Association study between XPG Asp1104His polymorphism and colorectal cancer risk in a Chinese population

Previous studies have reported that the Asp1104His polymorphism in Xeroderma Pigmentosum complementation group G (XPG) was associated with the susceptibility to colorectal cancer (CRC), although the results were inconsistent. This study was aim to investigate whether there existed an association between XPG Asp1104His polymorphism and CRC risk in the Chinese population, and a further meta-analysis was performed to consolidate the results. We found that XPG Asp1104His polymorphism was associated with a significantly increased CRC risk (dominant model: His/His 1 Asp/His vs. Asp/Asp, adjusted OR = 1.39, 95% CI = 1.14-1.69). Stratification analysis by clinical characteristics indicated that the His/His + Asp/His genotypes were associated with increased CRC susceptibility in patients with moderately differentiated grade, but not in poorly and well differentiated grade. Furthermore, a total of 5 eligible studies, including 2,649 CRC cases and 2,848 controls, were recruited for the meta-analysis. We identified that the meta-analysis reported a similar result in dominant model (OR = 1.35; 95% CI = 1.20-1.51). Especially, when stratified by ethnicity, an evidently increased risk was identified in the Asian population. In conclusion, our findings suggest that XPG Asp1104His polymorphism may increase the susceptibility of CRC, especially in Asian populations.