title: Influence of cigarette smoking on histological subtypes of stage I lung adenocarcinoma.
abstract: BACKGROUND
  The purpose of this study was to examine the association between cigarette smoking and histological subtypes of lung adenocarcinoma.
  
  
  METHODS
  We reviewed a total of 320 consecutive patients with stage I adenocarcinoma who underwent complete resections with systematic node dissections from January 2004 to December 2006 at the National Cancer Center Hospital East.
  
  
  RESULTS
  A statistically significant difference was observed in recurrence-free probabilities between never smokers and ever smokers (3-year recurrence-free probabilities of 95.6% and 88.6%, respectively, p = 0.034). Among adenocarcinoma histological subtypes, only a solid component was significantly more frequent in ever smokers than in never smokers (p < 0.001). Among patients with solid components, significantly more cases had lymphatic permeation (p = 0.007), intratumoral vascular invasion (p < 0.001), and visceral pleural invasion (p < 0.001). Multivariate analysis revealed that ever-smoking history was the only statistically significant independent clinical predictor for a solid component (p < 0.001). Among ever smokers, smoking extent in pack-years of patients with solid components was significantly greater than that of those without solid components (p < 0.001). With respect to predominant subtypes, smoking extent in pack-years of patients with predominantly solid adenocarcinomas was significantly greater than that of patients with predominantly bronchioloalveolar carcinoma, papillary, or acinar adenocarcinomas (all p < 0.001).
  
  
  CONCLUSIONS
  A greater smoking extent was associated with the presence of adenocarcinoma solid components, which may have more aggressive biological features resulting in poorer outcomes.
authors.affiliation: Department of Thoracic Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Maeda
authors.forename: Genichiro
authors.initials: G
authors.lastname: Ishii
authors.forename: Junji
authors.initials: J
authors.lastname: Yoshida
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Hishida
authors.forename: Mitsuyo
authors.initials: M
authors.lastname: Nishimura
authors.forename: Kanji
authors.initials: K
authors.lastname: Nagai
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000209:etiology / Q000473:pathology / Q000601:surgery; D000368:Aged; D018267:Carcinoma, Acinar Cell / Q000209:etiology / Q000473:pathology / Q000601:surgery; D002289:Carcinoma, Non-Small-Cell Lung / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D002291:Carcinoma, Papillary / Q000209:etiology / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D008297:Male; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D015996:Survival Rate