Impact of Extranodal Extension in Metastatic Cutaneous Squamous Cell Carcinoma of the Head and Neck: A Systematic Review and Meta‐Analysis

Objective The aim of this study is to analyze the impact of extranodal extension (ENE) on survival outcomes for patients with metastatic cutaneous head and neck squamous cell carcinoma (cHNSCC). Methods The pooled hazard ratios (HRs) and the 95% confidence interval (CI) were calculated to define the impact of ENE on overall survival (OS) and disease‐free survival (DFS). Results A total of 2076 patients (males: 84.4%) with a median age of 73.3 years were included. The incidence of ENE was 65.6% ( N = 1299/1979). The median follow‐up time was 38.4 months (95% CI: 21–38.4). The estimated pooled HRs were 1.31 (95% CI: 0.72–2.39; p = 0.28) and 1.80 (95% CI: 0.53–6.10; p = 0.22) for OS and DFS, respectively. Conclusions ENE may not be a reliable prognostic factor in metastatic cHNSCC. Further prospective studies are needed to refine risk stratification and improve the current nodal classification system.