Association Between the LIG1 Polymorphisms and Lung Cancer Risk: A Meta-analysis of Case-Control Studies

Non-homologous end joining (NHEJ) is one of the pathways used to repair the DNA double-strand breaks. A number of genes involved in NHEJ have been implicated as lung cancer susceptibility genes such as the LIG1. However, some studies have generated conflicting results. The aim of this review and meta-analysis was to investigate the association between the LIG1 gene polymorphism and lung cancer risk. Studies focusing on the relationship between the LIG1 gene polymorphisms and susceptibility to lung cancer were selected from several electronic databases, with the last search up to October 25, 2014. Data were extracted by two independent reviewers, and the meta-analysis was performed with STATA version 12.0 software, calculating odds ratios (ORs) with 95 % confidence intervals (95 % CIs). According to the inclusion criteria, we included ten studies with a total of 4012 lung cancer cases and 5629 healthy controls in the meta-analysis. The results showed that the rs156641 polymorphism was significantly associated with lung cancer risk (dominant model: OR 0.694, 95 % CI 0.549-0.878; homozygote model: OR 0.677, 95 % CI 0.526-0.871; heterozygote model: OR 0.712, 95 % CI 0.556-0.913; additive model: OR 0.859, 95 % CI 0.767-0.962), whereas no association was found between rs3730931/rs439132/rs20579 polymorphisms and lung cancer. Our meta-analysis suggested that the rs156641 polymorphism in the LIG1 gene might be associated with an increased risk of lung cancer.