Pediatric low-grade gliomas (pLGG) are the most common brain tumors in children — and as a group, they have some of the most hopeful outcomes in pediatric oncology. If your child has this diagnosis, understanding what it means can replace some of the early fear with realistic optimism.
What they are Low-grade gliomas are slow-growing tumors (WHO grade 1 or 2). The most common type is pilocytic astrocytoma, a grade 1 tumor that is often well-circumscribed and, when located in an accessible area, can sometimes be cured by surgery alone. Other pLGG types include pleomorphic xanthoastrocytoma, ganglioglioma, and diffuse low-grade gliomas.
Where they occur Common locations include the cerebellum, the optic pathways, the brainstem, and the deep midline. Location is one of the most important factors — a tumor in an area where the surgeon can safely remove it has a different outlook than one in a location where complete removal isn't possible.
The role of BRAF and targeted therapy Many pediatric low-grade gliomas are driven by changes in the BRAF gene — either a fusion/rearrangement or the BRAF V600E mutation. This discovery has transformed care. Targeted drugs are now available:
- Dabrafenib plus trametinib is approved for children with BRAF V600E mutations.
- Tovorafenib (Ojemda) is approved for children with BRAF fusions or rearrangements, or the V600 mutation, that have come back or progressed.
These oral targeted therapies offer alternatives to traditional chemotherapy for tumors that can't be fully removed.
Treatment approach Options depend on location and whether the tumor is causing problems. They include surgery (the first choice when safe), observation for tumors that aren't growing or causing symptoms, chemotherapy, and targeted therapy. Radiation is generally avoided in young children when possible, to protect the developing brain, and reserved for select situations.
Outlook Overall survival for pediatric low-grade glioma is very high — often well above 90% over the long term. Many of these tumors can be controlled for years, and some children are cured. The focus of care is increasingly on controlling the tumor while minimizing long-term effects on development, vision, hormones, and quality of life.
This is, in many ways, one of the more encouraging diagnoses in pediatric neuro-oncology. Your child's care team can explain what their specific tumor type and location mean for them.