title: Impact of chronic obstructive pulmonary disease on the mortality of patients with non-small-cell lung cancer.
abstract: BACKGROUND
  The impact of chronic obstructive pulmonary disease (COPD) on the mortality of patients with lung cancer has not been studied extensively. The objective of this study is to compare the mortality and clinical characteristics of patients with non-small-cell lung cancer (NSCLC) according to the presence of COPD.
  
  
  METHODS
  The medical records of 221 smokers diagnosed with NSCLC were reviewed. Eligible patients were dichotomized into the COPD group (n = 111) and the non-COPD group (n = 110). The overall survival and clinical characteristics were compared, and predictors of worse survival were analyzed using Cox proportional hazards regression.
  
  
  RESULTS
  COPD was present in 50.2% of all patients with NSCLC, and most of the patients (92.8%) with COPD were unaware of the disease before the diagnosis of lung cancer. Patients in the COPD group were older and had a lower body mass index, higher pack-years smoking history, higher frequency of dyspnea, and higher incidence of previous malignancy. The overall survival of enrolled patients and propensity score-matched subjects was comparable between the two groups (log-rank test, p = 0.2 and 0.396, respectively). Old age, low body mass index, advanced disease stage (stages III and IV), non-squamous histology, Eastern Cooperative Oncology Group performance status of greater than or equal to 2, weight loss, and coexistence of interstitial lung disease were independent risk factors for shorter survival.
  
  
  CONCLUSIONS
  COPD frequently and subliminally coexists with NSCLC. Although differences in clinical characteristic did exist, there was no impact of COPD on the mortality of patients with NSCLC with a positive smoking history in this study.
authors.affiliation: *Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Jinju; and †Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Lee
authors.forename: Jinwoo
authors.initials: J
authors.lastname: Lee
authors.forename: Young Sik
authors.initials: YS
authors.lastname: Park
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Lee
authors.forename: Sang-Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Jae-Joon
authors.initials: JJ
authors.lastname: Yim
authors.forename: Chul-Gyu
authors.initials: CG
authors.lastname: Yoo
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Han
authors.forename: Young Whan
authors.initials: YW
authors.lastname: Kim
mesh_terms: D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000473:pathology*; D015897:Comorbidity; D005260:Female; D006304:Health Status; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000401:mortality; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016609:Neoplasms, Second Primary / Q000401:mortality*; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality*; D012907:Smoking / Q000453:epidemiology; D015996:Survival Rate; D015431:Weight Loss