The expression and prognostic predictive value of PD-L2 in patients undergoing radical gastric cancer surgery.

BACKGROUND

The expression and prognostic predictive value of programmed death-ligand 2 (PD-L2) in patients undergoing radical gastric cancer (GC) surgery remains unclear.

METHODS

PD-L2 expression in tumor cells (TC) and tumor-infiltrating immune cells (TIIC) was evaluated by immunohistochemistry. Kaplan-Meier and Cox models were used to evaluate the association of PD-L2 with disease-free survival (DFS) and overall survival (OS).

RESULTS

This study included 299 patients and the average age was 63.76 ± 11.83 years, with 218 males (72.91%) and 81 females (27.09%). TC PD-L2 expression was significantly associated with poorer DFS (HR = 2.177, 95% CI 1.364-3.474, P = 0.001) and OS (HR = 1.943, 95% CI 1.191-3.169, P = 0.008). Multivariate analysis confirmed TC PD-L2 expression as an independent poor prognostic factor for DFS (HR = 2.121, 95% CI 1.325-3.393, P = 0.002) and OS (HR = 1.812, 95% CI 1.109-2.961, P = 0.018). PD-L2 in TIIC did not correlate with survival. Other poor prognostic factors included age ≥60, vascular invasion, advanced postoperative stage, and HER2 positivity.

CONCLUSIONS

PD-L2 expression in TC is an independent prognostic biomarker in GC, linked to poorer DFS and OS, suggesting its potential for identifying high-risk patients for personalized therapies.