Role of Systemic Immunoinflammation Landscape in the Overall Survival of Patients with Leptomeningeal Metastases from Lung Cancer

Purpose: Several biomarkers, such as baseline neutrophil-to-lymphocyte ratio (NLR), have been more investigated in patients with brain metastases (BM), while their role in patients with leptomeningeal metastases (LM) has not been clarified. Considering the difference between the clinical behaviour of BM and LM, there is the need for addressing the role of these biomarkers in LM.Methods: The present study retrospectively analyzed 95 consecutive patients with LM from lung cancer who were diagnosed at the National Cancer Center, Cancer Hospital of Chinese Academy of Medical Sciences between January 2016 and December 2019. Baseline NLR, platelet-to-lymphocyte ratio (PLR), systemic immunoinflammation index (SII), and lymphocyte-to-monocyte ratio at diagnosis of LM were calculated based on complete blood count and correlated, along with other characteristics, with overall survival (OS) using univariate and multivariate analyses. The best cutoff values for systemic immunoinflammation biomarkers were derived using the surv_cutpoint function in R software, which optimized the significance of the split between Kaplan-Meier survival curves. Results: Median OS of patients with LM was 12 months (95% CI 9-17 months). On univariate analysis, NLR, PLR, SII, LMR, sex, smoking history, ECOG performance status (PS) scores, histological subtypes and targeted therapy were all significantly associated with OS. Only NLR (P=0.034, 95% CI 1.060-4.578) and ECOG PS scores (P=0.019, 95% CI 0.137-0.839) maintained a significant association with OS on multivariate analysis. Furthermore, patients with baseline NLR >3.57 had significantly worse OS than patients with NLR <3.57 (median OS 7 vs 17 months), as did patients with ECOG PS scores >2 vs <2 (median OS 4 vs 15 months).Conclusion: Both baseline NLR and PS scores at the time of LM diagnosis are helpful and available prognostic biomarkers for patients with LM from lung cancer.