Single agent carboplatin for pediatric low-grade glioma: A retrospective analysis shows equivalent efficacy to multiagent chemotherapy

Pediatric low-grade gliomas (LGG) that are unresectable often require adjuvant chemotherapy such as carboplatin/vincristine. Small Phase II studies have suggested equivalent efficacy of single agent 4-weekly carboplatin. A single-institution retrospective review captured all patients aged 0 to 18 years diagnosed with LGG between 1996 and 2013 and treated with carboplatin monotherapy. The response and survival according to tumor site was compared to published results for multiagent chemotherapy. Of 268 children diagnosed with LGG diagnosed in this period, 117 received chemotherapy and 104 children received single agent carboplatin as first line chemotherapy. All patients received carboplatin at 560 mg/m(2), four-weekly for a median of 12 courses. The mean age at diagnosis was 5.8 years (range 3m-16y) and 32% had neurofibromatosis type 1. With a mean followup of 54 months, 86% of patients achieved stabilisation or better (SD/PR/CR). 3-year progression free survival (PFS) 66% (95% CI 57-76%), and 5-year PFS was 51% (95% CI 41-63%). 5-year overall survival was 97%. Multivariate analysis showed poorer PFS for those with chiasmatic/hypothalamic tumors. In this retrospective analysis single agent carboplatin shows comparable efficacy to historical multiagent chemotherapy for the treatment of patients with unresectable LGG. Equivalent outcomes are achieved with less chemotherapy, reduced side effects and fewer hospital visits. Further research is required to establish the place of this simplified regimen in the up-front treatment of unresectable LGG.