Polymorphisms in inflammation-related genes and risk of gastric cancer (Finland)

Prognostic Value of Inflammatory Markers in HBV-Related HCC After Hepatectomy Based on a Clinical Database

OBJECTIVE

Hepatitis B virus (HBV) remains an important risk factor for hepatocellular carcinoma (HCC), and inflammation plays an essential role in tumor development. This study aimed to investigate the impact of inflammatory markers in the postoperative outcomes of patients with HBV-related HCC, providing valuable prognostic indicators after hepatectomy.

METHODS

We retrospectively analyzed 222 patients with HBV-related HCC after surgical resection. The ROC curve was used to calculate biomarker cutoff values. The Kaplan-Meier method was used to estimate overall survival (OS) and recurrence-free survival (RFS), and univariate and multivariate analyses were used to identify the prognostic factors.

RESULTS

The Kaplan-Meier analysis revealed that patients with high albumin-bilirubin (ALBI) score, aspartate aminotransferase to platelet ratio index (APRI), and monocyte to lymphocyte ratio (MLR) had worse OS, while those with high ALBI score and MLR had shorter RFS. Multivariate Cox regression analysis identified alpha-fetoprotein >400 ng/mL (hazard ratio [HR]: 2.447, 95% confidence interval [CI]: 1.273-4.706, p = 0.007), alanine aminotransferase (HR: 0.377, 95% CI: 0.171-0.834, p = 0.016), platelet to lymphocyte ratio (HR: 0.385, 95% CI: 0.196-0.755, p = 0.006), systemic inflammatory response index (HR: 1.844, 95% CI: 1.049-3.239, p = 0.033), ALBI score (HR: 1.808, 95% CI: 1.020-3.203, p = 0.043), APRI score (HR: 3.193, 95% CI: 1.662-6.137, p < 0.001), tumor diameter (HR: 1.083, 95% CI: 1.012-1.160, p = 0.022), and portal vein tumor thrombosis (PVTT) (HR: 6.083, 95% CI: 2.774-13.338, p < 0.0001) as independent predictors for OS. MLR (HR: 2.285, 95% CI: 1.290-4.048, p = 0.005) and PVTT (HR: 2.672, 95% CI: 1.280-5.579, p = 0.009) were confirmed as significant prognostic markers of RFS in patients with HBV-related HCC.

CONCLUSIONS

ALBI score, APRI, and MLR are effective prognostic predictors in patients with HBV-related HCC after curative resection. Close monitoring and adjuvant therapies should be considered for high-risk patients.

The Association Between IL-8 Gene Polymorphisms and the Risk of Several Types of Cancer, Especially in Gastric Cancer

BACKGROUND

Changes in functional genetic polymorphisms may increase or decrease the risk of cancer in patients. Nowadays, the association between polymorphisms in the interleukin-8 (IL-8) gene and the susceptibility of cancer risk have been investigated in many studies, however, above relationships remain unclear.

AIM

The current study aims to comprehensively evaluate the association between IL-8 gene six polymorphisms and the whole cancer risk, especially -251 polymorphism and gastric cancer.

METHODS AND RESULTS

Six polymorphisms (-251, -353, +678, +1633, +2767, +781) were collected. The expression of serum IL-8 was calculated by ELISA assay. First, 104 case-control studies were conducted. Second, this research has made significant discoveries regarding the -251, -353 and +781 polymorphisms and the potential associations with cancer risk. Finally, the serum IL-8 levels in gastric cancer patients with AA/TT genotypes were significantly higher than those with the same genotypes of healthy controls and TT genotypes in gastric cancer patients.

CONCLUSION

Overall, the investigation has revealed that IL-8 gene polymorphisms significantly influence vulnerability to cancer development, especially for gastric cancer.

Influence of Cytokine Genetic Polymorphisms in Helicobacter pylori-Associated Gastric Inflammation According to Sex in South Korea

Background/Aims

: The relationship between genetic polymorphisms and gastric inflammation remains unclear. This study aimed to evaluate the impact of genetic polymorphisms on Helicobacter pylori (HP)-associated gastritis according to sex.

Methods

: Two hundred thirty-two male and 404 female subjects with current HP infection were prospectively enrolled. The genotyping of IL-1B-511 C/T, IL-1RN variable number of tandem repeats, IL-6-572 G/C, IL-8-251 A/T, IL-8-781 C/T, IL-10-1082 G/A, IL-10-592 C/A, TNF-A-308 G/A, and transforming growth factor (TGF)-B-509 C/T, was determined by polymerase chain reaction-restriction fragment length polymorphism. The degree of monocyte or neutrophil infiltration, atrophic gastritis, and intestinal metaplasia was evaluated using the updated Sydney system.

Results

: Among the male subjects, moderate/severe atrophic gastritis of the corpus was higher in IL-1B-511 CC carriers than in CT and TT carriers independent of age, alcohol consumption, and HP virulence factors (26.9% vs 10.4%; adjusted hazard ratio [HR], 4.377; 95% confidence interval, 1.387 to 13.814). In females, IL-8-251 AA carriers were independently and significantly associated with moderate/severe atrophic gastritis of the corpus compared with that in AT and TT carriers (21.4% vs 6.0%, adjusted HR=3.799). In males, the IL-8-251 TT genotype was associated with moderate/severe intestinal metaplasia of the corpus compared with the AT and AA genotypes (13.4% vs 5.6%, adjusted HR=3.128), while the IL-10-592 CA and CC genotypes were associated with moderate/severe monocyte infiltration of the antrum compared with AA genotype (83.6% vs 71.8%, adjusted HR=2.227).

Conclusions

: Genetic polymorphisms in cytokines play different roles in HP-associated gastritis according to sex.

The pertinence of gastric cancer and interleukin 10-819 single nucleotide polymorphisms: a meta-analysis and systematic review

PURPOSE

Cytokines regulate the interaction between the immune system and malignant tumors. Among them, interleukin-10 (IL-10) is a multifunctional anti-inflammatory cytokine mainly produced by immune cells. The correlation between gastric cancer and T/C single nucleotide polymorphism (SNP) of interleukin-10 (IL-10) promoter-819(rs1800871)was opaque and remained to be determined. We aim to explore the pertinence of gastric cancer and SNP of interleukin 10-819 by meta-analysis via five statistical models.

METHODS

Databases including PubMed, Cochrane Library, Embase, the Scopus, and Google Scholars were comprehensively retrieved for the eligible studies on the related topic from inception to March 2022. Odds ratios (ORs) were generated for dichotomous variants by meta-analysis in each model via STATA 17.0 MP. The statistical models comprised recessive model, over-dominant model, allele model, co-dominant model and dominant model. Subgroup analysis was performed to investigate the difference across races as well as the source of heterogeneity if necessary.

RESULTS

Eventually a total of 15 articles reporting 7779 patients were enrolled in our study. There were 2383 patients and 5396 controls, collectively. There was no correlation between gastric cancer and IL-10 819 in recessive model, co-dominant model or dominant model, and subgroup analysis showed that Asian, Latin American and Caucasian had no correlation with the risk of gastric cancer. In the allelic model, there was significant correlation between gastric cancer and IL-10 819 (OR = 3.96%, 95%CI: 3.28 to 3.78). In the over-dominant model, there is no correlation between gastric cancer and IL-10 819, but subgroup analysis uncovered significant vulnerability of Asian people with regard to gastric cancer.

CONCLUSIONS

In our study, both Asians, Latin Americans, and Europeans showed an increased risk of gastric cancer in the allelic model, whereas only Asians showed significant susceptibility in the super dominant model. Of course, more large cohort studies are needed to confirm our results.

The Effect of IL-6 174G > C Gene Polymorphism on Gastrointestinal Cancer: a Systematic Review and Meta-analysis

IL-6 gene polymorphisms can play a role in the development or control of cancer by affecting cytokines. Gastrointestinal cancer is one of the most common types of cancer worldwide. The aim of this study was to investigate the effect of polymorphism of the IL-6 174G > C gene on gastrointestinal cancers based on a systematic review and meta-analysis, including gastric, colorectal, and esophageal cancer. In this study, a systematic and meta-analytical review of the study data on the effect of polymorphism of IL-6 174G > C gene on gastrointestinal cancer (gastric, colorectal, and esophageal cancer) in Scopus, EMBASE, Web of Science, PubMed, and Science Direct Databases was extracted without any time limit until April 2020. In order to perform the analysis of eligible studies, the model of random effects was used and the heterogeneity of studies was investigated with I2 index. Data analysis was performed with Comprehensive Meta-Analysis software (Version 2). The total number of surveyed studies in patients with colorectal cancer was 22 studies. Based on the results of meta-analysis, the odds ratio of GG genotype in patients with colorectal cancer was 0.88. The odds ratio of GC genotype obtained in patients with colorectal cancer was 0.88 and the odds ratio of CC genotype in patients with colorectal cancer was 0.92. The total number of surveyed studies in patients with gastric cancer was 12. Based on the meta-analysis results, the odds ratio of GG genotype in patients with gastric cancer was 0.74, the odds ratio of GC genotype in patients with gastric cancer was 1.27, and the odds ratio of CC genotype in patients with gastric cancer was 0.78. The total number of surveyed studies in esophageal cancer patients was 3 studies. Based on the results of meta-analysis, the odds ratio of GG genotype in patients with esophageal cancer was 0.57, the odds ratio of GC genotype in patients with esophageal cancer was 0.44, and the odds ratio of chance of CC genotype in patients with esophageal cancer was 0.99. In general, different genotypes of polymorphism of the IL-6 174G > C gene reduce the risk of gastric, colorectal, and esophageal cancer. However, the GC genotype of this gene was associated with a 27% increased risk of gastric cancer.

