Extranodal extension in laryngeal squamous cell carcinoma.

OBJECTIVE: Although large retrospective database studies have associated extranodal extension (ENE) with worse survival in several head and neck cancers, the prognostic significance of ENE in laryngeal squamous cell carcinoma (LSCC) remains unclear. Our study examines ENE and overall survival (OS) in LSCC.

METHODS: The 2006-2017 National Cancer Database was queried for patients with LSCC undergoing surgical resection and neck dissection, with or without adjuvant therapy. Kaplan-Meier and multivariable Cox regression survival analyses were implemented to identify the independent impacts of pathologic nodal (pN) classification and ENE on OS.

RESULTS: Of 4208 patients satisfying inclusion criteria, 2343 (55.7%) were pN0/ENE-negative, 1059 (25.2%) were pN1-2/ENE-negative, and 806 (19.2%) were pN1-2/ENE-positive. The 5-year OS of pN0/ENE-negative, pN1-2/ENE-negative, and pN1-2/ENE-positive patients was 62.8%, 56.7%, and 32.9%, respectively ( p  < .001). Among pN1-2/ENE-positive patients undergoing no adjuvant therapy, adjuvant radiotherapy alone, and adjuvant chemoradiotherapy, 5-year OS was 24.1%, 30.7%, and 36.7%, respectively ( p  < .001). After adjusting for patient demographics, clinicopathologic features, and adjuvant therapy, ENE-positivity was associated with worse OS than ENE-negativity (adjusted hazard ratio [aHR] 1.76, 95% confidence interval [CI] 1.53-2.02, p  < .001). pN1/ENE-positivity (aHR 1.82, 95% CI 1.31-2.54) and pN2/ENE-positivity (aHR 1.89, 95% CI 1.49-2.40) were associated with worse OS than pN1/ENE-negativity ( p  < .001). Microscopic (aHR 1.83, 95% CI 1.54-2.18) and macroscopic ENE-positivity (aHR 1.75, 95% 1.35-2.26) were associated with worse OS than ENE-negativity ( p  < .001).

CONCLUSION: ENE-positivity has prognostic significance in LSCC and is associated with worse OS than ENE-negativity. pN classification did not have prognostic significance independent of ENE. ENE should be carefully considered when determining the prognosis of LSCC and selecting adjuvant therapy.

LEVEL OF EVIDENCE: 4.