The objective of this study is to quantitatively derive a more precise estimation of the association between X-ray repair cross-complementing group 1 (XRCC1) gene polymorphisms and differentiated thyroid carcinoma risk. A comprehensive literature search of three databases was conducted. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated with fixed-effect models and random-effect models when appropriate. Overall, no association of the XRCC1 Arg399Gln, Arg280His, and Arg194Trp polymorphisms with differentiated thyroid carcinoma risk was found. In subgroup analyses, a decreased differentiated thyroid carcinoma risk was observed among Caucasians (Gln vs. Arg, OR=0.86, 95% CI=0.77-0.96, P=0.343 for heterogeneity; Gln/Arg vs. Arg/Arg, OR=0.84, 95% CI=0.71-0.98, P=0.229 for heterogeneity; Gln/Gln vs. Arg/Arg, OR=0.77, 95% CI=0.60-0.99, P=0.477 for heterogeneity; dominant genetic model, OR=0.82, 95% CI=0.71-0.95, P=0.272 for heterogeneity), not among Asians. No publication bias was observed. Our results suggest that XRCC1 Arg399Gln polymorphism is not associated with differentiated thyroid carcinoma risk, while a decreased risk is observed among Caucasian population.
Keywords: BER; CI; Differentiated thyroid carcinoma; HWE; Hardy–Weinberg equilibrium; Meta-analysis; OR; Polymorphisms; SNP; X-ray repair cross-complementing group 1; XRCC1; base excision repair; confidence interval; odds ratio; single nucleotide polymorphism.
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