Pediatric low-grade gliomas can be molecularly stratified for risk

Pediatric low-grade gliomas (PLGGs) consist of a number of entities with overlapping histological features. PLGGs have much better prognosis than the adult counterparts, but a significant proportion of PLGGs suffers from tumor progression and recurrence. It has been shown that pediatric and adult low-grade gliomas are molecularly distinct. Yet the clinical significance of some of newer biomarkers discovered by genomic studies has not been fully investigated. In this study, we evaluated in a large cohort of 289 PLGGs a list of biomarkers and examined their clinical relevance. TERT promoter (TERTp), H3F3A and BRAF V600E mutations were detected by direct sequencing. ATRX nuclear loss was examined by immunohistochemistry. CDKN2A deletion, KIAA1549-BRAF fusion, and MYB amplification were determined by fluorescence in situ hybridization (FISH). TERTp, H3F3A, and BRAF V600E mutations were identified in 2.5, 6.4, and 7.4% of PLGGs, respectively. ATRX loss was found in 4.9% of PLGGs. CDKN2A deletion, KIAA1549-BRAF fusion and MYB amplification were detected in 8.8, 32.0 and 10.6% of PLGGs, respectively. Survival analysis revealed that TERTp mutation, H3F3A mutation, and ATRX loss were significantly associated with poor PFS ( p