Effect of Xeroderma pigmentosum complementation group F polymorphisms and H.pylori infection on the risk of gastric cancer

Impact of XPF rs2276466 polymorphism on cancer susceptibility: a meta-analysis

Association between the xeroderma pigmentosum complementation group F (XPF)rs2276466 located in the excision repair cross complementation group 4 (ERCC4) gene and cancer susceptibility has been widely investigated. However, results thus far have remained controversial. A meta-analysis was performed to identify the impact of this polymorphism on cancer susceptibility. PubMed, Embase and Science-Web databases were searched systematically up to May 20, 2018, to obtain all the records evaluating the association between the rs2276466 polymorphism and the risk of all types of cancers. We used the odds ratio (OR) as a measure of effect, and pooled the data in a Mantel-Haenszel weighed random-effects meta-analysis to provide a summary estimate of the impact of this polymorphism on gastrointestinal cancer, neurogenic cancer and other cancers (breast cancer and SCCHN). All the analyses were carried out in STATA 14.1.11 case–control studies that consisted of 5730 cases and 6756 controls, were eventually included in our meta-analysis. The significant association was observed between the XPFrs2276466 polymorphism and neurogenic cancer susceptibility (recessive model: OR = 1.648, 95% CI = 1.294–2.098, P<0.001). Furthermore, no significant impact of this polymorphism was detected on decreased gastrointestinal cancer risk (dominant model: OR = 1.064, 95%CI = 0.961–1.177, P = 0.233). The rs2276466 polymorphism might play different roles in carcinogenesis of various cancer types. Current evidence did not suggest that this polymorphism was directly associated with gastrointestinal susceptibility. However, this polymorphism might contribute to increased neurogenic cancer risk. More preclinical and epidemiological studies are still imperative for further evaluation

Relevance of DNA repair gene polymorphisms to gastric cancer risk and phenotype

Variations in DNA repair genes have been reported as key factors in gastric cancer (GC) susceptibility but results among studies are inconsistent. We aimed to assess the relevance of DNA repair gene polymorphisms and environmental factors to GC risk and phenotype in a Caucasian population in Spain. Genomic DNA from 603 patients with primary GC and 603 healthy controls was typed for 123 single nucleotide polymorphisms in DNA repair genes using the Illumina platform. Helicobacter pylori infection with CagA strains (odds ratio (OR): 1.99; 95% confidence interval (CI): 1.55–2.54), tobacco smoking (OR: 1.77; 95% CI: 1.22–2.57), and family history of GC (OR: 2.87; 95% CI: 1.85–4.45) were identified as independent risk factors for GC. By contrast, the TP53 rs9894946A (OR: 0.73; 95% CI: 0.56–0.96), TP53 rs1042522C (OR: 0.76; 95% CI: 0.56–0.96), and BRIP1 rs4986764T (OR: 0.55; 95% CI: 0.38–0.78) variants were associated with lower GC risk. Significant associations with specific anatomopathological GC subtypes were also observed, most notably in the ERCC4 gene with the rs1799801C, rs2238463G, and rs3136038T variants being inversely associated with cardia GC risk. Moreover, the XRCC3 rs861528 allele A was significantly increased in the patient subgroup with diffuse GC (OR: 1.75; 95% CI: 1.30–2.37). Our data show that specific TP53, BRIP1, ERCC4, and XRCC3 polymorphisms are relevant in susceptibility to GC risk and specific subtypes in Caucasians.

Lack of association between XPF polymorphisms and gastric cancer risk: a meta-analysis

BACKGROUND

Xeroderma pigmentosum complementation group F (XPF or ERCC4) plays a key role in DNA repair that protects against genetic instability and carcinogenesis. Several epidemiological studies have examined associations between XPF polymorphisms and gastric cancers risk, but the findings remain inconclusive. Therefore, we conducted the present meta-analysis to obtain the most reliable estimate of the association.

METHODS

PubMed, Embase, Web of Science, and Wanfang were searched. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were extracted and pooled to assess the strength of the association between 3 commonly studied polymorphisms of XPF (rs744154, rs6498486, rs1799801) and gastric cancer risk. The pooled ORs were performed for the co-dominant model (homozygous and heterozygous), dominant model, and recessive model. 3 studies on rs744154, 3 studies on rs6498486, and 4 studies on rs1799801 were included in our meta-analysis.

RESULTS

Our results show that the genotype distribution of the 3 polymorphisms was not associated with risk of gastric cancer in all genetic models.

CONCLUSION

This meta-analysis suggests that the 3 common XPF polymorphisms rs744154, rs6498486, and rs1799801 are not associated with gastric cancer risk. However, large-sample and representative population-based studies with homogeneous gastric cancer patients and well-matched controls are warranted to confirm this finding.