Association between IL8RB C1208T mutation and risk of cancer: A pooled analysis based on 5299 cases and 6899 controls

INTRODUCTION

The CXC chemokines are unique cytokines that play a vital role in the progression of many cancers. Association between chemokine (C-X-C motif) receptor 2 (IL8RB) C1208T mutation and cancer risk remains incomprehensive.

METHODS

We therefore utilized odds ratios and in silico analysis to explore the relationship of IL8RB polymorphism on risk to cancer. Furthermore, we adopted gene set enrichment analysis to investigate the IL8RB expression in prostate adenocarcinoma.

RESULTS

A total of 14 case-control studies combined with 5299 cases and 6899 controls were included in our analysis. We revealed that individuals carrying TT genotype had an 14% increased cancer risk compared with those with TC + colon cancer (CC) genotype (odds ratio [OR] = 1.14, 95% CI = 1.05-1.25, P = .003, I2 = 35.6). Stratification analysis by race showed that East Asians with TT + TC genotype may have a 25% decreased cancer risk compared with control. Stratification analysis by cancer type revealed that individuals with TT genotype were associated with elevated risk of urinary cancer than control. The expression of IL8RB was attenuated in prostate adenocarcinoma.

CONCLUSIONS

IL8RB C1208T may be correlated with the risk of cancer, especially prostate adenocarcinoma.

Impacts of Chemokine (C-X-C Motif) Receptor 2 C1208T Polymorphism on Cancer Susceptibility

Background

The CXC chemokines belong to a unique family of cytokines that participates in the progression and development of many malignant tumors. Evidence for the relationship between chemokine (C-X-C motif) receptor 2 (CXCR2) C1208T polymorphism and susceptibility to cancer remains inconsistent.

Methods

Odds ratios (ORs), 95% confidence intervals (CIs), and combined analysis were used to investigate the effect of CXCR2 variation on cancer risk. Gene Set Enrichment Analysis (GSEA) and enzyme-linked immunosorbent assay (ELISA) were also used to evaluate the expression of CXCR2 in prostate cancer (PCA).

Results

Across 11 case-control studies, 4,909 cases and 5,884 controls were involved in the current analysis. Individuals with a TT genotype were associated with increased risk of digestive cancer, compared to those with a TC+CC genotype (OR = 1.16, 95%CI = 1.02-1.31, P = 0.025). Individuals carrying the TT genotype had a 39% higher risk of urinary cancer than those carrying CC genotype (OR = 1.39, 95%CI = 1.04-1.87, P = 0.025). Individuals with a TT genotype showed a 56% augmented breast cancer risk, compared to those with a CC genotype (OR = 1.56, 95%CI = 1.03-2.35, P = 0.034). It was found that CXCR2 expression was downregulated in PCA. Compared with PCA subjects carrying the CC genotype, the expression of CXCR2 was decreased in patients with the TT genotype.

Conclusions

The CXCR2 C1208T variation was associated with elevated risk of urinary, breast, and digestive cancer. However, the C1208T polymorphism was correlated with attenuated risk of lung cancer.

Association of Interleukin-10 Polymorphisms with Susceptibility to Colorectal Cancer and Gastric Cancer: an Updated Meta-analysis Based on 106 Studies

BACKGROUND

The purpose of this study was to explore the association of IL-10 polymorphisms with susceptibility to colorectal cancer (CRC) and gastric cancer (GC).

METHODS

PubMed, Scopus, Embase, SciELO, medRxiv, China Biology Medicine Disc, DeepDyve, CNKI, and Web of Science were used to identify all relevant articles published up to 20th June 2021, without any restrictions on ethnicity. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were used to determine the strength of the associations.

RESULTS

A total of 106 case-control studies were included. For CRC, 15 studies with 2772 cases and 3719 controls on -1082A/G, 11 studies with 3259 cases and 4992 controls on -592C/A, and 3 studies with 477 cases and 544 controls on -819 T/C were selected. For GC, 31 studies with 6229 cases and 8666 controls on -1082A/G, 27 studies with 5457 cases and 8381 controls on -592C/A, and 19 studies with 3556 cases and 6218 controls on -819 T/C were included. Pooled data showed a significant association between IL-10-819 T/C polymorphism and CRC susceptibility in overall population, but not for IL-10-1082A/G and -592C/A polymorphisms. However, IL-10-592C/A polymorphism was associated with CRC risk in Asians. A significant association of IL-10-1082A/G polymorphism with the GC risk was found. In the ethnicity subgroup analysis, a significant association was found between IL-10-1082A/G polymorphism and GC risk among Asians. The IL-10-819 T/C was not associated with GC risk in overall population and by ethnicity.

CONCLUSIONS

Our pooled data show a significant association of IL-10-819 T/C and IL-10-1082A/G polymorphisms with CRC and GC in overall population, respectively. However, other factors may influence these associations, and large-scale studies with adequate methodological quality are necessary to confirm the impact on CRC and GC risk.

The Role of Tumor Necrosis Factor-α (TNF-α) Polymorphisms in Gastric Cancer: a Meta-Analysis

PURPOSE

Tumor necrosis factor alpha (TNF-α) is an inflammatory cytokine which may play a role in the development of gastric cancer (GC). This study aimed to investigate the association of five TNF-α polymorphisms including TNF-α-857, TNF-α-1031, TNF-α-863, TNF-α-308, and TNF-α-238 polymorphisms with GC risk.

METHODS

All eligible case-control studies were collected by searching PubMed, Scopus, and Web of Science. The association of the risk of GC with TNF-α polymorphisms was estimated using odds ratio (OR) and 95% confidence interval (CI). Heterogeneity was assessed via Cochrane's Q and I² analyses.

RESULTS

A total of 46 publications involving 16, 715 cases with GC and 27, 998 controls were recruited. The study revealed a significant association for TNF-α 308 (recessive model: OR = 0.646, P = 0.035), TNF-α-1031 (homozygote model: OR = 1.584, P = 0.027), and TNF-α-857 (homozygote model: OR = 1.760, P = 0.001) polymorphisms with the GC risk. The results of subgroup analysis based ethnicity found a significant association between GC risk and TNF-α-857 polymorphism in Caucasian subgroup (P = 0.005) and TNF-α-1031 polymorphism and GC risk in Asians (P = 0.018).

CONCLUSIONS

This study suggested that TNF-α-857 and TNF-α-1031 polymorphisms may be associated with the increased gastric cancer risk.

Effect of interleukin-8 receptor B (IL8RB) rs1126579 C>T variation on the risk to cancer

Chemokines are a type of cytokine that participate in the migration of macrophages and monocytes to inflammatory cells. In particular, CXC chemokines are involved in the development of many cancers. Evidence for the association between interleukin-8 receptor B (IL8RB) rs1126579 C > T variation and cancer risk remains contradictory. Here, we utilized a comprehensive analysis containing odds ratios (ORs), regression, and in silico tools to evaluate the effect of IL8RB polymorphism on cancer risk. We further employed Gene set enrichment analysis combined with ELISA to evaluate the IL8RB expression in patients with prostate cancer (PRAD). A total of 5,187 cancer cases and 6,691 controls were included in the present analysis. Individuals with the TT genotype were associated with an increased risk of cancer compared to those with the TC+CC genotype. In a subgroup analysis by type of cancer, individuals with the TT genotype had a 39% increased risk of urinary cancer compared to those with the CC genotype. A subgroup analysis by ethnicity showed that Asians carrying the TC genotype had a 26% lower risk of cancer than those carrying the CC genotype. We found that the expression of IL8RB was down-regulated in PRAD. Compared to that in PRAD subjects carrying the CC genotype, the expression of IL8RB was decreased in patients with the TT+TC genotype. In conclusion, the IL8RB rs1126579 C > T variation may be associated with cancer risk, especially in Asian populations and patients with PRAD.

The Ω-3 fatty acid docosahexaenoic acid selectively induces apoptosis in tumor-derived cells and suppress tumor growth in gastric cancer

Despite current achievements and innovations in cancer treatment, conventional chemotherapy has several limitations, such as unsatisfactory long-term survival, cancer drug resistance and toxicity against non-tumoral cells. In the search for safer therapeutic alternatives, docosahexaenoic acid (DHA) has shown promising effects inhibiting tumor growth without significant side effects in several types of cancer, but in gastric cancer (GC) its effects have not been completely described. In this study, we characterized the effects of DHA in GC using in vivo and in vitro models. Among all of the evaluated Ω-3 and Ω-6 fatty acids, DHA showed the highest antiproliferative potency and selectivity against the GC-derived cell line AGS. 10-100 μM DHA decreased AGS cell viability in a concentration-dependent manner but had no effect on non-tumoral GES-1 cells. To evaluate if the effects of DHA were due to apoptosis induction, cells were stained with Annexin V-PI, observing that 75 and 100 μM DHA increased apoptosis in AGS, but not in GES-1 cells. Additionally, levels of several proapoptotic and antiapoptotic regulators were assessed by qPCR, western blot and activity assays, showing similar results. In order to evaluate DHA efficacy in vivo, xenografts in an immunodeficient mouse model (BALB/cNOD-SCID) were used. In these experiments, DHA treatment for six weeks consistently reduced subcutaneous tumor size, ascitic fluid volume and liver metastasis. In summary, we found that DHA has a selective antiproliferative effect on GC, being this effect driven by apoptosis induction. Our investigation provides promising features for DHA as potential therapeutic agent in GC.

Statistical meta-analysis to investigate the association between the Interleukin-6 (IL-6) gene polymorphisms and cancer risk

A good number of genome-wide association studies (GWAS), including meta-analyses, reported that single nucleotide polymorphisms (SNPs) of the IL-6 gene are significantly associated with various types of cancer risks, though some other studies reported insignificant association with cancers, in the literature. These contradictory results may be due to variations in sample sizes and/or deficiency of statistical modeling. Therefore, an attempt is made to provide a more comprehensive understanding of the association between the IL-6 gene SNPs (rs1800795, rs1800796, rs1800797) and different cancer risks, giving the weight on a large sample size, including different cancer types and appropriate statistical modeling with the meta-dataset. In order to attain a more reliable consensus decision about the association between the IL-6 gene polymorphisms and different cancer risks, in this study, we performed a multi-case statistical meta-analysis based on the collected information of 118 GWAS studies comprising of 50053 cases and 65204 control samples. Results from this Meta-analysis indicated a significant association (p-value < 0.05) of the IL-6 gene rs1800796 polymorphism with an overall increased cancer risk. The subgroup analysis data based on cancer types exhibited significant association (p-value < 0.05) of the rs1800795 polymorphism with an overall increased risk of cervical, liver and prostate cancers; the rs1800796 polymorphism with lung, prostate and stomach cancers; and the rs1800797 polymorphism with cervical cancer. The subgroup analysis of ethnicity data showed a significant association (p-value < 0.05) of an overall cancer risk with the rs1800795 polymorphism for the African and Asian populations, the rs1800796 polymorphism for the Asian only and the rs1800797 polymorphism in the African population. Comparative discussion showed that our multi-case meta-analyses received more support than any previously reported individual meta-analysis about the association between the IL-6 gene polymorphisms and cancer risks. Results from this study, more confidently showed that the IL-6 gene SNPs (rs1800795, rs1800796 and rs1800797) in humans are associated with increased cancer risks. Therefore, these three polymorphisms of the IL-6 gene have the potential to be evaluated as a population based rapid, low-cost PCR prognostic biomarkers for different types of cancers diagnosis and research.

The TNF-A-857*T Polymorphism is Associated with Gastric Adenocarcinoma Risk in a Costa Rican Population

BACKGROUND

Costa Rica is ranked as one of the countries with highest incidence of gastric cancer worldwide. Previous studies in Costa Rican populations have revealed associations between gastric cancer risk and several cytokine polymorphisms that seem to play a role in the regulation of the expression of these proteins. In this study, we assessed associations of the polymorphisms IL-6-174 G/C, IFNGR1-56 C/T, IL-8-251 T/A and TNF-A (-857 C/T, -308 A/G) with gastric pathologies in a high-risk population of Latin America.

METHODS

DNA samples of 47 patients with gastric adenocarcinoma, 53 with chronic gastritis, 56 with duodenal ulcer and 94 healthy controls, were genotyped for the five mentioned SNPs. All participants were ≥50-years-old. Genotyping was performed by PCR-RFLP and 5'-nuclease PCR assay. H. pylori infection, CagA status, pepsinogen (PG) I and II blood levels were determined by ELISA. Logistic regression analysis was used to determine possible associations of the polymorphisms with cancer, gastritis and duodenal ulcer, and linear regression analysis to determine associations with blood PG levels.

RESULTS

A total of 86.6% of the population was positive for H. pylori; of them, 51.6% was CagA+. Patients with the TNF-A-857*T allele had an increased risk for gastritis (OR: 3.67, p = 0.015) and gastric adenocarcinoma (OR:6.15, p = 0.001). Associations between other polymorphisms and gastric diseases, or PG levels, were not found.

CONCLUSIONS

Our results indicate that the TNF-A-857*T SNP is among the risk factors associated with the risk of gastric cancer in Costa Rica.

ASSOCIATION OF IL-8 -251T>A (RS4073) POLYMORPHISM WITH SUSCEPTIBILITY TO GASTRIC CANCER: A SYSTEMATIC REVIEW AND META-ANALYSIS BASED ON 33 CASE-CONTROL STUDIES

BACKGROUND

The role of -251A>T polymorphism in the anti-inflammatory cytokine interleukin-8 (IL-8) gene in gastric cancer was intensively evaluated, but the results of these studies were inconsistent.

OBJECTIVE

Therefore, we performed a meta-analysis to provide a comprehensive data on the association of IL-8 -251T>A polymorphism with gastric cancer.

METHODS

All eligible studies were identified in PubMed, Web of Science, EMBASE, Wanfang and CNKI databases before September 01, 2019. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were derived from a fixed effect or random effect model.

RESULTS

A total of 33 case-control studies with 6,192 cases and 9,567 controls were selected. Overall, pooled data showed that IL-8 -251T>A polymorphism was significantly associated with an increased risk of gastric cancer under all five genetic models, i.e., allele (A vs T: OR=1.189, 95% CI 1.027-1.378, P=0.021), homozygote (AA vs TT: OR=1.307, 95% CI 1.111-1.536, P=0.001), heterozygote (AT vs TT: OR=1.188, 95% CI 1.061-1.330, P=0.003), dominant (AA+AT vs TT: OR=1.337, 95% CI 1.115-1.602, P=0.002) and recessive (AA vs AT+TT: OR=1.241, 95% CI 1.045-1.474, P=0.014). The stratified analysis by ethnicity revealed an increased risk of gastric cancer in Asians and mixed populations, but not in Caucasians. Moreover, stratified by country found a significant association in Chinese, Korean and Brazilian, but not among Japanese.

CONCLUSION

This meta-analysis suggests that the IL-8 -251T>A polymorphism is associated with an increased risk of gastric cancer, especially by ethnicity (Asian and mixed populations) and country (Chinese, Korean and Brazilian).

Association of IL-6 −174 G>C Polymorphism with Susceptibility to Colorectal Cancer and Gastric Cancer: a Systematic Review and Meta-Analysis

Background: The −174G>C (rs1800795) polymorphism at interleukin 6 (IL-6) gene has been reported to be related with the occurrence of colorectal (CRC) and gastric (GC) cancers. However, the results had been conflicting and controversial. In order to give a comprehensive and precise result, we summarized available data to analyze the association of this polymorphism with CRC and GC risk. Methods: A comprehensive literature search on PubMed, Elsevier Science Direct, and CNKI database was performed to identify all eligible studies up to May 15, 2019. The strength of association was assessed by odds ratios (ORs) with 95% confidence intervals (CI). Results: A total of 29 case-control studies including 16 studies with 7,560 cases and 9,574 controls on CRC and 13 studies with 1,445 cases and 2,918 controls on GC were selected. Overall, pooled data showed that the IL-6 −174G>C polymorphism was not significantly associated with increased risk of CRC and GC in overall. When stratified by ethnicity, we found a statistically significant association between the IL-6 −174 G>C polymorphism and CRC risk in Asians (CC vs. GG: OR = 1.860, 95% CI 1.061–3.258, p = 0.030; and CC vs. CG+GG: OR = 1.941, 95% CI 1.131–3.331, p = 0.016). Conclusion: The meta-analysis suggests that IL-6 −174G>C polymorphism was not significantly associated with the increased risk of CRC and GC in overall population. However, the results showed that IL-6 −174G>C polymorphism may be associated with risk of GC in Asians. Further studies including a larger sample size will be necessary to clarify these results.

Impact of radiotherapy on immunological parameters, levels of inflammatory factors, and clinical prognosis in patients with esophageal cancer

The aim of this study was to observe dynamic changes in immunological parameters and levels of inflammatory factors from pre-radiotherapy to post-radiotherapy in patients with esophageal cancer, and to evaluate the related clinical prognosis. In all, 110 patients with esophageal cancer who underwent radiotherapy were enrolled. Before radiotherapy, post-radiotherapy, and 3 months after radiotherapy, the percentages of T lymphocyte subsets and natural killer (NK) cells in peripheral blood were detected using flow cytometry. The levels of serum inflammatory factors were measured with the enzyme-linked immunosorbent assay (ELISA). Thirty peripheral blood samples from healthy people were similarly analysed as the control. Before radiotherapy, the percentages of CD4+ and CD8+ T cells and NK cells, and the CD4+/CD8+ rate in esophageal cancer patients were significantly different from those in the healthy control group (P < 0.001); the levels of inflammatory factors were increased significantly (P < 0.001). The percentages of the above cells and the levels of inflammatory factors also differed statistically significantly between pre- and post-radiotherapy (P < 0.001) in the esophageal cancer patients. Three months after radiotherapy, the percentages of CD3+ (P = 0.453), CD4+ (P = 0.108), and CD8+ T cells (P = 0.163) and NK cells (P = 0.103) had recovered to the level before radiotherapy; and the levels of TNF-α (P = 0.101), IL-6 (P = 0.302) and IL-8 (P = 0.250) were also restored. After radiotherapy, alterations in immunological parameters were associated with the irradiation volume and the myelosuppression condition. Patients with recovered immunological parameters showed a longer median survival time than those with poor recovery of immunological parameters. For esophageal cancer patients who were immunosuppressive and had an activated inflammatory response before radiotherapy, radiotherapy aggravated these symptoms, and this aggravation was positively associated with myelosuppression and irradiation volume. In addition, recovery of the immunological parameters indicated better prognosis.

ASSOCIATION OF INTERLEUKIN-10 -592A>C AND -819T>C POLYMORPHISMS WITH GASTRIC CANCER RISK: A SYSTEMATIC REVIEW AND META-ANALYSIS OF 44 CASE-CONTROL STUDIES

INTRODUCTION

A series of studies have evaluated the association between -592A>C and -819T>C polymorphisms in the promoter regions of Interleukin-10 (IL-10) and gastric cancer (GC) risk. However, the results remain inconclusive.

OBJECTIVE

To better understand the association of the polymorphisms with GC risk, we performed a comprehensive meta-analysis.

METHOD

An electronic search was performed of several databases to identify relevant studies up to April 2018.

RESULTS

A total of 44 case-control studies, including 26 studies on IL-10 -592A>C (5,332 cases and 8,272 controls) and 18 studies on IL-10 -819T>C (3,431 cases and 6,109 controls) were selected. Overall, -592A>C polymorphism was associated with the risk of GC under the heterozygote model (OR=1.153, 95% CI=1.020-1.305, p=0.023), but not -819T>C polymorphism. When stratified by ethnicity, significant association was only observed in the Asians under the allele model (OR=1.153, 95% CI=1.007-1.320, p=0.040) and the heterozygote model (OR=1.218, 95% CI=1.076-1.379, p=0.002) for -592A>C.

CONCLUSION

The current meta-analysis results inconsistent with previous meta-analyses; showed that the IL-10 -592A>C polymorphism, but not -819T>C polymorphism, may be contributed to the susceptibility of GC in overall and Asian populations.

Genetic Polymorphisms in Inflammatory and Other Regulators in Gastric Cancer: Risks and Clinical Consequences

Helicobacter pylori infection is associated with the development of a chronic inflammatory response, which may induce peptic ulcers, gastric cancer (GC), and mucosa-associated lymphoid tissue (MALT) lymphoma. Chronic H. pylori infection promotes the genetic instability of gastric epithelial cells and interferes with the DNA repair systems in host cells. Colonization of the stomach with H. pylori is an important cause of non-cardia GC and gastric MALT lymphoma. The reduction of GC development in patients who underwent anti-H. pylori eradication schemes has also been well described. Individual susceptibility to GC development depends on the host's genetic predisposition, H. pylori virulence factors, environmental conditions, and geographical determinants. Biological determinants are urgently sought to predict the clinical course of infection in individuals with confirmed H. pylori infection. Possible candidates for such biomarkers include genetic aberrations such as single-nucleotide polymorphisms (SNPs) found in various cytokines/growth factors (e.g., IL-1β, IL-2, IL-6, IL-8, IL-10, IL-13, IL-17A/B, IFN-γ, TNF, TGF-β) and their receptors (IL-RN, TGFR), innate immunity receptors (TLR2, TLR4, CD14, NOD1, NOD2), enzymes involved in signal transduction cascades (PLCE1, PKLR, PRKAA1) as well as glycoproteins (MUC1, PSCA), and DNA repair enzymes (ERCC2, XRCC1, XRCC3). Bacterial determinants related to GC development include infection with CagA-positive (particularly with a high number of EPIYA-C phosphorylation motifs) and VacA-positive isolates (in particular s1/m1 allele strains). The combined genotyping of bacterial and host determinants suggests that the accumulation of polymorphisms favoring host and bacterial features increases the risk for precancerous and cancerous lesions in patients.

An updated association between TNF-α -238G/A polymorphism and gastric cancer susceptibility in East Asians

Polymorphisms in the tumor necrosis factor α (TNF-α) gene are emerging as key determinants of gastric diseases. The TNF-α-238G/A single-nucleotide polymorphism (SNP) is the most extensively studied. However, this association is inconsistent amongst different populations. We therefore conducted an updated meta-analysis to obtain a more precise estimate of the association of TNF-α-238G/A polymorphism with gastric cancer (GC) risk. A comprehensive search of PubMed, Embase, Chinese (CNKI and WanFang) databases was performed to identify relevant studies through 5 May 2018. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of the association. Fourteen studies were included in our meta-analysis involving 2999 cases and 4685 controls. There was no significant association between TNF-α-238G/A polymorphism and GC risk in the overall populations. In the subgroup analysis, we found that TNF-α-238G/A polymorphism was associated with the increased risk of GC amongst Asians, especially in Chinese, but not in Caucasians. Subgroup analysis by genotyping methods revealed increased risk for other methods. In conclusion, our present meta-analysis shows that TNF-α-238G/A polymorphism is associated with the risk of GC in East Asian individuals.

Preliminary analysis of single-nucleotide polymorphisms in IL-10, IL-4, and IL-4Rα genes and profile of circulating cytokines in patients with gastric Cancer

Background

Gastric Cancer is highly prevalent and deadly worldwide. In Colombia, it is the most lethal form of cancer. Some single-nucleotide polymorphisms in IL-10, IL-4, and IL-4Rα genes have been associated with an anti-inflammatory environment and a Th2 profile in detriment of the antitumor Th1 response. This research sought to detect single-nucleotide polymorphisms in promoter sequences, like − 1082 (G/A), − 592 (C/A), and − 819 (C/T), as well as − 590 (C/T) of the IL-10 and IL-4 genes, respectively; in addition to the IL-4Rα mutation variants, Ile50Val and Q576R, together with circulating levels of IL-4, TNF-α, IL-10, and IFN-γ in patients with gastric carcinoma in Cúcuta, Colombia.

Methods

In a cross-sectional study, 17 patients and 30 healthy individuals were genotyped for the six polymorphisms mentioned through PCR-RFLP of DNA obtained from peripheral blood cells and serum samples were analyzed by sandwich ELISA to quantify cytokines. Statistical difference between groups was determined along with the association between the presence of polymorphisms and the risk of gastric cancer, as well as the mortality in patients, using Mann-Whitney U test and logistic regression analysis, respectively.

Results

An association between the − 1082 (G/A) and the risk of gastric cancer was found (OR = 7.58, range 0.77–74.06, P = 0.08). Furthermore, patients had a significant increase in IL-4 serum levels (P < 0.01) compared to healthy individuals, both variables showed a higher estimated risk of mortality in patients, although without statistical association (P > 0.05).

Conclusion

We infer that two possible biomarkers (one immunological and one genetic) could be considered in association with gastric cancer in our population, which should be confirmed by subsequent studies involving a greater number of individuals.

Associations of interleukin-6 gene polymorphisms with cancer risk: Evidence based on 49,408 cancer cases and 61,790 controls

Many molecular epidemiologic studies have shown that interleukin-6 (IL-6) polymorphisms are significantly associated with susceptibility for various cancers. However, the conclusions of these studies are inconsistent. The purpose of the present study was to explore the association between three common IL-6 loci (rs1800795, rs1800796, and rs1800797) and the risk for various cancers. We systematically searched the PubMed, Web of Science, Wanfang and China national knowledge infrastructure (CNKI) databases for relevant publications and obtained 108 eligible studies, involving 49,408 cancer patients and 61,790 cancer-free controls. Odds ratio (OR), 95% confidence interval (CI), and false positive reporting probability (FPRP) were used to evaluate cancer risk. All statistical analyses were performed using the R software meta package. We observed a non-significant association between rs1800795 and overall cancer risk, while rs1800797 was found to have a false positive association with overall risk of cancer. Subgroup analyses of rs1800797 also suggested non-significant association and rs1800795 played a protective role in liver cancer. Rs1800796 was found to be associated with overall cancer risk, particularly in Asian patients and those with prostate cancer. These findings provide evidence that IL-6 polymorphisms may affect cancer risk.

Relationship Between Tumor Necrosis Factor-α rs361525 Polymorphism and Gastric Cancer Risk: A Meta-Analysis

Tumor necrosis factor (TNF)-α, a major part in inflammatory, infectious and tumor processes, and is pivotal at the early stages of gastric cancer. Relationship between its risk and TNF-α rs361525 polymorphism has been demonstrated, but remains conflicting and controversial. Therefore, a meta-analysis was conducted to more precisely estimate this relationship. PubMed, Web of Science, EMBASE and CNKI were comprehensively searched to find out relevant articles through October 5, 2017. The strength of the relationship was assessed using pooled odds ratios and 95% confidence intervals. Totally 20 articles were included involving 4,084 cases and 7,010 controls. No significant relationship between TNF-α rs361525 polymorphism and increased GC risk was found in the whole populations. Subgroup analyses uncovered TNF-α rs361525 polymorphism intensified the risk of GC among Asians under five models, but decreased the risk of GC among Caucasiansin the allelic and dominant models. Subgroup analysis by genotyping methods revealed increased risk for other methods. In conclusion, this meta-analysis suggests TNF-α rs361525 polymorphism is related to the risk of GC, especially for Asians.

Association between interleukin-10 -592 A/C polymorphism and gastrointestinal tract cancer risk: A meta-analysis

BACKGROUND

Recent evidence suggests that -592 A/C polymorphism in the interleukin-10 (IL-10) gene may influence risk of gastrointestinal tract cancer; however, individual studies have provided conflicting and inconclusive results. Therefore, this meta-analysis was conducted to assess the association between IL-10 -592 A/C polymorphism and gastrointestinal tract cancer susceptibility.

