ObjectiveTo systematically review the association between LIG4 gene T9I polymorphism and cancer susceptibility. MethodsSuch databases as PubMed, EMbase, The Cochrane Library (Issue 10, 2013), CBM, CNKI, VIP and WanFang Data were electronically searched to collect case-control studies published up to Oct. 2013 on the association between LIG4 gene T9I polymorphism and cancer susceptibility. According to inclusion and exclusion criteria, two reviewers independently screened literature, extracted data, and assessed methodological quality of included studies. Then meta-analysis was performed using RevMan 5.0 software. ResultsA total of 11 case-control studies were included, which involved 5 016 cancer cases and 4 860 controls. The results of meta-analysis showed that, no significant association was found between LIG4 gene T9I polymorphism and the risk of cancer in the total analysis (TT+CT vs. CC:OR=0.96, 95%CI 0.80 to 1.15, P=0.63; TT vs. CT+CC:OR=1.10, 95%CI 0.78 to 1.56, P=0.59; TT vs. CC:OR=1.10, 95%CI 0.73 to 1.64, P=0.65; CT vs. CC:OR=0.94, 95%CI 0.80 to 1.11, P=0.48; T vs. C:OR=0.97, 95%CI 0.82 to 1.15, P=0.75). In the subgroup analysis, significant association was found in Caucasians (TT+CT vs. CC:OR=0.87, 95%CI 0.77 to 0.98, P=0.02) but not in Asians. ConclusionLIG4 gene T9I polymorphism could be associated with cancer susceptibility in Caucasians.