title: Towards further understanding of prognostic factors for head and neck cancer patients: the example of hypopharyngeal cancer.
abstract: OBJECTIVE
  Knowledge of prognostic factors is essential for patient care and research. The objectives of this study were to demonstrate that prognostic factors and their impact can vary depending on study design and to examine the relationships between select prognostic factors.
  
  
  METHODS
  Retrospective population-based study of patients with cancer of the hypopharynx in Ontario, Canada, from January 1990 to December 1999 identifying and comparing prognostic factors for different survival outcomes and different subpopulations using Kaplan Meier analysis and Cox Proportional Hazards models.
  
  
  RESULTS
  The impact of prognostic factors varies within subgroups of a study population, varies with treatment decisions, and varies with the outcome of interest.
  
  
  CONCLUSIONS
  N and T category were the dominant prognostic factors in hypopharyngeal cancer. Performance status was an independent predictor of survival.
authors.affiliation: Department of Otolaryngology, The Cancer Care and Epidemiology Division of Queen's Cancer Research Institute, Queen's University, Kingston, Ontario, Canada. sfh@post.queensu.ca
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Hall
authors.forename: Patti A
authors.initials: PA
authors.lastname: Groome
authors.forename: Jonathan
authors.initials: J
authors.lastname: Irish
authors.forename: Brian
authors.initials: B
authors.lastname: O'Sullivan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000437:Alcoholism / Q000453:epidemiology; D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000401:mortality*; D002423:Cause of Death; D015897:Comorbidity; D005260:Female; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000145:classification* / Q000401:mortality* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome