Biology of cutaneous squamous cell carcinoma.

Nonmelanoma skin cancer is the leading cause of cancer in the United States. Cutaneous squamous cell carcinoma is second only to basal cell carcinoma in prevalence and its incidence is increasing. The biology of squamous cell carcinoma is reviewed under the broad areas of etiology, immunobiology, biochemistry, metastatic potential, and therapy, with emphasis on prevention, diagnosis, and management.