title: Increased risk of lung cancer among patients with bronchiectasis: a nationwide cohort study.
abstract: BACKGROUND
  We conducted a longitudinal nationwide cohort study in Taiwan to determine whether patients with bronchiectasis are at an increased risk of developing lung cancer.
  
  
  METHODS
  This study investigated the incidence and risk for lung cancer in 57 576 patients newly hospitalized with bronchiectasis between 1998 and 2010 from the Taiwan National Health Insurance Research Database. The comparison cohort comprised 230 304 individuals from the general population without bronchiectasis. The follow-up period was from the time of the initial hospitalization for bronchiectasis to the date of a lung cancer diagnosis, censoring, or 31 December 2011. We used Cox proportional hazard regression models to analyse the risk of lung cancer by including the variables of sex, age and comorbidities.
  
  
  RESULTS
  The incidence of lung cancer was higher in patients with bronchiectasis than in the comparison cohort (4.58 vs. 2.02 per 1000 person-years). The bronchiectasis patients exhibited a 2.36-fold increased risk of lung cancer compared with the comparison cohort after adjustment for age, sex and comorbidities (adjusted hazard ratio [aHR] = 2.36, 95% confidence interval [CI] = 2.19-2.55). The sex-specific bronchiectasis cohort to comparison cohort revealed that the aHR was 2.41 (95% CI = 2.11-2.76) for the women and 2.33 (95% CI = 2.12-2.56) for the men. The incidence rate of lung cancer increased as age increased in both cohorts.
  
  
  CONCLUSIONS
  This nationwide study determined that the patients with bronchiectasis exhibited an increased risk of lung cancer compared with the general population.
authors.affiliation: From the Department of Internal Medicine, Taichung Hospital, Ministry of Health and Welfare, Taichung, Department of Health Services Administration, China Medical University, Department of Healthcare Administration, Central Taiwan University of Science and Technology, Taichung.
authors.forename: W-S
authors.initials: WS
authors.lastname: Chung
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, College of Medicine, China Medical University, Taichung.
authors.forename: C-L
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Department of Respiratory and Critical Care, China Medical University Hospital, Taichung, Graduate Institute of Clinical Medical Science and School of Medicine, College of Medicine, China Medical University, Taichung and.
authors.forename: W-H
authors.initials: WH
authors.lastname: Hsu
authors.affiliation: Graduate Institute of Clinical Medical Science and School of Medicine, College of Medicine, China Medical University, Taichung and Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan d10040@mail.cmuh.org.tw.
authors.forename: C-H
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001987:Bronchiectasis / Q000453:epidemiology*; D015897:Comorbidity; D016208:Databases, Factual; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008175:Lung Neoplasms / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D012737:Sex Factors; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult