title: Differential expression of biomarkers in primary non-small cell lung cancer and metastatic sites.
abstract: BACKGROUND
  The use of biomarkers to evaluate the presence of a target or to select a specific therapy is increasingly advocated. The correlation of biomarker expression between the primary tumor and its corresponding metastasis has not yet been well documented and analyzed in patients with non-small cell lung cancer (NSCLC).
  
  
  METHODS
  The expression of epidermal growth factor receptor (EGFR), excision repair cross-complementing (ERCC1), vascular-endothelial growth factor receptor, and Ki-67 was immunohistochemically analyzed in tumor samples of primary NSCLC and one corresponding metastasis in a population of 49 patients.
  
  
  RESULTS
  Sixteen cases (33%) displayed clear discordance in the EGFR status between the primary tumor and the metastasis, with a significant trend toward downregulation of EGFR in the metastasis (p = 0.01). The ERCC1 status was discordant in 20 cases (41%), with a trend toward overexpression in brain and adrenal metastases (p = 0.01 and p = 0.08, respectively). The vascular-endothelial growth factor receptor and Ki-67 statuses were discordant in 13 (27%) and 15 (31%) cases, respectively. No difference in expression was observed between synchronous and metachronous metastasis.
  
  
  CONCLUSIONS
  Biomarker expression is discordant between the primary tumor and its corresponding metastasis in about one third of patients with NSCLC. These findings should be considered in the setting of clinical trials and further explored using frozen material and high-throughput techniques.
authors.affiliation: Department of Medicine, Institut Gustave Roussy (IGR), Villejuif.
authors.forename: Carlos
authors.initials: C
authors.lastname: Gomez-Roca
authors.forename: Christophe M
authors.initials: CM
authors.lastname: Raynaud
authors.forename: Frederique
authors.initials: F
authors.lastname: Penault-Llorca
authors.forename: Olaf
authors.initials: O
authors.lastname: Mercier
authors.forename: Frederic
authors.initials: F
authors.lastname: Commo
authors.forename: Luc
authors.initials: L
authors.lastname: Morat
authors.forename: Laure
authors.initials: L
authors.lastname: Sabatier
authors.forename: Philipe
authors.initials: P
authors.lastname: Dartevelle
authors.forename: Estelle
authors.initials: E
authors.lastname: Taranchon
authors.forename: Benjamin
authors.initials: B
authors.lastname: Besse
authors.forename: Pierre
authors.initials: P
authors.lastname: Validire
authors.forename: Antoine
authors.initials: A
authors.lastname: Italiano
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Soria
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000378:metabolism / Q000473:pathology; D000310:Adrenal Gland Neoplasms / Q000378:metabolism* / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001859:Bone Neoplasms / Q000378:metabolism* / Q000556:secondary; D001932:Brain Neoplasms / Q000378:metabolism* / Q000556:secondary; D018287:Carcinoma, Large Cell / Q000378:metabolism / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D004268:DNA-Binding Proteins / Q000378:metabolism; D004720:Endonucleases / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D040262:Receptors, Vascular Endothelial Growth Factor / Q000378:metabolism; D015996:Survival Rate; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C512478:EGFR protein, human; D066246:ErbB Receptors; D040262:Receptors, Vascular Endothelial Growth Factor; C071447:ERCC1 protein, human; D004720:Endonucleases