Lack of association between XPD Lys751Gln and Asp312Asn polymorphisms and colorectal cancer risk: a meta-analysis of case–control studies

Abstract

The published data on the association between xeroderma pigmentosum group D (XPD) Lys751Gln and Asp312Asn polymorphisms and colorectal cancer remained controversial. The present meta-analysis of literatures was performed to derive a more precise estimation of the relationship. A comprehensive literature search was conducted to identify all case-control studies of Lys751Gln and Asp312Asn polymorphisms on the susceptibility of different tumor site of colorectal cancer (colon, rectum, and colon/rectum cancer). A total of 22 eligible studies were selected for this meta-analysis, including 3,042 cases and 4,627 controls for Lys751Gln and 1,581 cases and 2,846 controls for Asp312Asn. Overall, no significantly elevated colorectal cancer risk was found in all genetic models when all studies were pooled into the meta-analysis (for Lys751Gln polymorphism: Lys/Gln vs. Lys/Lys, OR = 1.01, 95% CI = 0.90-1.14; Gln/Gln vs. Lys/Lys, OR = 1.04, 95% CI = 0.85-1.26; dominant model, OR = 1.03, 95% CI = 0.93-1.15; recessive model, OR = 1.04, 95% CI = 0.87-1.25; and for Asp312Asn polymorphism: Asp/Asn vs. Asp/Asp, OR = 1.11, 95% CI = 0.91-1.35; Asn/Asn vs. Asp/Asp, OR = 1.13, 95% CI = 0.87-1.47; dominant model, OR = 1.09, 95% CI = 0.94-1.26; recessive model, OR = 1.11, 95% CI = 0.88-1.41). And for the additive model, individuals carrying the 751Gln or 312Asn allele were not significantly associated with increased risk to colorectal cancer (OR = 1.02, 95% CI = 0.94-1.11, OR = 1.07, 95% CI = 0.95-1.20). This meta-analysis suggests that XPD Lys751Gln and Asp312Asn polymorphisms may not be associated with colorectal cancer development.