Contemporary Knowledge Update of Pediatric Neuro-Oncology Management: An Overview for Neurosurgeons

Pediatric central nervous system (CNS) tumors are known to be a major factor in pediatric morbidity and mortality. CNS tumors are the most common form of solid tumors in children and adolescents between the age of 0 years and 19 years. The annual average age-specific incidence rate for this age group is 6.23 per 100,000 population according to the latest analysis. An estimated 5,260 new cases of pediatric CNS tumors are expected to be diagnosed in the USA in 2023 [1]. These tumors comprise a variety of disease entities including tumors of glial origin, embryonal origin, germ cell origin, and others. While the annual incidence of brain tumors in pediatric patients is much lower than that in adults, they are currently the most common cause of cancer-related mortality in children, which is attributed by many factors among the type of tumors and treatment options we have for pediatric brain tumors. The five-year relative survival rate following diagnosis of a CNS tumor in the pediatric population is 83.9% and is much higher in adolescents than infants (90.5% vs. 71.9%) [1].

In the wake of the 21st century, pediatric neurosurgery has become a multi-subspecialty field, composed of complex pathologies across the central and peripheral nervous system. Back in 1954 when Dr. Ingraham, with his junior partner Donald Matson, published the first dedicated book on pediatric neurosurgery “Neurosurgery of Infancy and Childhood,” the knowledge and depth of understanding of this could not anticipate the horizons and challenges we are facing now a days taking care of the pediatric patient with CNS tumors.

The changes in the WHO classification of CNS tumors first in 2016, the cIMPACT-NOW publications, and then in 2021 marked the start of the current molecular and genetic-driven subclassification, but definitely not giving even a glimpse of all the knowledge and evolution in the field of pediatric neuro-oncology and neurosurgery. The evolution of our understanding today can be described by many examples, such of the ependymomas as completely different entities that are differentiated by their anatomical location (supratentorial, infratentorial, and spinal) and by their molecular subtyping (ZFTA, Yap-1, groups A and B, spinal MYCN, etc.) gradually abandoning the previous histological classification [2]. The evolution of our understanding of medulloblastomas, the most common malignant brain tumor in kids, is quite remarkable from the first classification more than 10 years ago, delineating the 4 subgroups – wingless, Sonic hedgehog, group 3, and group 4 [3]. This growing knowledge and understanding is affecting almost all the fields of pediatric neuro-oncology and allow for significant advancement in our treatment modalities. Such is the case with the data emerging from the latest ACNS0831, showing very small benefit if any for the use of chemotherapy in ependymomas, or the possible use of targeted therapy for various brain tumors that were deemed before as non-treatable, such in the case of infantile hemispheric gliomas harboring alterations involving the ALK/ROS1/NTRK/MET cycles that now were shown to dramatically respond for ALK inhibitors (e.g., lorlatinib) or ROS1/NTRK inhibitors (e.g., entrectinib) [4]. Due to the expansion in knowledge and the technological advancement, we face new challenges such as the treatment for craniopharyngiomas that can now be comprised from minimal surgery and proton beam therapy only and not just radical resection [6]. Yet, we still have unsolved challenges such as diffuse midline gliomas and the H3k27m mutation-driven tumors, and we still have not seen an impact in the overall survival.

This special issue in Pediatric Neurosurgery, “Contemporary knowledge update of pediatric neuro-oncology management: an overview for neurosurgeons,” sheds light on selected topics in neuro-oncology from the neurosurgeon’s perspective. The topics are discussed by the leading clinicians and researchers in neuroscience and share updates in advanced imaging for pediatric CNS tumors, current clinical trials’ update, treatment update for neurofibromatosis, and of course current knowledge of molecular and genetic mutation for pediatric CNS tumors.

The brief overview presented here of the articles in this issue as well as the importance of further advancing our knowledge as pediatric neurosurgeons demonstrates how much has been accomplished in recent years for the benefit of the pediatric patient suffering from CNS-related tumors. This continued effort in this special topic as well as many others contributes greatly to advancing pediatric neuro-oncology and neurosurgery. The special topic presented here cannot of course cover all the aspects of pediatric neuro-oncology and the advancement related to them, future topics and publications should further expand the discussion on these important topics.

The editors would like to express many thanks to the authors, reviewers, and members of the editorial board for all the effort and hard work that were put into this project helping make this special issue of Pediatric Neurosurgery ready and well-edited for the readers. Our hope is that the discussion that will take place out of the articles presented here will further help in advancing the field of pediatric neuro-oncology and give a better hope for the well-being and survival of our patients.