title: Systematic review with meta-analysis: the association between human papillomavirus infection and oesophageal cancer.
abstract: BACKGROUND
  Human papillomavirus (HPV) infection might be one of the potential risk factors for oesophageal cancer. However, the previous epidemiological findings were heterogeneous.
  
  
  OBJECTIVE
  To explore the association between HPV infection and oesophageal cancer risk by means of meta-analysis.
  
  
  METHODS
  Studies on HPV infection and oesophageal cancer were identified, the prevalence of HPV infection and its association with oesophageal cancer risk were quantitatively summarised by meta-analysis.
  
  
  RESULTS
  A total of 8990 oesophageal squamous cell carcinoma (SCC) patients and 174 oesophageal adenocarcinomas patients were evaluated from 76 included studies. Summarised HPV prevalence in oesophageal SCC was 22.2% [95% confidence interval (CI), 18.3-26.7%], HPV-16 was the most frequently observed subtype with a summarised prevalence of 11.4% (95% CI: 8.2-15.7%). With respect to oesophageal adenocarcinoma, HPV prevalence was 35.0% (95% CI, 13.2-65.7%) and HPV-16 prevalence was 11.4% (95% CI: 8.2-15.7%). Due to the limited number of included studies on oesophageal adenocarcinoma, association analyses were performed to oesophageal SCC only. Significant association was observed between HPV infection and oesophageal SCC with a summarised odds ratio of 3.32 (95% CI, 2.26-4.87). According to HPV-16, the strength of the association was found to be 3.52 (95% CI, 2.04-6.07).
  
  
  CONCLUSIONS
  Human papillomavirus infection was observed to be associated with an increased risk of oesophageal SCC in this meta-analysis. However, due to the evident heterogeneity observed between the included studies and the strength of the association not as strong as observed for cervical cancer and laryngeal cancer, further studies are needed to clarify the relation and its underlying mechanisms.
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: C
authors.initials: C
authors.lastname: Gao
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: F
authors.initials: F
authors.lastname: Zhou
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: Q
authors.initials: Q
authors.lastname: Jin
authors.forename: L
authors.initials: L
authors.lastname: Gao
mesh_terms: D000230:Adenocarcinoma / Q000821:virology*; D002294:Carcinoma, Squamous Cell / Q000821:virology*; D004938:Esophageal Neoplasms / Q000821:virology*; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D006801:Humans; D007822:Laryngeal Neoplasms / Q000821:virology; D016017:Odds Ratio; D027383:Papillomaviridae / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000150:complications*; D015995:Prevalence; D012306:Risk; D012307:Risk Factors; D002583:Uterine Cervical Neoplasms / Q000821:virology