Helicobacter pylori infection and gastric cardia cancer in Chaoshan region

Kyoto international consensus report on anatomy, pathophysiology and clinical significance of the gastro-oesophageal junction

OBJECTIVE

An international meeting was organised to develop consensus on (1) the landmarks to define the gastro-oesophageal junction (GOJ), (2) the occurrence and pathophysiological significance of the cardiac gland, (3) the definition of the gastro-oesophageal junctional zone (GOJZ) and (4) the causes of inflammation, metaplasia and neoplasia occurring in the GOJZ.

DESIGN

Clinical questions relevant to the afore-mentioned major issues were drafted for which expert panels formulated relevant statements and textural explanations.A Delphi method using an anonymous system was employed to develop the consensus, the level of which was predefined as ≥80% of agreement. Two rounds of voting and amendments were completed before the meeting at which clinical questions and consensus were finalised.

RESULTS

Twenty eight clinical questions and statements were finalised after extensive amendments. Critical consensus was achieved: (1) definition for the GOJ, (2) definition of the GOJZ spanning 1 cm proximal and distal to the GOJ as defined by the end of palisade vessels was accepted based on the anatomical distribution of cardiac type gland, (3) chemical and bacterial (Helicobacter pylori) factors as the primary causes of inflammation, metaplasia and neoplasia occurring in the GOJZ, (4) a new definition of Barrett's oesophagus (BO).

CONCLUSIONS

This international consensus on the new definitions of BO, GOJ and the GOJZ will be instrumental in future studies aiming to resolve many issues on this important anatomic area and hopefully will lead to better classification and management of the diseases surrounding the GOJ.

Effect of Helicobacter pylori Eradication on Gastric Cancer Prevention: Updated Report From a Randomized Controlled Trial With 26.5 Years of Follow-up

BACKGROUND & AIMS

Helicobacter pylori infection is considered as the most important risk factor in the pathogenesis of gastric cancer. This study aims to evaluate the long-term effects of H pylori eradication treatment on the incidence and mortality of gastric cancer among a high-risk population.

METHODS

This prospective, randomized, placebo-controlled trial was conducted in a high-risk area in southern China in July 1994. A total of 1630 asymptomatic, H pylori-infected individuals were randomly assigned to receive standard triple therapy for H pylori eradication (n = 817) or placebo (n = 813), and were followed up until December 2020. The primary outcome was incidence of gastric cancer. Total and cause-specific mortalities were the secondary outcomes.

RESULTS

During 26.5 years of follow-up, 21 participants (2.57%) in the treatment arm and 35 (4.31%) in the placebo arm were diagnosed with gastric cancer. Participants receiving H pylori treatment had a lower incidence of gastric cancer compared with their placebo counterparts (hazard ratio [HR], 0.57; 95% CI, 0.33-0.98). More obvious risk reduction was observed among those without premalignant gastric lesions (HR, 0.37; 95% CI, 0.15-0.95) and those without dyspepsia symptoms at baseline (HR, 0.44; 95% CI, 0.21-0.94). Furthermore, compared with 32 cases of gastric cancer observed among 527 participants with persistent H pylori infection in the placebo group, only 16 were identified in 625 subjects with successful eradication in the treatment group (HR, 0.46; 95% CI, 0.26-0.83). However, there were no statistically significant differences for any mortality end points between the 2 groups.

CONCLUSIONS

Eradication of H pylori might confer a long-term protection against gastric cancer in high-risk populations, especially for infected individuals without precancerous gastric lesions at baseline.

Alterations of Gastric Microbiota in Gastric Cancer and Precancerous Stages

Objective

Microbial infections have been shown to contribute to gastric carcinogenesis, the knowledge of gastric microbiota alteration in this process may provide help in early diagnosis of gastric cancer. The aim of this study was to characterize the microbial changes and identify taxonomic biomarkers across stages of gastric carcinogenesis.

Methods

The gastric microbiota was investigated by 16S rRNA gene analysis in gastric mucosal specimens from 47 patients including superficial gastritis (SG), atrophic gastritis (AG), gastric intraepithelial neoplasia (GIN), and gastric cancer (GC). Differences in microbial composition across the disease stages, especially in GIN and GC were assessed using linear discriminant analysis effect size.

