PD-1 gene rs10204525 and rs7421861 polymorphisms are associated with increased risk and clinical features of esophageal cancer in a Chinese Han population

Programmed death-1 (PD-1) polymorphisms have been associated with esophageal cancer risk. Here, the aims of this case-control study were to explore whether three PD-1 polymorphisms (rs10204525, rs7421861, and rs36084323) were related with the risk and clinical features of esophageal cancer in Chinese Han subjects (n = 814 cases and 961 controls). We found that rs10204525 and rs7421861, but not rs36084323, conferred increased susceptibility to esophageal cancer. Subgroup analysis revealed that all three loci increased the risk of esophageal cancer among men, and that rs10204525 and rs7421861 correlated with increased risk among patients ≥ 60 years old. The rs10204525 and rs7421861 polymorphisms were associated with higher TNM stage, and rs10204525 was associated with distant metastasis. The combination of smoking and either the rs10204525 or rs7421861 genotype conferred an increased risk to esophageal cancer, which is indicative of potential gene-environment interactions. The rs10204525 and rs7421861 polymorphisms correlated with increased PD-1 gene and protein levels, and Kaplan-Meier survival curves showed higher PD-1 gene expression was related to poorer overall survival. These data indicate the rs10204525 and rs7421861 polymorphisms of PD-1 gene confer an increased risk of esophageal cancer among Chinese Han individuals.