XPA A23G polymorphism and lung cancer risk: a meta-analysis

Case-control studies on the association between XPA A23G and lung cancer have provided either controversial or inconclusive results. To clarify the effect of XPA A23G on the risk of lung cancer, a meta-analysis of all case-control observational studies was performed. Pooled odds ratios (ORs) for various polymorphisms were estimated using random and fixed effects models. The Q-statistic was used to evaluate the homogeneity, and Egger and Begg tests were used to assess publication bias. For the homozygote GG and G allele carriers (GA + GG), the pooled ORs were 1.24 (95% CI 1.05-1.46; P = 0.27 for heterogeneity) and 1.30 (95% CI 1.13-1.51; P = 0.45 for heterogeneity) compared to the homozygous genotype (AA). In the stratified analysis by ethnicity, the ORs of the G allele carriers and the homozygote GG were 1.28 (95% CI 1.10-1.49; P = 0.07 for heterogeneity) and 1.42 (95% CI 1.04-1.93; P = 0.39 for heterogeneity) among non-Caucasians. No significant associations were found in the Caucasian population in any of the genetic models. When studies that were not in Hardy-Weinberg equilibrium (HWE) were corrected, the pattern of the results remained the same. Our results indicated a significantly decreased risk of lung cancer in non-Caucasians with the G allele.