Helicobacter pylori infection, but not genetic polymorphism of CYP2E1, is highly prevalent in gastric cancer patients younger than 40 years

The global, regional, and national burden of stomach cancer among adolescents and young adults in 204 countries and territories, 1990-2019: A population-based study

Background

Stomach cancer is a significant health problem in many countries. But healthcare needs of adolescents and young adults (AYAs) stomach cancer patients have been historically neglected. An accurate appraisal of the burden of AYA stomach cancer is crucial to formulating effective preventive strategies. In this study, we report the most recent estimates of AYA stomach cancer burden concerning socio-demographic index (SDI) in 204 countries and territories between 1990 and 2019.

Methods

Estimates from the Global Burden of Disease study 2019 were used to analyze incidence, mortality, and disability-adjusted life years (DALYs) due to AYA stomach cancer at global, regional, and national levels. Association between AYA stomach cancer burden and SDI were investigated. All estimates are reported as absolute numbers and age-standardized rates, which were standardized to the GBD world population and reported per 100,000 population.

Results

In 2019, there were 49,000 incident cases, 27,895 deaths, and 1.57 million DALYs due to AYA stomach cancer globally. The highest age-standardized incidence rate occurred in East Asia [2.42 (women) and 4.71 (men) per 100,000 person-years] and high-income Asia Pacific [3.16 (women) and 2.61 (men) per 100,000 person-years]. Age-standardized death [1.53 (women) and 2.65 (men) per 100,000 person-years] and DALY [150.96 (women) and 87.13 (men) per 100,000 person-years] rates were highest in Oceania. Compared with 1990, in 2019 more than 1,075 more incident cases of AYA stomach cancer were estimated with a decrease of 7,784 deaths. Despite the increase in absolute number of incident cases, the worldwide age-standardized rates of AYA stomach cancer (incidence, deaths, and DALYs) have declined since 1990. The drop in the disease burden was associated with an improved SDI. Globally, 24.41% of the age-standardized DALYs were attributable to a high-sodium diet in both sexes combined, and 0.57% of the age-standardized DALYs were attributable to smoking in men.

Conclusion

The global burden of AYA stomach cancer is substantial, especially in developing regions. Capacity-building activities for AYA stomach cancer will benefit the younger generation and population health worldwide.

Helicobacter pylori associated factors in the development of gastric cancer with special reference to the early-onset subtype

Nowadays, gastric cancer is one of the most common neoplasms and the fourth cause of cancer-related death on the world. Regarding the age at the diagnosis it is divided into early-onset gastric carcinoma (45 years or younger) and conventional gastric cancer (older than 45). Gastric carcinomas are rarely observed in young population and rely mostly on genetic factors, therefore provide the unique model to study genetic and environmental alternations. The latest research on early-onset gastric cancer are trying to explain molecular and genetic basis, because young patients are less exposed to environmental factors predisposing to cancer. In the general population, Helicobacter pylori, has been particularly associated with intestinal subtype of gastric cancers. The significant association of Helicobacter pylori infection in young patients with gastric cancers suggests that the bacterium has an etiologic role in both diffuse and intestinal subtypes of early-onset gastric cancers. In this paper we would like to ascertain the possible role of Helicobacter pylori infection in the development of gastric carcinoma in young patients. The review summarizes recent literature on early-onset gastric cancers with special reference to Helicobacter pylori infection.

Association between hOGG1 polymorphism rs1052133 and gastric cancer

Purpose

To conduct a comprehensive evaluation of the association of the human8-oxoguanine glycosylase 1 (hOGG1) gene polymorphism rs1052133 with gastric cancer (GC) through a systematic review and meta-analysis of genetic association study.

Results

A total of 15 articles from published papers were included in our analysis. The meta-analyses for hOGG1 rs1052133, composed of 4024GC patients and 6022controls, showed low heterogeneity for the included populations in all the genetic models, except for the Caucasian population under allelic genetic model, the Asian population under addictive model and Caucasian population under dominant model. The analyses of all the genetic models in overall pooled populations did not identify any significant association between GC and hOGG1 rs1052133 (Allelic model: C vs. G, p = 0.746; Addictive model: CC vs. GG, p = 0.888; Recessive model: CC +GC vs. GG, p = 0.628; Dominant model: CC vs. GG+GC, p = 0.147), even though stratified analyses were conducted in different ethnicities under each genetic model.

Materials and Methods

All case-control association studies on hOGG1 and GC reported up to December 15, 2016 in PubMed, Embase, Web of Science, and the Chinese Biomedical Database were retrieved. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for single-nucleotide polymorphism (SNP) using fixed- and random- effects models according to between-study heterogeneity. Publication bias analyses were conducted using Begg test.

