Prognostic value of the 8th edition American Joint Commission Cancer nodal staging system for patients with head and neck cutaneous squamous cell carcinoma: A multi-institutional study.

ABSTRACT

BACKGROUND: The 8th edition American Joint Committee on Cancer staging manual (AJCC8) introduced a separate staging system for head and neck cutaneous squamous cell carcinoma (HNcSCC) which parallels mucosal SCC and incorporates extranodal extension (ENE). This study aims to evaluate its prognostic utility. METHODS: Univariate analysis of 1146 patients with metastatic HNcSCC from four Australian cancer centers was performed according to both AJCC 7th (AJCC7) and the 8th editions. RESULTS: AJCC8 increased classification of 924 (80.6%) patients to either pN2a or pN3b and 341 patients (29.8%) from stage III to IV compared to AJCC7. The disease-specific survival (DSS) was not significantly different between pN1, pN2 or pN3a categories per AJCC8. Estimates of model performance for the AJCC8 pN staging revealed modest predictive capacity (Harrell's C of 0.62 for DSS). CONCLUSIONS: The risk stratification according to pN classification of AJCC8 staging system performed poorly as a prognostic indicator.