Squamous cell carcinomas metastatic to cervical lymph nodes from an unknown head-and-neck mucosal site treated with radiation therapy alone or in combination with neck dissection

Abstract

Purpose: The present study presents the experience at the University of Florida with treatment of patients with squamous cell carcinomas (SCC) metastatic to cervical lymph nodes from an unknown head-and-neck mucosal (H&NM) site with radiotherapy (RT) alone or in combination with neck dissection (ND). Methods and Materials: The study included 126 patients treated with curative intent from 1964 to 1997. All patients had follow-up for at least 2 years. No patients were lost to follow-up. Results: Twelve patients (10%) developed SCC in H&NM sites at 0.5 to 10.9 years (median, 1.8 years). The rate of developing carcinomas in H&NM sites at 5 years was 13%. Histologic differentiation significantly affected the rate of developing carcinomas in H&NM sites in multivariate analysis. Sixteen patients (13%) had persistent nodal disease and 12 patients (10%) developed recurrent nodal disease at 0.5 to 10.9 years (median, 1.1 years). The nodal control rate at 5 years was 78%. Nodal size, N stage, and planned ND significantly affected the rate of nodal control in multivariate analysis. Nineteen patients (15%) developed distant metastasis at 0.2–5.1 years (median, 0.9 years). The distant metastases rate at 5 years was 14%. Extracapsular extension and RT dose significantly affected the risk of distant metastases in multivariate analysis. The overall absolute survival rate at 5 years was 47%. Extracapsular extension, N stage, RT dose for H&NM sites, and planned ND significantly affected absolute survival in multivariate analysis. The rate of cause-specific survival at 5 years was 67%. Extracapsular extension, nodal size, N stage, overall treatment time, and planned ND significantly affected cause-specific survival in multivariate analysis. Eight patients (6%) had severe postoperative complications and 6 patients (5%) had severe late complications. Conclusion: The present study supports the effectiveness of RT in lowering the rate of developing carcinomas in the H&NM sites.