Lymph node ratio as a prognostic factor in metastatic cutaneous head and neck squamous cell carcinoma.

BACKGROUND: The prognostic impact of the size and number of nodal metastases in head and neck cutaneous squamous cell carcinoma (SCC) is well established. The purpose of this study was to validate the prognostic significance of the lymph node ratio in metastatic head and neck cutaneous SCC.

METHODS: A retrospective review of 326 patients with head and neck cutaneous SCC with parotid and/or cervical nodal metastases was performed. The primary endpoints were overall survival (OS) and disease-free survival (DFS). The minimal-P approach was used to investigate the optimal lymph node ratio threshold.

RESULTS: Our data included 77 recurrences and 101 deaths. A lymph node ratio of 6% was a significant predictor of shorter DFS (hazard ratio [HR] 1.62; 95% confidence interval [CI] 1.11-2.38; P = .01) and OS (HR 1.63; 95% CI 1.03-2.58; P = 0.04) on multivariable analysis.

CONCLUSION: The lymph node ratio is an independent prognosticator of survival outcomes in patients presenting with metastatic head and neck cutaneous SCC. A lymph node ratio >6% is a significant threshold to categorize patients into low and high risk.