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

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). 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. 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. The present study supports the effectiveness of RT in lowering the rate of developing carcinomas in the H&NM sites.