METHODS

EMBASE, PubMed, Web of Science, and China National Knowledge Infrastructure databases were searched for case-control studies published before 1 May 2017. A total of 36 studies involving 8069 cases and 13,089 controls were included in the present meta-analysis according to the inclusion criteria. The random- or fixed-effect model was utilized to calculate pooled odds ratio (OR) with 95% confidence interval (CI), and to survey the association.

RESULTS

By and large IL-10 -592 A/C (rs1800872) polymorphism was not associated with gastrointestinal cancer risk in five genetic models (A vs. C: OR 1.00; 95% CI 0.93, 1.08; P_OR = 0.960; AA vs. CC: OR 0.98; 95% CI 0.85, 1.14; P_OR = 0.835; CA vs. CC: OR 1.01; 95% CI 0.94, 1.08; P_OR = 0.776; AA+CA vs. CC: OR 1.03; 95% CI 0.94, 1.12; P_OR = 0.592; AA vs. CA+CC: OR 0.98; 95% CI 0.87, 1.10; P_OR = 0.666). Similar results were also achieved after stratification by the Hardy-Weinberg equilibrium, ethnicity, source of controls, and cancer type.

CONCLUSION

The results of this meta-analysis indicated that there is no association between the IL-10 -592 A/C promoter polymorphism and gastrointestinal tract cancer susceptibility.

Genetic polymorphisms of IL-6 promoter in cancer susceptibility and prognosis: a meta-analysis

IL-6 is critical for tumorigenesis. However, previous studies on the association of IL-6 promoter polymorphisms with predisposition to different cancer types are somewhat contradictory. Therefore, we performed this meta-analysis regarding the relationship between IL-6 promoter single nucleotide polymorphisms and cancer susceptibility and prognosis. Up to April 2017, 97 original publications were identified covering three IL-6 promoter SNPs. Our results showed statistically significant association between IL-6 promoter and cancer risk and prognosis. Subgroup analysis indicated that rs1800795 was significantly associated with increased risk of cervical cancer, colorectal cancer, breast cancer, prostate cancer, lung cancer, glioma, non-Hodgkin’s lymphoma and Hodgkin’s lymphoma but not gastric cancer and multiple myeloma. Furthermore, rs1800796 was significantly associated with increased risk of lung cancer, prostate cancer and colorectal cancer but not gastric cancer. Additionally, rs1800797 was significantly association with breast cancer, non-Hodgkin’s lymphoma, B-cell lymphoma and diffuse large B-cell lymphoma but not gastric cancer. Simultaneously, rs1800795 and rs1800796 were associated with a significantly higher risk of cancer in Asia and Caucasian, rs1800797 was associated with a significantly risk of cancer in Caucasian but not in Asia. Furthermore, IL-6 promoter polymorphisms were significantly associated with the prognosis of cancer. Considering these promising results, IL-6 promoter including rs1800795, rs1800796 and rs1800797 may be a tumor marker for cancer therapy.

Associations of potentially functional variants in IL-6, JAKs and STAT3 with gastric cancer risk in an eastern Chinese population

The interleukin-6 (IL-6)/JAK/STAT3 signaling pathway plays a central role in inflammation-mediated cancers, including gastric cancer (GCa). We evaluated associations between 10 potentially functional single nucleotide polymorphisms (SNPs) of four essential genes in the pathway and GCa risk in a study of 1,125 GCa cases and 1,221 cancer-free controls. We found that a significant higher GCa risk was associated with IL-6 rs2069837G variant genotypes [adjusted odds ratios (OR) = 1.33; 95% confidence interval (CI) = 1.12-1.59 for AG + GG vs. AA)] and JAK1 rs2230587A variant genotypes (adjusted OR = 1.20; 95% CI = 1.02-1.43 for GA + AA vs. GG). We also found that a significant decreased GCa risk was associated with STAT3 rs1053004G variant genotypes (adjusted OR = 0.84; 95% CI = 0.71-0.99 for AG + GG vs. AA). The combined analysis of IL-6 rs2069837G and JAK1 rs2230587A variant risk genotypes revealed that individuals with one-or-two risk genotypes exhibited an increased risk for GCa (adjusted OR = 1.34; 95% CI = 1.13-1.59). Genotypes and mRNA expression correlation analysis using the data from the HapMap 3 database provided further support for the observed risk associations. Larger studies are warranted to validate these findings.

ASSOCIATION OF INTERLEUKIN-10 -1082 A/G (RS1800896) POLYMORPHISM WITH SUSCEPTIBILITY TO GASTRIC CANCER: META-ANALYSIS OF 6,101 CASES AND 8,557 CONTROLS

BACKGROUND

The promoter -1082 A/G (rs1800896) polymorphism of Interleukin-10 (IL-10) gene have been widely reported and considered to have a significant role on gastric cancer risk, but the results are inconsistent.

OBJECTIVE

To clarify the association, we conducted a meta-analysis to investigate the associations IL-10 -1082 A/G polymorphism with gastric cancer.

METHODS

Eligible articles were identified by searching databases including PubMed, Web of Science, and Google Scholar up to August 03, 2017. Odds ratios (OR) with corresponding 95% confidence intervals (CIs) were used to assess the association.

RESULTS

A total of 30 case-control studies with 6,101 cases and 8,557 controls were included in this meta-analysis. Overall, a significant association between IL-10 -1082 A/G polymorphism and gastric cancer risk was observed under the allele model (G vs A: OR=1.305, 95% CI=1.076-1.584; P=0.007), heterozygote model and (GA vs AA: OR=1.252, 95% CI=1.252-1.054; P=0.011) and dominant model (GG+GA vs AA: OR=1.264, 95% CI=1.053-1.516; P=0.012). In the subgroup analysis by ethnicity, increased gastric cancer risk were found in Asians under the allele model (G vs A: OR=1.520, 95% CI=1.172-1.973; P=0.002), homozygote model (GG+GA vs AA: OR=1.571, 95% CI=1.023-2.414; P= 0.039), heterozygote model (GA vs AA: OR=1.465, 95% CI=1.192-1.801; P≤0.001) and dominant model (GG+GA vs AA: OR=1.448, 95% CI=1.152-1.821; P=0.002), but not among Caucasian and Latinos populations.

CONCLUSION

These results suggested that the IL-10 -1082 A/G (rs1800896) polymorphism might contribute to the gastric cancer susceptibility, especially among Asians.

The impact of host's genetic susceptibility on Helicobacter pylori infection in children

The aim of our study was to investigate the impact of interleukin (IL)-6 190C/T, IL-6 174G/C, IL-6 572G/C, tumor necrosis factor-alpha (TNF-α) 308G/A, and angiotensin-converting enzyme (ACE) I/D gene polymorphisms on Helicobacter pylori (H. pylori) infection in children.A cross-sectional study was performed on 126 children (57 children with H. pylori infection and 69 children without H. pylori infection) aged between 3 and 18 years presenting to a Pediatrics Tertiary Hospital from Romania. Children were assessed clinically, endoscopically, histopathologically, and genetically.In our study, we found that the presence of the CT and CT+TT genotypes of IL-6 190C/T (P < .002 and P = .04), allele G of IL-6 572 G/C polymorphism (P = .01), genotypes GA and AA of TNF-α 308 G/A polymorphism (P = .04, P = .01), and genotype II of ACE I/D polymorphism (P = .02) were associated with H. pylori infection, while the CC genotype of IL-6 174G/C polymorphism was scarcely encountered in children with H. pylori infection [P = .02, odds ratio (OR) = 0.06; 95% confidence interval (95% CI): 0.003-0.128]. Taking under consideration the 4 variant genotypes (IL-6 572G/C, IL-6 190C/T, TNF-α 308G/A, and ACE I/D), we noticed a 2 times higher incidence of H. pylori infection (OR = 6.34; 95% CI: 2.15-25.8).We may consider that the IL-6 190C/T, IL-6 174G/C, IL-6 572G/C, TNF-α 308G/A, and ACE I/D gene polymorphisms may increase the children's susceptibility for acquiring H. pylori infection; therefore, they may contribute to the pathogenesis of H. pylori gastritis.

The relationship between tumor necrosis factor-α polymorphisms and gastric cancer risk: An updated meta-analysis

The aim of the present study was to evaluate the relationship between tumor necrosis factor-α (TNF-α) and the development of gastric cancer, and to investigate whether it can be used as a biological marker for gastric cancer. In the current study, a new meta-analysis was performed to assess the association between TNF-α gene polymorphisms and gastric cancer susceptibility. Subgroup analyses based on ethnicity, control population source and non-cardia cancers were also conducted. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model. TNF-α 308 polymorphisms indicated a significant relationship with gastric cancer risk among a normal population [GA/AA vs. GG; 1.17 (1.10–1.23)]. In analysis stratified by ethnicity, TNF-α 238 displayed an association with gastric cancer risk in eastern populations [GA/AA vs. GG: 1.24 (1.02–1.50)], but not in western populations [GA/AA vs. GG: 0.96 (0.79–1.18)]. The overall ORs (95% CIs) for TNF-α 857, TNF-α 1031 and TNF-α 863 were 1.13 (1.04–1.24), 0.94 (0.85–1.05) and 0.89 (0.78–1.02), respectively, under dominant genetic model comparison. Among the above three SNPs, only TNF-α 857 was robustly associated with gastric cancer inclination, and this association remained consistently robust when limited to non-cardia gastric cancers [GA/AA vs. GG: 1.16 (1.03–1.31)]. TNF-α 308 and TNF-α 857 genotypes were potential risk factors of statistical significance in gastric cancer, and TNF-α 238 indicated to be significantly associated with gastric cancer risk only in eastern populations. TNF-α 1031 and TNF-α 863 were not significantly associated with gastric cancer risk.

