Highlights
Breast cancer is a complex disease arising from the association and cumulation of multiple genetic alterations and environmental factors likely to alter cellular functions.
The implication of stem cells in breast cancer’s origin and development has been debated for many years. Analogies between stem cells and cancer cells can be drawn on many levels. Importantly not all cancer cells are stem cells or exhibit properties similar to stem cells.
There is no universal cell surface marker of the breast cancer stem cells, imputable to the diversity of the cell of origin, the heterogeneity and fluidity of the microenvironments, and a plethora of possible mutational events.
Breast cancer stem cell targeting should hold a great promise for preventing metastasis, reducing the risk of drug resistance, and decreasing recurrence. However, only a few clinical trials assess the effectiveness of treatments on this specific cancer cell population.
Additional considerations for the targeting of breast cancer stem cells need to be given to the tumor microenvironment. It is known to promote self-renewal, plasticity, and resistance to treatments. The fate of breast cancer stem cells is indissociable from its environment.