Correlation of systemic and local inflammation with survival prognosis in glioma patients.

Abstract

2052 Background: Immune modulating therapies have been a long withstanding treatment approach in glioma. However, gliomas are characterized by a particular absence of tumor infiltrating lymphocytes in the local tumor microenvironment. We aimed to gain insight on the distinct patterns of inflammation associated with survival prognosis in glioma. Methods: Patients were recruited at time of glioma diagnosis or progression in the prospective observational Vienna Cancer and Thrombosis Study (CATS). A single blood draw was performed at study inclusion. PD-L1 expression in the tumor tissue was investigated via immunohistochemistry. Optimal cut-off according to ROC curve was used to assess cut off values for survival analysis. Results: 193 patients with glioma (75.6% glioblastoma (WHO grade IV), 19.7% anaplastic glioma (WHO grade III), and 4.7% diffuse glioma (WHO grade II)) were included. 40/193 (20.7%) glioma had an IDH1 mutation. Membranous PDL1 expression in the tumor tissue was observed in 20/193 (10.4%) patients. 1/20 patient presented with PD-L1 expression and IDH1 mutation ( p = 0.082). PD-L1 significantly correlated with increased monocyte count (median: 0.657 vs. 0.450 [G/L], p = 0.008), higher C-reactive protein (CRP) (0.43 vs. 0.1 [mg/dL], p = 0.005) and higher fibrinogen (379 vs. 303 [mg/dL], p = 0.001). Presence of IDH1 mutation significantly correlated with increased platelet count (303 vs. 232 [G/L], p = 0.001) and lower Neutrophil/Lymphocyte (N/L) ratio (3.34 vs. 5.13, p = 0.016). Higher lymphocyte count ( > 1.484 [G/L], log-rank: p = 0.011), higher platelet count ( > 245.5 [G/L], p = 0.0001), as well as decreased N/L ratio ( < 5.13, p = 0.001) were significantly associated with increased survival prognosis. Conclusions: PD-L1 expression in tumor tissue was associated with markers of systemic inflammation in glioma patients. Systemic inflammation markers furthermore predicted improved survival. Immune modulating therapy approaches might be a promising approach in subgroups of glioma associated with increased baseline interaction of immune system and glioma.