XPG Asp1104His polymorphism and gastrointestinal cancers risk: a meta-analysis.

Several studies have reported the association between the Asp1104His polymorphism in xeroderma pigmentosum group G (XPG) gene and risk of gastrointestinal cancers. However, the results are inconsistent. This meta-analysis was performed to assess the association between XPG Asp1104His polymorphism and gastrointestinal cancers risk. Relevant studies were identified using PubMed, Web of Science, CNKI, WanFang and VIP databases up to July 22, 2014. The pooled odds ratio (OR) with a 95% confidence interval (CI) was calculated using the fixed- or random effects model. 13 case-control studies from twelve publications with 4275 patients and 5735 controls were included. Overall, a significant association was found between the XPG Asp1104His polymorphism and the risk of gastrointestinal cancers (dominant model: OR = 1.15, 95% CI: 1.05-1.26; His/His vs. Asp/Asp: OR = 1.15, 95% CI: 1.01-1.32). When the analysis was stratified by ethnicity, similar results were observed in Asians under homozygote model; in stratification analysis by cancer type, increased cancer risk was detected in colorectal and hepatocellular carcinoma, but not for other gastrointestinal cancers. Furthermore, in subgroup analysis by source of control, we failed to detect any association among population, hospital and family-based populations. This meta-analysis indicated that the XPG Asp1104His polymorphism may be a risk factor for gastrointestinal cancers, especially of colorectal cancer.