Lipid-associated sialoprotein in the cerebrospinal fluid - Association with brain malignancies

BACKGROUND. Changes in the glycosylation process by tumor cells result in l arger amounts of sialoproteins on their surface compared with normal cells. Sialoproteins then are released into the surrounding environment primarily by shedding or cell lysis. In the current study, the authors attempted to evaluate whether lipid-associated sialoprotein (LSP) in the cerebrospinal f luid (CSF) can distinguish patients with primary and metastatic brain tumor s from those without brain tumors as well as determine response to treatmen t. METHODS. CSF samples were obtained from a tissue bank. The concentration of LSP was determined after chloroform:methanol extraction followed by protei n precipitation. One-way analysis of variance end Scheffe pairwise comparis ons were used for statistical analysis. RESULTS. The CSF of neurologically normal controls, patients with a normal leukocyte count (less than or equal to 5/muL), and patients with various ne urologic disorders or systemic tumors without central nervous system (CNS) malignancies contained similar levels of LSP. The CSF from patients with a normal leukocyte count and newly diagnosed primary or metastatic brain tumo rs contained on average 3.7-fold higher levels of LSP compared with CSF fro m patients without CNS tumors (P = 0.0001). The CSF from patients with brai n tumors with progressive disease not responding to treatment contained hig h levels of LSP comparable to the levels found in newly diagnosed patients. The CSF from treatment-responsive patients contained decreased levels of L SP similar to that found in control patients. CONCLUSIONS. The LSP in CSF may be a useful marker with which to determine the presence of intracranial malignancies and assess response to treatment. (C) 2001 American Cancer Society.