The risk of metastases from squamous cell carcinoma of the skin.

Cutaneous squamous cell carcinoma (cSCC) is the second most common nonmelanoma skin cancer, accounting for 20% of all skin cancers. The risk of the disease continues to rise annually with an estimated 50-200% increase in incidence within the last three decades. Although cSCC is one of the most common skin cancers, reported having 1 million cases per year in the United States, there is inconsistency with its reported metastatic rate. Research exploring cSCC metastasis found an overall rate of 1.2-5% but this range varies, and some dermatologists are finding cSCC's ability to spread more worrisome. This allows for clinical variation in the appropriate treatments and follow-up guidelines when diagnosing a patient with cSCC. Poor prognosis in patients with a high metastatic potential makes cSCC clinically problematic. Clinician emphasis should be put on risk factors, anatomical site, tumor presentation, and histological features when evaluating cSCC's metastatic potential. In this review, specific skin conditions that predispose to cSCC and discrepancies in its reported metastatic potential will be discussed.