Results

There was no gradual changing trend in the richness or diversity of the gastric microbiota across stages of gastric carcinogenesis. The relative abundance of dominant taxa at phylum and genus levels didn’t show a gradual shift pattern, and the only four taxa that continuously enriched from SG to GC were Slackia, Selenomonas, Bergeyella, and Capnocytophaga, all of which were oral bacteria. The most representative taxa which were enriched in GC patients were oral bacteria including Parvimonas, Eikenella and Prevotella-2, and environmental bacteria including Kroppenstedtia, Lentibacillus, and Oceanobacillus. The gastric microbiota in GIN patients were characterized by enrichment of intestinal commensals including Romboutsia, Fusicatenibacter, Prevotellaceae-Ga6A1-group, and Intestinimonas. Gastric cardia cancer and non-cardia cancer patients had significantly different microbiota profiles characterized by a higher abundance of Helicobacter in the cardia cancer patients.

Conclusions

Our results provide insights on potential taxonomic biomarkers for gastric cancer and precancerous stages, and suggest that gastric microbiota might play different roles in the carcinogenesis of cardia cancer and non-cardia cancer.

Trefoil factor 1 and gastrokine 2 inhibit Helicobacter pylori-induced proliferation and inflammation in gastric cardia and distal carcinogenesis

Helicobacter pylori (H. pylori) infection has been associated with non-cardia adenocarcinoma in the stomach, while its role in gastric cardia adenocarcinoma (GCA) remains controversial. In addition, the association between H. pylori and the protective factors trefoil factor 1 (TFF1) and gastrokine 2 (GKN2) in gastroesophageal adenocarcinomas has not been fully investigated. Therefore, the mRNA and protein expression levels of TFF1 and GKN2 in GCA and distal gastric adenocarcinoma (DGA) were analyzed using quantitative PCR (qPCR) and immunohistochemistry, and the association with H. pylori infection was investigated. In addition, the effects of TFF1 and GKN2 overexpression on H. pylori-induced cells were investigated using western blot and reverse transcription-qPCR analysis. The comparative analysis of 16S rRNA-positive mRNA expression between GCA and DGA showed no statistically significant difference. However, the rate of the H. pylori vacuolating toxin A (VacA) genotype was significantly higher in GCA (49.2%) compared with that in DGA (26.9%; P<0.05). H. pylori infection downregulated the mRNA and protein expression levels of TFF1 and GKN2 in gastric tumor tissues, and the mRNA expression level of TFF1 and GKN2 was also markedly decreased in vitro. Furthermore, the cell proliferation varied in H. pylori total protein treatment group with the different doses. Notably, treatment with 20 µg/ml H. pylori total protein for 24 h resulted in the highest cellular proliferation rate. In addition, TFF1 and GKN2 overexpression inversely inhibited H. pylori-induced cell proliferation and upregulated NF-κB, tumor necrosis factor-α, IL-1β, IL-2, IL-4 and IL-6. The results of the present study indicate that H. pylori, particularly the VacA+ strain, plays an important role in GCA pathogenesis in high-risk areas of China, while TFF1/GKN2 inhibits H. pylori-induced cell proliferation and inflammation in GCA and DGA.

The Impact of Gastric Juice pH on the Intraluminal Therapy for Helicobacter pylori Infection

Background: Helicobacter pylori (H. pylori) can be topically eradicated in stomach lumen on endoscopic examination. The procedures of intraluminal therapy for H. pylori infection (ILTHPI) include the control of intragastric pH, mucolytic irrigation of the gastric mucosal surface, and a single-dose medicament containing antimicrobial agents. Aims: To detect gastric juice pH and evaluate its impact on the success rate of ILTHPI. Methods: We enrolled 324 patients with upper abdominal discomfort for endoscopic examinations. Among them, 13C-urea breath test was positive in 218 patients, where 100 underwent ILTHPI, and negative in 106. All patients had their gastric juice pH detected and set into three ranges, including normal acidity (pH < 4.0), low-level hypoacidity (pH 4.0–5.5), and high-level hypoacidity (pH ≥ 6.0). The impact of gastric juice pH on the success rate of ILTHPI was evaluated. Results: Distribution of pH level showed no significant difference between two groups of H. pylori-infected patients (p = 0.942). The eradication rate of ILTHPI is significantly lower in patients with gastric juice pH below 4 (p < 0.001). Conclusions: Detection of gastric juice pH in ILTHPI is extremely important. Rapid control of stomach pH at or above 4 for patients prior to ILTHPI is strongly recommended. (NCT03124420).

Microbiological evidences for gastric cardiac microflora dysbiosis inducing the progression of inflammation

BACKGROUND AND AIM

Nowadays, anti-inflammation treatment is a promising approach for preventing tumorigenesis, and human microflora is closely related to inflammation. This study aimed to investigate the gastric cardiac microbiome and identify inflammation-related microorganisms for gastric cardiac inflammation.

