title: Impact of smoking on mortality of patients with non-small cell lung cancer.
abstract: Cigarette smoking is one of the major causes of lung cancer. However, the correlation between smoking status and the survival of patients with lung cancer is uncertain. The present study aimed to evaluate the impact of smoking status on the mortality of patients with non-small cell lung cancer (NSCLC).
  
  
  
  The medical records of 313 patients newly diagnosed with NSCLC between January 2005 and January 2006 were reviewed. Eligible patients were divided into ever-smokers (221 patients) and never-smokers (92 patients), and the overall survival and clinical characteristics of the two groups were compared. Predictors of survival were analyzed using Cox's proportional hazards regression.
  
  
  
  In ever-smokers, the mean age was higher, and male gender and squamous histology were predominant compared to never-smokers. The median survival time was longer in never-smokers (21.1 vs. 41.9 months, ever-smokers vs. never-smokers, respectively; P = 0.027). Overall survival estimates at 12, 24, and 60 months were 62.9 versus 82.6%, 43.4 versus 65.2%, and 31.2 versus 42.4%, in each group. Advanced age, advanced disease stage (stages III and IV), and coexistence of interstitial lung disease were analyzed as independent risk factors for shorter survival. Although ever-smoking was not an independent risk factor, current smoking was a risk factor for higher mortality.
  
  
  
  The overall mortality of ever-smokers was higher than that of never-smokers in patients with newly diagnosed NSCLC, and current smoking was an independent risk factor for a poorer prognosis.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine Seoul, Korea; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Gyeongsang National University Hospital Jinju, Korea.
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine Seoul, Korea.
authors.forename: Jinwoo
authors.initials: J
authors.lastname: Lee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine Seoul, Korea.
authors.forename: Young Sik
authors.initials: YS
authors.lastname: Park
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine Seoul, Korea.
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine Seoul, Korea.
authors.forename: Sang-Min
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine Seoul, Korea.
authors.forename: Jae-Joon
authors.initials: JJ
authors.lastname: Yim
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine Seoul, Korea.
authors.forename: Chul-Gyu
authors.initials: CG
authors.lastname: Yoo
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine Seoul, Korea.
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Han
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine Seoul, Korea.
authors.forename: Young Whan
authors.initials: YW
authors.lastname: Kim
keywords: Mortality; non-small cell lung cancer; risk factors; smoking