Prognostic value of Neutrophil-to-Lymphocyte Ratio (NLR) in patients with Leptomeningeal Metastasis (LM) from solid tumors

Leptomeningeal metastasis (LM) arising from solid tumors signifies a late-stage complication in the cancer trajectory, often portending a poor prognosis. The prognostic factors remain elusive. Prior research has established the Neutrophil-to-Lymphocyte Ratio (NLR) as an independent prognostic marker in various malignancies; however, its prognostic utility in LM patients remains underexplored. This study aims to investigate the prognostic significance of NLR at the time of LM diagnosis. We conducted a retrospective analysis involving 490 diagnosed LM patients with solid tumor origins at Zhejiang Cancer Hospital. NLR was computed at the time of LM diagnosis. Kaplan-Meier curves and Cox proportional models were employed to examine the association between NLR and overall survival (OS). Following exclusions, the cohort comprised 384 patients. The median age was 55 years (interquartile range, IQR: 51-61.25), with a median OS was 6.45 months (IQR: 2.1–15.6) and a median NLR was 4.09 (IQR: 2.81–7.57). The median interval between LM diagnosis and NLR assessment was 1 day (IQR: 0–3). NLR proved effective in stratifying the prognosis of LM patients (HR = 1.02, 95% CI 1.01–1.04, p = 0.009). Stratifying patients based on the median NLR into low- and high-risk groups revealed that the high-risk group exhibited a 1.324-fold increased risk of death compared to the low-risk group (HR = 1.324, 95% CI 1.069–1.640, p = 0.010). Subgroup analysis indicated that NLR independently predicted prognosis specifically in the invasive breast cancer subgroup (p = 0.002). NLR emerges as a simple and accessible prognostic indicator in newly diagnosed patients with leptomeningeal metastasis stemming from solid tumors. 1. Elevated NLR independently predicts survival in leptomeningeal metastasis. 2. NLR prognostic specifically in invasive breast cancer subgroup. 3. NLR offers accessible biomarker for clinical risk stratification.