title: The impact of comorbidity on the survival of patients with squamous cell carcinoma of the head and neck.
abstract: BACKGROUND
  In North America, cigarette smoking and/or alcohol consumption not only cause head and neck cancer, they also cause many of the other diseases, illnesses, and conditions, also known as comorbidities, frequently found in our patients. Comorbidities can influence treatment decision making and treatment outcome. The aim of this study is to quantify the increased risk of comorbidity in our patients.
  
  
  METHODS
  The survival of 655 consecutive patients with squamous cell carcinoma from a regional cancer center is analyzed. We compare the survival curves for all-cause death, death from cancer, and death from noncancer causes to the expected survival of age/sex-matched populations of Ontario residents, Canadian smokers, and Canadian nonsmokers.
  
  
  RESULTS
  Of those patients who had not survived 5 years, 59% died of their index tumor, 23% would have been expected to die if they did not have head and neck cancer, and 18% died of the increased comorbidity associated with being a patient with head and neck cancer.
  
  
  CONCLUSIONS
  Comorbidity, and specifically the increased comorbidity found in patients with head and neck cancer, is an important factor in overall survival.
authors.affiliation: Departments of Otolaryngology and Oncology, Queen's University, Kingston, Ontario, Canada. sfh@post.queensu.ca
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
mesh_terms: D000206:Actuarial Analysis; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000401:mortality; D002423:Cause of Death; D015897:Comorbidity; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D009864:Ontario / Q000453:epidemiology; D012042:Registries; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000453:epidemiology; D016019:Survival Analysis