High Serum OX40 and OX40 Ligand (OX40L) Levels Correlate with Reduced Survival in Patients with Advanced Lung Adenocarcinoma

Abstract

Introduction: Interaction of OX40 and OX40 ligand (OX40L) is associated with immune activation. OX40-OX40L axis is also suggested to play a role in immunity against several solid malignancies. Objective: In this study, serum OX40 and OX40L levels in patients with advanced lung adenocarcinoma were assessed and their correlation with survival and clinicopathologic parameters was determined. Methods: Serum samples were collected from patients with advanced lung adenocarcinoma, then OX40 and OX40L were quantified via enzyme-linked immunosorbent assay. Immunohistochemical (IHC) analysis of OX40 and OX40L in resected primary lesions was also performed. The association between OX40 and OX40L levels and clinicopathologic status and patient survival was retrospectively analyzed. Results: A total of 56 patients were analyzed. Median serum OX40 and OX40L levels were 156.2 pg/mL and 186.6 pg/mL, respectively. IHC analysis in 5 patients indicated high positivity of OX40 in tumor-infiltrating lymphocytes and of OX40L in tumor cells in mucinous adenocarcinoma. Patients with a high OX40 level (≥152.2 pg/mL) had poorer prognosis than those with a low serum OX40 level (median survival, 7.36 vs. 21.19 months, respectively, p = 0.04). Patients with a high OX40L level (≥207.3 pg/mL) had poorer prognosis than those with a low serum OX40L level (median survival, 7.36 vs. 14.26 months, respectively, p = 0.04). In the subset of patients treated with immune checkpoint inhibitors (ICIs) (n = 12), those with a high OX40L level were found to have longer survival from ICI initiation than those with a low OX40L level (p = 0.023). Conclusions: High OX40 and OX40L levels are associated with poor prognosis and may reflect the immune-exhausted status against lung adenocarcinoma.