title: Comparison between epidermal growth factor receptor (EGFR) gene expression in primary non-small cell lung cancer (NSCLC) and in fine-needle aspirates from distant metastatic sites.
abstract: OBJECTIVE
  Epidermal growth factor receptor (EGFR) gene copy number obtained by fluorescence in situ hybridization (FISH) has been recently found to predict treatment outcome in non-small cell lung cancer (NSCLC) patients receiving EGFR tyrosine kinase inhibitors. However, it is still unknown whether EGFR status differs in metastases compared with primary NSCLC. In all studies FISH have been performed on histologic material. The possibility to perform FISH analysis on cytologic material obtained by fine-needle aspiration from superficial and visceral metastases would allow us to know the real EGFR status avoiding invasive diagnostic procedures.
  
  
  METHODS
  EGFR gene copy number was analyzed by FISH on fine-needle aspirates obtained from 31 patients with metastatic NSCLC and the results were compared with those obtained on corresponding paraffin histologic sections from the primary tumor.
  
  
  RESULTS
  The feasibility of EGFR FISH on cytology was 90% (28 of 31 patients). EGFR FISH was positive in 61% (17 of 28 patients) of the metastases and in 36% (10 of 28 patients) of the primary tumors. Nine of the 28 cases (32%) were EGFR positive on both primary tumor and metastatic site and 10 (36%) were negative on both primary tumor and metastasis. Nine of the 28 cases (32%) showed discordance of primary tumor versus metastasis (McNemar test; p = 0.041).
  
  
  CONCLUSIONS
  EGFR FISH can be reliably assessed on fine-needle aspirates obtained from NSCLC metastases. We found that EGFR gene copy number is discordant between primary NSCLC and the corresponding distant metastatic sites in a significant proportion of cases. These findings should be considered in future studies designed to elucidate the predictive role of EGFR FISH in NSCLC.
authors.affiliation: Division of Medical Oncology, University Hospital of Parma, Parma, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Bozzetti
authors.forename: Marcello
authors.initials: M
authors.lastname: Tiseo
authors.forename: Costanza
authors.initials: C
authors.lastname: Lagrasta
authors.forename: Rita
authors.initials: R
authors.lastname: Nizzoli
authors.forename: Annamaria
authors.initials: A
authors.lastname: Guazzi
authors.forename: Francesco
authors.initials: F
authors.lastname: Leonardi
authors.forename: Donatello
authors.initials: D
authors.lastname: Gasparro
authors.forename: Elena
authors.initials: E
authors.lastname: Spiritelli
authors.forename: Michele
authors.initials: M
authors.lastname: Rusca
authors.forename: Paolo
authors.initials: P
authors.lastname: Carbognani
authors.forename: Maria
authors.initials: M
authors.lastname: Majori
authors.forename: Vittorio
authors.initials: V
authors.lastname: Franciosi
authors.forename: Guido
authors.initials: G
authors.lastname: Rindi
authors.forename: Andrea
authors.initials: A
authors.lastname: Ardizzoni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005240:Feasibility Studies; D005260:Female; D018628:Gene Dosage; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis
chemical_list: D066246:ErbB Receptors