Background: More effective systemic therapies in metastatic breast cancer treatment has led to increased response rates, progression-free survival and overall survival (OS).  It is of importance to identify biological or treatment-related factors which may predict for CNS occurrence.

Methods:  Consecutive patients with breast cancer seen at 2 institutions from January 2000 (institution A) and January 2003 (institution B) to December 2012. Patient demographic data, tumour pathology and systemic treatment  were reviewed in patients who developed CNS recurrence.

Results: Of 4751 patients, 12.6% had metastatic disease at presentation. 228 (4.8%) of all patients developed CNS metastases. The proportion of patients developing CNS recurrence according to tumour subtypes were: 48% hormone receptor positive, 36% Her2 positive, and 20% triple negative. Median time from diagnosis to CNS recurrence was 44.9 months. The median time to CNS recurrence was 54, 43, 22.8m respectively according to tumour subtype. Median OS from diagnosis was 53.6m but from CNS recurrence, median OS was 4.8m. The impact of surgical resection of brain metastases and type of systemic therapy following developing of CNS disease on OS will be presented.

Discussion: Despite improvements in OS of metastatic BC with the use of systemic treatment, the prognosis following CNS recurrence remains extremely poor.