Performance of Staging Systems for Non–Head and Neck Cutaneous Squamous Cell Carcinoma

Abstract

BACKGROUND The performance of staging systems in non–head and neck cutaneous squamous cell carcinomas has not been well established. OBJECTIVE To evaluate the performance of the American Joint Committee on Cancer 8th Edition and Brigham and Women's Hospital staging systems in non–head and neck squamous cell carcinomas. MATERIALS AND METHODS Eligible tumors were identified and staged from an existing retrospective database. Cumulative incidence function curves of any poor outcome were generated. Distinctiveness, sensitivity, specificity, positive and negative predictive value, and concordance index were calculated. RESULTS 1,042 primary tumors were included, with 38 resulting in any poor outcome and 16 in any major poor outcome. High-stage tumors represented 2.2% and 3.5% of tumors; these accounted for 10/38 of the poor outcomes (26.3%) and 8/16 of the major poor outcomes (50%). High-stage tumors predicted major poor outcomes with a sensitivity of 0.5 and specificity of 0.99 for the Brigham and Women's Hospital system, and a sensitivity of 0.5 and specificity of 0.97 for the American Joint Committee on Cancer 8th edition system. The concordance index for both was 0.74. CONCLUSION Current staging systems can be used to predict poor outcomes in cutaneous squamous cell carcinomas off the head and neck.