Combination of Helicobacter pylori infection and the interleukin 8 -251 T > A polymorphism, but not the mannose-binding lectin 2 codon 54 G > A polymorphism, might be a risk factor of gastric cancer

Background

Mannose-binding lectin (MBL) acts in the innate immune response to Helicobacter pylori. Interleukin 8 (IL-8) is a potent cytokine produced by gastric epithelial cells in response to H. pylori. We aimed to investigate whether polymorphisms in MBL2 and IL-8 influence susceptibility to H. pylori infection, and the associations of these polymorphisms with the risk of gastroduodenal diseases in a Korean population.

Methods

We consecutively enrolled 176 H. pylori-negative control subjects, 221 subjects with H. pylori-positive non-atrophic gastritis, 52 mild atrophic gastritis (AG), 61 severe AG, 175 duodenal ulcer, and 283 gastric cancer (GC). Allele-specific PCR-RFLP was conducted for polymorphisms in MBL2 exon 1 (codon 52, 54, and 57) and IL-8 -251 T > A. IL-8 levels in gastric mucosal tissues and serum MBL levels were measured by enzyme-linked immunosorbent assay.

Results

MBL2 exon 1 polymorphic variants were found only in codon 54, and the allele frequencies did not differ significantly between the control and disease groups. Although serum MBL levels in codon 54 A/A mutants were markedly low, it did not influence susceptibility to H. pylori infection or the risk of gastroduodenal diseases. IL-8 levels were significantly different between T/T wild type, T/A heterozygote, and A/A mutant genotypes. IL-8 -251 A allele carriers (A/A + T/A) showed increased IL-8 levels, and were significantly associated with the risk of severe AG and GC.

Conclusions

We suggest that a combination of H. pylori infection and the IL-8 -251 T > A polymorphism might increase the risk of severe AG and GC in a Korean population.

TNF-α-308/-238 polymorphisms are associated with gastric cancer: A case-control family study in China

BACKGROUND

Associations of TNF-α-308 (rs1800629) and -238 (rs361525) with gastric cancer had the inconsistent indication among different populations.

METHODS

In this case-control family study, 47 families were determined with the probands diagnosed with gastric cancer (case family, n=296), accordingly 47 families without gastric cancer were matched with the case families by multivariate distribution of age, sex, social class, and pedigree size (control family, n=319). Polymerase chain reaction-restriction fragment length polymorphism (RFLP-PCR) was used to identify the TNF genotype. Chi-square test was used to compare the groups regarding genotype and the allele frequencies, HWE test for Hardy-Weinberg equilibrium.

RESULTS

The frequencies of TNF-α-308 GA and AA genotypes were significantly higher in case family than that in control family. The risk of gastric cancer was increased in GA and AA carriers in the first degree (OR=2.06, 95% CI=1.20-3.51 and OR=4.89, 95% CI=2.74-8.74), however the similar result was not found in the second degree. Helicobacter pylori infection status were significantly associated with risk of gastric cancer in first-degree relatives (OR=1.96, 95% CI=1.26-3.05) while no statistical significance was noted in the second-degree relatives. Haplotypes of TNF-α-308/-238 alleles, GA/GG, AA/GG and AA/GA indicated the susceptibilities to gastric cancer with OR and 95% confident intervals resulting 2.07 (1.34-3.21), 4.49 (2.74-7.33) and 4.98 (1.76-14.01) respectively.

CONCLUSIONS

TNF-α-G308A (rs1800629) polymorphisms are associated with gastric cancer in Chinese population. Haplotypes of TNF-α-308/-238 GA/GG, AA/GG and AA/GA increase the susceptibilities to gastric cancer. The first-degree relatives are more likely to develop into gastric cancer with TNF-α-G308 polymorphisms and H. pylori positive than the second-degree are.

Relationship Between Interleukin-10 Gene C-819T Polymorphism and Gastric Cancer Risk: Insights From a Meta-Analysis

BACKGROUND As a pleiotropic cytokine, interleukin-10 (IL-10) plays a regulatory role in carcinogenesis and tumor growth. The aim of this meta-analysis was to assess the susceptibility of the IL-10 gene C-819T polymorphism to gastric cancer. MATERIAL AND METHODS Study identification and data extraction were independently completed by 2 authors. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated and summarized. RESULTS In total, 11 articles including 1960 gastric cancer patients and 3705 controls were qualified. Overall analyses revealed a 13% reduced risk of gastric cancer conferred by the -819T allele relative to the -819C allele (OR=0.87; 95% CI: 0.77-0.97; P=0.016), without heterogeneity (I2=35.1%). In subgroup analyses, a significant difference was identified in East Asian populations (OR=0.85; 95% CI: 0.73-0.98; P=0.029, I2=43.6%), for gastric adenocarcinoma (OR=0.80; 95% CI: 0.66-0.96; P=0.017, I2=0.0%), and in population-based studies (OR=0.81; 95% CI: 0.70-0.93; P=0.003, I2=0.0%). The visual funnel plots and Egger's tests suggested no evidence of publication bias. CONCLUSIONS Extending previous findings, we demonstrate a protective role of the IL-10 gene -819T allele in susceptibility to gastric cancer, and this role was more evident for gastric adenocarcinoma.

Association of polymorphisms in interleukin-8 gene with cancer risk: a meta-analysis of 22 case-control studies

Interleukin-8 (IL-8) is a kind of chemokine that plays an important role in the development and progression of many human malignancies. Previous studies have uncovered that polymorphisms in IL-8 is associated with the risk of many cancer types, but the results were inconsistent and inconclusive. In the present study, we aimed to explore the roles of IL-8 polymorphisms (rs2227307, rs2227306, +678T/C, rs1126647, and +1633C/T) and cancer risk through a systematic review and meta-analysis. Potential source of heterogeneity was sought out through sensitivity analysis. Desirable data were extracted and registered into databases. Finally, a total of ten publications comprising of 22 case–control studies, including 4,259 cases and 7,006 controls were ultimately eligible for the meta-analysis. No significant association was uncovered for all the five polymorphisms and the overall cancer risk. However, in the stratification analysis by cancer type, a significantly decreased risk of hepatocellular carcinoma was identified for rs2227306 polymorphism (T vs C: odds ratio [OR] =0.721, 95% confidence interval [CI] =0.567–0.916, P_z=0.007; TT vs CC: OR =0.447, 95% CI =0.274–0.728, P_z=0.001; TT vs TC + CC: OR =0.480, 95% CI =0.304–0.760, P_z=0.002). In conclusion, our data shows that rs2227306 polymorphism plays a protective role in hepatocellular carcinoma risk. Future well-designed studies with a larger sample size are warranted to verify our findings.

A Causal Role of Genetically Elevated Circulating Interleukin-10 in the Development of Digestive Cancers: Evidence from Mendelian Randomization Analysis Based on 29,307 Subjects

Recent studies have observed a high level of circulating interleukin-10 (IL-10) in patients with digestive cancers, yet whether elevated IL-10 is causally associated with digestive cancers so far remained unresolved. We therefore meta-analyzed available observational studies with Mendelian randomization method to explore this causal association by employing IL-10 gene 3 variants (-592C>A, -819C>T, and -1082A>G) as instruments. Data were available from 52 articles encompassing 29,307 subjects. Subgroup analysis by cancer type indicated that -1082A>G was associated with increased risk of gastric cancer (odds ratio [OR] = 1.19; 95% confidence interval [CI]: 1.05-1.35; P = 0.006), and the association was reinforced for intestinal type gastric cancer (OR = 1.26; 95%CI: 1.09-1.44; P = 0.001). By ethnicity, risk estimate for -1082G allele carriers was increased by 21% for digestive cancers in East Asians (95%CI: 1.05-1.40; P = 0.009). As for the genotype-phenotype association, carriers of -1082G allele had an overall 20.21 pg/mL higher IL-10 level than those with -1082AA genotype (P = 0.023). In further Mendelian randomization analysis, the predicted OR for 10 pg/mL increment in IL-10 was 1.14 (95%CI: 1.01-16.99) in gastric cancer. Our findings provided evidence for a causal role of genetically elevated IL-10 in the development of gastric cancer, especially in East Asians and for intestinal type gastric cancer.

