Perivascular stem cell niche in head and neck cancer.

Cancers may contain a small sub-population of uniquely tumorigenic cells that exhibit self-renewal and multipotency, i.e. cancer stem cells (CSCs). These cells reside in invasive fronts in close proximity to blood vessels in many tumors, including head and neck squamous cell carcinomas (HNSCCs). Recent evidence suggests that CSC resist chemotherapy and "drive" local recurrence and metastatic spread. Notably, endothelial cell-initiated signaling is critical for the survival and self-renewal of CSC and may play a role in resistance to therapy. Therefore, patients with head and neck cancer might benefit from therapies that target the CSC directly or their supportive perivascular niche.