Treatment and survival of analysis in patients with leptomeningeal metastasis from lung cancer

Abstract Objectives: Leptomeningeal metastasis (LM) is a severe complication of advanced non-small cell lung cancer (NSCLC) and portends a grim prognosis. This study aimed to retrospectively analyzed the diagnosis, treatment, and survival analysis of 173 patients with LM from NSCLC. Materials and methods: We reviewed charts of 173 patients with diagnoses of LM from lung cancer (LC-LM) between May 2016 and May 2021. 173 patients who had unequivocal radiographic evidence comprised our “LM MRI+” cohort. Radiographic involvement (n=136) was scored by number of gadolinium-enhancing sites in 8 locations. Genetic testing of paired cerebrospinal fluid (CSF) and plasma samples from 22 patients at the time of LM diagnosis using second-generation sequencing (NGS). Clinical outcomes were compared with Kaplan-Meier log-rank test and Cox proportional hazards methodologies. Results: The median overall survival (OS) was 9.33 months (95% CI: 6.35‒12.31) with 77.5% maturity. 107 (61.8%) patients harbored a targetable mutation. Those with clinically actionable mutations were significantly longer OS than those without (6.30 vs 12.17 months; HR:0.63; 95% CI: 0.45-0.90; p=0.009). In the “LM MRI+” cohort, MRI site extent of radiographic involvement 3-4 sites was significantly shorter OS than that those involved 1-2 sites (3.77 vs 10.07 months; HR: 1.84; 95% CI: 1.02–3.31; p = 0.034). CSF was more sensitive than plasma and indicated the unique genetic profiles of LM. Multivariate analysis revealed that targetable mutations, PS, LM treat, and LM tyrosine kinase inhibitor (TKI) therapy were independent prognostic factors for LM. Conclusions: Our study provides real-world clinical evidence that patients with MRI site extent of radiographic involvement 3-4 sites was significantly shorter OS than that those involved 1-2 sites and those with clinically actionable mutations were significantly longer OS than those without.