title: Utility of insulin-like growth factor receptor-1 expression in gefitinib-treated patients with non-small cell lung cancer.
abstract: BACKGROUND
  Insulin-like growth factor receptor 1 (IGF1R) is a proposed mechanism of resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors. Newer agents targeting this pathway make it of clinical interest. This study evaluates the IGF1R expression in regard to outcomes and molecular markers of EGFR activity in lung cancer patients treated with gefitinib.
  
  
  METHODS
  Gefitinib-treated patients with sufficient archived tissue were included. The IGF1R activity was measured by immunohistochemistry and the EGFR by immunohistochemistry, fluorescent in situ hybridization, and gene mutation testing. Logistic regression and cox proportional hazards models were used.
  
  
  RESULTS
  A total of 83 patients were included in the study: 71% were positive for IGF1R expression which was not associated with EGFR parameters or clinical outcomes. Exploratory analyses showed counter-intuitive improved outcomes with co-expression of IGF1R and EGFR.
  
  
  CONCLUSIONS
  IGF1R expression measured by immunohistochemistry does not appear to be related to gefitinib resistance.
authors.affiliation: Section of Medical Oncology, Rush University Medical Center, Chicago, IL, USA. mary_fidler@rush.edu
authors.forename: Mary Jo
authors.initials: MJ
authors.lastname: Fidler
authors.forename: Sanjib
authors.initials: S
authors.lastname: Basu
authors.forename: Lela
authors.initials: L
authors.lastname: Buckingham
authors.forename: Kelly
authors.initials: K
authors.lastname: Walters
authors.forename: Sharon
authors.initials: S
authors.lastname: McCormack
authors.forename: Marta
authors.initials: M
authors.lastname: Batus
authors.forename: John
authors.initials: J
authors.lastname: Coon
authors.forename: Philip
authors.initials: P
authors.lastname: Bonomi
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000737:chemistry / Q000188:drug therapy*; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D000077156:Gefitinib; D018628:Gene Dosage; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000737:chemistry / Q000188:drug therapy*; D008297:Male; D011799:Quinazolines / Q000627:therapeutic use*; D017526:Receptor, IGF Type 1 / Q000032:analysis* / Q000037:antagonists & inhibitors* / Q000502:physiology; D015398:Signal Transduction
chemical_list: D000970:Antineoplastic Agents; D011799:Quinazolines; D066246:ErbB Receptors; D017526:Receptor, IGF Type 1; D000077156:Gefitinib