Document Type : Systematic Review and Meta-analysis
Department of Otolaryngology, Head and Neck Surgery, Otorhinolaryngology Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Department of Medical Genetics, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Department of Medical Laboratory Sciences, School of Paramedical Science, Shiraz University of Medical Sciences, Shiraz, Iran.
Department of Emergency Medicine, Iran University of Medical Sciences, Iran, Iran.
Department of General Surgery, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Department of Medical Genetics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Department of Food Science and Technology, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Background: We conducted a comprehensive meta-analysis to explore the association of polymorphisms at XRCC1, XRCC2 and XRCC3 genes with susceptibility to thyroid cancer (TC). Methods: We searched PubMed, EMBASE, Web of Science, and CNKI for relevant available studies. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of the associations. Results: A total of 67 studies including 17 studies with 6,806 cases and 5,229 controls on XRCC1 Arg399Gln, 13 studies with 3,234 cases and 4,807 controls on XRCC1 Arg280His, 13 studies with 2,956 cases and 3,860 controls on XRCC1 Arg194Trp, five studies with 1,287 cases and 1,422 controls on XRCC2 Arg188His, 13 studies with 2,488 cases and 3,586 controls on XRCC3 Thr241Met, and six studies with 1,828 cases and 2,060 controls on XRCC3 IVS5-14 polymorphism were selected. Polled data revealed that the XRCC1 Arg399Gln, Arg280His, Arg194Trp, XRCC2 Arg188His and XRCC3 Thr241Met and IVS5-14 polymorphisms were not significantly associated with an increased risk of TC. Stratified analyses by ethnicity showed that the XRCC1 Arg399Gln polymorphism was associated with TC risk in Caucasians, but not in Asians. Conclusions: Our meta-analysis indicated that the XRCC1 Arg399Gln, Arg280His, Arg194Trp, XRCC2 Arg188His, XRCC3 Thr241Met and IVS5-14 polymorphisms were not associated with risk of TC in the global population. Further well-designed investigations with large sample sizes are required to confirm our results.