NCCN Publishes Guidelines for Deadly Pediatric CNS Tumors

The recommendations follow the World Health Organization’s recent update to its classifications of central nervous system (CNS) tumors to now include a structure for pediatric patients with CNS tumors.

The National Comprehensive Cancer Network (NCCN) has published its recommendations for pediatric central nervous system (CNS) cancers, the leading cause of cancer-related death among children.

The recommendations, the fifth pediatric-specific set of guidelines offered by NCCN, follow the World Health Organization’s recent update to its classifications of CNS tumors to now include a structure for pediatric patients with CNS tumors. Within the recommendations, the network proposes a process that includes histologic, immunohistochemical, and molecular examination.

In the recommendations, NCCN emphasized the use of broad molecular testing for pediatric patients, as there is high degree of histologic overlap and nonspecificity of histologic features among pediatric tumors, in contrast to adult cases where molecular workup has narrowly focused on distinguishing between IDH-mutant and IDH-wild-type gliomas. The network underscored that underlying molecular alterations in pediatric cases are distinct from those seen in adult cases.

Testing strategies highlighted by NCCN include next-generation sequencing to identify fusions in ROS1, MET, NTRK1/2/3, ALK, and FGFR1/2/3; RNA sequencing; and high-resolution copy number assays. The network noted that while DNA methylation-based analysis may aid in objective and more precise tumor classification, it should not be used as first-line testing.

The network also highlighted the use of germline testing, which they say should be “strongly considered” in appropriate cases. However, they flagged that not all sequencing assays can readily distinguish between germline and somatic variants.

“Treating children with cancer is very different from adults, particularly for CNS tumors. We need to be extra careful to not impact physical and cognitive development and to protect against long term side-effects,” said NCCN Guidelines for Pediatric CNS Cancers Panel Chair Amar Gajjar, MD, Chair of the Department of Pediatrics, St. Jude Children’s Research Hospital, in a statement from the network. “For instance, radiation is a key component when treating adults, but options to avoid or reduce radiation in young children are important, especially those under age 3. These guidelines provide a snapshot of how leading experts from across the country are applying the current evidence to recommend the best approach for infants, young children, and adolescents into early adulthood.”

For adjuvant treatment, the recommendations include chemotherapy regimens as preferred regimens, with targeted therapies and immunotherapy included as other recommended regimens, including larotrectinib and entrectonib for TRK fusion-positive tumors; dabrafenib/trametinib and vemurafenib for MRAF V600E mutations; and nivolumab and pembrolizumab for hypermutant tumors. Targeted therapies and immunotherapy are recommended as the preferred regimen in cases of recurrent or progressive disease.

In NCCN’s statement, Gajjar indicated that the network plans to update these guidelines at least once a year.

Anita Mahajan, MD, Mayo Clinic, vice-chair of the NCCN Guidelines Panel for Pediatric CNS Cancers, added: “We’re planning to expand the guidelines to include other CNS tumor types. Right now, the science is advancing as we learn more about how to differentiate and characterize these tumors. In the future, with more trial results coming in, we anticipate an increase in personalized medicine with treatments targeted to the specific patient and tumor.”