METHODS

We performed 16S rRNA sequencing on a total of 11 healthy individuals and 89 individuals with different degree of gastric cardiac inflammation. Immunohistochemistry was used for verifying candidate bacteria. Phylogenetic reconstruction of unobserved states (picrust) was used for predicting the pathways involved by cardiac microflora.

RESULTS

The resident phyla in normal were Proteobacteria, Firmicutes, Bacteroides, and Actinobacteria, and the dominant genus in normal were Halomonas, shewanella, and Comamonas. In the progression of gastric cardiac inflammation, the diversity of cardiac microflora did not change (P > 0.05). However, the composition structure of cardiac microflora varied between healthy and inflamed tissues (P < 0.05). Meanwhile, there were 64 species parallel increased with inflammation degree, especially Helicobacter pylori, Lactobacillus spp. Additionally, inflammation-related species were detected (P < 0.05), including H. pylori, Acinetobacter ursingii, and Streptococcus agalactiae. Higher H. pylori colonization was positively related to the progression of cardiac inflammation (γ coefficient = 0.678, P < 0.001), and it also influenced the cardiac microbial community structure. Cardiac microflora also participated in DNA repair pathways and is affected by the relative abundance of H. pylori (P < 0.0001).

CONCLUSIONS

Cardiac microflora dysbiosis, especially the increasing of the relevant abundance of H. pylori, promotes the progression of cardiac inflammation.

Colonization of Helicobacter pylori in the gastric cardia: A comparison between the UFT300 and CLO tests

Background and aim

To assess the detection rates of Helicobacter pylori colonization in the gastric cardia with two commercial kits of rapid urease test: 5 min UFT300 and 24 h CLO test in H. pylori‐infected patients.

Methods

Eighty consecutive dyspeptic patients with confirmed H. pylori infection (serology and ¹³C‐urea breath test) were prospectively studied. During endoscopy, tissue samples using separate biopsy forceps from the cardia were taken for the UFT300 and CLO tests. The results of the UFT300 were read at 5 and 30 min, and those of the CLO test were read at 24 h.

Results

Of 80 enrolled patients, 17 (21.3%) and 44 (55%) had positive findings with the UFT300 at 5 and 30 min, respectively, while 72 (90%) had positive findings with the CLO test at 24 h. The CLO test is significantly more sensitive than the UFT300 in evaluating H. pylori status in the cardia. On comparing patients with and without carditis, the detection rates of the CLO test were similar (91.1% vs 88.6%; P = 0.724), and the rates of the UFT300 were also similar at 5 and 30 min.

Conclusions

The rate of H. pylori colonization in the gastric cardia was 90% in H. pylori‐infected patients detected with the CLO test. Although the UFT300 provides a more rapid reading of H. pylori status, the diagnostic yield of the CLO test is much higher than that of the UFT300. However, a positive result of the UFT300 may indicate a higher bacterial load in the cardia, which warrants a more effective therapeutic strategy.

Neuroendocrine carcinoma of esophageal and gastric cardia: clinicopathologic and immunohistochemistry study of 80 cases

Neuroendocrine carcinoma (NEC) of the esophagus and gastric cardia is a rare tumor, and the Chaoshan region has one of the highest incidences of esophageal and gastric cardia cancer (GCC) worldwide. The aim of this study was to characterize the clinicopathologic features of esophageal NEC (n = 67) and gastric cardia NEC (n = 13) cases identified over a 9-year period in the Chaoshan region. Esophageal NECs were either purely NEC (n = 47) or mixed with squamous cell carcinoma or adenocarcinoma (n = 20). For GCC; pure NEC was found in 5 cases, whereas 8 cases were mixed with adenocarcinomas. The majority of esophageal and gastric cardia NECs was of the small cell type, and 24/67 esophageal and 5/13 gastric cardia patients were found with lymph node metastasis. Immunohistochemistry was performed in all cases, and positive staining for synaptophysin (Syn) was found for all cases, with half the esophageal NEC cases being also chromogranin A (CgA)-positive. In the multivariate Cox regression model, lymph node and further metastasis were independent prognostic factors for esophageal NEC. Our study revealed the clinicopathological features of esophageal and gastric cardia NECs in the Chaoshan region and found mixed NECs patients may have a better prognosis than pure NECs patients, which may provide therapeutic clue for treating this rare tumor.

