EANO guideline on rational molecular testing of gliomas, glioneuronal and neuronal tumors in adults for targeted therapy selection

The mainstay of treatment for adult patients with gliomas, glioneuronal and neuronal tumors consists of combinations of surgery, radiotherapy and chemotherapy. For many systemic cancers, targeted treatments are a part of standard of care, however the predictive significance of most of these targets in CNS tumors remains less well studied. Despite that, there is an increasing use of advanced molecular diagnostics that identify potential targets, and tumor agnostic regulatory approvals on targets also present in CNS tumors have been granted. This raises the question when and for which targets it is meaningful to test in adult patients with CNS tumors. This evidence based guideline reviews the evidence available for targeted treatment for alterations in the RAS/MAPK pathway (BRAF, NF1), in growth factor receptors (EGFR, ALK, FGFR, NTRK, PDGFRA, ROS1), in cell cycle signaling (CDK4/6, MDM2/4, TSC1/2) and altered genomic stability (mismatch repair, POLE, high TMB, HRD) in adult patients with gliomas, glioneuronal and neuronal tumors. At present, targeted treatment for BRAF p.V600E alterations is to be considered part of standard of care for patients with recurrent gliomas, pending regulatory approval. For approved tumor agnostic treatments for NTRK fusions and high TMB, the evidence for efficacy in adult patients with CNS tumors is very limited, and treatment should preferably be given within prospective clinical registries and trials. For targeted treatment of CNS tumors with FGFR fusions or mutations, clinical trials are ongoing to confirm modest activity so far observed in basket trials. For all other reviewed targets, evidence of benefit in CNS tumors is currently lacking, and testing/treatment should be in the context of available clinical trials.