Review of high‐risk features of cutaneous squamous cell carcinoma and discrepancies between the American Joint Committee on Cancer and NCCN Clinical Practice Guidelines In Oncology

Cutaneous squamous cell carcinoma (SCC) is a malignancy that arises from epidermal keratinocytes. Although the majority of cutaneous SCC cases are easily treated without further complication, some behave more aggressively and carry a poor prognosis. These “high‐risk” cutaneous SCCs commonly originate in the head and neck and have an increased tendency toward recurrence, local invasion, and distant metastasis. Factors for high‐risk cutaneous SCC include large size (>2 cm), a deeply invasive lesion (>2 mm), incomplete excision, high‐grade/desmoplastic lesions, perineural invasion (PNI), lymphovascular invasion, immunosuppression, and high‐risk anatomic locations. Both the National Comprehensive Cancer Network^® (NCCN^®) and the American Joint Committee on Cancer (AJCC) identify several of these high‐risk features of cutaneous SCC. The purpose of this article was to review the high‐risk features included in these guidelines, as well as their notable discrepancies and omissions. We also provide a brief overview of current prophylactic measures, surgical options, and adjuvant therapies for high‐risk cutaneous SCC. © 2016 Wiley Periodicals, Inc. Head Neck 39: 578–594, 2017