Sites of distant recurrence and clinical outcomes in patients with metastatic triple-negative breast cancer: high incidence of central nervous system metastases.

BACKGROUND: The purpose of the current study was to characterize the outcomes of patients with metastatic triple-negative breast cancers, including the risk and clinical consequences of central nervous system (CNS) recurrence.
METHODS: Using pharmacy and pathology records, a study group of 116 patients who were treated for metastatic triple-negative breast cancer at Dana-Farber Cancer Institute between January 2000 and June 2006 was identified.
RESULTS: The median survival from time of metastatic diagnosis was 13.3 months. Sixteen patients (14%) were diagnosed with CNS involvement at the time of initial metastatic diagnosis; overall, 46% of patients were diagnosed with CNS metastases before death. The median survival after a diagnosis of CNS metastasis was 4.9 months. The age-adjusted and race-adjusted rate of death for patients whose first presentation included a CNS metastasis was 3.4 times (95% confidence interval, 1.9-6.1 times) that of patients without a CNS lesion at the time of first metastatic presentation. Of the 53 patients who developed brain metastases, only 3 patients were judged to have stable or responsive systemic disease in the face of progressive CNS disease at the last follow-up before death.
CONCLUSIONS: Triple-negative breast cancer is associated with poor survival after recurrence. CNS recurrence is common, but death as a direct consequence of CNS progression in the setting of controlled systemic disease is uncommon. Thus, it does not appear that the high rate of CNS involvement is because of a sanctuary effect, but rather is due to the lack of effective therapies in general for this aggressive subtype of breast cancer. New treatment strategies are needed.