title: Different prognostic models for different patient populations: validation of a new prognostic model for patients with oropharyngeal cancer in Western Europe.
abstract: OBJECTIVE
  The presence of human papillomavirus (HPV) infection in oropharyngeal squamous cell carcinoma (OPSCC) is a major determinant in prognostic risk modelling. Recently, a prognostic model was proposed in which HPV status, comorbidity and nodal stage were the most important prognostic factors to determine high-, intermediate- and low-risk survival groups. Here, we report on the validation of this model using an independent single-institutional cohort.
  
  
  METHODS
  A total number of 235 patients curatively treated for OPSCC in the period 2000-2011 at the MUMC (Maastricht University Medical Center, The Netherlands) were included. The presence of an oncogenic HPV infection was determined by p16 immunostaining, followed by a high-risk HPV DNA PCR on the p16-positive cases. The model variables included were HPV status, comorbidity and nodal stage. As a measure of model performance, the Harrell's Concordance index (Harrell's C-index) was used.
  
  
  RESULTS
  The 5-year overall survival (OS) estimates were 84.6%, 54.5% and 28.7% in the low-, intermediate- and high-risk group, respectively. The difference between the survival curves was highly significant (P<0.001). The Harrell's C-index was 0.69 (95% confidence interval (CI): 0.63-0.75).
  
  
  CONCLUSIONS
  In this study a previously developed prognostic risk model was validated. This model will help to personalise treatment in OPSCC patients. This model is publicly available at www.predictcancer.org.
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: M M
authors.initials: MM
authors.lastname: Rietbergen
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: B I
authors.initials: BI
authors.lastname: Witte
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands.
authors.forename: E R
authors.initials: ER
authors.lastname: Velazquez
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: P J F
authors.initials: PJ
authors.lastname: Snijders
authors.affiliation: Department of Oral and Maxillofacial Surgery/Oral Pathology, VU University Medical Center/Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Bloemena
authors.affiliation: Department of Pathology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: E J
authors.initials: EJ
authors.lastname: Speel
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: R H
authors.initials: RH
authors.lastname: Brakenhoff
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Kremer
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Lambin
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: C R
authors.initials: CR
authors.lastname: Leemans
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D005060:Europe; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D052162:Human papillomavirus 16 / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D011379:Prognosis; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor