Abstract
OBJECTIVE: The programmed cell death-1 receptor/programmed cell death-1 ligand (PD-1/PD-L1) pathway plays a crucial role in tumor evasion from host immunity. This study was designed to evaluate the association between circulating PD-L1 expression and prognosis in patients with advanced gastric cancer. METHODS: Totally 80 advanced gastric cancer patients and 40 health controls from Beijing Cancer Hospital were enrolled in the present study. Circulating PD-L1 expression was tested by enzyme-linked immunosorbent assay (ELISA). The associations between the expression level of PD-L1 and clinicopathological features and prognosis were analyzed statistically. RESULTS: Expression of PD-L1 in advanced gastric cancer patients was significantly up-regulated compared with health people (P=0.006). The expression of PD-L1 was significantly correlated with differentiation and lymph node metastasis (P=0.026 and P=0.041, respectively). Although we didn't find significant difference in all advanced gastric cancer patients with different PD-L1 expression, the adenocarcinoma patients with higher up-regulated PD-L1 expression had much better prognosis than low expression patients (65.6% vs. 44.7%, P=0.028). CONCLUSIONS: PD-L1 was elevated in advance gastric cancer patients and may play an important role in tumor immune evasion and patients prognosis.