title: Factors influencing the development of distant metastases in patients with head and neck squamous cell carcinoma.
abstract: OBJECTIVE
  the aim of this retrospective study was to evaluate the frequency of distant metastases (DM) and to define factors that influence DM free survival (DMFS) in patients with head and neck squamous cell carcinoma (HNSCC).
  
  
  METHODS
  the charts of 201 patients with oral cavity, pharyngeal, or laryngeal carcinoma, treated with postoperative radiotherapy (RT) or definitive RT between 1999 and 2004 and achieved locoregional control were analyzed.
  
  
  RESULTS
  DM occurred in 26 of 201 (12.9%) patients. The mean time of DM diagnosis was 16.5 months (range 5-35). The median time to death after diagnosis of DM was 5 months (range 1-13). The DMFS rate at 5 years was 84.8%. Univariate analysis demonstrated that the risk of DM was significantly influenced by age (p=0.047), cigarette smoking (p=0.024), ECOG performance status (PS) (p=0.008), location of the primary site (p=0.003), N stage (p<0.0001), overall stage (p<0.0001), histological differentiation (p<0.0001), levels of nodal involvement (p<0.0001), treatment modality (p<0.0002), presence of locoregional recurrence (LRR) (p<0.0001), and time to LRR (p<0.0001). In multivariate analysis nodal involvement (N1: p=0.007; N2: p=0.036; N3: p=0.043), and the time to LRR ≤ 6 months (p=0.037) were proven as independent factors that significantly influenced DMFS.
  
  
  CONCLUSIONS
  development of DM in patients with HNSCC was significantly influenced by the presence of positive nodal status and the presence of LRR whose appearance was within 6 months of RT.
authors.affiliation: Department of Head and Neck Cancer, University Clinic of Radiotherapy and Oncology, Faculty of Medicine, Skopje, FYROMakedonia. krstevskav@gmail.com
authors.forename: V
authors.initials: V
authors.lastname: Krstevska
authors.forename: I
authors.initials: I
authors.lastname: Stojkovski
authors.forename: B
authors.initials: B
authors.lastname: Zafirova-Ivanova
mesh_terms: D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000532:radiotherapy / Q000556:secondary* / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy / Q000556:secondary* / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D006801:Humans; D008113:Liver Neoplasms / Q000532:radiotherapy / Q000556:secondary* / Q000601:surgery; D008175:Lung Neoplasms / Q000532:radiotherapy / Q000556:secondary* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D011379:Prognosis; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015996:Survival Rate