title: Association between adult otitis media and nasopharyngeal cancer: a nationwide population-based cohort study.
abstract: OBJECTIVE
  To determine whether the diagnosis of otitis media (OM) in adults is associated with an increased risk for the subsequent development of nasopharyngeal cancer (NPC) using a nationwide population-based retrospective study.
  
  
  METHODS
  We selected 13,513 adult patients that had been previously diagnosed with OM between 2000 and 2005 from the Taiwan Longitudinal Health Insurance Database 2000 as the study cohort, and randomly extracted the data of 135,130 participants matched by sex, age, and baseline year for the comparison cohort. The follow-up period was terminated upon developing NPC, withdrawal from the national health insurance system, or the end of 2009. Cumulative incidences and hazard ratios (HRs) of NPC development were determined.
  
  
  RESULTS
  The subsequent NPC incidence rates in the OM and comparison cohorts were 6.41 and 0.58 per 10000 person-years, respectively (adjusted HR, 11.04; 95% CI, 7.68-5.87; P<0.0001). The NPC risk for males was significantly higher than that for females (adjusted HR=3.24; 95% CI, 2.16-4.85). In both female and male patients, the diagnosis of OM was associated with a significantly increased risk for NPC (adjusted HR, 11.91 vs. 10.78, respectively). Among the OM cohort, 62 participants were subsequently diagnosed with NPC, with 71% of them occurring within 1 year following the diagnosis of OM. However, even after 5-year follow-up, the OM cohort still displayed a higher risk for NPC (adjusted HR=2.50). Stratified by the frequency of OM episodes, more than one episode per year had a significantly greater risk of developing NPC, compared with the comparison cohort (HR=29.22; 95% CI, 20.19-42.27).
  
  
  CONCLUSIONS
  We found that adult OM is a warning sign for the development of NPC in Taiwan, with approximately an 11-fold higher risk for adult OM patients. We recommend that OM patients undergo follow-up examinations for at least 5 years. To extrapolate our findings, further studies are warranted in other areas in which NPC is endemic.
authors.affiliation: Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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: Kuen-Tze
authors.initials: KT
authors.lastname: Lin
authors.forename: Muh-Hwa
authors.initials: MH
authors.lastname: Yang
authors.forename: Chang-Ming
authors.initials: CM
authors.lastname: Chen
authors.forename: Ying-Nan
authors.initials: YN
authors.lastname: Chang
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000209:etiology*; D010033:Otitis Media / Q000150:complications*; D012189:Retrospective Studies; D012306:Risk; D012727:Sex Characteristics