Pattern of lymph node metastasis in hypopharyngeal squamous cell carcinoma and indications for level VI lymph node dissection.

BACKGROUND The purpose of this study was to determine the incidence, risk factors, and prognostic significance of level VI lymph node metastases from hypopharyngeal squamous cell carcinoma (SCC). METHODS A retrospective review of 68 previously untreated patients with hypopharyngeal SCC who underwent level VI node dissection was performed. RESULTS Level VI lymph node metastases occurred in 27.9% of patients. The occult metastasis rate of level VI node was 14.3%. Patients with level VI metastasis had significantly lower disease-specific (55.1% vs 26.3%) and overall survival rates (73.5% vs 31.6%). Level VI lymph node metastasis was significantly correlated with regional recurrence (83.7% vs 63.2%) and distant metastasis (67.3% vs 47.4%). Multivariate analysis revealed that pyriform sinus apex invasion (odds ratio [OR] = 5.106) was an independent factor for level VI nodal metastasis. CONCLUSION Level VI lymph nodes should be removed in patients with pyriform sinus apex invasion, especially in those with advanced nodal disease. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1969-E1973, 2016.