Published online Sep 14, 2019. doi: 10.3748/wjg.v25.i34.5152
Peer-review started: May 16, 2019
First decision: July 21, 2019
Revised: July 25, 2019
Accepted: August 19, 2019
Article in press: August 19, 2019
Published online: September 14, 2019
The xeroderma pigmentosum group G (XPG) gene at chromosome 13q33 consists of 15 exons, which may be related to the occurrence and development of gastric cancer (GC).
To examine the association of several common single nucleotide polymorphisms (SNPs) of the XPG gene with GC risk and survival.
Five SNPs of XPG (rs2094258, rs751402, rs873601, rs2296147, and rs1047768) were genotyped by PCR restriction fragment length polymorphism in 956 histologically confirmed GC cases and 1012 controls in North China. GC patients were followed for survival status and, if deceased, cause of death. Logistic regression and Cox regression were used for analysing associations of XPG SNPs with risk of GC and prognosis, respectively. For rs2094258, heterozygous model (CT vs CC), homozygous model (TT vs CC), recessive model (TT vs CT + CC), and dominant model (TT + CT vs CC) were analyzed.
None of the examined loci were statistically associated with GC risk, although rs2296147 was marginally associated with GC risk (P = 0.050). GC patients with the rs2094258 CT + CC genotype showed worse survival than those with the TT genotype (log-rank test, P = 0.028), and patients with the CC genotype had a tendency of unfavourable prognosis compared with those with the TT + CT genotype (log-rank test, P = 0.039). The increase in C alleles of rs2094258 [hazard ratio (HR) = 1.19, 95% confidence interval (CI): 1.02-1.45, P = 0.037] were associated with the long-term survival of GC cases. Other risk factors for survival included tumor differentiation (HR = 4.51, 95%CI: 1.99-8.23, P < 0.001), lymphovascular invasion (HR = 1.97, 95%CI: 1.44-3.01, P < 0.001), and use of chemotherapy (HR = 0.81, 95%CI: 0.63-0.98, P = 0.041).
The XPG rs2094258 polymorphism may be associated with overall survival in GC patients.
Core tip: This study investigated the relationships between five functional single nucleotide polymorphisms of the xeroderma pigmentosum group G (XPG) (rs2094258, rs751402, rs2296147, rs1047768, and rs873601) and gastric cancer (GC) risk and survival. The results showed an association between the XPG rs2094258 polymorphism and overall survival in patients with GC. GC patients with the rs2094258 CT + CC genotype showed a worse survival than those with the TT genotype, and patients with the CC genotype had a tendency of unfavourable prognosis compared with those with the TT + CT genotype. The increase in the number of C alleles of rs2094258 was associated with the long-term survival of GC cases.