Feasibility and efficacy of second-line chemotherapy at recurrence for pediatric low-grade gliomas: A comparative population-based study

Abstract

2069 Background: Chemotherapy is widely accepted as the first-line therapy for pediatric low-grade gliomas (PLGG). Treatment modalities for further progression are controversial. Radiation therapy is still widely used, but the role for repeated chemotherapy remains unclear. The aim of the study was to determine treatment outcome for PLGG treated by chemotherapy at recurrence. Methods: The study group consisted of patients who received chemotherapy due to progression after initial chemotherapy protocol. These were compared to patients treated with chemotherapy at diagnosis, patients who received chemotherapy at third progression and to patients who received radiotherapy at recurrence. Results: From 1990–2007, 80 patients received chemotherapy as first-line treatment for PLGG. 36 received chemotherapy as second-line and 11 at further recurrence. 31 patients were treated with radiation at recurrence. There was no gender preference. Median follow-up time was 6.85 yrs. Histology revealed grade 1 astrocytoma in 73%. The most common location was optic pathway with 49%, followed by brainstem and suprasellar (14 %) and thalamic and spinal location (11 %). The most common initial protocol was vincristine and carboplatin (80%). The most common protocol at relapse was vinblastine (87%). Five-year progression-free survival (PFS) for first-line chemotherapy was 49% ± 6 compared to 41 ± 9% with second-line chemotherapy (p=0.2). For further chemotherapy PFS was comparable but so far with shorter follow-up. Five years PFS for the second-line chemotherapy and radiotherapy at recurrence group were 41 ± 9% and 78 ± 5 % respectively (p=0.003). Only 4 patients died, out of whom only 2 due to tumor progression. Conclusions: This is the first study to address the role of chemotherapy for recurrent PLGG. In contrast to other tumours chemotherapy at diagnosis as well as at first recurrence is associated with similar outcome. Nevertheless in this study radiotherapy was superior to chemotherapy. Prospective studies to assess toxicity and long-term outcome are needed. No significant financial relationships to disclose.