Helicobacter Pylori-negative Gastric Cancer Research Articles

Combined DNA Methylation and Gastric Microbiome Marker Predicts Helicobacter pylori-Negative Gastric Cancer.

While DNA methylation and gastric microbiome are each associated with gastric cancer (GC), their combined role in predicting GC remains unclear. This study investigated the potential of a combined DNA methylation and gastric microbiome signature to predict Helicobacter pylori-negative GC. In this case-control study, we conducted quantitative methylation-specific polymerase chain reaction to measure the methylation levels of DKK3, SFRP1, EMX1, NKX6-1, MIR124-3, and TWIST1 in the gastric mucosa from 75 H. pylori-negative patients, including chronic gastritis (CG), intestinal metaplasia (IM), and GC. A combined analysis of DNA methylation and gastric microbiome, using 16S rRNA gene sequencing, was performed in 30 of 75 patients. The methylation levels of DKK3, SFRP1, EMX1, MIR124-3, and TWIST1 were significantly higher in patients with GC than in controls (all q<0.05). MIR124-3 and TWIST1 methylation levels were higher in patients with IM than those with CG and also in those with GC than in those with IM (all q<0.05). A higher methylation level of TWIST1 was an independent predictor for H. pylori-negative GC after adjusting for age, sex, and atrophy (odds ratio [OR], 15.15; 95% confidence interval [CI], 1.58 to 145.46; p=0.018). The combination of TWIST1 methylation and GC microbiome index (a microbiome marker) was significantly associated with H. pylori-negative GC after adjusting for age, sex, and atrophy (OR, 50.00; 95% CI, 1.69 to 1,476; p=0.024). The combination of TWIST1 methylation and GC microbiome index may offer potential as a biomarker for predicting H. pylori-negative GC.

Impact of metabolic dysfunction-associated fatty liver disease on the incidence of Helicobacter pylori-negative gastric cancer.

The incidence of Helicobacter pylori-negative gastric cancer (HPNGC) is increasing worldwide. Recently, metabolic dysfunction-associated fatty liver disease (MAFLD) has been reported to be associated with various cancers, but its association with HPNGC has not been reported. We aimed to identify important independent factors associated with HPNGC, including MAFLD. This multicenter observational cohort study enrolled patients with gastric cancer (n=1078) and health checkup examinees (n=17408). We analyzed patients with HPNGC (n=26) and healthy participants with no H. pylori infection or any abnormal findings on upper gastrointestinal endoscopy (n=1130). A logistic regression model was used to identify independent factors associated with HPNGC. The priority of the factors associated with HPNGC was evaluated using a decision-tree algorithm and random forest analysis. Among all patients with gastric cancer, 2.4% (26/1078) were diagnosed with HPNGC (mean age, 64years; male/female, 13/13). In the logistic regression analysis, age, smoking, and MAFLD (odds ratio, 6.5359; 95% confidence interval, 2.5451-16.7841; p<0.0001) were identified as independent factors associated with HPNGC. Metabolic dysfunction-associated fatty liver disease was also identified as the most important classifier for the presence of HPNGC in decision-tree analyses. Helicobacter pylori-negative gastric cancer was observed in 5.2% of patients with MAFLD and 0.8% of patients without MAFLD. In the random forest analysis of the HPNGC, MAFLD was identified as the distinguishing factor with the highest variable importance (0.32). Metabolic dysfunction-associated fatty liver disease was the most influential independent factor associated with HPNGC. These findings suggest that fatty liver and metabolic dysfunction could be involved in the pathogenesis of HPNGC.

Altered Gastric Microbiota and Inflammatory Cytokine Responses in Patients with Helicobacter pylori-Negative Gastric Cancer.

