Relevance of Stem Cells

The realization that, in addition to genetic and epigenetic events, the phenotypic and functional heterogeneity of breast cancers is also a function of their organization in a hierarchy of self-renewing cancer stem cells that drive tumorigenesis, while spawning a heterogeneous population of nontumorigenic progenitors, has resulted in a paradigm shift in our understanding of the underlying biology of breast cancer. By virtue of their intrinsic resistance to conventional radiation and cytotoxic therapies, breast cancer stem cells are also posited to contribute to disease progression and recurrence, eventually after transient therapy response. Therefore, a more complete understanding of the biology of breast cancer stem cells holds great promises for the identification of new prognostic and therapeutic biomarkers and for the development of new targeted anticancer stem cell therapies in the perspective of the personalized management of breast cancer.