XAB2 TagSNP Is Associated with the Risk of Gastric Cancer in Chinese Population: A Case-Control Study

XAB2 protein (xeroderma pigmentosum group A-binding protein 2) plays a significant role in the nucleotide excision repair pathway. Polymorphisms in the XAB2 gene may have an effect on the capability of DNA repair and further contribute to the risk of developing various cancers. In order to investigate the relationship between XAB2 genetic variants and the risk of gastric cancer, we performed a hospital-based case-control study. XAB2 tagSNPs were selected and then genotyped by iPlex Gold Genotyping Assay and Sequenom MassArray. By performing logistic regression analysis, odds ratio (OR) and 95% confidence interval (CI) were used to estimate the association of XAB2 tagSNPs with the risk of gastric cancer. Our results showed that XAB2 rs794078AA genotype was associated with a significantly lower risk of gastric cancer compared with GG genotype with OR (95% CI) of 0.33 (0.12-0.91). Stratified analysis indicated a significantly decreased risk for gastric cancer among smokers with rs794078AA genotype compared with nonsmokers with GG genotype (OR = 0.11, 95% CI = 0.01-0.91, p = 0.040). The gene-gene interactions by multifactor dimensionality reduction (MDR) showed that tagSNP rs794078 was the best predictive element for gastric cancers (Testing Bal. Acc = 51.68%, p = 0.055, cross-validation consistency = 9). Therefore, the XAB2 tagSNP rs794078 may play an important role in the development of gastric cancer.