Prognostic factors of brain metastasis and subsequent survival in breast cancer patients: An 11-year, single-center, retrospective study

Female breast cancer is among the most prevalent cancers globally, often metastasizing to the brain. Despite advancements in treatment, brain metastasis incidence is rising, with a poor prognosis. Moreover, limited data exist on how breast cancer subtypes and patient characteristics impact survival. This study aimed to investigate prognostic factors affecting breast cancer patients with brain metastasis. We retrospectively reviewed 131 breast cancer patients with brain metastasis diagnosed at a single institution between 2010 and 2020. Demographic, clinical, pathological, and radiographic variables were analyzed. The median interval between breast cancer diagnosis and brain metastasis was 27 months. Patients diagnosed with a higher stage of breast cancer (median survival: stage 1: 97.2 months, stage 2: 44.4 months, stage 3: 38.1 months, stage 4: 13.0 months, P < .001) and those with ER-negative tumors (median survival: negative 25.3 months, positive 37.5 months, P = .034) had a shorter time between initial diagnosis and brain metastasis. Median survival after brain metastasis was 8.0 months. Multivariate analysis showed that triple-negative breast cancer was correlated to a high risk of death after brain metastasis (hazard ratio = 2.320, P < .001). Higher histological grade, low-performance status, extensive brain metastases, and leptomeningeal seeding was associated with shorter survival. Systemic chemotherapy after brain metastasis was the only treatment that improved survival (hazard ratio = 0.332, P < .001). The study suggests potential benefits of aggressive treatment, especially in nontriple-negative breast cancer subtypes, limited brain metastases, and good overall health. Further research with larger patient populations is needed.