Interleukin-1B 31 C>T polymorphism combined with Helicobacter pylori-modified gastric cancer susceptibility: evidence from 37 studies

Gastric cancer is one of the most common malignancies worldwide. Interleukin‐1‐beta (IL‐1β) is a pro‐inflammatory cytokine and potent inhibitor of gastric acid secretion. Some studies provided evidence of the association between IL‐1B 31 polymorphism and gastric cancer risk while other studies did not. Therefore, we conducted a comprehensive meta‐analysis to reassess the association. A systematic literature search of the PubMed and EMBASE databases identified 37 studies with 6108 cases and 8980 controls for this meta‐analysis. The crude odd ratios (ORs) and the 95% confidence intervals (CIs) were calculated to evaluate the strength of the association. Meta‐regression was used to determine the major source of heterogeneity across the studies. The pooled analysis did not suggest the significant association of IL‐1B 31 C>T polymorphism with gastric cancer risk. Stratified analysis was performed by ethnicity, source of control, genotype method, and indicated a significantly increased gastric cancer risk associated with IL‐1B 31T variant in the population‐based subgroup (heterozygous model: OR = 1.22, 95% CI = 1.03–1.45). Moreover, stratified analysis by Helicobacter pylori infection status indicated that IL‐1B 31 polymorphism increased gastric cancer risk in infection‐positive subgroup (homozygous model: OR = 1.35, 95% CI = 1.02–1.78; heterozygous model: OR = 1.31, 95% CI = 1.04–1.66; recessive model: OR = 1.29, 95% CI = 1.04–1.61). The study suggested that IL‐1B 31 polymorphism might confer susceptibility to gastric cancer in the presence of H. pylori infection, indicating a gene–environment interaction in gastric carcinogenesis.

Helicobacter pylori Infection Synergistic with IL-1β Gene Polymorphisms Potentially Contributes to the Carcinogenesis of Gastric Cancer

Helicobacter pylori (H. pylori) infection is the most common chronic bacterial infection in the world and the etiological agent for most gastric cancer (GC). Interleukin-1β (IL-1β) is a potent proinflammatory cytokine, and its deregulation is closely associated with the tumorigenesis of several cancers. Recent studies have revealed that the IL-1β-31 and -511T alleles are closely associated with gastric carcinogenesis due to their roles in the induction of gastric precancerous lesions and hypochlorhydria. Furthermore, H. pylori infection has a synergistic effect on the development of GC with IL-1β gene polymorphisms, and the highest prevalence of severe gastric abnormalities are found in patients with both host and bacterial high-risk genotypes (cagA(+)/vacAs1(+)/IL-1β-511T). Therefore, these recent advances demonstrate that H. pylori synergistic with IL-1β gene polymorphisms contribute to the gastric carcinogenesis by their involvement in precancerous gastric lesions and low gastric acid secretion.

Helicobacter pylori vs immune system or antibiotics

Helicobacter pylori (H. pylori) infection has often no clinical signs and is one of the most common bacterial infections. All infected subjects have histology of active chronic gastritis. In some cases patients develop peptic ulcer and minority of them develop gastric cancer. Gastric cancer is multifactorial disease, thus various progressions of H. pylori infection and disease are dependent on the host genetic factors, the characteristics of the individual’s immune response, environmental factors, and different bacterial virulence factors of the individual bacterial strains. Eradication of the bacteria plays a crucial role in the treatment of these cases however antibiotic therapy does not always help. Bacteria often develop resistance to antibiotics so we recommend that not only screening for H. pylori also the strain determination should have some diagnostic value, especially in the patients who already developed gastritis. Furthermore, for such patients assessment of disease progression (atrophic or metaplastic gastritis) could be followed by polymorphism determination. Until now we cannot predict the disease based only on single polymorphism. Bacteria successfully neutralize the responses of the immune systems using different enzymes or even components of the host immune response. However, the influence of immune system and its components could represent new ways of treatments and could help to eradicate the infection.

The influence of cytokine gene polymorphisms on the risk of developing gastric cancer in patients with Helicobacter pylori infection

BACKGROUND

Helicobacter pylori infection is the main cause of gastric cancer. The disease progression is influenced by the host inflammatory responses, and cytokine single nucleotide polymorphisms (SNPs) may have a role in the course of the disease. The aim of our study was to investigate proinflammatory cytokine polymorphisms, previously associated with the development of gastric cancer, in a Slovenian population.

PATIENTS AND METHODS

In total 318 patients and controls were selected for the study and divided into three groups: (i) patients with gastric cancer (n = 58), (ii) patients with chronic gastritis (n = 60) and (iii) healthy control group (n = 200). H. pylori infection in patient groups was determined by serology, histology and culture. Four proinflammatory gene polymorphisms were determined (IL-1β, IL-1ra, TNF-α, TLR-4) in all subjects.

RESULTS

We found a statistically significant difference between males and females for the groups (p = 0.025). Odds ratio (OR) for gastric cancer risk for females was 0.557 (95% confidence interval [CI]: 0.233-1.329) and for chronic gastritis 2.073 (95% CI: 1.005-4.277). IL-1B-511*T/T homozygous allele for cancer group had OR = 2.349 (95% CI: 0.583-9.462), heterozygous IL-1B-511*T had OR = 1.470 (95% CI: 0.583-3.709) and heterozygotes in TNF-A-308 genotype for chronic gastritis had OR = 1.402 (95% CI: 0.626-3.139). Other alleles had OR less than 1.

CONCLUSIONS

We could not prove association between gastric cancer and chronic gastritis due to H. pylori in any cytokine SNPs studied in Slovenian population. Other SNPs might be responsible besides infection with H. pylori for the progression from atrophy to neoplastic transformation.

Association Between IL-4 and IL-6 Expression Variants and Gastric Cancer Among Portuguese Population

Introduction

Multiple studies have reported strong associations between Helicobacter pylori (Hp) inflammation and gastric cancer (GC) development. Altered expressions of pro/anti-inflammatory cytokines have a crucial role in Hp and GC proliferation. Although there are many studies related to cytokines polymorphisms involvement in GC risk, the role of Interleukin-4 (IL-4) and Interleukin-6 (IL-6) in gastric inflammation process is not yet clarified.

Aim

This study aimed to investigate the impact of common IL-4 and IL-6 polymorphisms in GC development risk among Portuguese population.

Methods

A total of 100 GC biopsies (50 with intestinal type, IGC, 50 with diffuse type, DGC) and 50 chronic gastritis cases, used as control group, were included in this case-control study. IL-4 and IL-6 common polymorphisms were genotyped by PCR-SSP, using commercially available kits.

Results

IL-4 low producer genotypes, IL-4-590TT (OR = 6.7; 95% CI 1.4–32.4) and IL-4-1098GG (OR = 4.4; 95% CI 1.7–16.9) were found associated with IGC and DGC, respectively. We also verified that IL-4 TTT haplotype was linked with both IGC (OR = 5.8; 95% CI 2.3–14.4) and DGC (OR = 2.3; 95% CI 1.0–5.5) groups. Concerning IL-6 results, IL-6-174CG genotype showed a higher prevalence among IGC cases (OR = 7.3; 95% CI 2.7–20.3), and IL-6-174CC (OR = 3.8; 95% CI 1.7–8.7) showed upper prevalence within DGC subjects. Finally, IL-6-174/nt565CG haplotype showed a significant association with both IGC (OR = 7.3; 95% CI 2.7–20.3) and DGC (OR = 7.9; 95% CI 4.2–14.9).

Conclusion

IL-6 and IL-4 expression variants seem to have an important role in GC risk mechanisms. This study provides preliminary evidence that IL-4 and IL-6 polymorphisms, although not directly linked to the disease, may be useful tools in the study of this multifactorial disease.

Circulating interleukin-6 and cancer: A meta-analysis using Mendelian randomization

Interleukin-6 (IL-6) plays a contributory role in the progression and severity of many forms of cancer; it however remains unclear whether the relevance between circulating IL-6 and cancer is causal. We therefore meta-analyzed published articles in this regard using IL-6 gene -174G/C variant as an instrument. Seventy-eight and six articles were eligible for the association of -174G/C variant with cancer and circulating IL-6, respectively. Overall analyses failed to identify any significance between -174G/C and cancer risk. In Asians, carriers of the -174CC genotype had an 1.95-fold increased cancer risk compared with the -174GG genotype carriers (P = 0.009). By cancer type, significance was only attained for liver cancer with the -174C allele conferring a reduced risk under allelic (odds ratio or OR = 0.74; P = 0.001), homozygous genotypic (OR = 0.59; P = 0.029) and dominant (OR = 0.67; P = 0.004) models. Carriers of the -174CC genotype (weighted mean difference or WMD = −4.23 pg/mL; P < 0.001) and -174C allele (WMD = −3.43 pg/mL; P < 0.001) had circulating IL-6 reduced significantly compared with the non-carriers. In further Mendelian randomization analysis, a reduction of 1 pg/mL in circulating IL-6 was significantly associated with an 12% reduced risk of liver cancer. Long-term genetically-reduced circulating IL-6 might be causally associated with a lower risk of liver cancer.

The tumor necrosis factor-α-238 polymorphism and digestive system cancer risk: a meta-analysis

Many studies have reported the association between tumor necrosis factor-α (TNF-α)-238 polymorphism and digestive system cancer susceptibility, but the results were inconclusive. We performed a meta-analysis to derive a more precise estimation of the relationship between TNF-α-238 G/A polymorphism and digestive system cancer risk. Pooled analysis for the TNF-α-238 G/A polymorphism contained 26 studies with a total of 4849 cases and 8567 controls. The meta-analysis observed a significant association between TNF-α-238 G/A polymorphism and digestive system cancer risk in the overall population (GA vs GG: OR 1.19, 95 % CI 1.00-1.40, P heterpgeneity = 0.016; A vs G: OR 1.19, 95 % CI 1.03-1.39, P heterpgeneity = 0.015; dominant model: OR 1.20, 95 % CI 1.02-1.41, P heterpgeneity = 0.012). In the analysis of the ethnic subgroups, however, similar results were observed only in the Asian population, but not in the Caucasian population. Therefore, this meta-analysis suggests that TNF-α-238 G/A polymorphism is associated with a significantly increased risk of digestive system cancer. Further large and well-designed studies are needed to confirm these findings.

