Sarah Rush, University of Colorado
2012, Summary research update
Pediatric pilocytic and pilomyxoid astrocytomas are slow growing and amenable to surgical cure if located in a favorable place. However, a significant number of children (> 55 %) will eventually suffer from tumor progression. Although this tumor is unlikely to become a more aggressive astrocytoma, repeated recurrences and surgery can eventually result in devastating damage. Currently, there is no way to identify those patients whose tumor is likely to progress or come back.
Insulin-like growth factor-II messenger RNA (mRNA)-binding protein-3 (IMP3, IGF2BP3) has recently been identified as predictive of an unfavorable outcome in a variety of other cancers. The aim of this study was to determine if there was expression of IMP3 in low grade astrocytomas and whether it could be used as a marker of outcome in these cases.
IMP3 protein expression was assessed in 81 pilocytic and pilomyxoid tumors and was scored from on a subjective scale by the pathologist. IMP3 mRNA expression was also evaluated in 22 tumors. Increased IMP3 was observed in 32% (26/81) of the tumors and these were the cases where tumor progression occurred most often as well. IMP-3 warrants further evaluation as a predictor of poor prognosis in pediatric pilocytic and pilomyxoid astrocytomas.