The role of the gastric mucosal microbiome in Helicobacter pylori-negative gastric cancer (GC) remains unclear. Therefore, we aimed to characterize the microbial alterations and host inflammatory cytokine responses in H. pylori-negative GC. Gastric mucosal samples were obtained from 137 H. pylori-negative patients with GC (n = 45) and controls (chronic gastritis or intestinal metaplasia, n = 92). We performed 16S rRNA gene sequencing (n = 67), a quantitative reverse transcription-polymerase chain reaction to determine the relative mRNA expression levels of TNF (tumor necrosis factor), IL1B (interleukin 1 beta), IL6 (interleukin 6), CXCL8 (C-X-C motif chemokine ligand 8), IL10 (interleukin 10), IL17A (interleukin 17A), TGFB1 (transforming growth factor beta 1) (n = 113), and the correlation analysis between sequencing and expression data (n = 47). Gastric mucosal microbiota in patients with GC showed reduced diversity and a significantly different composition compared to that of the controls. Lacticaseibacillus was significantly enriched, while Haemophilus and Campylobacter were depleted in the cancer group compared to the control group. These taxa could distinguish the two groups in a random forest algorithm. Moreover, the combined relative abundance of these taxa, a GC microbiome index, significantly correlated with gastric mucosal IL1B expression, which was elevated in the cancer group. Overall, altered gastric mucosal microbiota was found to be associated with increased mucosal IL1B expression in H. pylori-negative GC.

Microbiome changes in the gastric mucosa and gastric juice in different histological stages of Helicobacter pylori-negative gastric cancers.

BACKGROUNDThe gastric microbiota in patients with gastric cancer (GC) has received increasing attention, but the profiling of the gastric microbiome through the histological stages of gastric tumorigenesis remains poorly understood, especially for patients with Helicobacter pylori-negative GC (HPNGC).AIMTo characterize microbial profiles of gastric mucosa and juice for HPNGC carcinogenesis and identify distinct taxa in precancerous lesions.METHODSThe 16S rRNA gene analysis was performed on gastric mucosa from 134 Helicobacter pylori-negative cases, including 56 superficial gastritis (SG), 9 atrophic gastritis (AG), 27 intestinal metaplasia (IM), 29 dysplasia (Dys), and 13 GC cases, to investigate differences in gastric microbial diversity and composition across the disease stages. In addition, paired gastric mucosa and juice samples from 18 SG, 18 IM, and 18 Dys samples were analyzed. α-Diversity was measured by Shannon and Chao1 indexes, and β-diversity was calculated using partial least squares discrimination analysis (PLS-DA). Differences in the microbial composition across disease stages in different sample types were assessed using the linear discriminant analysis effect size.RESULTSThe diversity and composition of the bacterial microbiota in the gastric mucosa changed progressively across stages of gastric carcinogenesis. The diversity of the gastric mucosa microbiota was found to be significantly lower in the IM and Dys groups than in the SG group, and the patients with GC had the lowest bacterial community richness (P < 0.05). Patients with IM and those with Dys had similar gastric mucosa microbiota profiles with Ralstonia and Rhodococcus as the predominant genera. Microbial network analysis showed that there was increasing correlation strength between IM and Dys (|correlation threshold|≥ 0.5, P < 0.05). GC and its precancerous lesions have distinguishable bacterial taxa; our results identified HPNGC-associated bacteria Streptococcaceae and Lactobacillaceae (P < 0.05). Additionally, across precancerous lesion stages from AG to Dys in Helicobacter pylori-negative patients, Burkholderiaceae abundance continuously increased, while Streptococcaceae and Prevotellaceae abundance presented a continuous downward trend. Furthermore, the microbial diversity was higher in gastric juice (P < 0.001) than in the mucosa, while PLS-DA revealed a statistically significant difference between the two groups (ANOSIM, P = 0.001). A significant difference in the microbial structure was identified, with Proteobacteria being more prevalent in the gastric mucosa and Firmicutes being more abundant in gastric juice.CONCLUSIONOur results provide insights into potential taxonomic biomarkers for HPNGC and its precancerous stages and assist in predicting the prognosis of IM and Dys based on the mucosal microbiota profile.

Diagnostic value of combined prealbumin-to-fibrinogen and albumin-to-fibrinogen ratios in Hp-negative gastric cancer.

