What is the biologic behavior of cutaneous squamous cell carcinoma?

SCCs are more aggressive than BCCs and are more likely to metastasize. SCCs are currently estimated to metastasize at an overall rate of 2% to 6%. Certain sites have higher rates of metastasis—SCC arising from the lower lip metastasize in 10% to 14% of cases, and those arising from the ear metastasize in 11% of cases. Tumors arising in burn scars, draining sinuses, and modified epithelium (e.g., glans penis, vulva) and in immunocompromised patients are also more likely to metastasize. Other factors associated with a higher metastatic rate are increased depth of invasion, perineural invasion and recurrence, with recurrent tumors estimated to metastasize in about 33% of cases. Multiple genetic mutations are associated with the development of cutaneous SCCs, in particular 90% of these tumors have UV-induced mutations in the p53 tumor suppressor gene.

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Black A: The role of p53 in the immunobiology of cutaneous squamous cell carcinoma, Clin Exp Immunol 132:379–384, 2003.