between IL-6 gene and H. pylori infection on GC risk. Logistic regression analysis indicated that the rs1800795-C allele was associated with increased GC risk, adjusted ORs (95% CI) were 1.80 (1.21-2.41) (CC vs. GG) and 1.68 (1.09-2.30) (C vs. G), respectively. The rs10499563-C allele was associated with decreased risk of GC, and adjusted ORs (95% CI) were 0.62 (0.31-0.93) (TC vs. TT), 0.52 (0.18-0.89) (CC vs. TT) and 0.60 (0.29-0.92) (C vs. T), respectively. GMDR methods found a two-dimensional model combination (including rs1800795 and H. pylori infection) was statistically significant. The selected model had testing balanced accuracy of 59.85% and the best cross-validation consistencies of 10/10 ( P = 0.0107). Compared with H. pylori -negative subjects with rs1800795- GG genotype, H. pylori -positive participants with GC or CC genotype had the highest risk of GC, the OR (95% CI) was 3.34 (1.78-4.97). The rs1800795-C allele was associated with increased GC risk and the rs10499563-C allele was associated with decreased GC risk. The interaction between rs1800795 and H. pylori infection was also correlated with increased risk of GC.

Gastric Cancer Incidence and Mortality After Endoscopic Resection of Gastric Adenoma: A Nationwide Cohort Study.

Gastric adenoma is a precursor lesion of gastric cancer. We investigated whether the removal of gastric adenoma prevented gastric cancer incidence and its mortality. Using the linkage of nationwide databases, we assessed gastric cancer incidence and mortality among patients who had gastric adenomas removed between 2011 and 2013 in Korea. These outcomes were compared primarily with those of the Korean general population by estimating the standardized incidence and mortality ratio and secondarily with internal control subjects who did not have gastric neoplasm after esophagogastroduodenoscopy and were matched for age, sex, and calendar year by calculating hazard ratios (HR) with the Cox proportional hazards model. We identified 44,405 adenoma removal patients. During a median follow-up of 8.4 years, 1,038 (2.34%) of them were given a diagnosis of gastric cancer and a total of 524 gastric cancers were expected for a standard incidence ratio of 1.98 (95% confidence interval [CI], 1.84-2.13). A total of 199 deaths from gastric cancer were expected and 99 were observed for a standard mortality ratio of 0.50 (95% CI, 0.40-0.60). Compared with the nonadenoma cohort (n = 39,826), the adenoma removal patients had a higher risk of gastric cancer (HR, 2.84; 95% CI, 2.51-3.21) and associated mortality (HR, 1.66; 95% CI, 1.19-2.31). Removal of gastric adenoma resulted in lower-than-expected mortality but higher-than-expected incidence due to gastric cancer than that in the general population. Our analyses indicated the importance of follow-up strategy after removal of gastric adenoma.

Implementation of the updated Sydney system biopsy protocol improves the diagnostic yield of gastric preneoplastic conditions: Results from a real-world study

BackgroundThe updated Sydney system biopsy protocol (USSBP) standardizes the sampling of gastric biopsies for the detection of preneoplastic conditions (e.g., gastric intestinal metaplasia [GIM]), but the real-world diagnostic yield is not well-described. AimTo determine whether regular application of USSBP is associated with higher detection of chronic atrophic gastritis (CAG), GIM and autoimmune gastritis (AIG). MethodsWe performed a real-world retrospective study at an academic urban tertiary hospital in Chile. We manually reviewed medical records from consecutive patients undergoing esophagogastroduodenoscopy (EGD) from January to December 2017. Seven endoscopists who performed EGDs were categorized into two groups (USSBP ‘regular’ and USSBP ‘infrequent’) based on USSBP adherence, using minimum 20% adherence as the prespecified threshold. Multivariable logistic regression models were used to estimate the odds ratios (aOR) and 95% confidence intervals (CI) for the association between endoscopist groups and the likelihood of diagnosing CAG, GIM or AIG. Results1206 patients were included in the study (mean age: 58.5; 65.3% female). The USSBP regular group demonstrated a higher likelihood of detecting CAG (20% vs. 5.3%; aOR 4.03, 95%CI: 2.69–6.03), GIM (12.2% vs. 3.4%; aOR 3.91, 95%CI: 2.39–6.42) and AIG (2.9% vs. 0.8%; aOR 6.52, 95%CI: 1.87–22.74) compared to infrequent group. Detection of advanced-stage CAG (Operative Link for Gastritis Assessment stage III/IV) was significantly higher in the USSBP regular vs. infrequent group (aOR 5.84, 95%CI: 2.23–15.31). ConclusionsRoutine adherence to USSBP increases the detection rates of preneoplastic conditions, including CAG, GIM and AIG. Standardized implementation of USSBP should be considered in high gastric cancer risk populations.

Association between history of cholecystectomy and risk of gastric cancer: a meta-analysis of epidemiological studies

PurposeEvidence from previous studies on the association between cholecystectomy and risk of gastric cancer are still inconsistent. We aimed at conducting a meta-analysis of epidemiological studies to evaluate this association.MethodsResearchers...

The Helicobacter pylori single nucleotide polymorphisms SNPs associated with multiple therapy resistance in Colombia.

The eradication of Helicobacter pylori (H. pylori) using multiple therapies is used as a prevention strategy. However, its efficacy has been compromised by the emergence of single nucleotide polymorphisms in genes associated with H. pylori's resistance to multiple antibiotics. To estimate antibiotic resistance rates associated with mutations in H. pylori genes in the high-cancer-risk population in Colombia, we included 166 H. pylori whole genome sequences from a cohort of individuals with a high risk of gastric cancer. By using the reference strain ATCC 26695, we identified mutations in specific genes to evaluate resistance rates for different antibiotics: 23S rRNA for clarithromycin, 16S rRNA for tetracycline, pbp1A for amoxicillin, gyrA for levofloxacin, and rdxA for metronidazole. The phylogenomic analysis was conducted using the core genome consisting of 1,594 genes of H. pylori-ATCC 26695. Our findings revealed that the resistance rate of H. pylori to clarithromycin was 3.62%, primarily associated with mutations A2143G and A2142G in the 23S rRNA gene. For tetracycline, the resistance rate was 7.23%, with mutations A926G, A926T, and A928C observed in the 16S rRNA gene. Amoxicillin resistance was found in 25.9% of cases, with observed mutations in the pbp1A gene, including T556S, T593, R649K, R656P, and R656H. In the gyrA gene, mutations N87K, N87I, D91G, D91N, and D91Y were identified, resulting in a resistance rate of 12.04% to levofloxacin. The most common mutations in the rdxA gene associated with metronidazole resistance were a stop codon, and mutations at D59N and D59S, resulting in a resistance rate of 99.3%. The high resistance rate of H. pylori to metronidazole indicated that this drug should be excluded from the eradication therapy. However, the resistance rates for tetracycline and clarithromycin did not exceed the established resistance threshold in Colombia. The increased resistance rate of H. pylori to levofloxacin and amoxicillin may partially explain the observed therapeutic failures in Colombia. The phylogenomic tree showed that the H. pylori isolate belongs to its own lineage (hspColombia). These findings offer valuable insights to enhance the characterization of treatment protocols for the specific H. pylori lineage (hspColombia) at the local level.

Identification of a six-gene signature to predict survival and immunotherapy effectiveness of gastric cancer.

Gastric cancer (GC) ranks as the fifth most prevalent malignancy and the second leading cause of oncologic mortality globally. Despite staging guidelines and standard treatment protocols, significant heterogeneity exists in patient survival and response to therapy for GC. Thus, an increasing number of research have examined prognostic models recently for screening high-risk GC patients. We studied DEGs between GC tissues and adjacent non-tumor tissues in GEO and TCGA datasets. Then the candidate DEGs were further screened in TCGA cohort through univariate Cox regression analyses. Following this, LASSO regression was utilized to generate prognostic model of DEGs. We used the ROC curve, Kaplan-Meier curve, and risk score plot to evaluate the signature's performance and prognostic power. ESTIMATE, xCell, and TIDE algorithm were used to explore the relationship between the risk score and immune landscape relationship. As a final step, nomogram was developed in this study, utilizing both clinical characteristics and a prognostic model. There were 3211 DEGs in TCGA, 2371 DEGs in GSE54129, 627 DEGs in GSE66229, and 329 DEGs in GSE64951 selected as candidate genes and intersected with to obtain DEGs. In total, the 208 DEGs were further screened in TCGA cohort through univariate Cox regression analyses. Following this, LASSO regression was utilized to generate prognostic model of 6 DEGs. External validation showed favorable predictive efficacy. We studied interaction between risk models, immunoscores, and immune cell infiltrate based on six-gene signature. The high-risk group exhibited significantly elevated ESTIMATE score, immunescore, and stromal score relative to low-risk group. The proportions of CD4+ memory T cells, CD8+ naive T cells, common lymphoid progenitor, plasmacytoid dentritic cell, gamma delta T cell, and B cell plasma were significantly enriched in low-risk group. According to TIDE, the TIDE scores, exclusion scores and dysfunction scores for low-risk group were lower than those for high-risk group. As a final step, nomogram was developed in this study, utilizing both clinical characteristics and a prognostic model. In conclusion, we discovered a 6 gene signature to forecast GC patients' OS. This risk signature proves to be a valuable clinical predictive tool for guiding clinical practice.

