Figure 1. Model of genetic instability and progression in head and neck cancer.
Genetic instability increases and accumulates as a lesion acquires its malignant potential. With increasing heterogeneity of genetic instability, inactivation of tumor suppressor genes and activation of oncogenes account for the phenotypic changes of SCCHN carcinogenesis through normal histology, hyperplasia, dysplasia, carcinoma in situ and invasive carcinoma.