The prognostic significance of pretreatment plasma levels of insulin-like growth factor (IGF)-1, IGF-2, and IGF binding protein-3 in patients with advanced non-small cell lung cancer

Purpose: Insulin-like growth factor (IGF) system is related to cell proliferation and tumor growth. We tested whether pretreatment plasma levels of IGF-1, IGF-2, and IGF binding protein (IGFBP)-3 would predict the prognosis in patients with advanced non-small, cell lung cancer (NSCLC). Methods: Plasma levels of IGF-1, IGF-2, and IGFBP-3 were measured using enzyme-linked immunoassays from 77 patients with advanced NSCLC enrolled in a phase 11 study of irinotecan plus cisplatin chemotherapy. Results: IGF-2 and IGFBP-3 levels were elevated in female patients, non-squamous cell carcinoma, and never smokers. In a univariate Cox proportional hazards model, higher levels of IGF-1, IGF-2, and IGFBP-3 were predictive of Longer progression-free (P=0.001, 0.006, and 0.007, respectively) and overall survival (P=0.025, <0.0001, and 0.001, respectively). Multivariate analysis revealed that IGF-1 and IGFBP-3 are independent factors for progression-free survival (P< 0.0001 and P=0.001, respectively). In addition, IGF-1, IGF-2, and IGFBP-3 are independently predictive for overall survival (P = 0.004, 0.001, and 0.043, respectively). Conclusions: High plasma levels of IGF-1, IGF-2, and IGFBP-3 were associated with good prognosis in patients with advanced NSCLC. Further validation of these results is needed to determine the prognostic significance of IGF system in advanced NSCLC. (C) 2006 Elsevier Ireland Ltd. All rights reserved.