# Optic pathway glioma

Source: https://onco.cc/cancers/optic-pathway-glioma/  
OnCo record `optic-pathway-glioma` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Optic pathway glioma is a slow-growing childhood brain tumour of the nerves that carry sight, often in children with neurofibromatosis type 1. It rarely kills but can take away vision, so treatment aims to preserve sight: watching if stable, chemotherapy such as carboplatin and vincristine if vision is threatened, or the MEK-blocking tablet selumetinib, with radiotherapy avoided in young children.

## Summary

Optic pathway gliomas are pilocytic or other low-grade astrocytomas of the optic nerves, chiasm and hypothalamus, sporadic or associated with neurofibromatosis type 1, and treated within the paediatric low-grade glioma pathway (NCI PDQ). Because visual acuity rather than tumour size is what matters, the Response Evaluation in Neurofibromatosis and Schwannomatosis committee recommended quantitative visual acuity (Teller cards, then HOTV) as the main functional outcome for trials (Neurology 2013). In a single-institution series of 43 children treated with chemotherapy or radiotherapy, about 14 percent improved their vision during therapy and site and age strongly predicted long-term visual outcome (Cancer 2015). The MEK inhibitor selumetinib produced responses in recurrent or progressive NF1-associated and BRAF-aberrant paediatric low-grade glioma in the Pediatric Brain Tumor Consortium phase 2 trial (Fangusaro 2019), and MEK and RAF inhibitors are now first-line options on the parent page.

How it differs from its parent: the goal is sight, not tumour shrinkage; NF1-associated tumours are usually not biopsied and follow a gentler course; radiotherapy is avoided because of vascular and second-tumour risks in NF1 and cognitive harm in young children.

How common: no registry figure in the sources read.

Treatment: observation with ophthalmology follow-up when stable; carboplatin and vincristine chemotherapy or a MEK inhibitor (selumetinib) or RAF inhibitor (tovorafenib, dabrafenib with trametinib for BRAF V600E) when vision is threatened or the tumour progresses; surgery only for a blind, painful proptotic eye or hydrocephalus; radiotherapy deferred as long as possible.

## Fields

- Kind: Cancer
- Last checked: 2026-09-24
- Also known as: Optic nerve glioma; Optic glioma; NF1-associated optic pathway glioma; Hypothalamic-chiasmatic glioma; NF1-associated optic pathway glioma (paediatric low-grade glioma)
- Tags: subtype-page; wave4; rare
- Group: paediatric
- Burden: A common form of paediatric low-grade glioma and the commonest brain tumour of neurofibromatosis type 1, in which it arises in about 15 to 20 percent of children by the estimates the trial literature uses; no registry figure is in the sources read.
- Subtypes: NF1-associated optic nerve glioma (usually not biopsied; gentler course); Sporadic optic pathway glioma (often KIAA1549-BRAF fusion); Hypothalamic-chiasmatic glioma of infancy (diencephalic syndrome); Optic nerve glioma confined to one nerve
- Biomarkers: Quantitative visual acuity (Teller cards, HOTV); NF1 germline status; KIAA1549-BRAF fusion or BRAF V600E in sporadic tumours; MRI of the optic pathway and hypothalamus

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/optic-pathway-glioma/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/optic-pathway-glioma/#overview
- What it is (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/optic-pathway-glioma/#what-it-is [4 subtypes]
- Finding it (on the hub): How it shows itself, how it is confirmed, what screening exists, and the biomarkers clinicians test for. https://onco.cc/cancers/optic-pathway-glioma/#finding-it [4 biomarkers]
- Treating it (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/optic-pathway-glioma/#treating-it [2 settings, 1 decision with options]
- Evidence (on the hub): Trials recruiting now, the landmark trials, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/optic-pathway-glioma/#evidence
- The science (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/optic-pathway-glioma/#science [3 targets]
- Where you are (own page): Cases by country, the UK and NHS pathway and other country lenses, and the expert centres with trials on record. https://onco.cc/cancers/optic-pathway-glioma/where-you-are/
- Living with it (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/optic-pathway-glioma/#living-with-it [9 questions, 6 red cards]
- What is coming (own page): Everything in development, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/optic-pathway-glioma/coming/ [6 medicines]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/optic-pathway-glioma/data/ [19 connected records]

## Standard of care

- Stable vision: Observation with ophthalmology and MRI follow-up. ([Paediatric low-grade glioma](https://onco.cc/cancers/paediatric-low-grade-glioma/))
- Threatened vision or progression: Carboplatin and vincristine, or selumetinib (phase 2, Fangusaro 2019), tovorafenib, or dabrafenib with trametinib for BRAF V600E; radiotherapy deferred. ([Carboplatin](https://onco.cc/drugs/carboplatin/), [Vincristine](https://onco.cc/drugs/vincristine/), [Selumetinib](https://onco.cc/drugs/selumetinib/), [Tovorafenib](https://onco.cc/drugs/tovorafenib/), [Dabrafenib](https://onco.cc/drugs/dabrafenib/), [Trametinib](https://onco.cc/drugs/trametinib/))

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Optic_nerve_glioma
- NCI PDQ: childhood glioma (including astrocytoma): https://www.cancer.gov/types/brain/patient/childhood-glioma-astrocytoma
- Neurology 2013: functional outcome measures for NF1-associated optic pathway glioma trials (REiNS): https://doi.org/10.1212/01.wnl.0000435745.95155.b8
- Cancer 2015: long-term visual outcome after chemotherapy for optic pathway glioma in children: https://doi.org/10.1002/cncr.29649
- Fangusaro 2019, Lancet Oncology: selumetinib in paediatric BRAF-aberrant or NF1-associated low-grade glioma, phase 2: https://doi.org/10.1016/s1470-2045(19)30277-3

## Connected records

- cancers: [Adamantinoma of bone](https://onco.cc/cancers/adamantinoma/), [Brain and spinal cord tumours (all types)](https://onco.cc/cancers/brain-tumours/), [Childhood cancers (all types)](https://onco.cc/cancers/childhood-cancers/), [Paediatric low-grade glioma](https://onco.cc/cancers/paediatric-low-grade-glioma/), [Vestibular schwannoma (acoustic neuroma)](https://onco.cc/cancers/vestibular-schwannoma/)
- targets: [NF1 (neurofibromin)](https://onco.cc/targets/nf1/)
- drugs: [Carboplatin](https://onco.cc/drugs/carboplatin/), [Dabrafenib](https://onco.cc/drugs/dabrafenib/), [Selumetinib](https://onco.cc/drugs/selumetinib/), [Tovorafenib](https://onco.cc/drugs/tovorafenib/), [Trametinib](https://onco.cc/drugs/trametinib/), [Vincristine](https://onco.cc/drugs/vincristine/)

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JSON: https://onco.cc/api/v1/entities/optic-pathway-glioma.json