Does node location affect the incidence of distant metastases in head and neck squamous cell carcinoma?

An analysis of 455 patients with head and neck carcinomas and clinically positive neck nodes who were treated with radiation therapy alone to their primary tumors (with or without a neck dissection) was conducted to determine the relative role of several prognostic factors in the subsequent development of distant metastases (DM). The factors analyzed were N stage, node location (upper neck only vs. lower with or without upper neck), T stage, primary site (oral cavity, oropharynx, nasopharynx, hypopharynx, supraglottic larynx), modified AJCC stage, and neck treatment. All patients were treated between 1964 and 1985 and had a minimum follow-up of 2 years. The N stage and node location were the most significant prognostic factors in the subsequent development of distant metastases. The incidence of distant metastases increased with increasing neck stage (N1, 11%; N2, 18%; N3, 27%), and in four of five neck stages (N2B being the exception), the incidence of distant metastases was greater for those patients with metastatic adenopathy in the lower neck. The incidence of distant metastases by modified AJCC stage was 12 111 (11%) for Stage III, 34 146 (23%) for Stage IVA, and 41 198 (19%) for Stage IVB. The primary site and T stage had little influence on the subsequent development of distant metastases. A multivariate analysis of the clinical factors confirmed the importance of neck stage and node location in estimating the probability of distant metastases. Control of disease above the clavicles and the addition of a neck dissection also significantly affected the chance of developing distant metastases.