Molecular alterations in the integrated diagnosis of pediatric glial and glioneuronal tumors: A single center experience

• Published in: PloS one 2022-04, Vol.17 (4), p.e0266466-e0266466
• Main Authors: Colli, Sandra Lorena, Cardoso, Nazarena, Massone, Carla Antonella, Cores, María, García Lombardi, Mercedes, De Matteo, Elena Noemí, Lorenzetti, Mario Alejandro, Preciado, María Victoria
• Format: Article
• Language: English
• Subjects: Age; Astrocytoma; Astrocytoma - pathology; Auroral kilometric radiation; Biology and life sciences; Brain cancer; Brain Neoplasms - diagnosis; Brain Neoplasms - genetics; Brain Neoplasms - pathology; Cell cycle; Central nervous system; Central Nervous System Neoplasms - genetics; Cerebral hemispheres; Child; Cloning; Developing countries; Diagnosis; Gastrointestinal cancer; Gene fusion; Genes; Genetic aspects; Glioma; Glioma - diagnosis; Glioma - genetics; Glioma - pathology; Health aspects; Histones; Histones - genetics; Humans; Kinases; LDCs; Markers; Medical diagnosis; Medical prognosis; Medicine and Health Sciences; Mutants; Mutation; Nervous system; Neuroglia; Pediatrics; Physiological aspects; Proto-Oncogene Proteins B-raf - genetics; Radiation; Radiation therapy; Research and analysis methods; Solid tumors; Survival; Tumors; Tumors in children
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0266466

Tumors of the central nervous system (CNS) are the most common pediatric solid tumors, where low grade (LGG) and high grade gliomas (HGG) represent up to 55% of CNS tumors. Current molecular classification of these tumors results in a more accurate diagnosis and risk stratification, which ultimately enables individualized treatment strategies. Identifying known alterations is a suitable approach, particularly in developing countries, where NGS approaches are not easily accessible. We sought to assess molecular alterations in BRAF and histone 3 genes. FISH, IHC and Sanger sequencing were performed in a series of 102 pediatric glial and glioneuronal tumors. We also correlated these results with clinical and histological findings to evaluate their usefulness as diagnostic and/or prognostic tools. We found that the KIAA1549-BRAF gene fusion was a relevant diagnostic tool for pilocytic astrocytoma, but not related to progression free survival (PFS) and overall survival (OS). BRAFV600E mutation was associated with a decreased OS in LGG, and with decreased PFS and OS among pilocytic astrocytomas. All HGG of the midline were H3K27M mutants, while H3G34R mutant cases were located in brain hemispheres. HGG harboring the H3K27M variant were associated with a decreased PFS and OS. Assessing druggable molecular markers with prognostic value is particularly important in those cases where complete resection or further radiation therapy is not possible. These potential diagnostic/prognostic markers may be suitable as further screening tests to reduce the requirement on NGS, which is not available in all laboratories. Furthermore, these results broaden data on BRAF and Histone 3 alterations in children from geographic regions, other than USA and Europe.