title: Intrathecal synthesis of tumor markers is a highly sensitive test in the diagnosis of leptomeningeal metastasis from solid cancers.
abstract: BACKGROUND
  Identification of neoplastic cells in cerebrospinal fluid (CSF) by cytological analysis is the key diagnostic feature of leptomeningeal metastasis (LM). Because of the lack of sensitivity of this test, considerable efforts have been made to identify alternative diagnostic markers. Data from the literature suggest that measurement of tumor markers (TM) in CSF may be helpful for improving the diagnosis.
  
  
  METHODS
  We analyzed the concentrations of the TM carcinoembryonic antigen (CEA), CA15.3, CA125 and CA19.9 in both CSF and serum from 18 patients with neoplastic meningitis diagnosed by CSF cytology. We also performed these same measurements in 50 patients affected by other neurological diseases (OND) in order to evaluate putative intrathecal synthesis. In addition, CSF and serum concentrations of the proangiogenic factor VEGF (vascular endothelial growth factor) were evaluated.
  
  
  RESULTS
  All LM patients showed intrathecal synthesis for at least one TM. In one patient, a negative CSF cytology after treatment paralleled normalization of tumor marker synthesis. None of the OND patients displayed intrathecal TM synthesis. The VEGF Index (CSF/serum VEGF relative to CSF/serum albumin ratios) was significantly higher in LM patients compared with the control group. However, significant overlap between LM patients and values seen in those with OND was observed.
  
  
  CONCLUSIONS
  Evaluation of intrathecal TM synthesis is a specific, sensitive, reliable, and reproducible diagnostic tool, and is useful to support diagnosis of carcinomatous meningitis.
authors.affiliation: Laboratory of Clinical Investigations, Fondazione Istituto Neurologico C. Besta, Milan, Italy. elena.corsini@istituto-besta.it
authors.forename: Elena
authors.initials: E
authors.lastname: Corsini
authors.forename: Gaetano
authors.initials: G
authors.lastname: Bernardi
authors.forename: Paola
authors.initials: P
authors.lastname: Gaviani
authors.forename: Antonio
authors.initials: A
authors.lastname: Silvani
authors.forename: Ugo
authors.initials: U
authors.lastname: de Grazia
authors.forename: Emilio
authors.initials: E
authors.lastname: Ciusani
authors.forename: Danilo
authors.initials: D
authors.lastname: Croci
authors.forename: Andrea
authors.initials: A
authors.lastname: Salmaggi
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000097:blood / Q000134:cerebrospinal fluid; D002272:Carcinoembryonic Antigen / Q000032:analysis* / Q000097:blood / Q000134:cerebrospinal fluid; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D055756:Meningeal Carcinomatosis / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D008875:Middle Aged; D020033:Protein Isoforms / Q000032:analysis / Q000097:blood / Q000134:cerebrospinal fluid; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis / Q000097:blood / Q000134:cerebrospinal fluid
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D020033:Protein Isoforms; D042461:Vascular Endothelial Growth Factor A