Abstract In most cases, pediatric low-grade gliomas (pLGGs) have alterations of the MAPK/ERK pathway. However, the detailed knowledge of prognostic genetic alterations that differ in clinical outcomes is poorly understood. We conducted a retrospective chart review of 90 patients diagnosed with non-NF1 pLGG between 2005 and 2024 at the Children’s Hospital of Orange County. We analyzed clinical courses and molecular diagnosis to identify the prognostic gene alterations. In our cohort, the most common diagnosis was pilocytic astrocytoma (50%; n = 45), followed by ganglioglioma (14%; n = 13) and diffuse astrocytoma (4%; n = 4). Twenty-six percent (n = 23) of patients experienced progressive disease. Only 46% (n = 41) of tumors were partially or fully analyzed using molecular analysis at diagnosis; some had only the immunohistochemistry evaluation. Out of the 41 patients with molecular analysis performed, the most common genetic alteration was BRAFV600E (n = 19), which was found to undergo multiple courses of treatment in 42% of cases (n = 8). The alteration with the highest prevalence of necessitating multiple treatments was FGFR (n = 5), which occurred in 60% of cases (n = 3). Our findings contrast with other studies demonstrating BRAFV600E as more deleterious than FGFR. A prospective branch of the study is underway to uncover the additional 49 tumor samples to be molecularly profiled. The prospective branch of the study will help elucidate the prognostic gene alterations further and analyze the response to the therapy.
Ballew et al. (Fri,) studied this question.