Conclusions

This meta-analysis showed there was no association between hOGG1 rs1052133 and GC. Given the limited sample size, further investigations including more ethnic groups are required to validate the association.

Gastric cancer: epidemiology, prevention, classification, and treatment

Gastric cancer is the second most common cause of cancer-related deaths in the world, the epidemiology of which has changed within last decades. A trend of steady decline in gastric cancer incidence rates is the effect of the increased standards of hygiene, conscious nutrition, and Helicobacter pylori eradication, which together constitute primary prevention. Avoidance of gastric cancer remains a priority. However, patients with higher risk should be screened for early detection and chemoprevention. Surgical resection enhanced by standardized lymphadenectomy remains the gold standard in gastric cancer therapy. This review briefly summarizes the most important aspects of gastric cancers, which include epidemiology, risk factors, classification, diagnosis, prevention, and treatment. The paper is mostly addressed to physicians who are interested in updating the state of art concerning gastric carcinoma from easily accessible and credible source.

Genetic polymorphism of miR-146a is associated with gastric cancer risk: a meta-analysis

Several studies have investigated the associations between miR-146a rs2910164 and gastric cancer (GC) risk, but results have been inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. PubMed and China National Knowledge Infrastructure searches were carried out for relevant studies published before July 2014. Meta-analysis was performed with the stata, version 11.0. A total of seven case-control studies, including 3283 cases and 4535 controls, were selected. A significant association was found between rs2910164 and GC risk under all genetic models (CC vs. GG, OR = 0.76, 95% CI = 0.66-0.87; CC vs. GC+GG, OR = 0.84, 95% CI = 0.71-0.99; CC+GC vs. GG, OR = 0.82, 95% CI = 0.73-0.91) for the total data. In the subgroup analysis by ethnicity, statistically significant association was found in Asian. This meta-analysis suggested that the miR-146a rs2910164 was a risk factor for developing GC.

NEDD9 overexpression correlates with the progression and prognosis in gastric carcinoma

The aim of this study was to investigate neural precursor cell expressed developmentally down-regulated 9 (NEDD9) expression in human gastric carcinoma (GC) and to explore its clinic significance. NEDD9 expression was detected by immunohistochemistry in GC, their corresponding paracancerous histological normal tissues (PCHNTs), and gastric normal tissues. And this result was further confirmed at the protein and mRNA level by Western blotting and quantitative real-time PCR, respectively. The Kaplan-Meier method and log-rank test were employed to compare the overall survival between NEDD9 low-level expression group and NEDD9 high-level expression group. We ascertained frequently NEDD9 up-regulation in both protein and mRNA levels in GC tissues as compared to PCHNTs and normal controls. Immunohistochemical staining indicated that NEDD9 is higher expressed in GC tissues (102 out of 125, 81.8%) than that in PCHNTs (eight out of 42, 19.05%) and gastric normal tissues (one out of eight, 12.50%). NEDD9 expression levels were closely associated with poor differentiation (P=0.002), venous invasion (P=0.012), invasive depth (P<0.001), preset lymph node metastasis (P=0.023), distant metastasis (P=0.017), and high clinical stage (P=0.005). NEDD9 expression was positively correlated with clinical tumor node metastasis (TNM) stage that implied the more advanced clinical TNM stage corresponding to the higher expression level of NEDD9 (rs=0.467, P<0.001). And we also detected frequently NEDD9 up-regulation in both protein and mRNA levels in GC tissues as compared to PCHNTs. Kaplan-Meier survival analysis showed that high NEDD9 expression exhibited a significant correlation with poor prognosis for gastric cancer patients. Our data suggested that NEDD9 could be used as prognostic molecular marker to be applied in the clinical setting to diagnosis, evaluating patient's outcome (prognosis and recurrence) for GC patients.

CYP2E1 genetic polymorphism with dietary, tobacco, alcohol habits, H. pylori infection status and susceptibility to stomach cancer in Mizoram, India

BACKGROUND

The incidence of stomach cancer in India is highest in the state of Mizoram. In this population based matched case-control study, we evaluated the relationship between CYP450 2E1 RsaI polymorphism and risk of stomach cancer taking into considering various important dietary habits along with tobacco, alcohol consumption and H. pylori infection status.

MATERIALS AND METHODS

A total of 105 histologically confirmed stomach cancer cases and 210 matched healthy population controls were recruited. CYP2E1 RsaI genotypes were determined by PCR-RFLP and H. pylori infection status by ELISA. Information on various dietary, tobacco and alcohol habits was recorded in a standard questionnaire.

RESULTS

Our study revealed no significant association between the CYP2E1 RsaI polymorphism and overall risk of stomach cancer in Mizoram. However, we observed a non-significant protective effect of the variant allele (A) of CYP2E1 against stomach cancer. Tobacco smokers carrying C/C genotype have three times more risk of stomach cancer, as compared to non-smokers carrying C/C genotype. Both Meiziol and cigarette current and past smokers who smoked for more than 10 times per day and carrying the (C/C) genotype are more prone to develop stomach cancer. Smoke dried fish and preserved meat (smoked/sun dried) consumers carrying C/C genotype possesses higher risk of stomach cancer. No significant association between H. pylori infection and CYP2E1 RsaI polymorphism in terms of stomach cancer was observed.

CONCLUSIONS

Although no direct association between the CYP2E1 RsaI polymorphism and stomach cancer was observed, relations with different tobacco and dietary risk habits in terms of developing stomach cancer exist in this high risk population of north-eastern part of India. Further in-depth study recruiting larger population is required to shed more light on this important problem.

Association between IL-4 -590C>T polymorphism and gastric cancer risk

Published studies on the association between interleukin-4 (IL-4) -590C>T polymorphism and gastric cancer risk have yielded conflicting results. Thus, a meta-analysis of published studies was performed to assess the possible association. All eligible studies of -590C>T polymorphism and gastric cancer risk were collected from the PubMed, the Cochrane Library, and the Embase electronic databases. Statistical analyses were performed by Review Manager 5.0 and Stata 11.0. When all groups were pooled, we did not detect a significant association of -590C>T polymorphism with gastric cancer risk. When stratifying for race, there was a significant association between -590C>T polymorphism and decreased gastric cancer risk under dominant model and allelic model in the subgroup of Caucasians. However, significant association was absent in Asians. Based on our meta-analysis, -590C>T polymorphism was associated with a lower gastric cancer risk under dominant model and allelic model in Caucasians. Nevertheless, we suggest that further studies should be made to confirm these findings.

Prevalence and characteristics of nodular gastritis in Japanese elderly

BACKGROUND AND AIM

Nodular gastritis (NG) is defined as antral gastritis with endoscopic findings usually characterized by a miliary pattern resembling "goose flesh." There is a possible association between NG and gastric cancer. The aim of our study is to investigate whether there are some differences between young and elderly people in incidence and characteristics of NG and estimate potential risk factors for gastric cancer in adults with NG.

METHODS

Patients underwent upper gastrointestinal endoscopy for abdominal symptoms or cancer screening. Incidence rates and relationship between an elderly group (40 years or older) and young group (< 40 years) were assessed by endoscopic grade of NG, atrophic grade, concomitant diseases, and serum pepsinogen (PG).

RESULTS

NG was found in 62 cases (0.94%) out of 6623 patients who underwent endoscopy, with a mean age of 47.3 ± 13.3 years. Female patients were present at a significantly higher rate in the elderly group (P < 0.001). The grade of neutrophil infiltration in the greater curvature of the upper gastric body was recognized at a significantly higher rate in the elderly group (P < 0.05). PG II was present at a higher rate and PG I/II at a lower rate in the elderly group (P < 0.05). The odds ratio for the risk of gastric cancer in patients with NG was 2.1 (95% confidence interval 0.3-15.3) in the elderly group.

CONCLUSION

NG in the elderly was also suggested to be a risk factor for gastric cancer as well as in the young.

Overexpression of S100A4 is closely associated with the progression and prognosis of gastric cancer in young patients

The aim of this study was to determine the correlation of S100A4 expression with the progression, prognosis and clinical pathology of gastric cancer (GC) in young pateints. A total of 85 tumor tissues with corresponding adjacent normal tissues and 62 non-metastatic lymph nodes (LNs) with corresponding metastatic LNs were obtained from young GC patients (<40 years old) who underwent surgery between January 2001 and December 2006. The expression of S100A4 was detected by RT-PCR and immunohistochemistry. Differences in the expression of S100A4 mRNA or protein were observed among the GC tissues, matched normal gastric mucosa, non-metastatic LNs and metastatic LNs. The expression of S100A4 mRNA and protein in GC tissues and metastatic LNs was significantly higher compared with that in the matched normal gastric mucosa and non-metastatic LNs, respectively (P<0.05). The overexpression of S100A4 was significantly associated with parameters involved in tumor progression and poor prognosis, including tumor size (P=0.017), Lauren classification (P=0.002), histological classification (P= 0.010), histological differentiation (P= 0.000), Borrmann classification (P=0.020), tumor-node-metastasis (TNM) stage (P=0.000), LN metastasis (P=0.000) and distant metastasis (P=0.024). Multivariate analysis suggested that patient age (P=0.035), tumor size (P=0.002), TNM stage (P=0.001) and S100A4 upregulation (P=0.000) were independent prognostic indicators for the disease. The overexpression of S100A4 in young GC patients is significantly associated with the clinicopathological characteristics. S100A4 may be used as a biomarker to predict the progression and poor prognosis of GC in young patients.

