Outcomes of Multidisciplinary Management in Pediatric Low-Grade Gliomas

Abstract

To evaluate the outcomes in pediatric low-grade gliomas managed in a multidisciplinary setting. We conducted a single-institution retrospective study of 181 children with Grade I-II gliomas. Log-rank and stepwise Cox proportional hazards models were used to analyze freedom from progression (FFP) and overall survival (OS). Median follow-up was 6.4 years. Thirty-four (19%) of patients had neurofibromatosis Type 1 (NF1) and because of their favorable prognosis were evaluated separately. In the 147 (81%) of patients without NF1, actuarial 7-year FFP and OS were 67 ± 4% (standard error) and 94 ± 2%, respectively. In this population, tumor location in the optic pathway/hypothalamus was associated with worse FFP (39% vs. 76%, p < 0.0003), but there was no difference in OS. Age ≤5 years was associated with worse FFP (52% vs. 75%, p < 0.02) but improved OS (97% vs. 92%, p < 0.05). In those with tissue diagnosis, gross total resection (GTR) was associated with improved 7-year FFP (81% vs. 56%, p < 0.02) and OS (100% vs. 90%, p < 0.03). In a multivariate model, only location in the optic pathway/hypothalamus predicted worse FFP (p < 0.01). Fifty patients received radiation therapy (RT). For those with less than GTR, adjuvant RT improved FFP (89% vs. 49%, p < 0.003) but not OS. There was no difference in OS between patient groups given RT as adjuvant vs. salvage therapy. In NF1 patients, 94% of tumors were located in the optic pathway/hypothalamus. With a conservative treatment strategy in this population, actuarial 7-year FFP and OS were 73 ± 9% and 100%, respectively. Low-grade gliomas in children ≤5 years old with tumors in the optic pathway/hypothalamus are more likely to progress, but this does not confer worse OS because of the success of salvage therapy. When GTR is not achieved, adjuvant RT improves FFP but not OS. Routine adjuvant RT can be avoided and instead reserved as salvage.