Association of heparan sulfate proteoglycans SDC1 and SDC4 polymorphisms with breast cancer in an Australian Caucasian population

Breast cancer is a common disease in both developing and developed countries with early identification and treatment improving prognosis and survival. Heparan sulfate proteoglycans (HSPGs) are key components of the extracellular matrix (ECM) that mediate cell adhesion, motility, proliferation, invasion and cell signalling. Members of the syndecan family of HSPGs have been identified to be involved in breast cancer progression through their varied interactions with a number of growth factors, ligands and receptors. Specifically, high expression levels of syndecan-1 (SDC1) have been demonstrated in more invasive breast tumours while elevated syndecan-4 (SDC4) levels have been identified to correspond with improved prognosis. With genetic changes in the syndecans and their association with breast cancers plausible, we examined two single nucleotide polymorphisms in SDC1 (rs1131351) and SDC4 (rs67068737) within an Australian Caucasian breast cancer case/control population. No association was found with SDC4 and breast cancer in our population. However, a significant association between SDC1 and breast cancer was identified in both our case/control population and in a replication cohort. When both populations were combined for analysis, this association became more significant (genotype, p = 0.0003; allele, p = 0.0001). This data suggests an increased risk of developing breast cancer associated with the presence of the C allele of the SDC1 rs1131351 single nucleotide polymorphism (SNP) and may provide a marker toward early breast cancer detection.

Effects of the interleukin-1β-511 C/T gene polymorphism on the risk of gastric cancer in the context of the relationship between race and H. pylori infection: a meta-analysis of 20,000 subjects

The interleukin (IL)-1β-511 C/T polymorphism has been shown to be functional and to contribute to the risk of gastric cancer. However, the relationship between the IL-1β-511 C/T polymorphism and gastric carcinogenesis remains inconclusive. A systematical electronic search was conducted of the MEDLINE, EMBASE, and CENTRAL databases. A random and a fixed effects model were exploited to estimate summary odds ratios and 95 % confidence intervals. Subgroup and sensitivity analyses were carried out with respect to ethnicity, quality assessment scores, control sources, genotyping methods, cancer histopathology and location, and Helicobacter pylori (H. pylori) infection. A total of 45 studies containing 9,066 cases of gastric cancer and 11,192 control subjects satisfied the inclusion criteria. The IL-1β-511 C/T polymorphism was found to enhance the risk of stomach cancer for overall and HWE-satisfying studies. Asians showed a positive relationship in both the overall and HWE-satisfying groups, whereas Caucasians did not. Based on subgroup analysis, H. pylori infection and genotype analysis using PCR-RFLP methods increase the association between IL-1β-511 T allele carrier and risk of stomach cancer. A positive relationship was found between the IL-1β-511 C/T SNP and stomach carcinoma susceptibility, and the results suggest that Asian ethnicity, H. pylori infection and methodologically, PCR-RFLP genotyping strengthen this relationship. Reflecting on prevalence of H. pylori in Asian countries, additional studies on the IL-1β-511 C/T SNP in the context of ethnicity and H. pylori infection may provide key insights into the mechanism underlying gastric cancer carcinogenesis. It was found PCR-RFLP is the most reliable genotyping method, and thus, it is recommendable to adopt it to determine the presence of the IL-1β-511 C/T SNP.

Genetic variants in the IL1A gene region contribute to intestinal-type gastric carcinoma susceptibility in European populations

The most studied genetic susceptibility factors involved in gastric carcinoma (GC) risk are polymorphisms in the inflammation-linked genes interleukin 1 (IL1) B and IL1RN. Despite the evidence pointing to the IL1 region, definite functional variants reproducible across populations of different genetic background have not been discovered so far. A high density linkage disequilibrium (LD) map of the IL1 gene cluster was established using HapMap to identify haplotype tagSNPs. Eighty-seven SNPs were genotyped in a Portuguese case-control study (358 cases, 1,485 controls) for the discovery analysis. A replication study, including a subset of those tagSNPs (43), was performed in an independent analysis (EPIC-EurGast) containing individuals from 10 European countries (365 cases, 1284 controls). Single SNP and haplotype block associations were determined for GC overall and anatomopathological subtypes. The most robust association was observed for SNP rs17042407, 16Kb upstream of the IL1A gene. Although several other SNP associations were observed, only the inverse association of rs17042407 allele C with GC of the intestinal type was observed in both studies, retaining significance after multiple testing correction (p = 0.0042) in the combined analysis. The haplotype analysis of the IL1A LD block in the combined dataset revealed the association between a common haplotype carrying the rs17042407 variant and GC, particularly of the intestinal type (p = 3.1 × 10(-5) ) and non cardia localisation (p = 4.6 × 10(-3) ). These results confirm the association of IL1 gene variants with GC and reveal a novel SNP and haplotypes in the IL1A region associated with intestinal type GC in European populations.

Polymorphism of the IL-8 gene and the risk of ovarian cancer

Ovarian cancer still represents a challenge in gynecological oncology. Most patients are diagnosed in an advanced tumor stage. No specific screening or prevention strategies for ovarian cancer exist as of yet. Interleukin 8 (IL-8) is a pro-inflammatory chemokine known for its angiogenetic activity, and is supposedly responsible for tumor-associated angiogenesis in several malignant tumors. The aim of the study was to investigate the susceptibility of patients with an IL-8 gene polymorphism to developing ovarian cancer. Four single nucleotide polymorphisms (SNPs) (IL-8 -251, IL-8 +781, IL-8 +1633 and IL-8 +2767) of the IL-8 gene were screened, using the PCR method in 268 patients with ovarian cancer and 426 healthy women as a control group. Significant associations were noted in patients with the IL-8 +781 (T/T) genotype (p=0.0048) with increased frequencies of ovarian cancer, while women with the IL-8 +781 (C/C) allele suffer from ovarian cancer significantly less frequently (p=0.0003). Furthermore, the IL-8 +2767 (T/T) genotype is also associated with a higher risk of ovarian cancer (p=0.0177). Our results indicate, for the first time, that IL-8 polymorphism is associated with ovarian cancer.

Association between TNF-α-308 G/A gene polymorphism and gastric cancer risk: a systematic review and meta-analysis

OBJECTIVE

Tumor necrosis factor-alpha (TNF-α) has been found to be associated with gastric carcinogenesis, but individually published results have been inconclusive. The aim of this study was to explore the relationship between the TNF-α-308 G/A polymorphism and gastric cancer risk.

METHODS

MEDLINE, EMBASE and the COCHRANE library databases were searched for relevant articles to identify all available data. The odds ratios (ORs) with 95% confidence intervals (95% CIs) from each study were used to assess the association between the TNF-α-308 G/A polymorphism and gastric cancer risk.

RESULTS

This meta-analysis included 30 studies (32 datasets) involving 7009 gastric cancer cases and 12,119 control subjects. Overall, a significant association was found between the TNF-α-308 G/A polymorphism and gastric cancer in AA+GA vs. GG (dominant contrast model) (OR=1.20, 95% CI=1.07-1.34, p=0.001). With stratification based on ethnicity, the TNF-α-308 G/A polymorphism was correlated with gastric cancer risk in Caucasians, using the dominant contrast model (OR=0.74, 95% CI=0.57-0.96, p=0.02), but not in East Asians and other ethnic groups. In the comprehensive subgroup analysis, a significant association was also found in recent articles (published after 2005), population-based high-quality studies, hospital-based high-quality studies, studies using the TaqMan method and non-cardia subgroups. However, the TNF-α-308 G/A polymorphism was not associated with specific histological types of gastric cancer risk.

CONCLUSIONS

The TNF-α-308 G/A polymorphism may contribute to susceptibility to gastric cancer in Caucasians, especially for non-cardia gastric cancer, as most strongly demonstrated in high-quality studies and in studies using the TaqMan genotyping method. Furthermore, we recommend the TaqMan method as the preferred genotyping method in DNA polymorphism studies.

The -1082A>G polymorphism in promoter region of interleukin-10 and risk of digestive cancer: a meta-analysis

The -1082A>G polymorphism is located in promoter region of interleukin-10 (IL-10) and it could affect the production of IL-10. Numerous studies have investigated the association between IL-10 -1082A>G and risk of digestive cancer. However, the conclusion is still inconsistent. Here, we have performed a meta-analysis and systematic review to determine the association between the IL-10 -1082A>G and susceptibility to digestive cancer. In this meta-analysis, we identified 40 eligible studies, involving 7195 patients of digestive cancer and 11755 controls. By pooling all eligible studies, we found the variant -1082G allele significantly increased risk of digestive cancer (G vs. A: OR = 1.181, 95% CI: 1.057-1.319). Further stratified analysis was performed to evaluate the influence of cancer types, ethnicities, study design, sample size and Hardy-Weinberg equilibrium. Stratified analysis suggested that, the -1082A>G polymorphism was only associated with increased risk for gastric cancer (G vs. A: OR = 1.281, 95% CI: 1.102-1.488) and in Asian population (G vs. A: OR = 1.399, 95% CI: 1.188-1.646). No significant publication bias was detected. Based on 40 studies and 18950 participants, we found the variant IL-10 -1082G allele significantly increased susceptibility to digestive cancer, especially for gastric cancer and in Asian population.