Abstract P6-11-10: Central nervous system metastases in breast cancer: Impact of tumour sub-type and outcome from current treatments

Abstract

Abstract Background: The use of more effective systemic therapies in the management of metastatic breast cancer has led to increased response rates, progression-free survival and overall survival. The incidence of central nervous system (CNS) metastases has become an increasingly important area of unmet need. It is important to identify tumour-related factors which may predict for CNS occurrence and assess the efficacy of treatments in current use. Methods: Consecutive patients (pts) with breast cancer (BC) seen at 2 institutions following establishment of breast cancer databases were included: January 2000 (institution A) and January 2003 (institution B) to December 2012. Patient demographic data, tumour pathology and systemic treatment given were reviewed in those patients who developed CNS metastases. Multivariate analysis of factors impacting on overall survival in this patient population will be performed. Results: Over the study period, 4751 pts with a median age of 52.7 yrs were seen, where 86.4% and 13.6% of pts presented with early and metastatic disease, respectively. In the entire population, 77% of tumours were hormone receptor positive, 21% HER2 positive, and 15% triple negative. Overall, 228 (4.8%) pts had CNS metastases with a median age of 48.9 yrs. CNS involvement was present at the time of first metastatic recurrence in 27% of pts who had CNS metastases. The proportion of pts developing CNS metastases according to tumour subtypes were: 48% hormone receptor positive, 36% Her2 positive, and 20% triple negative. Median time from diagnosis to development of CNS metastases (excluding pts with CNS involvement at the time of first metastatic disease) was 48.9 (4.7-248 months, m). The median time to development of CNS recurrence was 61m, 43m, 23m respectively, according to tumour subtype. CNS disease was parenchymal only, leptomeningeal only or both in 78%, 9%, 13% respectively. Pts who died from BC, had a median overall survival from initial BC diagnosis of 53.6m, whereas median overall survival from CNS metastases was 4.8 m. The impact of whole brain radiation with or without stereotactic therapy, surgical resection of brain metastases and type of systemic therapy administered following development of CNS disease on overall survival will be presented. Discussion: CNS metastases occurred in up to 5% of breast cancer pts seen at two large cancer centres. Despite improvements in overall survival of metastatic BC pts with the use of more effective systemic treatments, the prognosis following CNS involvement remains extremely poor. Until specific interventions are available to manage CNS metastases in pts with breast cancer, it remains important to assess outcomes from current standard treatment in these pts. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-11-10.