PD1 gene polymorphism is associated with a poor prognosis in hepatocellular carcinoma following liver resection, cohort study

Background: This study examined whether single nucleotide polymorphism (SNP) in programmed cell death protein (PD)-1 is related to the postoperative prognosis of patients with hepatocellular carcinoma (HCC). The immune checkpoint protein PD-1 is an important inhibitor of T cell responses. SNP in the promoter region of PD-1 -606 G/A has been reported to result in high activation and expression of PD-1 associated with cancer risk. Materials and methods: We analyzed 321 patients with HCC who underwent hepatectomy between 2010 and 2015. PD-1 SNP was analyzed by polymerase chain reaction, and the prognosis after surgical treatment of patients with HCC was analyzed. Results: The PD-1 SNP statuses were as follows: 90 AA (28.1%), 163 GA (50.8%), 68 GG (21.2%). The baseline parameters did not statistically differ between the three groups. The overall survival (OS) of patients with the GG genotype was significantly lower than that of those with the other genotypes (P = 0.031). The GG genotype was an independent risk factor for OS (P = 0.009; HR 2.201). There was no significant difference between the GG genotype and other genotypes in recurrent-free survival. The extrahepatic recurrence (EHR) rate of those with the GG genotype was significantly higher than that of those with the other genotypes (P = 0.036). The GG genotype was an independent risk factor for EHR (P = 0.008; HR 2.037). Conclusions: The PD-1 SNP GG genotype is associated with poor survival and increased EHR in HCC. Furthermore, the GG genotype is an independent predictive factor for OS and EHR.