XPC Lys939Gln polymorphism contributes to colorectal cancer susceptibility: evidence from a meta-analysis
1 Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning 530021, Guangxi, China
2 Department of Anal and Colorectal Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
3 Department of Occupational Health and Environmental Health, School of Public Health at Guangxi Medical University, Nanning, Guangxi, China
4 Department of Medicine Research, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
Diagnostic Pathology 2014, 9:120 doi:10.1186/1746-1596-9-120Published: 19 June 2014
Published studies investigating the association between XPC Lys939Gln polymorphism and colorectal cancer (CRC) risk reported inconclusive results. We performed a meta-analysis to derive a precise estimation of the relationship.
A comprehensive literature search was done in databases PubMed, EMBASE, and Cochrane library up to December 2013. The association between XPC Lys939Gln polymorphism and CRC risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).
Eight studies with 3,301 cases and 4,177 controls were included in the meta-analysis. We observed that the XPC Lys939Gln polymorphism was correlated with an increased CRC risk when all studies were pooled into the meta-analysis (Gln/lys vs. Lys/Lys: OR = 1.293, 95% CI 1.169–1.430, P = 0.000; Gln/Gln + Gln/lys vs. Lys/Lys: OR = 1.260, 95% CI 1.145–1.388, P = 0.000). In stratified analyses by ethnicity, smoking, and study quality, significant increased CRC risk was found in Asians (Gln/lys vs. Lys/Lys: OR = 1.345, 95% CI 1.187–1.523, P = 0.000; Gln/Gln + Gln/lys vs. Lys/Lys: OR = 1.317, 95% CI 1.170–1.484, P = 0.000), nonsmokers (Gln/Gln + Gln/lys vs. Lys/Lys: OR = 1.286, 95% CI 1.020–1.622, P = 0.033), and high quality studies. In subgroup analysis by source of control, significant increased CRC risk was found in both hospital-based studies and population-based studies. However, in subgroup analysis according to cancer location, no any significant association was detected.
This meta-analysis suggests that the XPC is a candidate gene for CRC susceptibility. The XPC Lys939Gln polymorphism may play an important role in CRC development among Asians and nonsmokers. Further large and well-designed studies are needed to confirm this association.
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