HSR22-134: Outcomes of Patients who Received Radiation Therapy for Brain Metastases From Gynecologic Malignancies

Background: Even among patients with stage IV gynecologic cancers, metastases to the brain are rare and prognosis remains poor. Given the paucity of data, this study aimed to describe the outcomes of this patient population who underwent radiation therapy (RT). Methods: Retrospective data was collected on 66 patients with a primary diagnosis of gynecologic cancer who received RT for brain metastases (BM) at a single institution from 2001-2021. Survival analysis was performed using Kaplan-Meier method with differences compared by the log-rank test, and a multivariate Cox proportional hazards regression model was generated. Results: The median age was 61 years (range 30-90). 97% of patients had neurologic symptoms at presentation. 14% of patients had cervical cancer, 35% ovarian, 46% uterine, and 6% vulvar or vaginal. The median follow up was 4.2 months (IQR 2.2-9.8), and the median overall survival (OS) was 4.3 months (range 0.8-88.9). At diagnosis of BM, 54 patients had extracranial disease (ED); of those, 80% had distant progression, 15% stable ED, 2% local progression, and 4% were previously untreated. Patients with ED had lower median OS (3.8 vs. 18.7 months, p=.02), and control of ED was not associated with OS (p=.88). 25 patients underwent surgery with post-operative RT and 41 received radiation alone, with no significant difference in type of RT delivered between groups. The median OS for those with and without surgery was 6.6 vs. 3.5 months, respectively (p=.05). The median size of the largest BM was 3.0 cm (range 0.7-8.9), and more patients with BM >3cm underwent surgery (67 vs. 33%, p<.001). Regarding RT, 58% of the overall cohort received whole brain radiation therapy (WBRT), 27% stereotactic radiosurgery (SRS), and 14% both; the respective median OS were 2.7, 7.0, and 9.8 months (p=.002). Overall, 32% of patients had a single BM, 49% 2-10, and 15% >10; the median OS were 7.5, 4.2, and 2.7 months, respectively (p=.05). More patients with 2-10 BM received WBRT compared to SRS (65 vs. 35%, p=.01), and no patients with >10 BM received SRS. On multivariate analysis of patients who had 10 or less BM, WBRT was associated with worse survival compared to SRS (HR 2.75, 95% CI 1.26-6.01). Conclusion: Presence of extracranial disease in patients with brain metastases from gynecologic cancers may portend a particularly poor prognosis. Stereotactic radiosurgery for limited brain metastases may be appropriate in select patient groups.