Insulin-like growth factor receptor 1 (IGF1R) expression and survival in surgically resected non-small-cell lung cancer (NSCLC) patients

Abstract

BackgroundThe purpose of this study is to investigate the prognostic role of insulin-like growth factor receptor 1 (IGF1R) expression in surgically resected non-small-cell lung cancer (NSCLC). Patient characteristics and methodsThis retrospective study was conducted in 369 stage I–II–IIIA, surgically resected, NSCLC patients. Patients exposed to anti-epidermal growth factor receptor (EGFR) agents were excluded. IGF1R expression was evaluated by immunohistochemistry in tissue microarray sections. ResultsA positive IGF1R expression (score≥100) was observed in 282 cases (76.4%) and was significantly associated with squamous cell histology (P=0.04) and with grade III differentiation (P=0.02). No difference in survival was observed between the positive and negative group when score 100 was used as cut-off for discriminating a positive versus a negative IGF1R result (52 versus 48 months, P=0.99) or when median value of IGF1R expression was used (45 versus 55 months, P=0.36). No difference in survival was observed between IGF1R-positive and -negative patients in a subgroup of stage I–II adenocarcinoma (n=137) with known EGFR mutation and copy number status. ConclusionsIGF1R expression does not represent a prognostic factor in resected NSCLC patients. Patients with squamous cell carcinoma overexpress IGF1R more frequently than patients with nonsquamous histology, justifying the different sensitivity to anti-IGF1R agents observed in clinical trials.