Programmed Death-1 Ligand-1 (PDL1) Expression Is Associated with the Prognosis of Patients with Stage II/III Gastric Cancer.

Background/Aim: The cell surface receptor programmed death-1 (PD1) and its ligand (PDL1) have been detected in various cancer types. It has been reported that expression of PDL1 and PD1 in a tumor is associated with poor prognosis of the patient. In the present study, we retrospectively examined tumor expression of PDL1 and intratumoral PD1(+) cell infiltration, and assessed their relationship with patient prognosis according to the pathological stage of gastric cancer. Materials and Methods: PDL1 and PD1 expression in primary tumors from 431 patients was evaluated using immuno histochemistry. The association between the expression of PDL1/PD1 and clinicopathological features was assessed. Results: High expression of PDL1 was observed in 128 (29.6%) patients. PDL1 expression was correlated with tumor infiltration of PD1(+) cells. In multivariate analysis, PDL1 expression was associated with worse overall survival. In subset analysis, PDL1 expression was significantly associated with survival in patients with stage II/III gastric cancer. In conclusion, PDL1 was an independent prognostic factor for patients with stage II/III gastric cancer. Our results suggested that patients with stage II/III gastric cancer might be appropriate for PD1/PDL1targeted therapy.