title: Subsequent risk of nasopharyngeal carcinoma among patients with allergic rhinitis: a nationwide population-based cohort study.
abstract: BACKGROUND
  The purpose of this study was to examine the risk of nasopharyngeal carcinoma (NPC) after a diagnosis of allergic rhinitis.
  
  
  METHODS
  We identified 67,532 patients with allergic rhinitis (allergic rhinitis cohort) and a 135,064 control cohort with the same mean age and sex ratio by using a Taiwan Longitudinal Health Insurance Database (LHID) sample from 2000 to 2005.
  
  
  RESULTS
  After adjusting for the possible confounding factors of the study, the allergic rhinitis cohort had a 2.33-fold higher risk of developing NPC than did the comparison cohort. The frequency of allergic rhinitis visits was correlated with the risk of subsequent NPC. Patients with 4 or more allergic rhinitis visits per year were significantly associated with increasingly developing NPC risk.
  
  
  CONCLUSIONS
  Patients with allergic rhinitis might be associated with subsequent NPC in Taiwan. Those who had repeated visits for allergic rhinitis had even higher risk for NPC. Physicians should be aware of the link when assessing patients with allergic rhinitis.
authors.affiliation: Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Kuen-Tze
authors.initials: KT
authors.lastname: Lin
authors.forename: Wen-Yen
authors.initials: WY
authors.lastname: Huang
authors.forename: Che-Chen
authors.initials: CC
authors.lastname: Lin
authors.forename: Yee-Min
authors.initials: YM
authors.lastname: Jen
authors.forename: Chun-Shu
authors.initials: CS
authors.lastname: Lin
authors.forename: Cheng-Hsiang
authors.initials: CH
authors.lastname: Lo
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D011230:Precancerous Conditions / Q000453:epidemiology* / Q000473:pathology; D011379:Prognosis; D012016:Reference Values; D012189:Retrospective Studies; D065631:Rhinitis, Allergic / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D012720:Severity of Illness Index; D016019:Survival Analysis; D013624:Taiwan; D016896:Treatment Outcome
keywords: National Health Insurance; National Health Insurance Research Database; allergic rhinitis; cohort study; nasopharyngeal carcinoma