Risk factors for distant metastases in head and neck squamous cell carcinoma.

To evaluate the frequency of distant metastases (DM) and to determine the ability of certain clinical and pathologic factors to predict the development of distant metastases. Retrospective analysis. University hospital. A total of 1972 patients with oral, oropharyngeal, hypopharyngeal, and laryngeal squamous cell carcinomas who were treated from 1981 to 1998 and who were not diagnosed as having DM at the time of initial treatment. We evaluated the frequency of DM and the influence of different variables in their appearance. A total of 181 patients (9.2%) (95% confidence interval, 7.9%-10.5%) developed DM. Younger age (<45 years), hypopharyngeal localization, an advanced T stage and/or N stage tumor according to the TNM staging system, high histologic grade, and locoregional control were found to be significantly associated with the risk of DM at both univariate and multivariate analyses. The incidence of DM in subjects with head and neck squamous cell carcinoma is relatively low. The risk of DM is influenced by age, site of primary cancer, local and/or regional extension, grading, and achievement of locoregional control.