Association Studies Between XRCC1, XRCC2, XRCC3 Polymorphisms and Differentiated Thyroid Carcinoma.

BACKGROUND/AIMS DNA HRR pathway and BER pathway play vital roles in differentiated thyroid cancer (DTC) development, thus we supposed that polymorphisms of XRCC1, XRCC2, XRCC3 DNA repair genes are associated with thyroid cancer risk and progression. METHODS We searched the NCBI database for relevant literatures to determine eight SNPs to be included in our study (XRCC1: rs25487, rs25489, rs1799782; XRCC2: rs3218536; XRCC3: rs1799794, rs56377012, rs1799796, rs861539). RESULTS SNP of rs25487 was linked with a 53% decrease in DTC risk (OR: 0.47; 95%CI: 0.268-0.82; P = 0.01). For SNP of rs1799782, the homozygous TT genotype indicated a statistically significant 2-fold increased risk of DTC (OR: 2.09; 95%CI: 1.27-3.43; P < 0.001) after multivariate adjustment. For SNP of rs861539, the homozygous TT genotype suggested statistically significant 3-fold increased risk of DTC (OR: 3.02; 95%CI: 1.68-5.42; P < 0.001). No significant association between the other five SNPs and DTC risk. Besides that, female was linked with 47% increase in DTC risk (OR: 1.47; 95%CI: 1.062-2.04; P = 0.02) after multivariate adjustment. Similar results for most of the SNPs were obtained from subgroup analysis by different histological types of DTC. Haplotype analysis revealed that AGC and GGT haplotypes of XRCC1 polymorphisms were associated with DTC. Moreover, results from gene-gene interaction showed that XRCC1-rs25487, XRCC1- rs1799782 and XRCC3- rs861539 variants jointly contributed to a specifically increased risk of DTC, with the combination variant of rs1799782-CT heterozygote and rs861539-TT homozygote exhibiting a higher 3.66-fold risk of DTC (OR: 3.66; 95% CI: 1.476-9.091, P = 0.005). CONCLUSION Polymorphisms of XRCC1 (rs25487, rs1799782) and XRCC3 (rs861539), may play a critical role in DTC development and progression. Furthermore, XRCC1 variant can interact with XRCC3 variant to significantly increase DTC susceptibility. Identifying these genetic risk markers could provide evidence for exploring the insight pathogenesis and develop novel therapeutic strategies for DTC.