EBV antibody and gastric cancer risk: a population-based nested case-control study in southern China

BackgroundWe aim to clarify the controversial associations between EBV-related antibodies and gastric cancer risk.MethodsWe analysed the associations between serological Epstein-Barr nuclear antigen 1 immunoglobulin A (EBNA1-IgA) and viral capsid antigen immunoglobulin A (VCA-IgA) by enzyme-linked immunosorbent assay and the risk of gastric cancer in a nested case-control study originated from a population-based nasopharyngeal carcinoma (NPC) screening cohort in Zhongshan, a city of southern China, including 18 gastric cancer cases and 444 controls. Conditional logistic regression was used to calculate the odds ratios (ORs) and corresponding 95% confidence intervals (CIs).ResultsAll the sera of cases were sampled before diagnosis and the median time interval was 3.04 (range: 0.04, 7.59) years. Both increased relative optical density (rOD) values of EBNA1-IgA and VCA-IgA were associated with higher risks of gastric cancer with age adjusted ORs of 1.99 (95%CI: 1.07, 3.70) and 2.64 (95%CI: 1.33, 5.23), respectively. Each participant was further classified as high or medium/low risk based on a combination of two anti-EBV antibody levels. Participants in the high-risk group had substantially higher odds of developing gastric cancer than that in the medium/low risk group with an age adjusted OR of 6.53 (95%CI: 1.69, 25.26).ConclusionsOur research reveals positive associations between EBNA1-IgA and VCA-IgA and gastric cancer risk in southern China. We thus postulate that EBNA1-IgA and VCA-IgA might appear to be potential biomarkers for gastric cancer. More research to further validate the results among diverse populations and investigate its underlying biological mechanism is needed.

Clinical Application of the Kyoto Classification of Gastritis

Recent advances in endoscopic technology, including high-definition and image-enhanced endoscopy such as narrow-band imaging have facilitated close observation and detailed imaging of the gastric mucosa. Currently, endoscopy is performed in Korea primarily for evaluation of premalignant conditions and gastric cancer detection. Recent research has established the Kyoto classification of gastritis, a novel grading system for endoscopic gastritis, which enables prediction of Helicobacter pylori (H. pylori) infection. The Kyoto classification score is calculated based on the sum of scores for five main items (of 19 endoscopic findings indicative of H. pylori infection) such as atrophy, intestinal metaplasia, enlarged gastric folds, nodularity, and diffuse redness with/without regular arrangement of collecting venules (RAC). Of these five endoscopic findings, atrophy, intestinal metaplasia, enlarged gastric folds, and nodularity are associated with an increased risk and RAC with a decreased risk of gastric cancer. Previous studies have reported that a Kyoto classification score ≥2 indicates current or past H. pylori infection. An increase in the Kyoto classification score is associated with a high risk of gastric cancer; specifically, a Kyoto classification score ≥4 indicates a high risk of gastric cancer. However, H. pylori eradication is followed by disappearance of enlarged gastric folds, nodularity, and diffuse redness; therefore, this grading system cannot accurately reflect the gastric cancer risk in patients with previous H. pylori infection. Limited studies have discussed the Kyoto classification of gastritis in Korea. Therefore, further large-scale multicenter studies are warranted for validation of the Kyoto classification to predict H. pylori infection and gastric cancer risk.

P-134 Biomolecules with potential inhibitor of Helicobacter pylori isolated from patients with high risk of gastric cancer in Colombia

P-134 Biomolecules with potential inhibitor of Helicobacter pylori isolated from patients with high risk of gastric cancer in Colombia

Identification and validation of an epithelial-mesenchymal transition-related lncRNA pairs prognostic model for gastric cancer.

Gastric cancer (GC) is a common malignancy. A mounting body of evidence has demonstrated the correlation between GC prognosis and epithelial-mesenchymal transition (EMT)-related biomarkers. This research constructed an available model using EMT-related long noncoding RNA (lncRNA) pairs to predict the survival for GC patients. The transcriptome data along with clinical information on GC samples were derived from The Cancer Genome Atlas (TCGA). Differentially expressed EMT-related lncRNAs were acquired and paired. Univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses were applied to filter lncRNA pairs, and the risk model was built to investigate its effect on the prognosis of GC patients. Then, the areas under the receiver operating characteristic curves (AUCs) were calculated and the cutoff point for distinguishing low- or high-risk GC patients was identified. And the predictive ability of this model was tested in the GSE62254. Furthermore, the model was evaluated from the perspectives of survival time, clinicopathological parameters, infiltration of immunocytes, and functional enrichment analysis. The risk model was built by using the identified twenty EMT-related lncRNA pairs, and it was not necessary to know the specific expression level of each lncRNA. Survival analysis pointed out that GC patients with high risk had poorer outcomes. Additionally, this model could be an independent prognostic variable for GC patients. The accuracy of the model was also verified in the testing set. The new predictive model constructed here is composed of EMT-related lncRNA pairs, with reliable prognostic values, and can be utilized to predict the survival of GC.

Factors associated with detection of hereditary diffuse gastric cancer on endoscopy in individuals with germline CDH1 mutations

Individuals with germline pathogenic CDH1 variants have a high risk of hereditary diffuse gastric cancer. The sensitivity of EGD in detecting signet ring cell carcinoma (SRCC) in this population is low. We aimed to identify endoscopic findings and biopsy practices associated with detection of SRCC. This retrospective cohort included individuals with a germline pathogenic/likely pathogenic CDH1 variant undergoing at least 1 EGD at Memorial Sloan Kettering Cancer Center between January 1, 2006, and March 25, 2022. The primary outcome was detection of SRCC on EGD. Findings on gastrectomy were also assessed. The study included periods before and after implementation of the Cambridge protocol for endoscopic surveillance, allowing for assessment of a spectrum of biopsy practices. Ninety-eight CDH1 patients underwent at least 1 EGD at our institution. SRCC was detected in 20 (20%) individuals on EGD overall and in 50 (86%) of the 58 patients undergoing gastrectomy. Most SRCC foci were detected in the gastric cardia/fundus (EGD, 50%; gastrectomy, 62%) and body/transition zone (EGD, 60%; gastrectomy, 62%). Biopsy results of gastric pale mucosal areas were associated with detection of SRCC (P< .01). The total number of biopsy samples taken on EGD was associated with increased detection of SRCC (P= .01), with 43% detected when≥40 samples were taken. Targeted biopsy sampling of gastric pale mucosal areas and increasing number of biopsy samples taken on EGD were associated with detection of SRCC. SRCC foci were mostly detected in the proximal stomach, supporting updated endoscopic surveillance guidelines. Further studies are needed to refine endoscopic protocols to improve SRCC detection in this high-risk population.

Importance of Early Surveillance Endoscopy in Patients at a High Risk of Gastric Cancer

Importance of Early Surveillance Endoscopy in Patients at a High Risk of Gastric Cancer

Abstract 6014: Cancer risk diagnosis by epimutation burden: a multicenter prospective study

Abstract Aberrant DNA methylation, induced by aging and accelerated by chronic inflammation, accumulates in normal tissue. Accumulation of DNA methylation in multiple genes, namely epimutation burden, is closely associated with cancer risk. Indeed, we demonstrated that the measurement of the methylation level of a marker gene in normal tissue is useful for cancer risk prediction of metachronous cancers, by a multicenter prospective study with gastric cancer patients (Asada, Gut, 64:388, 2015: Maeda, Gut, 66:1721, 2017). In this study, we attempted to predict the risk of primary gastric cancer by performing a new multicenter prospective study. We recruited 1,880 healthy people, after Helicobacter pylori eradication, with a clinically high risk of gastric cancer. Biopsy specimens were obtained from the antrum and body, and the methylation level of RIMS1, which is a preselected epigenomic risk marker for this study, was measured in 1,757 participants. The participants are annually being followed-up to detect primary gastric cancer, for 5-8 years. Currently, the median follow-up is 4.05 years, and 27 people have developed primary gastric cancers (as of September 2022). The results of statistical analysis are being determined. This study will establish the clinical utility of a cancer risk diagnosis by epimutation burden in normal tissue, and is promising for application in various inflammation-associated cancers. Citation Format: Harumi Yamada, Masahiro Maeda, Seiichiro Abe, Taichi Shimazu, Takayuki Ando, Kazunari Murakami, Shinji Tanaka, Takao Maekita, Osamu Inatomi, Ken Sugimoto, Tetsuro Kawagoe, Nobutake Yamamichi, Toshikazu Ushijima. Cancer risk diagnosis by epimutation burden: a multicenter prospective study. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6014.

Abstract 6460: Smoking initiation at young age increases risk of gastric cancer among Korean men

Abstract Objective: Early initiation of smoking is associated with adverse health outcomes. This study aimed to investigate the association of various smoking-related factors with the risk of gastric cancer in a population with a high incidence rate of gastric cancer. Method: From 2004 to 2013, Korean adults 40-69 years of age were enrolled in the large-scale prospective cohort, the Health Examinees-Gem study. Incident gastric cancer cases were identified until December 31, 2017, through linkage to the Korea Central Cancer Registry. Participants’ information regarding socio-demographics, smoking-related factors, and other lifestyle factors was obtained via self-reported questionnaires. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for gastric cancer risk associated with smoking-related factors such as smoking duration, amount, pack-years, and age of smoking initiation. Results: Among 44,207 men included in the final analysis, 565 gastric cancer cases were identified during a mean (±SD) follow-up period of 8.6 (±2.0) years. Compared to non-smokers, current smokers who smoked for more than 35 years (HR 1.44, 95% CI 1.06-1.96) or with ≥30 pack-years of smoking (HR 1.40, 95% CI 1.05-1.87) were positively associated with gastric cancer. These associations were shown to be significant with increasing smoking years (p trend 0.019) and pack-years (0.016) as well. Compared to non-smokers, current smokers who initiated smoking at a younger age, before or at 20 years, were at a higher risk of gastric cancer (HR 1.46, 95% CI 1.10-1.93). No significant associations were observed among former smokers. When stratified by smoking duration, increased risk of gastric cancer was observed among those who smoked for more than 25 years in the younger smoking initiation age group (≤20 years; HR 1.50, 95% CI 1.15-1.94). In terms of smoking intensity, those who smoked less than 20 cigarettes or 1 pack a day showed an increased risk of gastric cancer in the younger smoking initiation age group that began smoking before or at 20 years of age (HR 1.78, 95% CI 1.30-2.44). Conclusion: Our findings suggest that earlier initiation of smoking is associated with a greater risk of gastric cancer. Among those who began smoking early, longer duration is an important factor, but increased gastric cancer risk was also observed among those who smoked moderate amount on a daily basis. Thus, measures to manage and control onset age of cigarette smoking among teenagers may be considered when taking actions against the health burden of gastric cancer. Citation Format: Hwi-Won Lee, Woo-Kyoung Shin, Dan Huang, Katherine De la Torre, Jae Jeong Yang, Minkyo Song, Aesun Shin, Kyoung-Mu Lee, Hyuk-Joon Lee, Jong-koo Lee, Daehee Kang. Smoking initiation at young age increases risk of gastric cancer among Korean men. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6460.

Abstract 761: Integrated environmental, lifestyle, and epigenetic risk prediction of primary gastric cancer

Abstract Aberrant DNA methylation accumulates in non-malignant gastric mucosa after exposure to environmental pathogens such as H. pylori (HP). To understand how environmental factors and DNA methylation interplay to influence primary gastric cancer (GC) risk, we performed an integrated analysis of clinical factors and DNA methylation data of gastric tissues from a longitudinally monitored cohort in Japan, with validation in a separate cohort from Singapore. The Japanese check-up cohort included 4,234 healthy subjects who underwent gastric mucosal biopsy. The median observation period was 4.2 years, and 77 subjects developed GC. GC incidence correlated with age, drinking, smoking, GC family history, and HP status in the multivariable Cox model. Next, we conducted comprehensive DNA methylation analysis using Infinium MethylationEPIC arrays on gastric tissues (n=164), including (1) mucosal biopsies from subjects who later developed GC (“future GC patients”), (2) mucosal biopsies from HP(+) subjects who did not later develop GC (“future non-GC subjects”), (3) mucosal biopsies from future non-GC HP(−) subjects (“control mucosae”), and (4) GCs and surrounding mucosae. Infinium data of gastric mucosae (n=137) collected in the GCEP cohort (Singapore) were also analyzed. DNA methylation of promoter region observed in GCs, accumulated not only in mucosae adjacent to GCs but also in the biopsy mucosae of future GC patients. Mucosae of future non-GC subjects were more methylated than control mucosae but less methylated than mucosae of future GC patients. Similar findings were observed in the GCEP cohort. DNA methylation levels were associated with clinical factors and histopathological alterations - however, in multivariable analyses, DNA methylation remained an independent GC risk factor. Methylation levels were predictive of not only higher GC risk but also a shorter period to GC incidence. We then focused on the associations between environmental factors and methylation. Heavy drinking and smoking were associated with the accumulation of DNA methylation only in HP(+) subjects. The increases in methylation over time in subjects who quit smoking were significantly attenuated compared to continuous smokers. These results suggest that pro-carcinogenic epigenetic alterations initiated by HP exposure are amplified by unfavorable but modifiable lifestyle choices. Furthermore, target genes methylated by each environmental factor may overlap in part; however, they were not necessarily methylated similarly, suggesting that the best markers for stratifying GC risk may differ for each subgroup classified by exposure to environmental factors. Indeed, candidate markers for stratifying GC risk overlapped among subgroups, whereas markers unique to each subgroup were also identified, highlighting the potential of integrating environmental, lifestyle, and epigenetic information to inform GC precision prevention. Citation Format: Genki Usui, Keisuke Matsusaka, Kie K. Huang, Feng Zhu, Tomohiro Shinozaki, Masaki Fukuyo, Bahityar Rahmutulla, Norikazu Yogi, Tomoka Okada, Motoaki Seki, Eiji Sakai, Kazutoshi Fujibayashi, Stephen K. Tsao, Christopher Khor, Tiing L. Ang, Hiroyuki Abe, Hisahiro Matsubara, Masashi Fukayama, Toshiaki Gunji, Nobuyuki Matsuhashi, Teppei Morikawa, Tetsuo Ushiku, Khay G. Yeoh, Patrick Tan, Atsushi Kaneda. Integrated environmental, lifestyle, and epigenetic risk prediction of primary gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 761.

Joint Effects Between CDKN2B/P15 Methylation and Environmental Factors on the Susceptibility to Gastric Cancer.

The incidence of gastric cancer has long been at a high level in China, seriously affecting the health of Chinese people. This case‒control study was performed to identify gene methylation biomarkers of gastric cancer susceptibility. A total of 393 gastric cancer cases and 397 controls were included in this study. Gene methylation in peripheral blood leukocytes was detected by a methylation-sensitive high-resolution melting method, and the Helicobacter pylori antibody presence was semi-quantified in serum by ELISA. Individuals with total methylation of CDKN2B/P15 had a 1.883-fold (95%CI: 1.166-3.040, P = 0.010) risk of gastric cancer compared with unmethylated individuals. Individuals with both CDKN2B/P15 and NEUROG1 methylation had a higher risk of gastric cancer (OR = 2.147, 95% CI: 1.137-4.073, P = 0.019). The interaction between CDKN2B/P15 and NEUROG1 total methylation on gastric cancer risk was affected by the pattern of adjustment. In addition, the joint effects between CDKN2B/P15 total methylation and environmental factors, such as freshwater fish intake (OR = 6.403, 95% CI = 2.970-13.802, P < 0.001), irregular diet (OR = 5.186, 95% CI = 2.559-10.510, P < 0.001), unsanitary water intake (OR = 2.238, 95% CI = 1.144-4.378, P = 0.019), smoking (OR = 2.421, 95% CI = 1.456-4.026, P = 0.001), alcohol consumption(OR = 2.163, 95% CI = 1.309-3.576, P = 0.003), and garlic intake(OR = 0.373, 95% CI = 0.196-0.709, P = 0.003) on GC risk were observed, respectively. However, CDKN2B/P15 and NEUROG1 total methylation were not associated with gastric cancer prognosis. CDKN2B/P15 methylation in peripheral blood may be a potential biomarker for evaluating susceptibility to gastric cancer. The joint effects between CDKN2B/P15 methylation and environmental factors may also contribute to gastric cancer susceptibility.