title: The prognostic impact of the amount of tobacco smoking in non-small cell lung cancer--differences between adenocarcinoma and squamous cell carcinoma.
abstract: BACKGROUND
  The purpose of this study was to investigate the relationship between the level of tobacco smoking and the clinicopathological features of non-small cell lung cancer (NSCLC) patients, individually for adenocarcinoma (Ad) and squamous cell carcinoma (Sq).
  
  
  METHODS
  We retrospectively reviewed the clinical records of 1825 consecutive lung cancer patients who underwent surgery in our department. Among these, the data sets of 750 Ad patients and 364 Sq patients who received lobectomy or more extensive resection were available.
  
  
  RESULTS
  In Ad patients, those who had never smoked (never-smokers) (n=309) were more likely to be female, to have less advanced stage tumors, and to have a significantly better prognosis than those who had ever smoked (ever-smokers) (n=441) (5-year OS: never-smokers, 67.9%; ever-smokers, 53.7%, p<0.0001). In Sq patients, the never-smokers (n=15) were more likely to be female than the ever-smokers (n=349). Among ever-smokers, the light-smokers (PY≤30; n=56) were associated with more female patients, more advanced stage tumors, and significantly worse prognoses than were the heavy smokers (PY>30; n=292) (p=0.0003). The multivariate survival analysis showed that light smoking was related to a worse prognosis compared with heavy smoking (HR=2.06, 95% CI 1.43-2.98, p=0.0001).
  
  
  CONCLUSIONS
  The never-smokers had a significantly better prognosis than ever-smokers among Ad patients, whereas the light-smokers had a significantly worse prognosis than heavy smokers among Sq patients. There may be factors other than tobacco carcinogens that influence the development of Sq in never and/or light smokers.
authors: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan. Electronic address: tatsuro@surg2.med.kyushu-u.ac.jp.
authors: Tatsuro
authors: T
authors: Okamoto
authors: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan.
authors: Yuzo
authors: Y
authors: Suzuki
authors: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan.
authors: Takatoshi
authors: T
authors: Fujishita
authors: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan.
authors: Hirokazu
authors: H
authors: Kitahara
authors: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan.
authors: Shinichiro
authors: S
authors: Shimamatsu
authors: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan.
authors: Mikihiro
authors: M
authors: Kohno
authors: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan.
authors: Yosuke
authors: Y
authors: Morodomi
authors: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan.
authors: Daigo
authors: D
authors: Kawano
authors: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan.
authors: Yoshihiko
authors: Y
authors: Maehara
mesh_terms: D000230:Adenocarcinoma; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology* / Q000601:surgery; D002294:Carcinoma, Squamous Cell; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D016019:Survival Analysis
keywords: Adenocarcinoma; Non-small cell lung cancer; Prognosis; Smoking; Squamous cell carcinoma; Tobacco