Enumeration and Molecular Characterization of Circulating Tumour Cells in Women With Metastatic Breast Cancer

Inclusion Criteria: * Women with metastatic breast cancer * ECOG performance status 0-2 * Age over18 years * Signed informed concent * Predicted life expectancy over 2 months * Planned for first line systemic treatment for metastatic disease (chemotherapy, antibody treatment or endocrine treatment) * Standard imaging evaluation within 4 weeks of inclusion * Planned for standard imaging within 16 weeks after start of therapy Exclusion Criteria: * Prior medical therapy for metastatic disease (prior adjuvant chemotherapy, radiotherapy or endocrine therapy is permitted) * Inability to understand information about the study * Other malignant disease with the exception of curatively treated basal cell or squamous cell cancer of the skin and cancer in situ of the cervix