Abstract Introduction Low-grade gliomas (LGGs) are the most common central nervous system tumors in children and are most frequently driven by alterations in the RAS/MAPK signaling pathway.1-3 Fibroblast growth factor receptor (FGFR) alterations define a distinct molecular subgroup that is well characterized genomically but poorly described from a surgical perspective. Given the association between extent of resection and recurrence risk in LGG, we aimed to compare surgical outcomes between FGFR-altered and FGFR wild-type (WT) tumors. Methods We conducted a single-center retrospective cohort study of patients 21 years of age who underwent resection of a low-grade glioma between 1989 and 2024. Clinical, pathologic, molecular, and surgical variables were analyzed. Statistical analyses were performed in R (v4.2.2) using descriptive statistics, chi-square or Fisher’s exact tests for categorical variables, and logistic regression for repeat surgery outcomes. Results A total of 569 pLGG were included, comprising 66 tumors harboring FGFR alterations and 503 FGFR WT tumors. FGFR-altered tumors presented at an older median age than WT tumors (12.4 vs. 9.3 years, p = 0.023), with similar sex distribution (p = 0.60). FGFR-altered tumors were more often WHO grade II (59.1% vs. 15.1%, p 0.001) and supratentorial (77.3% vs. 51.5%, p 0.001). FGFR-alteration was associated with lower rates of gross total resection at index surgery (28.8% vs. 44.5%, p 0.023) and a higher likelihood of repeat resection (34.8% vs. 20.5%; OR 2.07, 95% CI 1.14-3.70; p = 0.011). Conclusions FGFR-altered pediatric low-grade gliomas are associated with lower rates of gross total resection and increased need for repeat surgery compared with FGFR WT tumors. This likely reflects a propensity for these tumors to infiltrate eloquent or surgically high-risk brain structures, which constrains the extent of safe resection and emphasizes the importance of targeted strategies for residual disease.
Keusch et al. (Tue,) studied this question.