Collection of Circulating Tumor Cells From the Peripheral Blood of Metastatic Breast Cancer Patients

To address the challenges of isolating and analyzing rare cells, this study aims to validate the instrumentation, the test protocols, and the analysis of patient's outcome to show the instrument's capability to reproducibly and accurately detect CTCs in cancer patients. In order to facilitate the validation process, investigators will only focus on metastatic patients for whom CTCs supposedly present at higher abundance. Investigators propose to enroll cohorts of metastatic breast cancer patients. Blood samples will be collected from these patients before they start any new line of therapy as determined by their doctors. The specific aims are to isolate, enumerate and analyze the number and/or molecular information of circulating tumor cells in patient blood using microfluidic chip-based sorting, imaging, and molecular profiling techniques. Investigators will use this study to optimize diagnostic instrumentation, test blood processing protocols and CTC analysis algorithm. During this study investigators will collect patients' clinical information related to cancer, as well as the patients' survival status to validate the system's prognosis ability.