Biom-51. Factors Associated With Declining Sex Discrepancy in Meningioma With Increasing Tumor Aggressiveness: Retrospective Review of a Rural Pennsylvania Cohort

Abstract

INTRODUCTION Meningioma is the most common benign primary brain tumor in adults comprising 37% of all primary CNS tumors. Approximately 81.1% of meningiomas are grade I, 16.9% - grade II, and 1.7% - grade III. While females are 2.5 times more likely to have meningiomas, males more commonly have aggressive grades. Loss of progesterone receptor (PR) and presence of androgen receptor (AR) are associated with tumor aggressiveness. We observed a declining sex-discrepancy with increasing tumor grade. We present an ongoing assessment of a rural population to define potential factors contributing to this observation. METHODS We completed a single institutional retrospective review of 406 pathology confirmed meningiomas in rural Northeast Pennsylvania. We compared WHO grade, hormone receptors, and proliferative indices between males and females. We further evaluated tumor location and comorbid endocrine disease for possible association. RESULTS Our patient cohort had a high frequency of aggressive tumors 73.5% (n= 297) grade I, 24% (n= 99) grade II, and 2.5% (n= 10) grade III. The ratio of females versus males was 3.1:1, 1.3:1, and 1:1 in grades I, II, and III respectively. Factors contributing to closing the sex-gap were: (1) grade II: males expressed less PR than females (76% vs 94%); (2) grade III: females expressed less AR than males (0% vs 100%), while PR expression remained equivalent; and (3) males had higher tumor proliferative indices compared to females (7% and 22% vs 2% and 14%), grades I and II respectively. There was no relationship determined for tumor location or comorbid endocrine disease between the sexes. CONCLUSION The association between declining sex discrepancy in meningioma with increasing tumor aggressiveness is potentially related to the expression PR, AR, and increased tumor proliferation indices with increasing meningioma grade.