[The role of breast cancer stem cells in metastasis].

Cancer stem cells (CSCs) possess self-renewal and heterogeneous cancer cell lines formation. Numerous data confirm the existence of a model in which CSCs have an important role in cancer initiation, progression and clinical outcome. Analysis of CSCs role in metastasis, in contrast, remains mainly conceptual and hypothetical. Recent data are summarized in this review which support the CSCs theory as a source of breast cancer metastatic lesions with noting the key role of the microenvironment.