title: The association between combined non-cystic fibrosis bronchiectasis and lung cancer in patients with chronic obstructive lung disease.
abstract: BACKGROUND
  Whereas the epidemiological association between lung cancer and chronic obstructive pulmonary disease (COPD), a chronic inflammatory respiratory disease, is well known, limited studies have examined the association between lung cancer and non-cystic fibrosis bronchiectasis, a representative chronic airway inflammatory disease. This study evaluated the association between bronchiectasis and lung cancer in patients with COPD.
  
  
  METHODS
  A matched case-control study was conducted in a referral hospital in South Korea. Among COPD patients with moderate to very severe airflow limitation (forced expiratory volume in one second/forced vital capacity <0.7 and forced expiratory volume in one second ≤70% [% predicted]) who underwent chest computed tomography (CT) between January 1, 2010 and May 30, 2013, patients with lung cancer and controls matched for age, sex, and smoking history were selected. The risk of lung cancer was assessed according to the presence of underlying bronchiectasis confirmed by chest CT.
  
  
  RESULTS
  The study enrolled 99 cases and 198 controls. Combined bronchiectasis on chest CT was inversely associated with the risk of lung cancer compared with controls (odds ratio [OR] 0.25, 95% confidence interval [CI] 0.12-0.52, P<0.001). Significant associations were found in patients with squamous cell carcinoma (OR 0.11, 95% CI 0.03-0.49, P=0.001) and history of smoking (OR 0.27, 95% CI 0.12-0.57, P<0.001). However, the severity and location of bronchiectasis were not associated with the risk of lung cancer.
  
  
  CONCLUSIONS
  Interestingly, the concomitant presence of bronchiectasis in COPD patients was associated with a lower risk of lung cancer.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yeon Wook
authors.initials: YW
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Republic of Korea.
authors.forename: Kwang-Nam
authors.initials: KN
authors.lastname: Jin
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Republic of Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Heo
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Republic of Korea.
authors.forename: Sung Soo
authors.initials: SS
authors.lastname: Park
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Republic of Korea.
authors.forename: Hee Soon
authors.initials: HS
authors.lastname: Chung
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Republic of Korea.
authors.forename: Deog Kyeom
authors.initials: DK
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D000077192:Adenocarcinoma of Lung; D000368:Aged; D001987:Bronchiectasis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012720:Severity of Illness Index; D055752:Small Cell Lung Carcinoma / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D014057:Tomography, X-Ray Computed; D014797:Vital Capacity
keywords: COPD; bronchiectasis; chronic inflammation; lung cancer