Association Of Cerebrospinal Fluid Protein Concentration And Overall Survival In Lung Adenocarcinoma Patients With Leptomeningeal Metastasis

Objective:Leptomeningeal metastasis(LM)is dramatically elevated in non-small cell lung cancer(NSCLC)patients,especially those with lung adenocarcinoma.However,it is difficult to determine the tumor burden of LM using routine radiographic findings.This study explored the associations between cerebrospinal fluid(CSF)protein concentrations at baseline and lung adenocarcinoma with LM patients’ outcomes.Methods:We retrospectively analyzed lung adenocarcinoma patients with LM between May 4,2016,and August 19,2021,at a single center.X-tile software was used to calculate the CSF protein concentration cut-off value.Univariate and multivariate Cox regression analyses were conducted to determine the association between CSF protein concentration and overall survival(OS).OS was defined as the time from diagnosis of LM to death or the last follow-up.Cox proportional hazards regression with smooth curve fitting(the cubic spline method)was used to identify their relationship.Results:A total of 131 patients with LM of lung adenocarcinoma were screened,and 87 patients who underwent CSF protein level assay were included in the study.Univariate and multivariate Cox regression analyses showed that high CSF protein was a poor prognostic factor for OS(Hazard ratio: 1.06,95% confidence interval:1.03–1.09;p = 0.0002).A high baseline cerebrospinal fluid protein concentration predicts an increased risk of death for the patient.The cut-off value was 960 mg/L as determined by X-title software.Our study showed that patients with low CSF protein levels had longer OS than those with high CSF protein levels(16.2 months vs.7.3months,p<0.0001).Conclusions:In lung adenocarcinoma patients with LM,the higher the baseline cerebrospinal fluid protein concentration,the worse their prognosis.