Abstract BACKGROUND Brain tumors are the leading cause of cancer-related death in adolescents and young adults (AYA). These tumors possess both pediatric-type and adult-type qualities, with up to 30% of gliomas harboring pediatric-type alterations. Specialized expertise and significant collaboration between pediatric and adult providers is needed to guide therapy for AYAs. To address this, we have developed the Canadian Adolescent and Young Adult Neuro-Oncology Network (CANON). METHODS In April 2021, we established a national virtual AYA tumor board integrating comprehensive molecular analysis of available tumors. Rounds included representatives from both pediatric and adult neuro-oncology, radiation oncology, neurosurgery, neuropathology and neuroradiology. We collected clinical data and recommendations from rounds. RESULTS In the first 2 years of rounds through CANON, 156 cases have been reviewed. Gliomas (108) accounted for most cases followed by medulloblastoma (18) and ependymoma (7). Sequencing was available in 47% of cases. Of those with molecular data available, the majority (36) had a pediatric-type alteration, followed by IDH mutation (10). Additional molecular analysis was recommended in 29% of cases presented. Of those with sequencing data available, 35% had a potentially targetable alteration identified. Despite this, only 8% were eligible for a clinical trial based on their diagnosis and age. Recurrent clinical questions included access to molecular analysis, use of “off-label” targeted agents, lack of clinical trial options for AYA patients and the practice variation in treatment of AYA tumors typically seen in childhood such as medulloblastoma and germ cell tumor. DISCUSSION Dedicated AYA rounds have highlighted many inequities in care of these patients, highlighting a need for inclusion of AYAs in clinical trials and further study of tumor biology and clinical outcomes of this cohort. AYAs with pediatric-type tumors would also benefit from management by dedicated physicians with expertise in these complex tumors.

OTHR-21. DEVELOPING A NEURO-ONCOLOGY PROGRAM FOR ADOLESCENTS AND YOUNG ADULTS IN CANADA – THE CANON EXPERIENCE