Programmed death-1 (PD-1) polymorphism is associated with gastric cardia adenocarcinoma

Polymorphisms in gene encoding programmed death-1 (PD-1) were suggested to be associated with the risk of multiple cancers. To the best of our knowledge, no investigation has been carried out for gastric cardia adenocarcinoma (GCA) and PD-1 polymorphisms. Thus, we studied PD-1 rs10204525 A>G, rs7421861 T>C and rs2227982 C>T single nucleotide polymorphisms (SNPs) in 330 GCA cases and 608 cancer-free controls. Genotypes of PD-1 SNPs were determined by ligation detection reaction (LDR) assays. The distributions of the allele and genotype were not statistically significant in two groups for the three PD-1 SNPs. However, in stratified analyses by various characteristics (eg., age, sex, smoking condition and alcohol consumption status), we found a significantly increased risk of GCA associated with the PD-1 rs2227982 C>T polymorphism was evident among ever drinking cases (TT vs. CC: adjusted OR = 2.53, 95% CI = 1.11-5.79, P = 0.028; TT+CT vs. CC: adjusted OR = 2.04, 95% CI = 1.01-4.13, P = 0.047). For the other SNPs, in stratified analyses, no correlation between the SNPs and susceptibility of GCA was observed. In conclusion, our results highlight that rs2227982 C>T polymorphism in PD-1 gene may contribute to the risk of GCA.