Regional Metastasis in Head and Neck Cutaneous Squamous Cell Carcinoma: An Update on the Significance of Extra-Nodal Extension and Soft Tissue Metastasis

Background Soft tissue metastases (STMs) are reported to predict worse prognosis than extra-nodal extension (ENE) in metastatic head and neck cutaneous squamous cell carcinoma. This study aimed to update the authors’ previous analysis of STM in a larger series. Methods The study analyzed 535 cases of consecutive cSCC metastatic to the parotid and/or neck treated by primary surgical resection between 1987 and 2007. A Cox proportional hazard model was used to determine the effect of STM, with adjustment for other relevant prognostic factors. Overall survival (OS) and disease-specific survival (DSS) were the primary end points. Results Of the 535 patients, 275 (51.4%) had STM. After adjustment for the effects of age, tumor location, number of metastatic deposits, and adjuvant radiotherapy, both STM (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.08–2.22; p = 0.018) and ENE (HR, 1.56; 95% CI 1.10–2.22; p = 0.013) were shown to be independent predictors of reduced OS, with similar size of effect. Conclusion In metastatic cSCC of the head and neck, STM is an independent predictor of reduced survival and has an impact on survival similar to that of ENE.