Ovarian cancer stem cells: Are they real and why are they important?

- Growing evidence supports the presence of a chemoresistant cancer cell population that relies on stem cell pathways for enhanced survival.
- Examination of patient specimens confirms enrichment of stem cell pathways in surviving tumors.
- Targeting ovarian cancer stem cells is a promising approach to overcoming chemotherapy resistance in this subpopulation of heterogeneous tumors.

The cancer stem cell hypothesis has been put forward as a paradigm to describe varying levels of aggressiveness in heterogeneous tumors. Specifically, many subpopulations have been clearly demonstrated to possess increased tumorigenicity in mice, broad differentiating capacity, and resistance to therapy. However, the extent to which these experimental findings are potentially clinically significant is still not clear. This review will describe the principles of this emerging hypothesis, ways in which it may be appropriate in ovarian cancer based on the clinical course of the disease, and how we might exploit it to improve outcomes in ovarian cancer patients.