Prognostic significance of insulin growth factor-I receptor and insulin growth factor binding protein-3 expression in primary breast cancer

We analyzed insulin-like growth factor receptor I (IGF-IR) and insulin growth factor binding protein-3 (IGFBP-3) expression with respect to overall survival and relapse-free survival (RFS) in 460 patients with primary invasive breast cancer using immunohistochemistry. IGF-IR expression had a significant positive correlation with positive estrogen receptor (ER), positive progesterone receptor (PR) and Bcl-2 expression. Univariate analysis showed significantly better overall survival (p=0.000) and RFS (p=0.004), in the IGF-IR-positive group. Multivariate analysis showed a significant reduction in relative risk for overall survival (p=0.019, HR=0.221, 95% CI=0.062-0.780) and RFS (p=0.026, HR=0.462, 95% CI=0.234-0.913) in the IGF-IR-positive group. IGF-IR expression in primary breast cancer is an independent favorable prognostic factor. IGFBP-3 expression in breast cancer is associated with poor outcome.