High-grade glioma in infants and very young children: characteristics, treatment, and outcomes.

Purpose: High-grade gliomas in infants and very young children (less than 3 to 5 years old) pose significant challenges due to the limited scientific literature available and high risks associated with treatments. This study aims to investigate their characteristics, treatment, and outcomes.

Methods: A cohort study was conducted at Children's Cancer Hospital, Egypt. Cases included children aged < 5 years old with confirmed CNS high-grade glioma. Baseline clinical and radiological characteristics, besides potential prognostic factors were assessed.

Results: In total, 76 cases were identified, 7 of them were < 1 year old. Gross- or near-total resection (GTR/NTR) was achieved in 32.9% of all cases. Of the tested cases, H3K27M-alteration was present in 5 subjects only. The 3-year OS and EFS for all cases were 26.9% and 15.4%, respectively. Extent of resection was the most important prognostic factor, as those achieving GTR/NTR experienced more than double the survival compared to those who do not (p = 0.05). Age had a "bimodal" effect on EFS, with those aged 1 to 3 years old faring better than younger and older age groups. Subjects with midline tumors had worse survival compared to non-midline tumors (1-year EFS = 18.5% vs 35%, respectively, p = 0.02).

Conclusion: This study in a large cohort of HGG in infants and very young children offers insights into the characteristics and treatment challenges. Extent of resection, age group, and tumor localization are important prognostic factors. Further research with larger sample size is warranted to refine treatment approaches and improve outcomes.