EPID-13. CHARACTERIZATION OF PEDIATRIC RADIATION-INDUCED MENINGIOMA: A SEER ANALYSIS

Abstract

Abstract OBJECTIVE Radiation-induced meningiomas (RIM) are the most common secondary neoplasm arising from radiation therapy. RIM have not been characterized in pediatric populations on a national scale despite displaying shorter latency and higher malignancy rates in institutional studies. The objective of this study was to characterize pediatric RIM and compare latency and malignancy rates to those of adult RIM using the National Cancer Institute’s Surveillance, Epidemiology and End Results Program (SEER) database. METHODS From the SEER Research Plus Nov 2020 (1975-2018) dataset, 56161 patients treated with EBRT for ocular/orbital tumors, brain/nervous system tumors, and leukemia were identified. 185 patients meeting criteria for RIM were selected: cranial/spinal EBRT (presumed from diagnostic indication), histologically distinct precedent tumor treated with EBRT, and a minimum 5-year latency from EBRT to meningioma diagnosis. This sub-population was divided into 2 groups – pediatric (ages 0-19, n = 10) and adult (ages > 20, n = 175) RIM – and latency, recurrence rate and multiplicity were compared for each group. The number of tumors classified as malignant (as opposed to benign or borderline malignant) was also compared between groups. Additionally, demographic data were compared for each group. RESULTS Of the pediatric RIM patients, 70% were male, 70% were Caucasian, and 10% were African American. No pediatric RIM patients experienced a recurrence or presented with multiple RIMs. The pediatric group showed lower latency (11.00 ± 1.94 years, p < 0.001) and a higher malignancy rate (30%, p = 0.002) than the adult group (latency of 23.38 ± 8.69 years; malignancy rate 5.1%). CONCLUSION These data represent the first characterization of pediatric RIM from a national database and support prior findings of shorter latency and higher malignancy rates in pediatric vs adult RIM, as well as lay the groundwork for future nationwide monitoring of this rare yet highly significant complication.