Role of CSF interleukin-6 in the prognosis of patients with Leptomeningeal metastases of glioblastoma

BACKGROUND: To explore the correlation between cerebrospinal fluid (CSF) and peripheral blood cytokines and survival in patients with Leptomeningeal metastases (LM) of glioblastoma. METHODS: The study retrospectively included 35 patients with glioblastoma LM diagnosed from September 2022 to August 2024 at Beijing Tiantan Hospital. CSF and peripheral blood cytokines were collected from patients and associated with other characteristics with overall survival (OS) using univariate and multivariate analyses. The optimal cutoff values for cytokines were derived using the surv_cutpoint function in the R software. RESULTS: The median OS for LM patients was 11.8 months (95% confidence intervals (CI) 6.1-17.5 months). After univariate and multivariate analyses, CSF IL-6 (95% CI 0.072-0.683; P = 0.009) and Karnofsky Physical Status (KPS) (95% CI, 0.136-0.876; P = 0.025) remained significantly associated with OS. We further combined CSF interleukin-6 (IL-6) with KPS to construct nomogram to predict survival and demonstrated good predictive performance. CONCLUSION: Both CSF IL-6 and KPS are meaningful prognostic biomarkers for patients with LM from glioblastoma.