ABSTRACT
Cancer stem cells (CSCs) have been a focus of research and controversy for over a decade. CSCs are thought to be a small subpopulation of self-renewing stem cells within a tumor or blood-borne cancer, which are responsible for maintaining and growing the malignancy. The concept has profound clinical implications. However, although experimental evidence for CSCs has accumulated, clinical translation of these results has been lacking. This paper examines conceptual and evidential challenges blocking clinical translation of CSC, and proposes a way forward. The solution is to distinguish two CSC concepts with different substantive content, suited to their respective purposes and criteria for success: basic and clinic-oriented. Successful clinical translation requires empirical validation of the latter. I indicate how such evidence could be obtained, building on existing experimental support for the basic CSC model.