CYP2E1 RsaI/PstI polymorphism and gastric cancer susceptibility: meta-analyses based on 24 case-control studies

Background

Previous reports implicate CYP2E1 RsaI/PstI polymorphism as a possible risk factor for several cancers. Published studies on the relationship of CYP2E1 RsaI/PstI polymorphisms with the susceptibility to gastric cancer are controversial. This study aimed to determine this relationship accurately.

Methods

Meta-analyses that assessed the association of CYP2E1 RsaI/PstI variations with gastric cancer were conducted. Subgroup analyses on ethnicity, smoking status, alcohol consumption, and source of controls were also performed. Eligible studies up to Mar 2012 were identified.

Results

After rigorous searching and screening, 24 case-control studies comprising 3022 cases and 4635 controls were selected for analysis. The overall data failed to indicate the significant associations of CYP2E1 RsaI/PstI polymorphisms with the gastric cancer risk [c2 vs. c1: odds ratio (OR) = 1.06; 95% confidence interval (CI) = 0.88–1.28; c2c2 vs. c1c1: OR = 1.23; 95% CI = 0.78–1.92; c2c2+c1c2 vs. c1c1: OR = 0.93; 95% CI = 0.79–1.10]. Similar results were observed in the subgroup analyses on ethnicity, drinking status, and source of controls. However, in the subgroup analysis on smoking status, a borderline increase in cancer risk was found among long-term smokers (c2c2+c1c2 vs. c1c1: OR = 1.39; 95% CI = 1.00–1.92).

Conclusion

CYP2E1 RsaI/PstI polymorphisms may modify the susceptibility to gastric cancer among individuals who have a smoking history. Large and well-designed studies are needed to confirm this conclusion.

Future candidates for indications of Helicobacter pylori eradication: do the indications need to be revised?

Since the discovery of Helicobacter pylori in 1982, the development of several treatment guidelines has allowed a consensus on the indications for H. pylori eradication. Beyond these currently accepted indications, including various upper gastrointestinal disorders and extragastric diseases, a significant amount of new information regarding H. pylori eradication is emerging. Certain types of acute gastritis, such as nodular gastritis, hypertrophic gastritis, Ménétrier's disease, hemorrhagic gastritis, and granulomatous gastritis are reversible after H. pylori eradication. Further, for chronic gastritis, closed-type atrophic gastritis and complete-type intestinal metaplasia appear to be more reversible after H. pylori eradication than open-type atrophic gastritis and incomplete-type intestinal metaplasia. Eradication can also be considered in subjects younger than 40 years who have a family history of gastric cancer and in subjects with long-term medications that might lead to bleeding (antiplatelet agents) or atrophy (proton pump inhibitors). Emerging evidence indicates that H. pylori eradication could be an effective treatment for some extragastric diseases that are unresponsive to conventional therapy. In such conditions, routine screening for eradication of H. pylori has not previously been recommended; a "test-and-treat" approach is suggested in the aforementioned situations. Given that H. pylori eradication is effective when the gastritis is reversible, future indications should be expanded to include acute gastric lesions that show marked improvement upon H. pylori eradication rather than just focusing on chronic gastric lesions. Future indications for H. pylori eradication should focus more on reversible lesions before preneoplastic conditions develop.

Helicobacter pylori infection and histological changes in siblings of young gastric cancer patients

BACKGROUND AND AIM

Helicobacter pylori infection is a risk factor for gastric cancer. We evaluated whether H. pylori infection and premalignant histological changes are more prevalent in siblings of young gastric cancer patients.

METHODS

Young (age ≤ 40) gastric cancer patients (n = 185), their young siblings (n = 130), and young control participants (n = 287) were recruited. H. pylori infection and histological changes were assessed using the updated Sydney system in biopsy specimens from three regions. We analyzed the association of H. pylori infection and histological changes with gastric cancer using logistic regression analysis.

