Breast cancer brain metastases - A 12 year review of treatment outcomes

BackgroundBreast cancer (BC) is the 2nd commonest cause of brain metastases (BM). This retrospective review investigates the applicability of prognostic scores and highlights different outcomes for patients with HER2 positive compared to triple negative (TN) subtypes.MethodsTwo hundred and seventy four patients received whole brain radiotherapy for BC BM (01/2000-12/2011). The primary objective was to determine factors influencing overall survival (OS). All information relevant to primary BC, disease recurrence, treatment, outcome and cause of death (either neurological (NP) or systemic progression (SP)) were collected. Univariate (UV) and multivariate (MV) Cox regression analysis were used.ResultsOne hundred and forty four patients (53%) were ER positive, 104 (38%) HER2 positive and 57 (21%) TN. Median age at BM was 53 (27-81) years and median OS from BM diagnosis 7.3 (5.7-8.9) months.On MV analysis, Her2 status, RPA score, surgery, stereotactic radiotherapy, and absence of TN disease were independent prognostic factor for OS. NP was the cause of death in 69.2% of HER2 positive patients and 17.3% had SP. Of the TN patients, 29.8% had NP and 54.4% SP (p < 0.001).ConclusionA consistent OS advantage is noted for HER2 positive BM cases and inclusion of BC subtype in the breast GPA score should improve the prognostic factors' sensitivity. The unique presentations, response to treatment and causes of death for HER2 positive patients means more aggressive focal therapy should be considered and studied in the context of clinical trials. For TN BM patients with poor performance status, best supportive care may be appropriate.