title: Prevalence of Human Papillomavirus in Oropharyngeal Cancer: A Systematic Review.
abstract: OBJECTIVE
  The global incidence of oropharyngeal squamous cell carcinoma (OPSCC) has been increasing, and it has been proposed that a rising rate of human papillomavirus (HPV)-associated cancers is driving the observed changes in OPSCC incidence. We carried out this systematic review to further examine the prevalence of HPV in OPSCC over time worldwide.
  
  
  METHODS
  A systematic literature search was performed to identify all articles through January 31, 2014, which reported on the prevalence of HPV in OPSCC. Articles that met the inclusion criteria were divided into 4 time frames (pre-1995, 1995-1999, 2000-2004, and 2005 to present) based on the median year of the study's sample collection period. Using a weighted analysis of variance model, we examined the trends of HPV-positivity over time worldwide, in North America, and in Europe.
  
  
  RESULTS
  Our literature search identified 699 unique articles. One hundred seventy-five underwent review of the entire study, and 105 met the inclusion criteria. These 105 articles reported on the HPV prevalence in 9541 OPSCC specimens across 23 nations. We demonstrated significant increases in the percentage change of HPV-positive OPSCCs from pre-1995 to present: 20.6% worldwide (P for trend: P < 0.001), 21.6% in North America (P = 0.013), and 21.5% in Europe (P = 0.033).
  
  
  CONCLUSIONS
  Interestingly, whereas in Europe there was a steady increase in HPV prevalence across all time frames, reaching nearly 50% most recently, in North America HPV prevalence appears to have plateaued over the past decade at about 65%. These findings may have important implications regarding predictions for the future incidence of OPSCC.
authors.affiliation: From the Departments of *Human Oncology, University of Wisconsin Carbone Cancer Center, Madison, WI; †Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI; and ‡Biostatistics, University of Wisconsin, Madison, WI.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Stein
authors.forename: Sandeep
authors.initials: S
authors.lastname: Saha
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Kraninger
authors.forename: Adam D
authors.initials: AD
authors.lastname: Swick
authors.forename: Menggang
authors.initials: M
authors.lastname: Yu
authors.forename: Paul F
authors.initials: PF
authors.lastname: Lambert
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Kimple
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D009959:Oropharyngeal Neoplasms / Q000453:epidemiology* / Q000821:virology; D027383:Papillomaviridae / Q000472:pathogenicity; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000821:virology; D011379:Prognosis