This study aimed to investigate the diagnostic value of prealbumin-to-fibrinogen ratio (PFR) and albumin-to-fibrinogen ratio (AFR) alone or in combination in Helicobacter pylori-negative gastric cancer (Hp-NGC) patients. This study included 171 healthy controls, 180 Hp-NGC patients, and 215 Helicobacter pylori-negative chronic gastritis (HpN) patients. We compared the differences of various indicators and pathological characteristics between groups with Mann-Whitney U test and Chi-square test. The diagnostic value of PFR and AFR alone or in combination for Hp-NGC patients was assessed by the receiver operating characteristic (ROC) curve. PFR and AFR were related to the progression and clinicopathological characteristics of Hp-NGC. As the disease progressed, PFR and AFR values gradually decreased and were negatively related to the tumor size and depth of invasion. In addition, the area under the curves (AUCs) that resulted from combining PFR and AFR to distinguish Hp-NGC patients from healthy controls and HpN patients were 0.908 and 0.654, respectively. When combined with PFR and AFR in the differential diagnosis of tumors with a maximum diameter ≥ 5 cm and the T3 + T4 stage, the AUCs were 0.949 and 0.922; the sensitivity was 86.32% and 80.74%; and the specificity was 94.74% and 92.98%, respectively. PFR and AFR may be used as diagnostic biomarkers for Hp-NGC. The combination of PFR and AFR was more valuable than each indicator alone in the diagnosis of Hp-NGC.

Identifying the Profile of Helicobacter pylori-Negative Gastric Cancers: A Case-Only Analysis within the Stomach Cancer Pooling (StoP) Project.

The prevalence of Helicobacter pylori-negative gastric cancer (HpNGC) can be as low as 1%, when infection is assessed using more sensitive tests or considering the presence of gastric atrophy. HpNGC may share a high-risk profile contributing to the occurrence of cancer in the absence of infection. We estimated the proportion of HpNGC, using different criteria to define infection status, and compared HpNGC and positive cases regarding gastric cancer risk factors. Cases from 12 studies from the Stomach cancer Pooling (StoP) Project providing data on H. pylori infection status determined by serologic test were included. HpNGC was reclassified as positive (eight studies) when cases presented CagA markers (four studies), gastric atrophy (six studies), or advanced stage at diagnosis (three studies), and were compared with positive cases. A two-stage approach (random-effects models) was used to pool study-specific prevalence and adjusted odds ratios (OR). Among non-cardia cases, the pooled prevalence of HpNGC was 22.4% (n = 166/853) and decreased to 7.0% (n = 55) when considering CagA status; estimates for all criteria were 21.8% (n = 276/1,325) and 6.6% (n = 97), respectively. HpNGC had a family history of gastric cancer more often [OR = 2.18; 95% confidence interval (CI), 1.03-4.61] and were current smokers (OR = 2.16; 95% CI, 0.52-9.02). This study found a low prevalence of HpNGC, who are more likely to have a family history of gastric cancer in first-degree relatives. Our results support that H. pylori infection is present in most non-cardia gastric cancers, and suggest that HpNGC may have distinct patterns of exposure to other risk factors.

Systematic profiling of alternative splicing in Helicobacter pylori-negative gastric cancer and their clinical significance

BackgroundAlternative splicing (AS) may cause structural and functional variations in the protein to promote the proliferation of tumor cells. However, there is no comprehensive analysis of the clinical significance of AS in Helicobacter pylori-negative gastric cancer (HP− GC).MethodsThe clinical, gene expression profile data and AS events of 138 HP− GC patients were obtained from the database named the cancer genome atlas. Differently expressed AS (DEAS) events were determined by a comparison of the PSI values between HP− GC samples and adjacent normal samples. Unsupervised clustering analysis, proportional regression and Kaplan–Meier analysis were used to explore the association between clinical data and immune features and to establish two nomograms about the prognosis of HP− GC. Finally, splicing networks were constructed using Cytoscape.ResultsA total of 48141 AS events and 1041 DEAS events were found in HP− GC. Various functions and pathways of DEAS events parent genes were enriched, such as cell-substrate junction, cell leading edge, focal adhension, and AMPK signaling. Seven overall survival (OS)-related and seven disease-free survival (DFS)-related AS events were used to construct the prognostic signatures. Based on the independent prognostic factors, two nomograms were established and showed excellent performance. Then, splicing regulatory networks among the correlations suggested that splicing factors were significantly associated with prognostic DEASs. Finally, the unsupervised clustering analysis revealed that DEAS-based clusters were associated with clinical characteristics, tumor microenvironment, tumor mutation burden, and immune features.ConclusionSeven OS-related and seven DFS-related AS events have been found to be correlated with the prognosis of HP− GC and can be used as prognostic factors to establish an effective nomogram.

Mo1358 CLINICOPATHOLOGIC AND ENDOSCOPIC FEATURES OF HELICOBACTER PYLORI NEGATIVE EARLY GASTRIC CANCER TREATED BY ENDOSCOPIC SUBMUCOSAL DISSECTION

Helicobacter pylori negative gastric cancer (HpNGC) is a rare disease of less than 5%, and its clinical features are not well known. Early gastric cancer usually develops according to the Correa’s hypothesis, therefore, Helicobacter pylori negative early gastric cancer is less common. The aim of this study was to evaluate the endoscopic and pathologic features of Helicobacter pylori negative early gastric cancer treated by endoscopic resection.

Distinct Clinicopathological Features and Prognosis of Helicobacter pylori Negative Gastric Cancer.

BackgroundWhether the characteristics and prognosis of gastric cancer (GC) are different in patients with and without Helicobacter pylori (HP) remains controversial. The definitions of HP status in patients with atrophic gastritis but negative tests for HP are heterogeneous. We aimed to assess the impact of HP on the prognosis of GC using different definitions.MethodsFrom 1998 Nov to 2011 Jul, five hundred and sixty-seven consecutive patients with GC were included. HP status was determined by serology and histology. Patients with any positive test were defined as HP infection. Patients without HP infection whose serum pepsinogen (PG) I <70 ng/dl and PG I/II ratio < 3.0 were defined as atrophic gastritis and they were categorized into model 1: HP positive; model 2: HP negative; and model 3: exclusion of these patients.ResultsWe found four characteristics of HP negative GC in comparison to HP positive GC: (1) higher proportion of the proximal tumor location (24.0%, P = 0.004), (2) more diffuse histologic type (56.1%, p = 0.008), (3) younger disease onset (58.02 years, p = 0.008) and (4) more stage IV disease (40.6%, p = 0.03). Patients with negative HP had worse overall survival (24.0% vs. 35.8%, p = 0.035). In Cox regression models, the negative HP status is an independent poor prognostic factor (HR: 1.34, CI:1.04–1.71, p = 0.019) in model 1, especially in stage I, II and III patients (HR: 1.62; CI:1.05–2.51,p = 0.026).ConclusionWe found the distinct characteristics of HP negative GC. The prognosis of HP negative GC was poor.

Tu1716 Characterization of Helicobacter pylori-Negative Gastric Cancer

The prevalence of Helicobacter pylori-negative gastric cancer (Hp-negative GCA) is quite low, and its clinicopathological features are not well documented. Our aim is to characterize and categorize Hp-negative GCAs in early stages.

238 Distinct Clinicopathological Features and Prognosis of Helicobacter pylori Negative Gastric Cancer

238 Distinct Clinicopathological Features and Prognosis of Helicobacter pylori Negative Gastric Cancer

Prostate stem cell antigen rs2294008 polymorphism differentially contributes to Helicobacter pylori-negative gastric cancer among various populations in China.

Gastric cancer is a lethal disease with a high mortality rate. Studies have suggested that prostate stem cell antigen (PSCA) rs2294008 polymorphism is associated with gastric cancer (GC). In this case-control study, we investigated rs2294008 polymorphism in the Tibet, Hui and Han nationalities in the Qinghai area of China. Genomic DNA was extracted from the peripheral blood of 286, 315 and 350 healthy volunteers and from 219, 233 and 265 Helicobacter pylori-negative non-cardia GC patients from the Tibet, Hui and Han populations, respectively. The rs2294008 polymorphism was analyzed by denaturing high-performance liquid chromatography. rs2294008 CT and TT genotypes were associated with GC both in the Tibet and Han populations (adjusted OR=1.51, 1.47, 2.01, 1.85; 95% CI, 1.04-2.19, 1.05-2.06, 1.04-3.88, 1.03-3.34; P=0.030, 0.025, 0.039, 0.040, respectively). rs2294008 TT genotype was associated with GC in the Hui population (adjusted OR=2.14; 95% CI, 1.29-3.55; P=0.003). Furthermore, when stratified by histopathology, the rs2294008 CT and TT genotypes were associated with diffuse GC in the Tibet and Han nationalities (adjusted OR=1.93, 1.73, 2.69, 2.86; 95% CI, 1.09-3.44, 1.01-2.95, 1.06-6.84, 1.27-6.46; P=0.025, 0.045, 0.038, 0.011, respectively). However, the rs2294008 TT genotype was associated with both intestinal and diffuse types of GC (adjusted OR=2.10, 2.21; 95% CI, 1.17-3.75, 1.12-4.38; P=0.012, 0.023, respectively) and the rs2294008 CT genotype was only associated with intestinal-type GC in the Hui nationalitiy group (adjusted OR=1.60; 95% CI, 1.04-2.47; P=0.034). The results therefore showed that rs2294008 may differentially contribute to GC among different nationalities in one area and its role is independent from Helicobacter pylori-infection.

Frequency of Helicobacter pylori-Negative Gastric Cancer and Gastric Mucosal Atrophy in a Japanese Endoscopic Submucosal Dissection Series Including Histological, Endoscopic and Serological Atrophy

Background: The definition of Helicobacter pylori-negative gastric cancer depends on the accuracy of diagnosis of H. pylori infection. The aim of this study was to determine the frequency of H. pylori-negative gastric cancer and to clarify relationships with histological atrophy, endoscopic atrophy, and serological atrophy. Methods: A total of 240 early gastric cancers were included in this study. The status of H. pylori infection was determined from the rapid urease test, ¹³C-urea breath test, H. pylori culture, histopathological examination and examination of IgG antibodies. In H. pylori-negative gastric cancer, histological atrophy and intestinal metaplasia, endoscopic atrophy and serological atrophy were assessed by pepsinogen. Results: The rate of H. pylori infection was 77.9% and 19 patients (7.9%) had a history of eradication. 34 patients (14.2%) were diagnosed with H. pylori-negative gastric cancer using diagnostic tools of H. pylori. However, most of the patients with H. pylori-negative gastric cancer had histological atrophy and intestinal metaplasia. Only 1 gastric cancer (0.42%) occurred in the mucosa without histological atrophy, endoscopic atrophy or serological atrophy. Conclusion: Early gastric cancers in the Japanese endoscopic submucosal dissection series were strongly related to current or past infection with H. pylori and to gastric mucosal atrophy.

Low Prevalence of Helicobacter pylori-negative Gastric Cancer among Japanese

The true prevalence of Helicobacter pylori-negative gastric cancer (HpNGC) is unknown. We attempt to clarify the prevalence and clinicopathologic features of HpNGC in Japanese. Helicobacter pylori infection was detected by antibody titer and microscopic observation. In addition, we confirmed the lack of endoscopic atrophy and histologic gastritis. In these cases, we added urea breath test or rapid urease test to confirm the absence of H. pylori. The mucus phenotype of gastric cancer tissue was also evaluated by immunohistochemistry. We screened 3161 gastric cancer cases from 1996 to 2010, and 21 cases were regarded as H. pylori negative. Clinically, patients with HpNGC were younger than patients with H. pylori-positive gastric cancer (controls), and revealed a lack of male dominancy. Histologically, diffuse type was frequently found. All patients examined were pepsinogen negative. Among HpNGC cases with endoscopic resection, the depressed macroscopic appearance was dominant. The prevalence of HpNGC was calculated as 0.66% (95% confidence interval = 0.41-1.01). The mucus phenotype of HpNGC was similar to that of the controls. The prevalence of HpNGC is very low and its pathological characteristics are different from common gastric cancer.

Helicobacter pylori-Negative Gastric Cancer in South Korea: Incidence and Clinicopathologic Characteristics

It is difficult to determine the exact incidence rate of Helicobacter pylori (H. pylori) infection-negative gastric cancer (HPIN-GC) because H. pylori detection rates decrease with the progression of gastric atrophy and intestinal metaplasia. The aim of this study was to evaluate the incidence and clinicopathologic characteristics of HPIN-GC in South Korea. Helicobacter pylori infection status was evaluated by histology, a rapid urease test (CLO test), culturing, serology, and history of H. pylori eradication for 627 patients with gastric cancer. Current H. pylori infection was defined as positive results from histology, the CLO test, and culturing. Previous H. pylori infection was defined as negative in all three biopsy-based tests and positive serology or history of H. pylori eradication. Patients were considered to be negative for H. pylori infection if all results from five methods were negative. However, patients who were found to have severe gastric atrophy by the serum pepsinogen test or metaplastic gastric atrophy by histology were assumed to have had a previous H. pylori infection even if results from other tests for H. pylori infection were all negative. The number of patients with gastric cancer with current or previous H. pylori infection was 439 (70.0%) and 154 (24.6%), respectively. The rate of HPIN-GC occurrence was 5.4% (n = 34). Sex, age, Lauren type, location of the tumor, and treatment modalities were not different according to H. pylori infection status. However, HPIN-GC had a more advanced pT classification (T3/T4; 51.9 vs 31.1%, p = .025) and a more advanced stage (more than stage I; 63 vs 41.3%, p = .027) than H. pylori-positive gastric cancer. At least 5.4% cases of gastric cancer were H. pylori negative among South Korean patients. HPIN-GC looks like to have a poorer prognosis than H. pylori-positive cases.

Interleukin 1B gene (IL-1B) and interleukin 1 receptor antagonist gene (IL-1RN) polymorphisms in Helicobacter pylori-negative gastric cancer of intestinal and diffuse histotype

Background:: Polymorphisms in the interleukin 1β gene (IL-1B-31T/C and IL-1B-511C/T single nucleotide changes) and in the interleukin 1 receptor anatagonist gene (IL-1RN2 variable number of tandem repeats) have been studied with respect to gastric cancer susceptibility. Available data support an aetiologic role of these genetic variants in the presence of concomitant Helicobacter pylori infection. Their contribution without H. pylori infection is still an open field of investigation.Materials and methods:: IL-1B and IL-1RN polymorphisms were investigated in 138 H. pylori-negative Italian patients with sporadic gastric cancer and 100 H. pylori-negative controls. Unconditional regression with odd ratios (OR) and 95% confidence intervals (CI), haplotype and linkage disequilibrium analyses were used to investigate the association of the polymorphisms with disease.Results:: In all gastric cancer cases, carriers of the homozygous IL-1B-511T/T genotype showed a significant risk for the development of the disease (OR 3.2 with 95% CI 1.27–8.05). In cases with intestinal-type gastric cancer, however, both IL-1B-511T and IL-1RN2 alleles were associated with disease. In this subgroup, the odds ratio for carriers of both IL-1B-511T and IL-1RN2 was 6.49 (95% CI 2.07–20.4). Haplotype analysis supported the aetiologic contribution of these alleles in gastric cancer of the intestinal histotype.Conclusions:: In conclusion, IL-1B-511T and IL-1RN2 may contribute to intestinal gastric cancer risk in the absence of concomitant H. pylori infection. In this setting, future epidemiologic studies should consider dietary habits and exposure to carcinogens interacting with pro-inflammatory host genotypes.