title: Detection of common and less frequent EGFR mutations in cytological samples of lung cancer.
abstract: OBJECTIVE
  Lung cancer represents the leading cause of cancer death. EGFR mutations, detected in 10-40% of lung adenocarcinomas, are an essential key to therapeutic management. EGFR-activated mutations comprise mainly deletions in exon 19 and point mutations in exon 21. Although histology is the traditional method of detection, we investigated the role of cytology in EGFR mutations.
  
  
  METHODS
  A total of 774 lung cancers were studied for EGFR mutations (676 histological and 98 cytological samples), including 424 adenocarcinomas, 326 non-small cell lung carcinomas not otherwise specified, and 24 squamous cell carcinomas.
  
  
  RESULTS
  We had a total of 164 (21.2%) cases of mutations. Common mutations were short in-frame deletions in exon 19 (53.7%) and single-nucleotide substitutions in exon 21 (34.1%); less frequent mutations included single-nucleotide substitutions in exon 18 (3.7%) and in-frame insertions/deletions in exon 20 (8.5%). Histologically, EGFR mutations in exons 19 and 21 occurred in 19.4% and in exons 18 and 20 in 2.2%, while the rates cytologically were 13.3% for exons 19 and 21 and 5.1% for exons 18 and 20.
  
  
  CONCLUSIONS
  The sensitivity for the detection of EGFR mutations in cytological samples overlaps histology, so the use of cytological material constitutes an adequate approach for treatment selection in patients with locally advanced or metastatic lung cancer.
authors.affiliation: Anatomic Pathology and Histology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Esther D
authors.initials: ED
authors.lastname: Rossi
authors.forename: Renê
authors.initials: R
authors.lastname: Gerhard
authors.forename: Luis
authors.initials: L
authors.lastname: Cirnes
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Machado
authors.forename: Fernando
authors.initials: F
authors.lastname: Schmitt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000235:genetics*; D003581:Cytodiagnosis; D005260:Female; D018773:Genes, erbB-1 / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D055815:Young Adult