Objective:

To evaluate the prevalence and natural history of gliomas in a cohort of Neurofibromatosis Type I (NF1) patients.

Background:

Neurofibromatosis type 1 (NF1) is a multisystem autosomal dominant disorder which predisposes individuals to central nervous system tumors and intracranial lesions, including gliomas. We describe the natural history, surveillance, and treatment of these lesions in a large cohort. 

Design/Methods:

We performed a retrospective chart review of 178 NF1 patients with a diagnosis of non-optic glioma followed at our institution from 2012 to 2023. Patient demographics, clinical presentation, imaging findings, survival and progression-free survival, and treatment information was collected. 

Results:

Our patients ranged from ages 5 to 76 years. The median age at which gliomas were first noted was 7 years and were most commonly found incidentally. The median overall survival of patients with glioma was 10.79 years, with median progression-free survival of 5 years. Of those with glioma, 75 (42.1%) did not receive treatment. Of those who did receive treatment, 37 (20.8%) had surgery, 36 (20.2%) underwent chemotherapy, and 41 (23%) were given other treatments. Multiple types of chemotherapy regimens were administered, the majority of which was Carboplatin and Vincristine. Of the 23 patients who underwent biopsy, the majority were pilocytic astrocytoma (47.8%), followed by glioblastoma (17.4%). Many patients had additional intracranial tumors: 89 (50%) with an optic pathway glioma, 115 (64.6%) had an additional low-grade glioma, and 3 (1.7%) had an additional high-grade glioma. 

Conclusions:

Our data provides a description of the clinical course of a large cohort of NF1 patients with non-optic gliomas. In our cohort, the prevalence of non-optic gliomas is 26.1%. Many patients are diagnosed incidentally at a young age and biopsy results indicate that the majority are classified as low-grade. These gliomas often remain stable over time and do not require treatment intervention.