XPD Lys751Gln polymorphism and breast cancer susceptibility: a meta-analysis involving 28,709 subjects

Published data on the association between Xeroderma Pigmentosum complementation group D (XPD) Lys751Gln polymorphism and breast cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Crude ORs with 95% CIs were used to assess the strength of association between them. A total of 30 studies including 14,283 cases and 14,426 controls were involved in this meta-analysis. Overall, significantly elevated breast cancer risk was associated with XPD 751Gln allele when all studies were pooled into the meta-analysis (Lys/Gln vs. Lys/Lys: OR = 1.13, 95% CI = 1.02-1.25; Gln/Gln vs. Lys/Lys: OR = 1.21, 95% CI = 1.06-1.38; dominant model: OR = 1.16, 95% CI = 1.05-1.29; and recessive model: OR = 1.14, 95% CI = 1.02-1.27). In the subgroup analysis by ethnicity, borderline significantly increased risks were found for Caucasians (Lys/Gln vs. Lys/Lys: OR = 1.09, 95% CI = 0.98-1.22; dominant model: OR = 1.10, 95% CI = 0.99-1.22) and significantly increased risks were found for Africans in dominant model (OR = 1.10, 95% CI = 1.04-1.15). When stratified by study design, statistically significantly elevated risk was found in population-based studies (Lys/Gln vs. Lys/Lys: OR = 1.10, 95% CI = 1.01-1.20; Gln/Gln vs. Lys/Lys: OR = 1.15, 95% CI = 1.01-1.31; dominant model: OR = 1.12, 95% CI = 1.03-1.23). In conclusion, this meta-analysis suggests that the XPD 751Gln allele is a low-penetrant risk factor for developing breast cancer.