The oncofetal protein IMP3: a novel molecular marker to predict aggressive meningioma.

CONTEXT: One of the major clinical challenges is to predict recurrence of meningioma. Recently, we have found that IMP3, an oncofetal RNA-binding protein, is a biomarker to predict aggressive tumors.

OBJECTIVE: To investigate whether IMP3 can be used as a new biomarker to predict the recurrence and overall survival of patients with meningiomas.

DESIGN: One hundred seven patients with primary meningiomas were investigated for expression of IMP3 by immunohistochemistry and whether expression of this molecule correlated with tumor recurrence and overall survival.

RESULTS: Tumor recurrence was found in 13 of 107 patients with primary meningioma. Seven of 107 patients (6.5%) with primary meningiomas expressed IMP3. Kaplan-Meier plots and log-rank tests showed that patients with IMP3-positive tumors had a much higher recurrence rate (P = .004) and a poorer overall survival (P < .001) than did patients with IMP3-negative tumors. The 5-year recurrence-free and overall survival rates were 0% and 36% in IMP3-positive patients versus 89% and 94% in IMP3-negative patients, respectively. Multivariable analysis of IMP3 status (positive versus negative) in primary tumors showed a hazard ratio of 17.89 for recurrence (P = .01), which was much higher than hazard ratios associated with all other known risk factors including higher tumor grades and Ki-67 labeling index.

CONCLUSIONS: IMP3 is a potential independent prognostic biomarker that can be used at the time of initial diagnosis of meningioma to identify patients who have a high risk of developing a recurrence.