Factors impacting survival after diagnosis of breast cancer (BC) brain metastases (BM).

Abstract

31 Background: With improvements in control of systemic disease, subsets of breast cancer patients (pts) including those with HER2+ and triple negative (TN) BC appear to have an increased risk of BM. We sought to evaluate factors influencing outcomes after diagnosis of BM. Methods: We collected treatment information and outcomes for pts diagnosed with BM who received ongoing care at our center from 1997 to 2011. We correlated clinical, treatment, and pathologic characteristics including age, hormone receptor (HR) and HER2 status, Karnofsky Performance Score (KPS) and number of BM (#BM) at diagnosis with outcomes. Patients were characterized as one of three subtypes: HR+/HER2+, HER2+, or TN. Results: 184 patients are included in this analysis. Median time to BM diagnosis (TTBM) was 38.8 months (mo) (range, 0–274); median survival (OS) after diagnosis of BM was 14.9 mo. Both varied by tumor subtype. Multivariate analysis revealed that TN disease, age >50 and KPS <90 were associated with decreased OS after diagnosis of BM. Progression of systemic disease and >3 BM at diagnosis were univariate predictors of decreased OS (P=0.0005 and P=0.02 respectively) but were not significant in multivariate analysis. Pts treated with gamma knife (GK) as initial therapy followed by whole brain radiation therapy (WBRT) as salvage had similar OS to patients who received WBRT first then had GK as salvage (31.8 vs. 28 mo). Patients who received WBRT or GK only had worse OS (7.7 and 16.3 mo respectively). Since the year 2000, OS after diagnosis of BM remained relatively constant. Conclusions: Underlying tumor biology appears to drive outcomes, and patients with TN BC continue to have a poor prognosis after BM diagnosis. Despite the reported improvement in OS following BM diagnosis compared to previous decades, we did not observe a reduction in risk of death based on calendar year of diagnosis of BM. [Table: see text]