The Association between Polymorphisms of XPD and Susceptibility of Lung Cancer: A meta Analysis

Background and objective Many studies concluded that the polymorphisms of XPD were involved in the risk of lung cancer. However, several other studies suggested no association. To explore whether the polymorphisms of XPD contribute to the genetic susceptibility to lung cancer, we carried a meta-analysis based on the published works. Methods All works related to XPD and lung cancer risk were searched and carefully selected. The genotype frequencies of XPD and related variables were abstracted and the pooled ORs were calculated after the heterogeneity test with the software Stata 10. Publication bias and sensitivity were evaluated at the same time. Results Twenty-two studies were included according to the selection criteria, of which fifteen investigated the codon 312 of XPD and twenty studied the codon 751. The pooled OR of susceptibility to lung cancer with XPD312 Asn/Asn genotype compared to the wild Asp/Asp were 1.18 (95%CI: 1.03-1.34, P=0.018). And the polymorphisms of XPD codon 751 were also associated with increased lung cancer risk (Lys/Gln OR=1.09, 95%CI: 1.02-1.18; Gln/Gln OR=1.24, 95%CI: 1.10-1.41). However, subgroup analysis indicated that the association between XPD751 and lung cancer could only be found in Europeans and Americans. The publication bias analysis had no statistically significant results. Conclusion Polymorphisms of XPD codons 312 and 751 seem to be involved in elevated risk of lung cancer.