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.