Cancer stem cells as a potential therapeutic target in breast cancer.

Cancer stem cells (CSCs) are defined as the small population of cancer cells that have stem cell properties as in hierarchically organized tumors. They are considered as the source of tumor initiation and maintenance. These cells are highly resistant to current cancer treatment and may be responsible for the disease recurrence after therapy as well. Therefore, considerable efforts have been made to elucidate the molecular and pathological properties of the CSCs to develop effective therapies targeting CSCs. A growing body of experimental evidence has revealed that therapeutic targeting CSCs may offer a new strategy for patients with breast cancer (BC). In this review, we summarized the evidence for existence of CSCs, followed by an overview of their molecular biomarkers, signaling pathways and potential therapeutic strategies to target these CSCs in BC.