Circulating Tumor Cells: Detection Methods and Potential Clinical Application in Breast Cancer

Circulating tumor cells (CTCs) are defined as tumor cells circulating in the peripheral blood of patients. CTCs have long been regarded as an attractive research topic. Because of recent technological advances, it is now possible to detect CTCs in the bloodstream. Interestingly, CTCs are present in both of patients with metastatic disease and early stage localized disease in patients with breast cancer. An assay detecting CTCs seems to have significant future potential value in the clinical management of breast cancer as a prognostic marker, monitoring treatment response and selecting target therapy. This review addresses the technical overview of detection methods, possible clinical application and future direction of CTCs research.