Association between x-ray repair cross-complementing group 3 (XRCC3) genetic polymorphisms and papillary thyroid cancer susceptibility in a Chinese Han population.

Papillary thyroid cancer (PTC) is a predominant type of thyroid cancer. Ionizing radiation is the only well-established risk factor and may result in double-strand breaks. The x-ray repair cross-complementing group 3 (XRCC3) gene plays a vital role in DNA repair through homologous recombination. We aimed at investigating the association between XRCC3 genetic polymorphisms and PTC susceptibility. Eighty-three PTC patients and 367 controls in a Chinese population were enrolled in the study. Tag single-nucleotide polymorphisms (SNPs) were identified by HaploView 4.2 software. Genomic DNAs were isolated from peripheral blood samples by using TaqMan Blood DNA kits. The genotyping of XRCC3 SNPs was performed by TaqMan SNPs genotyping assay. Odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were calculated to evaluate the association between XRCC3 SNPs and PTC susceptibility. The statistical analyses were conducted by using SPSS 13.0 software. Four tag-SNPs were initially identified by HaploView 4.2 software. Only one SNP (rs861539) was shown to be significantly associated with increased risk of PTC. There was a significant difference in smoking and drinking status between PTC cases and controls. And the stratified analysis suggested that the polymorphisms of rs861539 in XRCC3 were correlated with PTC risk in the four subgroups of smokers (ex-smokers included), non-smokers, drinkers (ex-drinkers included), and non-drinkers. The meta-analysis showed that only two studies reported a significant association between XRCC3 polymorphisms and PTC risk. In this study, we find a significant association between rs861539 polymorphisms and PTC susceptibility. However, there were inconsistent results in previous published studies. Therefore, further studies in a large population are required to gain insights into the PTC risk conferred by XRCC3 SNPs.