A Retrospective Cohort Study of Cutaneous Squamous Cell Carcinoma With Lymph Node Metastasis: Risk Factors and Clinical Course

BACKGROUND The single most important prognostic indicator for mortality in patients with cutaneous squamous cell carcinoma (SCC) is the development of nodal metastasis (NM). OBJECTIVE To characterize the risk factors for and clinical course of cutaneous SCC with NM. METHODS Ten-year retrospective cohort study (2006-2017) at an academic tertiary care center reviewing 53 cutaneous SCC tumors with NM. RESULTS Most patients were men (84.6%, 44/52), and almost all primary tumors were on the head and neck (96.2%, 51/53). Most primary tumors were characterized by known "high-risk features" including perineural invasion (56.6%, 30/53), diameter >= 2 cm (54.7%, 29/53), invasion beyond subcutaneous fat (43.4%, 23/53), and poor differentiation (32.1%, 17/53). In addition, many tumors were recurrent (52.8%, 28/53), and many patients were immunosuppressed (30.8%, 16/52). Disease-free survival after treatment of nodal disease was 7.5%(4/53) at 5 years. CONCLUSION To the best of the authors' knowledge, this study is the largest retrospective cohort of cutaneous SCC with NM to date. The results verify the significance of "high-risk features" used by current staging systems while highlighting additional features that may have prognostic value. This study may be used to refine current staging systems, improve early detection, and optimize management for these aggressive tumors.