title: Cigarette smoking is strongly associated with mutation of the K-ras gene in patients with primary adenocarcinoma of the lung.
abstract: BACKGROUND
  The majority of lung carcinoma cases occur in current or former smokers. K-ras gene mutations are common in lung adenocarcinoma and have been associated with cigarette smoking, asbestos exposure, and female gender.
  
  
  METHODS
  In the current study, the authors examined the contribution of cigarette smoking to K-ras gene mutations in patients with primary lung adenocarcinoma. Smoking histories were obtained from 106 prospectively enrolled patients with primary adenocarcinoma of the lung.
  
  
  RESULTS
  K-ras mutations were detected in the primary tumor using an allele-specific ligation assay. Ninety-two of the 106 patients (87%) with lung adenocarcinoma were smokers. Nonsmokers with this tumor were more likely to be women (11 of 14; 79%), whereas the majority of smokers (57%) were men. K-ras mutations were detected in 40 of 106 tumors (38%) and were significantly more common in smokers compared with nonsmokers (43% vs. 0%; P = 0.001).
  
  
  CONCLUSIONS
  The results of the current study confirm and extend previous observations that smokers with adenocarcinoma of the lung are more likely to have K-ras mutant tumors compared with nonsmokers. The strong link between cigarette smoking and K-ras mutations in adenocarcinoma of the lung supports the role of specific tobacco carcinogens in the etiology of this malignancy.
authors.affiliation: Department of Surgery, University of Rochester, Rochester, New York 14642, USA. Steven_Ahrendt@urmc.rochester.edu
authors.forename: S A
authors.initials: SA
authors.lastname: Ahrendt
authors.forename: P A
authors.initials: PA
authors.lastname: Decker
authors.forename: E A
authors.initials: EA
authors.lastname: Alawi
authors.forename: Y R
authors.initials: YR
authors.lastname: Zhu Yr
authors.forename: M
authors.initials: M
authors.lastname: Sanchez-Cespedes
authors.forename: S C
authors.initials: SC
authors.lastname: Yang
authors.forename: G B
authors.initials: GB
authors.lastname: Haasler
authors.forename: A
authors.initials: A
authors.lastname: Kajdacsy-Balla
authors.forename: M J
authors.initials: MJ
authors.lastname: Demeure
authors.forename: D
authors.initials: D
authors.lastname: Sidransky
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology*; D000368:Aged; D005260:Female; D011905:Genes, ras / Q000276:immunology*; D006801:Humans; D008175:Lung Neoplasms / Q000276:immunology*; D008297:Male; D009154:Mutation; D011446:Prospective Studies; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects*