China CellSearch Study

A longitudinal, multi-center, prospective study will be conducted in MBC patients to evaluate the ability of CTC to predict the patients' prognosis. A separate population of healthy and benign disease subjects will serve as controls to compare the CTC incidence in this control group versus the MBC group at baseline. Correlation between CTC and radiographic response to the systemic therapies in the MBC study group will also be assessed. 300 MBC patients, each of whom will provide a series of at least 3 blood draws (baseline, 3-4 weeks and 6-8 weeks after the initiation of the systemic therapy) for CTC analysis, will be enrolled. All MBC patients will be followed for a maximum of 36 months for disease progression and survival. 200 healthy and benign disease volunteers, each of whom will donate blood 1 time for CTC analysis, will be enrolled as controls.