Clinicopathological Features and Increased Expression of Toll-Like Receptor 4 of Gastric Cardia Cancer in a High-Risk Chinese Population

The incidence of gastric cardia cancer (GCC) is high in China. However, the clinicopathological characteristics and the carcinogenesis of GCC are unclear. Toll-like receptor 4 (TLR4) is an important innate immunity receptor and has a role in non-GCC (NGCC). We compared the clinicopathological characteristics of GCC patients from a high-risk area in China to esophageal cancer (EC) patients. Immunohistochemistry for TLR4 was performed in 201 histological samples of normal gastric cardia mucosa (n = 11), gastric cardia inflammation (n = 87), and GCC (n = 103). We included 84 patients with EC and 99 with GCC. GCC tissue was more poorly differentiated than EC tissue and more invasive, with more histomorphologic variation. Lymph node metastasis was more frequent in GCC than in EC. The Helicobacter pylori infection rate was higher but not significantly with GCC than EC. Survival was shorter with lymph node metastasis. We found a statistically significant trend for progressive increase of TLR4 expression from normal mucosa to inflammation in GCC. GCC in this high-risk area displays clinicopathologic characteristics different from those of EC and different from those of gastroesophageal junction carcinomas in other countries, although this was not analyzed statistically. Increased TLR4 expression in gastric cardia lesions may be associated with GCC tumorigenesis.

Genetic Alterations in Esophageal Tissues From Squamous Dysplasia to Carcinoma

BACKGROUND & AIMS

Esophageal squamous cell carcinoma (ESCC) is the most common subtype of esophageal cancer. Little is known about the genetic changes that occur in esophageal cells during the development of ESCC. We performed next-generation sequence analyses of esophageal nontumor, intraepithelial neoplasia (IEN), and ESCC tissues from the same patients to track genetic changes during tumor development.

METHODS

We performed whole-genome, whole-exome, or targeted sequence analyses of 227 esophageal tissue samples from 70 patients with ESCC undergoing resection at Shantou University Medical College in China from 2012 through 2015 (no patients had received chemotherapy or radiation therapy); we analyzed normal tissues, tissues with simple hyperplasia, dysplastic tissues (IEN), and ESCC tissues collected from different regions of the esophagus at the same time. We also obtained 1191 nontumor esophageal biopsy specimens from the Chaoshan region (a high-risk region for ESCC) of China (a high-risk region for ESCC) and performed immunohistochemical and histologic analyses to detect inflammation.

RESULTS

IEN and ESCC tissues had similar mutations and copy number alterations, at similar frequencies; these differed from mutations detected in tissues with simple hyperplasia. IEN tissues had mutations associated with apolipoprotein B messenger RNA editing enzyme, catalytic polypeptide-like-mediated mutagenesis (a DNA damage mutational signature). Genetic analyses indicated that most ESCCs were formed from early stage IEN clones. Trunk mutations (mutations shared by >10% of paired IEN and ESCC tissues) were in genes that regulate DNA repair and cell apoptosis, proliferation and adhesion. Mutations in TP53 and CDKN2A and copy number alterations in 11q (contains CCND1), 3q (contains SOX2), 2q (contains NFE2L2), and 9p (contains CDKN2A) were considered to be trunk variants; these were dominant mutations detected at high frequencies in clones of paired IEN and ESCC samples. In the esophageal biopsy samples from high-risk individuals (residing in the Chaoshan region), 68.9% had an evidence of chronic inflammation; the level of inflammation was correlated with atypical cell structures and markers of DNA damage.

CONCLUSIONS

We analyzed mutations and gene copy number changes in nontumor, IEN, and ESCC samples, collected from 70 patients. IEN and ESCCs each had similar mutations and markers of genomic instability, including apolipoprotein B messenger RNA editing enzyme, catalytic polypeptide-like. Genomic changes observed in precancerous lesions might be used to identify patients at risk for ESCC.

Increased Oxidative Stress in the Proximal Stomach of Patients with Barrett's Esophagus and Adenocarcinoma of the Esophagus and Esophagogastric Junction

OBJECTIVES: Oxidative stress (OS) is an essential element in the pathogenesis of Barrett’s esophagus (BE) and its transformation to adenocarcinoma (EAC). The state of OS in the proximal stomach of patients with BE and EAC is unknown. Isoprostanes are a specific marker of OS not previously used to determine OS from BE/EAC tissue samples. PATIENTS AND METHODS: OS was measured in 42 patients with BE (n = 9), EAC (n = 9), or both (n = 24) and 15 control patients. A STAT-8-Isoprostane EIA Kit served to identify 8-Isoprostanes (8-IP), and a Glutathione Assay Kit was used to measure glutathione reduced form (GSH) and glutathione oxidized form. An OxiSelect Oxidative DNA Damage ELISA Kit (8-OHdG) served to measure 8-OH-deoxyguanosine. RESULTS: The 8-IP (P = .039) and 8-OHdG (P = .008) levels were higher, and the GSH level lower (P = .031), in the proximal stomach of the study group than in that of the controls. Helicobacter pylori infection was present in 8% of the study patients. CONCLUSIONS: In the proximal stomach of BE and EAC patients, OS was elevated and antioxidative capacity was reduced. This finding suggests that the gastroesophageal reflux causing BE also induces oxidative stress in the proximal stomach and may contribute to the development of cancer in the proximal stomach and gastric cardia.

