89P A single-centre retrospective study of patients with brain metastases and gynaecologic cancers

Brain metastases (BrM) among patients (pts) with gynecological cancers (GC) have historically been considered rare events. We aimed to characterize treatment patterns and outcomes of pts with GC and BrM. We conducted a retrospective analysis of pts with GC and BrM who were treated with whole brain radiotherapy (WBRT) or stereotactic radiation (SRS) to the brain at the Sunnybrook Odette Cancer Centre, Toronto between 2010 and 2022. Analyses were performed using R software. Median follow up from time of BrM development was 7.5 (range 2.9 - 15) months. We identified 94 pts with BrM who had primary GC. Median age at time of BrM diagnosis was 66 (range 30-85) years. Median time from primary GC cancer diagnosis to BrM development was 28.5 (range 0 - 218) months. Presentation of BrM was with neurologic symptoms (96%, n=90) and multiple BrM (62%, n=58). All patients received radiotherapy; 63% (n=59) underwent SRS delivered in 1 to 5 fractions, and 36% (n=34) received WBRT; 40% (n=38) also had surgery for BrM. Patients with endometrial cancer (EC) accounted for 54% (n=51) of cases, ovarian cancer (OC) 26% (n=24), cervical cancer 17% (n=16). Among pts with EC, 41% had endometrioid (n=21) histology, 24% serous (n=12), 14% carcinosarcoma (n=7) and sarcoma 7.8% (n=4). Where status was known, BrM occurred in 33% (n=4/12) of patients with mismatch repair protein deficiency and 84% (n=10/12) of patients with protein TP53 overexpression. High grade serous (HGSC) was the most common subtype of OC, (83%, n=20). Both squamous 44% (n=7) and adenosquamous 31% (n=5) histology were observed among pts with cervical cancer (CC). Two pts with neuroendocrine CC developed BrM. Median overall survival (OS) from the time of BrM diagnosis was 10.6 months (0.1-143). The median OS among pts with OC and BrM (27.2 months) was longer than for those with EC (7.6 months) or CC (5.8 months), p=0.0034. Among pts with GC and BrM in our cohort, the most common primary malignancy was EC and about two thirds of pts were treated with SRS. Patients with OC and BrM lived longer than those with other primary GC. Investigation of molecular events that "drive" the development of BrM among pts with GC is warranted.