Prognostic significance of surgical extranodal extension in head and neck squamous cell carcinoma patients.

BACKGROUND: Lymph node metastasis with extranodal extension represents one of the most important adverse prognostic factors for survival in patients with head and neck squamous cell carcinoma. We propose that extranodal extension occurs to differing extents. The aim of this study was to determine the prognostic significance of extranodal extension in patients with head and neck squamous cell carcinoma. METHODS: Two hundred and ninety-eight patients with head and neck squamous cell carcinoma who underwent surgical resection and neck dissection were included. Cervical lymph nodes were classified into four categories: (i) pathological N negative, (ii) extranodal extension negative, (iii) non-surgical extranodal extension and (iv) surgical extranodal extension. RESULTS: Lymph node metastases were detected in 67.1% of laryngeal/hypopharyngeal cancer patients and 52.7% of oral cancer patients. The 3-year disease-specific survival rates for patients in the pathological N negative, extranodal extension negative, non-surgical extranodal extension and surgical extranodal extension groups were 90.9%, 79.6%, 63.8% and 48.3%, respectively. In laryngeal/hypopharyngeal cancer patients, surgical extranodal extension was associated with a significantly poorer disease-specific survival than a pathological N negative, extranodal extension negative or non-surgical extranodal extension status. In oral cancer patients, no significant differences were observed between the non-surgical and surgical extranodal extension groups. However, non-surgical extranodal extension was associated with a poorer disease-specific survival than a pathological N negative or extranodal extension negative status. CONCLUSIONS: Surgical extranodal extension was a poor prognostic factor in patients with head and neck squamous cell carcinoma. The prognostic significance of surgical extranodal extension differed between laryngeal/hypopharyngeal and oral cancer patients. The clinical significance of surgical extranodal extension was much greater for patients with laryngeal/hypopharyngeal cancer than oral cancer.