title: Distant metastases after definitive radiotherapy for squamous cell carcinoma of the head and neck.
abstract: OBJECTIVE
  To analyze parameters that influence the risk of distant metastases after definitive radiotherapy.
  
  
  METHODS
  Between 1983 and 1997, 873 patients were treated with definitive radiotherapy and had follow-up for 2 years or more. Univariate and multivariate analyses were performed to evaluate risk factors that might influence the risk of distant metastases.
  
  
  RESULTS
  The 5-year distant metastasis-free survival rate was 86%. Univariate analyses revealed that the risk of distant metastases was significantly influenced by gender (p =.0092), primary site (p =.0023), T stage (p <.0001), N stage (p <.0001), overall stage (p <.0001), level of nodal metastases in the neck (p <.0001), histologic differentiation (p =.0096), control above the clavicles (p <.0001), and time to locoregional recurrence (p <.0001). Multivariate analysis of freedom from distant metastases revealed that gender (p =.0390), T stage (p <.0001), N stage (p =.0060), nodal level (p <.0001), and locoregional control (p <.0001) significantly influenced this end point. Multivariate analysis revealed that gender (p =.0049), T stage (p <.0001), N stage (p <.0001), and locoregional control (p <.0001) significantly influenced cause-specific survival.
  
  
  CONCLUSIONS
  The risk of distant metastases after definitive radiotherapy is 14% at 5 years and is significantly influenced by gender, T stage, N stage, nodal level, and locoregional control.
authors.affiliation: Department of Radiation Oncology, University of Florida College of Medicine, 2000 SW Archer Road, Gainesville, Florida 32608, USA.
authors.forename: Majid O F
authors.initials: MO
authors.lastname: Al-Othman
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Morris
authors.forename: Russell W
authors.initials: RW
authors.lastname: Hinerman
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Amdur
authors.forename: William M
authors.initials: WM
authors.lastname: Mendenhall
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D011237:Predictive Value of Tests; D012307:Risk Factors; D012737:Sex Factors; D016019:Survival Analysis