Multi-institutional Study of the Frequency, Genomic Landscape, and Outcome of IDH-Mutant Glioma in Pediatrics

Neuro-Oncology, Tempus-authored Manuscript
Authors Kee Kiat Yeo, Sanda Alexandrescu, Jennifer A Cotter, Jayne Vogelzang, Varun Bhave, Marilyn M Li, Jianling Ji, Jamal K Benhamida, Marc K Rosenblum, Tejus A Bale, Nancy Bouvier, Kristiyana Kaneva, Tom Rosenberg, Mary Jane Lim-Fat, Hia Ghosh, Migdalia Martinez, Dolly Aguilera, Amy Smith, Stewart Goldman, Eli L Diamond, Igor Gavrilovic, Tobey J MacDonald, Matthew D Wood, Kellie J Nazemi, AiLien Truong, Andrew Cluster, Keith L Ligon, Kristina Cole, Wenya Linda Bi, Ashley S Margol, Matthias A Karajannis, Karen D Wright

The incidence and biology of IDH1/2 mutations in pediatric gliomas are unclear. Notably, current treatment approaches by pediatric and adult providers vary significantly. We describe the frequency and clinical outcomes of IDH1/2-mutant gliomas in pediatrics.

We performed a multi-institutional analysis of the frequency of pediatric IDH1/2-mutant gliomas, identified by next-generation sequencing (NGS). In parallel, we retrospectively reviewed pediatric IDH1/2-mutant gliomas, analyzing clinico-genomic features, treatment approaches, and outcomes.

Incidence: Among 851 patients with pediatric glioma who underwent NGS, we identified 78 with IDH1/2 mutations. Among patients 0–9 and 10–21 years old, 2/378 (0.5%) and 76/473 (16.1%) had IDH1/2-mutant tumors, respectively. Frequency of IDH mutations was similar between low-grade glioma (52/570, 9.1%) and high-grade glioma (25/277, 9.0%). Four tumors were graded as intermediate histologically, with one IDH1 mutation. Outcome: Seventy-six patients with IDH1/2-mutant glioma had outcome data available. Eighty-four percent of patients with low-grade glioma (LGG) were managed observantly without additional therapy. For low-grade astrocytoma, 5-year progression-free survival (PFS) was 42.9% (95%CI:20.3–63.8) and, despite excellent short-term overall survival (OS), numerous disease-related deaths after year 10 were reported. Patients with high-grade astrocytoma had a 5-year PFS/OS of 36.8% (95%CI:8.8–66.4) and 84% (95%CI:50.1–95.6), respectively. Patients with oligodendroglioma had excellent OS.

A subset of pediatric gliomas is driven by IDH1/2 mutations, with a higher rate among adolescents. The majority of patients underwent upfront observant management without adjuvant therapy. Findings suggest that the natural history of pediatric IDH1/2-mutant glioma may be similar to that of adults, though additional studies are needed.