title: Using TNM staging to predict survival in patients with squamous cell carcinoma of head & neck.
abstract: BACKGROUND
  There is a need for a classification system for prognosis based on the TNM system for patients with squamous cell carcinoma of the head and neck such that patient groupings are homogeneous within and heterogeneous between.
  
  
  METHODS
  Six hundred fifty-five consecutive patients with invasive squamous cell carcinoma of the head and neck followed prospectively are split into a training set and a test set. Using the training set, the Cox Proportional Hazards Model and the outcome of dead with disease, we created homogeneous prognostic levels (PLs) based on RR. Using the test set, we compare our model to others in the literature.
  
  
  RESULTS
  Using the training set, we identified five PLs, and using the test set, we demonstrated that our model is superior to others for both within-group homogeneity and between-group heterogeneity.
  
  
  CONCLUSIONS
  A simple classification system can be used to group patients for survival and is valid for future study in prognostication.
authors.affiliation: Department of Otolaryngology, Queen's University, Kingston, Ontario, Canada.
authors.forename: S F
authors.initials: SF
authors.lastname: Hall
authors.forename: P A
authors.initials: PA
authors.lastname: Groome
authors.forename: D
authors.initials: D
authors.lastname: Rothwell
authors.forename: P F
authors.initials: PF
authors.lastname: Dixon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000145:classification / Q000401:mortality* / Q000473:pathology*; D005260:Female; D006258:Head and Neck Neoplasms / Q000145:classification / Q000401:mortality* / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models