Risk stratification for metastasis from cutaneous squamous cell carcinoma of the head and neck

BACKGROUND: The purpose of the study was to develop a system of risk stratification, based on clinical and histological factors that would aid prediction of metastasis from cutaneous squamous cell carcinoma (SCC) of the head and neck. METHOD: The method used was a retrospective case control study comparing clinical and histological parameters of 78 patients who developed metastasis with 92 patients who did not develop metastasis over a 5-year period. RESULTS: The two 'absolute' (highest) risk factors for development of metastatic disease are poor histological differentiation and perineural/lymphovascular infiltration. The three 'relative' risk factors are moderate histological differentiation, diameter ≥20 mm and Clark level 5. RISK STRATIFICATION: High-risk lesions have either one of the absolute risk factors or all three of the relative risk factors with a predicted incidence of metastasis of 37%. Intermediate risk lesions have two of three relative risk factors and a predicted incidence of metastasis of 5%. Low-risk lesions have one or none of the relative risk factors and a predicted incidence of metastasis of 0.3%. CONCLUSION: Ongoing management of patients with histo-pathologically proven invasive SCC of the head and neck should be based upon risk stratification for metastasis.