RESULTS

  The H. pylori infection rate was significantly higher in young cancer patients than their siblings (odds ratio [OR]= 2.42, P = 0.001) or control participants (OR = 3.60, P < 0.001). In H. pylori-infected subjects, corpus gastritis and premalignant changes of the corpus lesser curvature (LCv) were also more prevalent in patients than in siblings or controls. In terms of the antrum, intestinal metaplasia was more prevalent in H. pylori-infected patients than in siblings or controls, while atrophy was not affected. Siblings also had a higher H. pylori infection rate (OR = 1.60, P = 0.046) and higher prevalence of intestinal metaplasia at the corpus LCv (OR = 2.88, P =0.027) than control participants.

CONCLUSIONS

Even in young adults, H. pylori infection is a risk factor for gastric cancer. Young adults with histological findings including corpus predominant gastritis, corpus atrophy, or intestinal metaplasia are at increased risk. Since young siblings share risk factors, screening and treatment should be considered for these family members.

Analysis of demographic characteristics in 3242 young age gastric cancer patients in Korea

AIM: To evaluate the epidemiologic features of young age gastric cancer (GC).

METHODS: Retrospectively, a total of 3242 patients with GC between 18 and 45 years of age and 3000 sex- and age-matched controls were reviewed. All subjects were stratified into 3 groups based on age (A, 18-30 years; B, 31-40 years; C, 41-45 years). Epidemiologic characteristics and risk factors were investigated with reference to their age and gender.

RESULTS: Compared to controls, more frequent intake of high risk diet (P = 0.00075), history of heavy smoking (P = 0.00087), intake of heavy alcohol (P = 0.00091), lower social economic status (P = 0.00083), body mass index > 30 (P = 0.00097), urban residence (P = 0.00065), and more frequent exposure to harmful occupational environments (P = 0.00072) were observed in all age groups and both genders in young age GC. These relationships were weaker in females compared to males of the same age, and were stronger as the age of patients increased. However, in group C of young age GC patients, environmental factors played important roles in females and males with a similar body weight. In females, older age at first delivery (> 35 years), lack of lactation history, nulliparity, and poor nutritional status during pregnancy were significantly associated with an increased risk of GC (P = 0.00034). In this study, 252 patients (7.8%) had a family history of GC with high odds ratio (OR) (3.22-4.21). In particular, family history was more closely associated with GC in males (OR, 4.21 in male vs 3.46 in female) and more advanced cases (P = 0.00051).

CONCLUSION: Hormonal associated factors were more commonly associated with females whereas environmental factors were more commonly associated with males in young age GC patients.

Helicobacter pylori and gastric cancer

Helicobacter pylori is now well known as an important pathogen related to the development of gastric cancer. However, some clinicians still doubt the causal association of H. pylori with the development of gastric cancer. To summarize the recent clinical data on the link between H. pylori and gastric cancer, we reviewed related articles published over the past 3 years, after the award of the Nobel Prize for Physiology or Medicine to Drs. J.R. Warren and B.J. Marshall for the first culture and isolation of H. pylori and the investigation of their relevance to peptic ulcer disease. This updated summary of the relationship between H. pylori and gastric cancer highlights the strong link between the organism and the development of gastric cancer, and suggests eradication of this bacterial infection as a possible prophylactic measure against the development of this lethal malignancy. At present, clinicians and researchers in the field emphasize the strong need for H. pylori eradication from the human stomach.

XRCC1 genetic polymorphism Arg399Gln and gastric cancer risk: A meta-analysis

AIM: To evaluate the association between X-ray cross-complementing gene 1 (XRCC1) genetic polymorphism Arg399Gln and gastric cancer risk by means of meta-analysis.

METHODS: We searched PubMed and NCBI up to June 1, 2008. A total of 16 clinical trials and reports were identified, but only 8 trials qualified under our selection criteria. Statistical analysis was performed with the software program Review Manage, version 4.2.8.

RESULTS: Of the 8 case-control studies selected for this meta-analysis, a total of 1334 gastric cancer cases and 2194 controls were included. For Arg399Gln, the Gln/Gln genotype carriers did not have a decreased cancer risk compared with those individuals with the Arg/Arg genotype (OR = 0.92, 95% CI, 0.71-1.19; P = 0.51). Similarly, no associations were found in the recessive and dominant modeling (Gln/Gln vs Arg/Gln + Arg/Arg: OR = 0.96; 95% CI, 0.77-1.19; P = 0.70 and Gln/Gln + Arg/Gln vs Arg/Arg: OR = 0.90, 95% CI, 0.77-1.05; P = 0.18).

CONCLUSION: No association is found between the XRCC1 polymorphism Arg399Gln and gastric cancer risk.