P13.10.A THE EPIDEMIOLOGICAL AND CLINICAL CHARACTERISTICS OF MENINGIOMAS IN AYA PATIENTS.

Abstract INTRODUCTION Central nervous system tumors are the third cause of morbidity and the fifth cause of mortality in Adolescent Young Adults (AYA) patients. The incidence of meningioma in this age group is low, 1.5-2.38 /100000 and little is known regarding the characteristics of meningioma in this age group. The aim of the study was to characterize this group of patients. METHODS We retrospectively evaluate the electronic medical records (EMR) of patients with meningioma younger than 40 year old at diagnosis who were treated in Sheba medical center between 2014-2024. Clinical data was extracted from the EMR using SQL software, OncoMind RWD of the Jusidman Cancer Center in Sheba medical center. Patients with Cancer Predisposition Syndromes (CPS) or a single hospital visit were excluded from analysis. RESULTS Of the 62 patients identified in our databases 74% were females and 26% were males (2.8: 1 ratio). The mean age at diagnosis was 29/27 years for females/males respectively (p = 0.76). Three patients were exposed to radiation therapy in childhood due to other CNS tumors. Ten female patients were diagnosed during pregnancy or shortly after childbirth and one patient was diagnosed after a period of fertility treatments (20%). The tumors were incidental findings in 4 female and 6 male patients. All tumors except two were intracranial. The intracranial locations of the lesions were 43.8% convexital, 25% base of the skull, 10% Tubercullum sella, 16.7% posterior fossa and 2%-Optic Nerve Sheath Meningioma (ONSM) in the female population; and 46.6% convexital, 20% skull base, 13.5% posterior fossa and ONSM each and only 1 lesion in the Tubercullum sella in the male group (χ² = 6.4, p = 0.04). In both groups, 50% of the convexital processes were frontal. Thirty three patients (40% / 58.3% male/ female respectively) underwent a surgical intervention and a pathological diagnosis was available. Of these, WHO2 tumors were diagnosed in 32% / 28% of females/males respectively, WHO 3 tumors were diagnosed only in females (4%). Fisher’s exact test showed no significant sex difference in WHO 2-3 tumor rates (p = 1.00). One of the WHO3 tumors underwent transformation to sarcoma at recurrence and another - developed systemic metastases. Advanced molecular tests were performed in 14 patients. The first line of treatment was surgery in 56% of patients, radiotherapy in 9.6% and follow up in 33.8%. Most of the patients were under neurosurgical follow-up only. CONCLUSION Our findings indicate that meningiomas in the AYA population may represent a distinct clinical entity suggesting underlying biological or developmental distinctions and possible hormonal influence. The low incidence of the disease and the paucity of pathological information in light of non-surgical treatment preferences constitute a challenge in making treatment decisions at this age and require international collaborations in clinical studies.