O8.07 * HISTOLOGY, LOCALISATION, TREATMENT AND OUTCOME OF 339 CONSECUTIVE CHILDREN AND ADOLESCENTS WITH LOW GRADE GLIOMAS TREATED AT THE MEDICAL UNIVERSITY OF VIENNA BETWEEN 1993 AND 2012

Abstract

Low grade gliomas (LGG) comprise a spectrum of different tumor entities corresponding to WHO grade I and II, including pilocytic astrocytoma, diffuse glioma and glioneuronal tumors. LGG in children differ in histologic distribution, molecular profile, localisation in the CNS and outcome from LGGs in adults. We report on a series of patients treated at a single center over 20 years. PATIENTS: Between 1993 and 2012, 339 consecutive patients with a median age of 8 years (range 4 months - 18 years, p25 = 3.7 years, p75 = 13.4 years) were treated at the Medical University of Vienna. 19.5% of the patients were <3 years of age at diagnosis. Gender distribution was equal. Tumors were associated with syndromes in 84 of the patients (NF1: n = 64, TSC: n = 17, and other: n = 3). Localisation was supratentorial midline in 112, cerebral hemispheres in 105, posterior fossa in 86, ventricular system in 27 and spinal in 9 patients. 66 patients with a median age of 4.4 years had optic pathway gliomas. RESULTS: Gross total resection was performed in 109, subtotal resection in 49, partial resection in 57, and biopsy in 22 patients. 83 patients had no surgery (patients with NF1, TSC, tectal glioma or tumors confined to the optic nerves and chiasm), and in the remaining the degree of resection was not evaluable. 37 patients had 2 tumor surgeries, 14 three, 5 four and one had 5 tumor surgeries during their course of disease. Histology was pilocytic astrocytoma in 122, pilomyxoid astrocytoma in 10, diffuse astrocytoma in 42, ganglioglioma in 30, subependymal giant cell astrocytoma in 17, oligoastrocytoma in 11, and other rarer histologies in the remaining patients. Twelve patients (3.5%) died and 84 patients (24.8%) had at least one event. After a median follow-up of 107 months (14-300) the 1-year overall survival (OS) was 100%, the 10-year OS 96.1 ± 1.2%, and the 20-year OS 95.3 ± 1.4%. Event-free survival (EFS) after 1 year was 92.9 ± 1.4%, after 10 years 73.8 ± 2.6% and after 20 years 67.9 ± 3.4%. CONCLUSION: While long term survival of children and adolescents with low grade gliomas is better than of adults, recurrence and death may occur even in WHO grade I tumors and regular surveillance MRI is recommended.