OBJECTIVE: Previous studies on the association between X-ray repair cross-complementing protein 1 (XRCC1) polymorphisms and nasopharyngeal carcinoma (NPC) risk showed inconsistent results. The aim of this study was to evaluate the effects of XRCC1 variants on NPC risk. METHODS: A meta-analysis was performed with all eligible studies covering a total of 1,341 cases and 1,425 controls for the Arg194Trp polymorphism, 1,260 cases and 1,207 controls for the Arg280His polymorphism, and 1,644 cases and 1,678 controls for the Arg399Gln polymorphism. RESULTS: No associations was found between Arg194Trp and Arg280His polymorphisms with NPC risk under all contrast models (co-dominant, dominant, and recessive models). However a deleterious effect of the 399Gln genotype was observed under the co-dominant model (Gln/Gln versus Arg/Arg, OR = 1.30, 95% CI : 1.01-1.69, P = 0.04). Under the recessive model (Gln/Gln versus Arg/Arg+Arg/Gln), the P value was marginally significant (OR = 1.28, 95% CI : 1.00-1.65, P = 0.05). However, the effect of the 399Gln genotype on NPC became non-significant after excluding one study from the meta-analysis because of departure from Hardy-Weinberg equilibrium. CONCLUSIONS: No associations were found between Arg194Trp and Arg280His polymorphisms with NPC risk, whereas the Arg399Gln genotype was associated with increased risk.
OBJECTIVE: Previous studies on the association between X-ray repair cross-complementing protein 1 (XRCC1) polymorphisms and nasopharyngeal carcinoma (NPC) risk showed inconsistent results. The aim of this study was to evaluate the effects of XRCC1 variants on NPC risk. METHODS: A meta-analysis was performed with all eligible studies covering a total of 1,341 cases and 1,425 controls for the Arg194Trp polymorphism, 1,260 cases and 1,207 controls for the Arg280His polymorphism, and 1,644 cases and 1,678 controls for the Arg399Gln polymorphism. RESULTS: No associations was found between Arg194Trp and Arg280His polymorphisms with NPC risk under all contrast models (co-dominant, dominant, and recessive models). However a deleterious effect of the 399Gln genotype was observed under the co-dominant model (Gln/Gln versus Arg/Arg, OR = 1.30, 95% CI : 1.01-1.69, P = 0.04). Under the recessive model (Gln/Gln versus Arg/Arg+Arg/Gln), the P value was marginally significant (OR = 1.28, 95% CI : 1.00-1.65, P = 0.05). However, the effect of the 399Gln genotype on NPC became non-significant after excluding one study from the meta-analysis because of departure from Hardy-Weinberg equilibrium. CONCLUSIONS: No associations were found between Arg194Trp and Arg280His polymorphisms with NPC risk, whereas the Arg399Gln genotype was associated with increased risk.