Impact of chemotherapy and radiation therapy on local control and survival of metastatic breast cancer to the brain: Single-institution review of 792 cases.

146 Background: There are various treatment modalities for metastatic breast cancer to the brain (MBC-b), with wide variation of reported outcomes. Methods: There were 1,513 patients (pts) with MBC-b treated at MD Anderson Cancer Center October 2009-December 2012. We reviewed medical records of the first consecutive 1015 and included 792 with confirmed brain metastases (BM). A Cox multivariate model was used to identify the effect of treatment on time-to-progression in the brain (TTP-b) and overall survival (OS). Results: Disease subtypes: ER+/HER2- (27%); ER+/HER2+ (16%); ER-/HER2+ (18%); ER-/HER2- (29%), missing (10%). Number of BM: 1 (20%), >1 (73%), missing (7%). Local treatment: metastasectomy (S) (13%), radio-surgery (SRS) (12%), whole-brain radiation (WBRT) (57%), combination of S/SRS with WBRT (11%), no treatment (7%). Systemic treatment: Any (64%), HER2 directed (24%). Median OS was 11.33 months(m) (4.4-25.8). Clinical characteristics associated with OS in multivariate analysis: ER+, HER2+, age <...