A longitudinal prospective study of YKL-40 and matrix metalloproteinase-9 (MMP-9) as serum tumor markers in gliomas

2038 Background: YKL-40, an extracellular matrix glycoprotein, is overexpressed in high-grade gliomas (HGG). MMP-9, a matrix metalloproteinase associated with tumor infiltration and angiogenesis, has been detected both in tumor and endothelial cells in gliomas. These two proteins are secreted and our previous work suggested that they are serum marker candidates for gliomas. Methods: From 08/02 to 11/06, serum samples were collected prospectively from patients (pts) with histologically confirmed gliomas. Serum was obtained concurrently with MRI scans at multiple time points during the course of the disease. YKL-40 and MMP-9 were determined by ELISA and the values correlated with radiographic disease status and survival. Because the distribution for YKL-40 and MMP-9 were skewed, the data were log transformed. To study the relationship between each serum marker and radiographic disease status all measurements were used in a logit model with generalized estimating equations that corrected for within-patient c...