Characteristics and Outcomes of Pediatric Glioblastoma in the Post-Temozolomide Era

Abstract

Abstract INTRODUCTION Glioblastoma multiforme (GBM) is the most common brain tumor, however, is a rare occurrence in children and is poorly characterized. We evaluated the characteristics and outcomes of pediatric GBM (pGBM). METHODS Retrospective analysis of pediatric (age < 18) patients diagnosed with GBM undergoing first glioblastoma resection at our brain tumor center (2005-2016). RESULTS From 1457 GBM patients, we identified 24 (1.65%) pGBMs (Median Age = 9 yr, Females = 45.8%). Median overall survival (OS) was 32.1 mo, while the median progression-free survival was 11.5 mo. The commonest symptoms at presentation were headaches (54.2%, n = 13) and motor symptoms (50%, n = 12). Mean tumor diameter was 4.5 cm and 25% of the cohort underwent gross total resection (GTR) of their tumor. Univariate analysis revealed median OS significantly associated with tumor extent of resection (GTR = 56.4 mo; STR/Biopsy = 13.7 mo, P = .001), age at surgery (>10 yr = 43.9 mo, <10 yr = 17.2 mo, P = .01), tumor size (>4 cm = 9.1 mo, <4 cm = 56.9 mo, P = .01), motor symptoms at presentation (present = 14.9 months, absent = 41.04 mo, P = .02) and infratentorial tumors (infratentorial = 17.4 vs supratentorial = 53.4 mo, P = .02). Cox proportional hazard multivariate analysis revealed GTR (HR 0.2[95% CI 0.07-0.72]; P = .03), Age > 10 yr (HR 0.6[95% CI 0.02-0.64]; P = .002), tumor > 4 cm (HR 2.89[95% CI 1.88-4.11]; P = .001), and EGFR amplification (HR 3.48[95% CI 0.82-17.4]; P = .005) to be independent predictors of OS. Comparing patients under and over 10 yr, we found that older patients had smaller tumors at presentation (4.9 vs 3.6 cm, P = .03), greater rates of preoperative temozolomide (n = 1, 7.7% vs n = 6, 54.5%) and bevacizumab (n = 1, 7.7% vs n = 4, 36.4%) treatment, and lower rates of EGFR amplification (66.7% vs 11.1%) that could explain survival disparities among these groups. CONCLUSION Motor symptoms, larger tumors at presentation and tumor EGFR amplification may be indictive of poorer outcomes in pGBM. However, maximal tumor resection, aggressive chemoradiation, and tumor presentation at age >10 yr may confer better prognosis in these patients.