Incidence and Prevalence
- 0.5–0.7 per 100,000: The incidence of HGGs is low, with 5–7 children per 1,000,000 afflicted.
Adapted from Ries et al (33)
- Minority of CNS tumors anaplastic: Only 15–20% of all pediatric CNS tumors are HGGs (4). 20% of hemispheric gliomas in children are AAs or GBMs (1), and only 6.5% of newly diagnosed brain tumors in children are HGGs (2).
- Even distribution with regard to age: The mean age of presentation of GBM is 9 years (5). In the US, GBM represents 2.8% of primary brain tumors in children ages 0–14 years and 3.2% in children 15–19 years (3).
- Even sex distribution: The male:female ratio for HGG in children is 1:1 (4).
- None: There are no data to imply any geographical influence with regard to the incidence or prevalence of HGG in children.
- No definitive evidence: Diet, tobacco use, and occupational exposures have been implied as risk factors in developing HGG, but there is no definitive evidence for environmental risk factors contributing to HGG (6).
- Prior radiation: Previous cranial radiation in childhood increases the risk of developing a HGG (7).
Relationships to Other Disease States and Syndromes
- Syndromes associated with CNS tumors: Other disease states such as TSC, Turcot syndrome, Li Fraumeni syndrome, and neurofibromatosis type 1 are associated with increased risk for both LGGs and HGGs.