Higher postoperative plasma EV PD-L1 predicts poor survival in patients with gastric cancer.

Background: The satisfactory prognostic indicator of gastric cancer (GC) patients after surgery is still lacking. Perioperative plasma extracellular vesicular programmed cell death ligand-1 (ePD-L1) has been demonstrated as a potential prognosis biomarker in many types of cancers. The prognostic value of postoperative plasma ePD-L1 has not been characterized.

Methods: We evaluated the prognostic value of preoperative, postoperative and change in plasma ePD-L1, as well as plasma soluble PD-L1, in short-term survival of GC patients after surgery. The Kaplan-Meier survival model and Cox proportional hazards models for both univariate and multivariate analyzes were used. And the comparison between postoperative ePD-L1 and conventional serum biomarkers (carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9) and CA72-4) in prognostic of GC patients was made.

Results: The prognostic value of postoperative ePD-L1 is superior to that of preoperative ePD-L1 on GC patients after resection, and also superior to that of conventional serum biomarkers (CEA, CA19-9 and CA72-4). The levels of postoperative ePD-L1 and ePD-L1 change are independent prognostic factors for overall survival and recurrence free survival of GC patients. High plasma level of postoperative ePD-L1 correlates significantly with poor survival, while high change in ePD-L1 level brings the significant survival benefit.

Conclusions: The level of plasma postoperative ePD-L1 could be considered as a candidate prognostic biomarker of GC patients after resection.