Plasma IGFBP-2 levels predict clinical outcomes of patients with high-grade gliomas

Insulin-like growth factor binding protein 2 (IGFBP-2) is a malignancy-associated protein measurable in tumors and blood. Increased IGFBP-2 is associated with shortened survival of advanced glioma patients. Thus, we examined plasma IGFBP-2 levels in glioma patients and healthy controls to evaluate its value as a plasma biomarker for glioma. Plasma IGFBP-2 levels in 196 patients with newly diagnosed glioma and 55 healthy controls were analyzed using an IGFBP-2 ELISA kit. Blood was collected before surgery, after two-cycle adjuvant chemotherapy, and at recurrence. Plasma IGFBP-2 levels were correlated with disease-free survival DFS) using Cox regression analyses. We found that preoperative plasma IGFBP-2 levels were significantly higher in high-grade glioma patients n = 43 for grade III glioma; n = 72 for glioblastoma multiforme [GBM]) than in healthy controls n = 55; p < 0.001) and low-grade (grade II) glioma patients n 5 81; p, 0.001). No significant differences in preoperative plasma IGFBP-2 levels were observed between grade III glioma and GBM patients or between grade II glioma patients and healthy controls. After recurrence, plasma IGFBP-2 levels were significantly increased in GBM patients (n = 26; p < 0.001). Preoperative plasma IGFBP-2 levels were significantly correlated with DFS in GBM patients ( hazard ratio, 1.404; 95% confidence interval, 1.078-1.828; p = 0.012). We conclude that preoperative plasma IGFBP-2 levels are significantly higher in high-grade glioma patients than in low-grade glioma patients and healthy subjects, and are significantly correlated with recurrence and DFS in patients with GBM. Longitudinal studies with a larger study population are needed to confirm these findings. Neuro-Oncology 11, 468-476, 2009 (Posted to Neuro-Oncology [serial online], Doc. D08-00199, January 22, 2009. URL http://neuro-oncology. dukejournals. org; DOI: 10.1215/15228517-2008-114)