title: Lungs don't forget: Comparison of the KRAS and EGFR mutation profile and survival of collegiate smokers and never smokers with advanced lung cancers.
abstract: BACKGROUND
  We hypothesize that among patients with lung cancers the KRAS/EGFR mutation profile and overall survival of collegiate smokers (former smokers who smoked between 101 lifetime cigarettes and 5 pack-years) are distinct from those of never smokers and former smokers with 15 pack-years or more.
  
  
  METHODS
  We collected age, sex, stage, survival, and smoking history for patients evaluated from 2004 to 2009 with advanced stage lung cancers and known KRAS/EGFR status. Mutation profile and overall survival were compared using Fisher's exact test and log-rank test, respectively.
  
  
  RESULTS
  Data were available for 852 patients with advanced-stage lung cancers with known KRAS/EGFR status, of which 6% were collegiate smokers, 36% were never smokers, and 30% were former smokers with 15 pack-years or more. The mutation profile of collegiate smokers (15% KRAS mutations, 27% EGFR mutations) was distinct from those of never smokers (p < 0.001) and former smokers with 15 pack-years or more (p < 0.001) and not significantly different from those of former smokers with 5 to 15 pack-years (p = 0.9). Median overall survival for collegiate smokers was 25 months, compared with 32 months for never smokers (p = 0.4), 33 months for former smokers with 5 to 15 pack-years (p = 0.48), and 21 months for former smokers with 15 pack-years or more (p = 0.63).
  
  
  CONCLUSIONS
  Collegiate smokers with advanced-stage lung cancers represent a distinct subgroup of patients with a higher frequency of KRAS mutations and lower frequency of EGFR mutations compared with never smokers. These observations reinforce the recommendation for routine mutation testing for all patients with lung cancers and that no degree of tobacco exposure is safe.
authors.affiliation: Department of Medicine, Division of Solid Tumor Oncology, Thoracic Oncology Service, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Varghese
authors.forename: Camelia S
authors.initials: CS
authors.lastname: Sima
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Chaft
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Johnson
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Riely
authors.forename: Marc
authors.initials: M
authors.lastname: Ladanyi
authors.forename: Mark G
authors.initials: MG
authors.lastname: Kris
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018278:Carcinoma, Neuroendocrine / Q000235:genetics* / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000473:pathology; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009367:Neoplasm Staging; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D012907:Smoking / Q000009:adverse effects*; D016540:Smoking Cessation; D018631:ras Proteins / Q000235:genetics*
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D066246:ErbB Receptors; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins