Molecular epidemiology of EGFR and KRAS mutations in 3,026 lung adenocarcinomas: higher susceptibility of women to smoking-related KRAS-mutant cancers. Academic Article uri icon



  • PURPOSE: The molecular epidemiology of most EGFR and KRAS mutations in lung cancer remains unclear. EXPERIMENTAL DESIGN: We genotyped 3,026 lung adenocarcinomas for the major EGFR (exon 19 deletions and L858R) and KRAS (G12, G13) mutations and examined correlations with demographic, clinical, and smoking history data. RESULTS: EGFR mutations were found in 43% of never smokers and in 11% of smokers. KRAS mutations occurred in 34% of smokers and in 6% of never smokers. In patients with smoking histories up to 10 pack-years, EGFR predominated over KRAS. Among former smokers with lung cancer, multivariate analysis showed that, independent of pack-years, increasing smoking-free years raise the likelihood of EGFR mutation. Never smokers were more likely than smokers to have KRAS G > A transition mutation (mostly G12D; 58% vs. 20%, P = 0.0001). KRAS G12C, the most common G > T transversion mutation in smokers, was more frequent in women (P = 0.007) and these women were younger than men with the same mutation (median 65 vs. 69, P = 0.0008) and had smoked less. CONCLUSIONS: The distinct types of KRAS mutations in smokers versus never smokers suggest that most KRAS-mutant lung cancers in never smokers are not due to second-hand smoke exposure. The higher frequency of KRAS G12C in women, their younger age, and lesser smoking history together support a heightened susceptibility to tobacco carcinogens.

publication date

  • September 26, 2012



  • Adenocarcinoma
  • ErbB Receptors
  • Lung Neoplasms
  • Mutation, Missense
  • Proto-Oncogene Proteins
  • Smoking
  • ras Proteins


PubMed Central ID

  • PMC3500422

Scopus Document Identifier

  • 84869224992

Digital Object Identifier (DOI)

  • 10.1158/1078-0432.CCR-11-3265

PubMed ID

  • 23014527

Additional Document Info


  • 18


  • 22