[Translational approaches in cancer stem cell research]

There has been a growing body of evidence in recent years to indicate that the presence of cancer stem cells may be responsible for tumour development and early recurrence after conventional therapy strategies such as surgery, radiation, or chemotherapy. Although this concept of a small subpopulation of cancer cells with stem cell properties is not new as such and was already discussed by Virchow decades ago, the identification of cells of this kind in human malignancies was first successful in 1997 in acute myeloid leukemia. The recent identification of cancer stem cells and the detection of their fundamental signalling pathways (e.g. Hedgehog, Notch) may offer new therapeutic options in the future and become part of a therapeutic concept. In this article, we introduce the cancer stem cell model, provide an overview of current cancer stem cell markers in different human malignancies as well as head and neck squamous cell carcinoma, and discuss studies on the first targeted therapies against cancer stem cells and their signalling pathways.