High Cell-Free DNA Levels in Cerebrospinal Fluid Predict Leptomeningeal Seeding of Hematologic Malignancy

BACKGROUND AND PURPOSE: The main difficulty when diagnosing leptomeningeal metastases (LMSs) is the low sensitivity of cytology. Cancer cells release cell-free DNA (cfDNA) during proliferation and apoptosis, and so we analyzed the cfDNA level as a biomarker for LMSs in hematologic malignancy. METHODS: This study prospectively enrolled 20 patients with hematologic malignancy who underwent cerebrospinal fluid (CSF) analysis. LMS was diagnosed based on both CSF cytology and clinical findings. RESULTS: The CSF level of cfDNA was higher in patients with LMSs (108.17±84.84 ng/mL, mean±standard deviation) than in non-LMS patients (14.23±2.78 ng/mL). The sensitivity of cfDNA was higher than that of cytology (100% vs. 87%). CONCLUSIONS: The cfDNA level in the CSF can be used as a supplemental marker for diagnosing LMS in hematologic malignancy patients.