Background
* Breast cancer (BC) is the most common cancer among women and the second leading cause of cancer-related deaths in women.
* Among the four common metastatic sites of BC - liver, lung, bone, and brain - brain metastases result in the most severe adverse effects and poorest survival outcomes.
* Despite robust preclinical data on potential drugs for brain metastasis prevention, designing prevention trials remains challenging due to the difficulty of identifying high-risk populations, the long time required for outcomes to develop, and the associated costs.
* Circulating-tumor DNA (ctDNA) from cerebrospinal fluid (CSF) collected from patients who had been locally treated for brain metastases and showed no evidence of metastases on MRI displayed a distinct mutation profile compared to plasma collected at the same time.
Primary Objective
-To collect CSF samples from participants with metastatic triple negative breast cancer (TNBC) and HER2+ breast cancer (BC) with no prior history nor active radiographically detectable brain metastases
Eligibility
* Confirmed metastatic HER2+ BC or TNBC
* Age \>=18 years
Design
* This pilot, single-site tissue collection trial aims to collect CSF samples for analysis as potential predictors of brain metastases.
* CSF, blood, tumor tissue, and saliva or buccal mucosa will be collected at baseline and optionally during the study.
* All participants will be followed up for brain metastasis development every 6 months for up to 3 years.
