Cancer Stem Cells in Head and Neck Cancer

Each year, malignancies of the head and neck account for approximately 500,000 new cases cancer diagnoses worldwide. The prognosis for patients affected by head and neck cancer has remained largely unchanged in recent years, despite significant advances in the understanding of tumor biology and etiologic factors. This is largely due to the fact that two-thirds of patients present with disease that has already spread regionally or metastasized. Unfortunately, for patients presenting with advanced-stage disease, complete cure is often not possible with our current treatment modalities. The consistently poor prognosis of head and neck cancer patients underscores the need for a better understanding of tumor biology and how to target malignant cells. The re-emergence of the cancer stem cell (CSC) hypothesis offers hope in this area. This chapter reviews the current knowledge about CSCs in head and neck cancer, including markers used for CSC identification and isolation, as well as their potential clinical implications.