High risk cutaneous squamous cell carcinoma of the head and neck

Nonmelanoma skin cancers (squamous cell and basal cell carcinomas) occur at an epidemic rate in many countries with the worldwide incidence increasing. The sun-exposed head and neck are the most frequent sites for these cancers to arise and in most patients diagnosed with a cutaneous squamous cell carcinoma, local treatment is usually curative. However, a subset is diagnosed with a high-risk cutaneous squamous cell carcinoma. High-risk factors include size (>2 cm), thickness/depth of invasion (>4 mm), recurrent lesions, the presence of perineural invasion, location near the parotid gland, and immunosuppression. These patients have a higher risk (>10-20%) of developing metastases to regional lymph nodes (often parotid nodes), and in some cases also of experiencing local morbidity (perineural invasion), based on unfavourable primary lesion and patient factors. Despite treatment, many patients developing metastatic cutaneous squamous cell carcinoma experience mortality and morbidity usually as a consequence of uncontrolled metastatic nodal disease. It is therefore important that clinicians treating nonmelanoma skin cancers have an understanding and awareness of these high-risk patients. The aim of this article is to discuss the factors that define a high-risk patient and to present some of the issues pertinent to their management.