The incidence and significance of retropharyngeal lymph node metastases in hypopharyngeal cancer.

Objective: To evaluate the incidence and clinical significance of retropharyngeal lymph node metastasis in hypopharyngeal cancer.
Methods: Pretreatment computed tomography and/or magnetic resonance images of 152 patients treated between 1998 and 2009 were retrospectively reviewed. The prognostic significance of retropharyngeal lymph node metastasis for 116 patients who received definitive treatment was also analyzed.
Results: Twelve patients (8%) were radiologically positive for retropharyngeal lymph node metastasis. Tumors originating from the posterior wall showed significantly higher incidence of retropharyngeal lymph node than those originating from other sites (23.8 vs. 5.3%, P = 0.01). The majority of patients with retropharyngeal lymph node involvement experienced distant metastasis. The overall survival rate of patients with retropharyngeal lymph node metastasis was worse than in those lacking retropharyngeal lymph node involvement (0 vs. 68.8% at 2 years, P < 0.01), and so was the cause-specific survival rate (0 vs. 74% at 2 years, P < 0.01).
Conclusions: Patients with hypopharyngeal cancer, especially those with posterior wall tumors, are at high risk for retropharyngeal lymph node involvement. Patients with retropharyngeal lymph node metastasis developed distant metastasis frequently, and showed dismal outcomes.