PATH-17. INCREASING VALUE OF AUTOPSIES IN PATIENTS WITH BRAIN TUMORS IN THE MOLECULAR ERA

Many pediatric brain tumors are associated with high morbidity and mortality, which is due to insufficient understanding of tumor biology. Limited tissue allocation for research from small surgical specimens is a key barrier to improved understanding but brain tumor autopsies have been a valuable resource. This study reviews the brain tumor autopsy practice at our institution, and describes emerging research ultilization patterns beyond the clinical autopsy report.

Brain tumor autopsies in the interval 2007–2017 were identified, and we analyzed the method of tissue triaging for research and documented its specific uses.

Of 1602 deaths at Boston Children’s Hospital (636 with autopsies), 96 had a diagnosis of brain tumor (56 consented for autopsy,). Diffuse intrinsic pontine glioma (DIPG) and other high-grade gliomas accounted for the greatest proportion of diagnoses (52% of brain tumor autopsies). The tumors that resulted in the highest number of autopsies were DIPGs (25 deaths, 21 autopsies). Other frequent diagnoses were atypical teratoid rhabdoid tumors (13 deaths, 8 autopsies) and medulloblastomas (12 deaths, 3 autopsies). Fourteen DIPGs (56%) had tissue samples contributed to the DIPG registry consortium. Mapping was performed on 20 DIPG tumors in order to study heterogeneity; ten underwent whole genome sequencing, RNA expression studies and arrayCGH. Cell lines were successfully generated from 2 DIPGs and 1 ATRT (attempted on 12 autopsies) that had a post-mortem interval of less than 8 hours. CONCLUSIONS: Our institutional pediatric brain tumor autopsy experience demonstrates the increasing utility of autopsy-derived tissue for multiple types of research. Our experience demonstrates a wide utilization of brain tumor autopsy material in translational research, and might encourage research consent for brain tumor autopsy and active collection of unfixed autopsy material in the molecular era.