Cutaneous squamous carcinoma and related lesions.

The epidemiologic, etiologic, and prognostic factors in cutaneous squamous carcinoma depend heavily upon the status of the immune systems of the skin and body. Because UV radiation is both mutagenic and immunosuppressive, exposure to it will ultimately set the stage for the development of cutaneous carcinoma. If other immunobiologic-altering factors are added to UV radiation exposure, then both a susceptibility to invasion by oncogenic viruses and the development of squamous cell disorders, including squamous cell carcinoma, will exist. Although these factors are not totally controllable, a better understanding of them will allow the physician to more effectively tailor preventive care, treatment decisions, and counseling advice.