O3-029 - Time to Brain Metastasis (TTBM) from Initial Diagnosis of Distant Metastasis in Breast Cancer: Prediction of TTBM According to Breast Cancer Subtypes and Treatment Effect

Abstract

ABSTRACT Background Brain metastasis (BM) from breast cancer (BC) is a growing problem. About 10–15% patients with metastatic breast cancer (MBC) developed BM, with a 1-year survival of 20%. Currently, one-third of MBC patients with either HER2 + ve tumors or triple negative BC (TNBC) tumors develop brain metastases. We hypothesized that MBC patients may predispose to BM differently during the disease courses according to BC subtype and treatment. We analyzed TTBM from initial diagnosis of distant metastasis how BC subtypes and treatment affect on TTBM. Methods We retrospectively investigated 189 consecutive patients who were diagnosed with BM from BC between 2000 and 2009 at Samsung Medical Center. We analyzed TTBM according to BC subtypes and treatment effect. Results The median age of 189 BM patients from BC was 48 (range 26–87) years. The numbers of patients with hormone receptor (HR) + ve and HER2-ve, HER2 + ve irrespective of HR status, and TNBC were 43 (22.8%), 88 (46.6%), and 58 (30.7%), respectively. Median TTBM of all 189 patients was 10.4 (95% CI, 7.7–13.1) months. We analyzed TTBC into four groups considering BC subtypes and treatment; HR + ve/HER2-ve (n = 43), HER2 + ve with trastuzumab (T) (n = 59), HER2 + ve without T (n = 29), and TNBC patients (n = 58). The median TTBMs for each group were 17.7, 13.8, 4.3, and 2.9 months, respectively (P = 0.002). BM as an initial site of distant metastasis was much more common in HER2 + ve without T and TNBC patients than in the other patient groups (40.2% versus 20.6%, P = 0.003). Conclusions TTBMs were much shorter in patients with HER2 + ve without T and TNBCs than in other BC patients. Different approaches for evaluation and therapeutic strategy for BM at the time of distant metastasis may be considered for these populations.