Clonal evolution model strikes back at cancer stem cell hierarchical model in the Head & Neck tumor

The two models of tumor progression in head and neck squamous cell carcinoma are proposed: stochastic clonal evolution model and cancer stem hierarchy model. Cell surface marker analysis and clonal cell analysis in combination with a xenotransplant approach have been performed to determine the model, but the interpretation is sometimes difficult due to multiple biological parameters and the stromal environment permissive to tumor growth. Understanding of which model is most applicable to head and neck squamous cell carcinoma as well as other cancers should be further promoted because it suggests differential approaches in treatment.