[1494] The Oncofetal Protein IMP3: A Novel Molecular Marker To Predict Aggressive Meningioma

S Hao, TW Smith, PG Chu, Q Liu, BA Woda, D Lu, P Lin, SA Wang, KL Rock, Z Jiang. University of Massachusetts Medical Center, Worcester, MA; City of Hope National Medical Center, Los Angeles, CA; M.D. Anderson Cancer Center, Houston, TX

Background: One of major clinical challenges is to predict recurrence of meningioma. In this study, we investigated whether IMP3, an oncofetal RNA-binding protein, can be used as a new biomarker to predict the recurrence and overall survival of meningiomas.
Design: 107 patients with primary brain meningiomas were investigated the expression of IMP3 by immunohistochemistry, and were further evaluated for survival analysis.
Results: Tumor recurrence was found in 13 of 107 patients with primary meningioma. Seven (6.5%) of 107 patients' meningiomas expressed IMP3. Kaplan-Meier plots and log-rank tests showed that patients with IMP3+ tumors had higher recurrent rate (P=0.0035), poor overall survival (P<0.0001) than those with IMP3- tumors. The 5-year recurrence-free and overall survival rates were 0% and 36% in IMP3+ patients vs. 89% and 94% in IMP3- patients.

Multivariate analysis of IMP3 status in primary tumors showed hazard ratio of 21.68 for recurrence (P= 0.006) and 14.45 for overall survival (P=0.001) , which were much higher than hazard ratio associated with other risk factors. Analysis of recurrence-free survival in grade 2 and 3 tumor patients showed that grade 2 or 3 patients with IMP3+ tumor had higher risk to develop recurrence than those with IMP3- tumor.

The median recurrence-free survival was 17.5 months in patients with IMP3+ tumors vs 109 months in patients with IMP3- tumors.
Conclusions: IMP3 is an independent prognostic marker that can be used at initial diagnosis of meningioma to identify patients who have high potential to develop recurrence.
Category: Neuropathology

Monday, March 9, 2009 2:45 PM

Platform Session: Section H, Monday Afternoon