Clinical and treatment factors determining long-term outcomes for adult survivors of childhood low-grade glioma: A population-based study

Cancer. 2016 Apr 15;122(8):1261-9. doi: 10.1002/cncr.29907. Epub 2016 Mar 10.


Background: The determinants of outcomes for adult survivors of pediatric low-grade glioma (PLGG) are largely unknown.

Methods: This study collected population-based follow-up information for all PLGG patients diagnosed in Ontario, Canada from 1985 to 2012 (n = 1202) and determined factors affecting survival. The impact of upfront radiation treatment on overall survival (OS) was determined for a cohort of Ontario patients and an independent reference cohort from the Surveillance, Epidemiology, and End Results database.

Results: At a median follow-up of 12.73 years (range, 0.02-33 years), only 93 deaths (7.7%) were recorded, and the 20-year OS rate was 90.1% ± 1.1%. Children with neurofibromatosis type 1 had excellent survival and no tumor-related deaths during adulthood. Adverse risk factors included pleomorphic xanthoastrocytoma (P < .001) and a thalamic location (P < .001). For patients with unresectable tumors surviving more than 5 years after the diagnosis, upfront radiotherapy was associated with an approximately 3-fold increased risk of overall late deaths (hazard ratio [HR], 3.3; 95% confidence interval [CI], 1.6-6.6; P = .001) and an approximately 4-fold increased risk of tumor-related deaths (HR, 4.4; 95% CI, 1.3-14.6; P = .013). In a multivariate analysis, radiotherapy was the most significant factor associated with late all-cause deaths (HR, 3.0; 95% CI, 1.3-7.0; P = .012) and tumor-related deaths (HR, 4.4; 95% CI, 1.3-14.6; P = 0.014). A similar association between radiotherapy and late deaths was observed in the independent reference cohort (P < .001). In contrast to early deaths, late mortality was associated not with PLGG progression but rather with tumor transformation and non-oncological causes.

Conclusions: The course of PLGG is associated with excellent long-term survival, but this is hampered by increased delayed mortality in patients receiving upfront radiotherapy. These observations should be considered when treatment options are being weighed for these patients.

Keywords: children; glioma; low-grade; neurofibromatosis type 1 (NF1); outcome; radiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Brain Neoplasms / mortality*
  • Brain Neoplasms / pathology*
  • Brain Neoplasms / therapy
  • Child
  • Child, Preschool
  • Confidence Intervals
  • Databases, Factual
  • Disease-Free Survival
  • Female
  • Follow-Up Studies
  • Glioma / mortality*
  • Glioma / pathology*
  • Glioma / therapy
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Multivariate Analysis
  • Neoplasm Invasiveness
  • Neoplasm Recurrence, Local / mortality
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Staging
  • Ontario
  • Proportional Hazards Models
  • Registries*
  • Regression Analysis
  • Retrospective Studies
  • Sex Factors
  • Survival Analysis
  • Survivors
  • Time Factors
  • Young Adult