Expression of CDX2 in gastric cardia adenocarcinoma and its correlation with H. pylori and cell proliferation

BACKGROUND

Gastric cardia cancer (GCC) is located in the distal stomach, and strongly correlates with atrophic gastritis and Helicobacter pylori (H.pylori) infection. Caudal-related homeobox transcription factor 2 (CDX2) is homeobox gene encoding an intestine-specific transcription factor usually expressed in the intestinal epithelium cells. However, in several recent published papers, CDX2 was found to be aberrantly expressed in gastric, thyroid and ovarian cancer.

RESULTS

Higher expression of CDX2 was found in GCC tissues in comparison with non-malignant cardia mucosa (p<0.05). Moreover, immunohistochemical analysis demonstrated that CDX2 expression correlated with lymphatic metastasis. In addition, we found that CDX2 expression progressively increased with the level of H. pylori infection (p<0.05), and also correlated with cell proliferation, based on Ki67 staining.

METHODS

To investigate the relationship between CDX2, cell proliferation and H. pylori infection, we detected CDX2, Ki62 and H.pylori expression in 83 non-malignant gastric cardia mucosacases and 60 GCC specimens in the Chaoshan area, a high-risk region for esophageal and gastric cardia cancer.

CONCLUSION

These findings provide pathological evidence that H. pylori infectionis a driving force of gastric cardia carcinogenesis by upregulating CDX2 and inducing inflammation. These results provide new pathological evidence that H. pylori infection induces GCC tumorigenesis.

PSCA rs2294008 Polymorphism with Increased Risk of Cancer

Background

Published data on the association between PSCA rs2294008 polymorphism and cancer risk have implicated inconclusive results. To determine the relationship and to precisely assess the effect size estimate of the association, we performed a meta-analysis.

Methods

We searched published literature in Embase and PubMed databases using the search terms “PSCA”, “prostate stem cell antigen”, “variants”, “polymorphism”, “polymorphisms”, and “cancer”. A total of 21 eligible articles were retrieved, with 27, 197 cancer cases and 48, 237 controls.

Results

On the whole, we found the association between PSCA rs2294008 polymorphism and cancer risk was statistically significant: TT vs CC: OR = 1.18, 95% CI, 1.10 to 1.27; TT + CT vs CC: OR = 1.08, 95% CI, 1.05 to 1.10; TT vs CT + CC: OR = 1.14, 95% CI, 1.07 to 1.21; T vs C: OR = 1.10, 95% CI, 1.06 to 1.14; CT vs CC: OR = 1.10, 95% CI, 1.06 to 1.13. Stratified analyses in cancer type and ethnicity showed similar results.

Conclusions

Based on the statistical evidence, we can draw a conclusion that the rs2294008 polymorphism of PSCA gene is likely to play a role in cancer carcinogenesis, especially in gastric cancer and bladder cancer.

Chronic inflammation-related DNA damage response: a driving force of gastric cardia carcinogenesis

Gastric cardia cancer (GCC) is a highly aggressive disease associated with chronic inflammation. To investigate the relationship between DNA damage response (DDR) and chronic inflammation, we collected 100 non-tumor gastric cardia specimens of Chaoshan littoral, a high-risk region for esophageal and gastric cardia cancer. A significantly higher proportion of severe chronic inflammation was found in dysplastic epithelia (80.9%) in comparison with that in non-dysplastic tissues (40.7%) (P<0.001). Immunohistochemical analysis demonstrated that DNA damage response was parallel with the chronic inflammation degrees from normal to severe inflammation (P<0.05). We found that DNA damage response was progressively increased with the progression of precancerous lesions (P<0.05). These findings provide pathological evidence that persistent chronic inflammation-related DNA damage response may be a driving force of gastric cardia carcinogenesis. Based on these findings, DNA damage response in non-malignant tissues may become a promising biomedical marker for predicting malignant transformation in the gastric cardia.