Clinical implication of PD-L2 in the prognosis assessment of HNSCC immunotherapy

Abstract

Background and purpose: Programmed death-1 (PD-1) monoclonal antibody therapy plays an increasingly important role in the treatment of head and neck squamous cell carcinoma (HNSCC). However, low response rate and lack of predictive biomarkers are still the challenging problems. This study aimed to confirm that programmed death ligand-2 (PD-L2) is a predictive biomarker for the outcome of HNSCC anti-PD-1 immunotherapy. Methods: The samples and clinical data of 50 HNSCC patients undergoing PD-1 monoclonal antibody immunotherapy were collected. Immunohistochemical staining was used to analyze the level of programmed death ligand-1 (PD-L1) and PD-L2. Kaplan-Meier overall survivals were analyzed using SPSS 26.0 software, grouped by the basic clinical characteristics and the PD-L1 and PD-L2 levels. Survival curves were plotted using GraphPad Prism. Results: HNSCC had a relatively high expression rate of PD-L2 with more than 80% of cases detected as PD-L2 positive. The expression of PD-L2 significantly correlated with the clinical outcome of immunotherapy, with a mean survival of 18.8 (16.0-21.7) months for patients with high PD-L2 expression and 11.0 (9.1-12.8) months for patients with low PD-L2 expression, this difference being statistically significant. Conclusion: PD-L2 has the potential to be used as a predictive biomarker for HNSCC anti-PD-1 immunotherapy.

Keywords

• |head and neck squamous cell carcinoma|immunotherapy|programmed death ligand-2