title: Prognosis: a variable parameter: dynamic prognostic modeling in head and neck squamous cell carcinoma.
abstract: BACKGROUND
  In general, the estimated prognosis of patients with cancer is based on patient characteristics known at the time of diagnosis and presented as if a lifetime verdict. However, the prognosis of patients with cancer who survive the first critical years changes, along with the prognosis for those with local or regional recurrences or distant metastases.
  
  
  METHODS
  This study concerns 2927 patients with a primary head and neck squamous cell carcinoma (HNSCC). We developed prognostic models after initial treatment and at different time points during follow-up.
  
  
  RESULTS
  The developed models show the effects of survival time, recurrences, and distant metastasis during follow-up. The C-statistics ranged from 0.76 to 0.69.
  
  
  CONCLUSIONS
  Prognosis is dynamic: the passage of time and the occurrence of life events change the predicted probabilities of survival. The models enhance our insight in the effect of recurrences and metastasis during follow-up and could be used for better patient counseling.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Erasmus Medical Center, Rotterdam, The Netherlands. m.vanderschroeff@erasmusmc.nl
authors.forename: Marc P
authors.initials: MP
authors.lastname: van der Schroeff
authors.forename: Ewout W
authors.initials: EW
authors.lastname: Steyerberg
authors.forename: Marjan H
authors.initials: MH
authors.lastname: Wieringa
authors.forename: Ton P M
authors.initials: TP
authors.lastname: Langeveld
authors.forename: Jan
authors.initials: J
authors.lastname: Molenaar
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Baatenburg de Jong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000401:mortality; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D011379:Prognosis; D016019:Survival Analysis; D055815:Young Adult