Prognostic Significance of Cerebrospinal Fluid Glucose, Protein, and White Blood Cell Count in Breast Cancer Leptomeningeal Disease.

BackgroundLeptomeningeal disease (LMD) is a serious complication of metastatic breast cancer (MBC) with poor survival. This single-institution retrospective study compares overall survival (OS) among MBC patients with LMD based on CSF parameters (glucose, protein, and WBC count) MethodologyMBC patients who were diagnosed with LMD between 2010-2023 at Wilmot Cancer Institute were screened for eligibility. Only those with available data on CSF glucose, protein, and WBC count were included. OS was assessed via the Kaplan-Meier method and compared using the log-rank test. Cox models were used for multivariate analysis. ResultsOut of 69 patients with MBC LMD, 28 had CSF data and were included in the final analysis. The CSF cytology-positive cohort had significantly lower glucose levels vs the CSF cytology-negative cohort [median (IQR) 40 (18-58) vs 64 (53-92) mg/dl, p=0.006]. Median CSF WBC count was significantly higher in the CSF cytology positive cohort vs the CSF cytology negative cohort [median (IQR) 13 (6-44) vs. 2(2-4)cells/mm3, p=0.001]. When stratified by CSF cytology results and CSF glucose levels, the CSF cytology negative, glucose-low group was associated with the worst OS, while the CSF cytology negative, normal/high glucose group was associated with the best OS(p=0.03) in an unadjusted analysis. Multivariate analysis confirmed that low CSF glucose was independently associated with poorer survival [HR 4.64 (1.71, 13.2)]. Neither CSF protein levels nor CSF WBC counts were significantly associated with OS in unadjusted and multivariate analyses. ConclusionLow CSF glucose was associated with worse OS than normal/high CSF glucose. There was insufficient evidence to suggest that CSF protein or CSF WBC counts were associated with OS.