Extranodal Extension as an Independent Prognostic factor in Laryngeal Squamous Cell Carcinoma Patients

The presence of Lymph node metastasis with extranodal extension (ENE) is considered to be an important adverse prognostic factor for survival in patients with head and neck cancer. The aim of this study was to determine the prognostic significance of ENE in patients with laryngeal squamous cell carcinoma (LSCC). Three hundred and fifty-five patients with LSCC who underwent surgical resection and neck dissection were included. The status of cervical lymph node was classified into three groups: pathological negative nodal (pN-), pathological positive nodal without ENE (ENE-), and pathological positive nodal with ENE (ENE+). A total of 85 of 355 (23.9%) LSCC were pathological nodal positive, and ENE was detected in 22/355 (6.2%) patients. ENE was associated with drinking (p=0.005), T stage (p=0.000), tumor location (p=0.000), and differentiation degree (p=0.000). The number of lymph node metastasis in ENE+ group was associated with almost twice compared to ENE- group (p=0.005). The 5-year overall survival rates for patients in the pN-, ENE-, and ENE+ groups were 86.4±2.6%, 75.9±6.3%, and 53.7±12.7%, respectively (p=0.000). After adjusting for confounding variables, ENE+ was associated with more than five times the hazard of death than pN- cases (p=0.000), and more than twice the hazard of death than ENE- cases (p=0.036). Compared to N2-3/ENE- cases, N2-3/ENE+ cases had the poorest survival rate (p=0.013). ENE+ was associated with worse outcomes compared to pN - or ENE- status. ENE is an independent prognostic factor in LSCC, and could be an indicator of the need for adjuvant treatment.