Supplementary Material for: New Concept of X-Ray Repair Cross-Complementing Groups 1 Polymorphisms and Gynecologic Cancer Risk

<p><b><i>Background:</i></b> Several meta-analyses have been conducted to examine the possible link between X-ray repair cross-complementing groups 1 (<i>XRCC1</i>) Arg399Gln polymorphism and cervical cancer risk. However, the results are controversial. Therefore, we carried out a more comprehensive meta-analysis to examine whether <i>XRCC1</i> polymorphisms are associated with general gynecologic cancer risk. <b><i>Methods:</i></b> Twenty studies, comprising 4,230 cases and 5,458 controls that included analyses of <i>XRCC1</i> polymorphisms (Arg194Trp, Arg280His, or Arg399Gln) were included in our study. <b><i>Results:</i></b> Overall, no significant association between any of the studied XRCC1 polymorphisms and gynecologic cancer risk was observed. However, in further stratified analyses, the Arg399Gln was definitely associated with increased gynecologic cancer risk in Asians (A vs. G: OR 1.24; 95% CI 1.02-1.53), which was also associated with increased cervical cancer risk (A vs. G: OR 1.20; 95% CI 1.00-1.44). Similarly, the Arg194Trp was significantly associated with increased gynecologic cancer risk in Asians (TT vs. CC: OR 1.87; 95% CI 1.02-3.42) and endometrial cancer (T vs. C: OR 1.45; 95% CI 1.05-2.02). <b><i>Conclusions:</i></b> These findings provided evidence that XRCC1 Arg399Gln and Arg194Trp variants may modify the susceptibility to gynecologic cancers based on ethnicity and type. Further studies with large sample size are warranted to extend our findings.