Abstract 2229: Clinico-pathologic analysis and survival of patients with breast cancer diagnosed with de novo brain metastasis: An NCDB-based analysis

Abstract Introduction: Patients with breast cancer with brain metastasis (BCBM) have poor survival outcomes. In this study, we aimed to explore the clinico-pathologic and therapeutic factors predicting the survival in de novo BCBM patients using the National Cancer Database (NCDB). Methods: The NCDB was queried for patients with BC between 2010-2020. Survival analysis with Kaplan-Meier curves and log rank tests were used to find median overall survival (OS) in months (95% CI) across the different variables. A multivariate cox regression model was computed to identify significant predictors of survival. All values in the results were statistically significant at p0. 05. Results: N=9, 005 (0. 34%) had de novo BM out of 2, 610, 598 BC patients with a median OS of 10. 9 (10. 3-11. 5). A trend of decreasing median OS was observed with increasing age: highest in the ≤50 group at 18. 96 (16. 92-20. 86) and lowest in the ≥70 group at 4. 70 (4. 07-5. 29), Charlson-Deyo score (CDS): 12. 42 (11. 76-13. 17) in the 0 score and 2. 86 (2. 17-3. 78) in ≥3 score, and number of extracranial metastatic sites (EMS): 13. 17 (12. 02-14. 36) in the 1 site and 7. 59 (6. 70-8. 84) in the ≥3 sites group. The HR (+) /HER2 (+) subgroup had the highest median OS at 22. 05 (18. 73-24. 67) compared to the lowest in the HR (-) /HER2 (-) group at 5. 62 (5. 19-6. 18). Based on treatment regimen, surgery + whole brain radiation therapy (WBRT), chemotherapy + hormonal therapy + immunotherapy (biologic therapy including anti-HER2), and combination of BM + BC therapy achieved the highest median OS in their respective subgroups of 32. 33 (23. 98-40. 44), 42. 35 (35. 48-54. 14), and 16. 30 (15. 11-17. 38), respectively. Similar trends were found in the BC subgroup analysis with immunotherapy demonstrating a survival benefit when added to systemic therapy. The multivariate cox regression model showed that age, race, ethnicity, insurance, median income, facility type, CDS, BC subtype, metastatic location sites, and treatment combinations received were significantly associated with risk of death. Age ≥70 years, CDS ≥3, ≥3 EMS, and receiving no treatment for either BM or BC had the highest risks of death with Hazard Ratio (95% CI) of 1. 53 (1. 31-1. 79), 1. 74 (1. 39-2. 18), 2. 06 (1. 78-2. 38), and 2. 65 (2. 36-2. 98), respectively. The HR (+) /HER2 (+) subgroup had the lowest risk of death at 0. 43 (0. 38-0. 49) and receiving only local treatment for BM increased the risk of death 2. 3 (2. 00-2. 63). Conclusions: This analysis suggests that treatment of systemic disease is the major factor influencing survival in BCBM patients and surgery + WBRT yields the best survival outcomes. Moreover, anti-HER2 therapy and biologic treatment increased survival when added to systemic therapy. To date, this represents the biggest cohort of de novo BCBM survival analysis which provides critical insights that may guide clinical management. Citation Format: Ali Hijazi, Mohamed Mohanna, Saad Sabbagh, Maria Jose Herran Montes, Barbara Dominguez, Kaylee Sarna, Zeina Nahleh. Clinico-pathologic analysis and survival of patients with breast cancer diagnosed with de novo brain metastasis: An NCDB-based analysis abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 2229.