Brain metastases in breast cancer: clinical and pathologic characteristics associated with improvements in survival.

Background: As breast cancer patients live longer with control of systemic disease, survival after the diagnosis of brain metastases (BM) also appears to be improving.

Methods: The authors conducted a retrospective review of 112 breast cancer patients diagnosed with BM from 1997 to 2007 and correlated clinical and pathologic characteristics including hormone receptor (HR) and Her2/neu status with outcomes.

Findings: Median time to BM diagnosis (TTBM) was 38 months (range, 0-204 months). TTBM was shorter for patients with HR- versus HR+ disease (median 28.8 vs. 61.2 months, P < 0.001, Wilcoxon test). No difference in TTBM was observed for patients with HER2- versus HER2+ disease (median 37.4 vs. 34.9 months, P = 0.81). Median survival after the diagnosis of BM was 14.4 months. There was no significant difference in median survival after BM diagnosis for patients with HR+ versus HR- cancers (19.9 vs. 11.0 months, P = 0.18, log rank) or for patients with HER2+ versus HER2- disease (23.1 vs. 13.3 months, P = 0.11, log rank). Survival was significantly longer in patients with stable or responding systemic disease at BM diagnosis compared to patients with progressing systemic disease (31 vs. 6.3 months, P < 0.001). Multivariate analysis revealed that HR positivity, age <50, Karnofsky Performance Score (KPS) > or =80, and stable or responding systemic disease at BM diagnosis were associated with improved survival.

Interpretation: Subsets of patients with breast cancer BM are surviving longer. Control of systemic disease was most strongly associated with improved outcomes, and HER2/neu overexpression did not shorten survival after the diagnosis of BM.