The effect of XPD polymorphisms on digestive tract cancers risk: a meta-analysis

PLoS One. 2014 May 2;9(5):e96301. doi: 10.1371/journal.pone.0096301. eCollection 2014.

Abstract

Background: The Xeroderma pigmento-sum group D gene (XPD) plays a key role in nucleotide excision repair. Single nucleotide polymorphisms (SNP) located in its functional region may alter DNA repair capacity phenotype and cancer risk. Many studies have demonstrated that XPD polymorphisms are significantly associated with digestive tract cancers risk, but the results are inconsistent. We conducted a comprehensive meta-analysis to assess the association between XPD Lys751Gln polymorphism and digestive tract cancers risk. The digestive tract cancers that our study referred to, includes oral cancer, esophageal cancer, gastric cancer and colorectal cancer.

Methods: We searched PubMed and EmBase up to December 31, 2012 to identify eligible studies. A total of 37 case-control studies including 9027 cases and 16072 controls were involved in this meta-analysis. Statistical analyses were performed with Stata software (version 11.0, USA). Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association.

Results: The results showed that XPD Lys751Gln polymorphism was associated with the increased risk of digestive tract cancers (homozygote comparison (GlnGln vs. LysLys): OR = 1.12, 95% CI = 1.01-1.24, P = 0.029, P heterogeneity = 0.133). We found no statistical evidence for a significantly increased digestive tract cancers risk in the other genetic models. In the subgroup analysis, we also found the homozygote comparison increased the susceptibility of Asian population (OR = 1.28, 95% CI = 1.01-1.63, P = 0.045, P heterogeneity = 0.287). Stratified by cancer type and source of control, no significantly increased cancer risk was found in these subgroups. Additionally, risk estimates from hospital-based studies and esophageal studies were heterogeneous.

Conclusions: Our meta-analysis suggested that the XPD 751Gln/Gln genotype was a low-penetrate risk factor for developing digestive tract cancers, especially in Asian populations.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asian People / genetics
  • Case-Control Studies
  • Colorectal Neoplasms / ethnology
  • Colorectal Neoplasms / genetics*
  • Esophageal Neoplasms / ethnology
  • Esophageal Neoplasms / genetics*
  • Gene Frequency
  • Genetic Predisposition to Disease / ethnology
  • Genetic Predisposition to Disease / genetics*
  • Genotype
  • Humans
  • Linkage Disequilibrium
  • Mouth Neoplasms / ethnology
  • Mouth Neoplasms / genetics*
  • Odds Ratio
  • Polymorphism, Genetic*
  • Risk Factors
  • Stomach Neoplasms / ethnology
  • Stomach Neoplasms / genetics*
  • White People / genetics
  • Xeroderma Pigmentosum Group D Protein / genetics*

Substances

  • Xeroderma Pigmentosum Group D Protein
  • ERCC2 protein, human

Grants and funding

This study was partially supported by the Postdoctoral Science Foundation of Jiangsu Province (528), the Health Department guidance project of Jiangsu Province (Z201201), the Program for Development of Innovative Research Team in the First Affiliated Hospital of NJMU and the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (JX10231801), the Jiangsu Province Clinical science and technology projects (Clinical Research Center, BL2012008) and the Summit of the Six Top Talents Program of Jiangsu Province (2013-WSN-034). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.