Clinicopathologic study of glioblastoma in children with neurofibromatosis type 1.

BACKGROUND: Neurofibromatosis type 1 (NF1) is characterized by low-grade tumors of the central and peripheral nervous system. There is also an increased risk of developing malignant tumors. Glioblastoma is an uncommon, malignant tumor of children that is even less frequently observed in children with NF1. PROCEDURE: We performed a retrospective review of patients with NF1 and glioblastoma to determine specific clinical and pathologic indicators of overall prognosis.
RESULTS: Five patients were identified from the CHB/DFCI database for whom pathologic and imaging studies were available. All pathologic specimens demonstrated vascular proliferation and necrosis. All samples stained positively for p53. Chromogenic in situ hybridization (CISH) for epidermal growth factor receptor (EGFR) copy numbers was increased, PTEN copy numbers were normal and the promoter of the O(6)-methylguanine-DNA methyltransferase (MGMT) gene was unmethylated in the one patient evaluated. In the same time period, there were 56 patients without NF1 diagnosed with glioblastoma who were treated at our institution. Although the small sample size precludes formal statistical analysis, the 2-year survival of patients with NF1 is 60% with median overall survival of 9.25 years compared to non-NF1 patients with a 2-year survival of 25% and median overall survival 1.08 years.
CONCLUSIONS: This study provides preliminary evidence that children with NF1 may be at risk for glioblastoma, but that these patients have an increased survival compared to children without NF1. Additional molecular studies will be required to determine if the pathogenesis of these tumors differs from glioblastoma in children without NF1. Copyright 2010 Wiley-Liss, Inc.