title: HPV DNA, E6/E7 mRNA, and p16INK4a detection in head and neck cancers: a systematic review and meta-analysis.
abstract: BACKGROUND
  We aimed to provide updated information about the global estimates of attributable fraction and type distribution of human papillomavirus (HPV) in head and neck squamous cell carcinomas by doing a systematic review and meta-analysis.
  
  
  METHODS
  We did a literature search on PubMed to identify studies that used PCR for detection of HPV DNA in head and neck squamous cell carcinomas with information about HPV genotype distribution. We included studies that tested 20 or more biopsies per cancer site and were published between July 15, 1990, and Feb 29, 2012. We collected information about sex, risk factors, HPV detection methods, and biomarkers of potentially HPV-induced carcinogenesis (E6/E7 mRNA and p16(INK4a)). If it was not possible to abstract the required information directly from the paper, we contacted the authors. We did a meta-analysis to produce pooled prevalence estimates including a meta-regression to explore sources of heterogeneity.
  
  
  RESULTS
  148 studies were included, contributing data for 12 163 cases of head and neck squamous cell carcinoma from 44 countries. HPV DNA was detected in 3837 cases. HPV16 accounted for 82·2% (95% CI 77·7-86·4) of all HPV DNA positive cases. By cancer site, pooled HPV DNA prevalence estimates were 45·8% (95% CI 38·9-52·9) for oropharynx, 22·1% (16·4-28·3) for larynx (including hypopharynx), and 24·2% (18·7-30·2) for oral cavity. The percent positivity of p16(INK4a) positive cases in HPV-positive oropharyngeal cancer cases was 86·7% (95% CI 79·2-92·9) and of E6/E7 mRNA positive cases was 86·9% (73·2-96·8). The estimate of HPV attributable fraction in oropharyngeal cancer defined by expression of positive cases of E6/E7 mRNA was 39·8% and of p16(INK4a) was 39·7%. Of subsites, tonsils (53·9%, 95% CI 46·4-61·3) had the highest HPV DNA prevalence. HPV DNA prevalence varied significantly by anatomical site, geographic region, but not by sex or tobacco or alcohol consumption.
  
  
  CONCLUSIONS
  The contribution of HPV prevalence in head and neck squamous cell carcinoma and in particular that of HPV16 in the oropharynx shows the potential benefit of prophylactic vaccines.
  
  
  BACKGROUND
  European Commission.
authors.affiliation: Department of Social and Preventive Medicine, Université de Montréal, Montreal, QC, Canada; Sainte-Justine Hospital Research Center, Montreal, QC, Canada.
authors.forename: Cathy
authors.initials: C
authors.lastname: Ndiaye
authors.affiliation: Institut Català d'Oncologia (ICO) - Catalan Institute of Oncology, IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain. Electronic address: mmena@iconcologia.net.
authors.forename: Marisa
authors.initials: M
authors.lastname: Mena
authors.affiliation: Institut Català d'Oncologia (ICO) - Catalan Institute of Oncology, IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; CIBER Epidemiología y Salud Pública, CIBERESP, Barcelona, Spain.
authors.forename: Laia
authors.initials: L
authors.lastname: Alemany
authors.affiliation: Unit of Cancer Epidemiology, Scientific Institute of Public Health, Brussels, Belgium; University of Antwerp, Antwerp, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Arbyn
authors.affiliation: Institut Català d'Oncologia (ICO) - Catalan Institute of Oncology, IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; CIBER Epidemiología y Salud Pública, CIBERESP, Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Castellsagué
authors.affiliation: Sainte-Justine Hospital Research Center, Montreal, QC, Canada.
authors.forename: Louise
authors.initials: L
authors.lastname: Laporte
authors.affiliation: Institut Català d'Oncologia (ICO) - Catalan Institute of Oncology, IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: F Xavier
authors.initials: FX
authors.lastname: Bosch
authors.affiliation: Institut Català d'Oncologia (ICO) - Catalan Institute of Oncology, IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; CIBER Epidemiología y Salud Pública, CIBERESP, Barcelona, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: de Sanjosé
authors.affiliation: Department of Social and Preventive Medicine, Université de Montréal, Montreal, QC, Canada; Sainte-Justine Hospital Research Center, Montreal, QC, Canada.
authors.forename: Helen
authors.initials: H
authors.lastname: Trottier
mesh_terms: D063646:Carcinogenesis / Q000235:genetics; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics* / Q000302:isolation & purification; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D006258:Head and Neck Neoplasms / Q000150:complications / Q000235:genetics* / Q000821:virology; D052162:Human papillomavirus 16 / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D006801:Humans; D009856:Oncogene Proteins, Viral / Q000235:genetics* / Q000302:isolation & purification; D050725:Papillomavirus E7 Proteins / Q000235:genetics* / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000150:complications / Q000235:genetics / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D012097:Repressor Proteins / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D004279:DNA, Viral; C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16