Overexpression of IGF-II and IGF-binding protein (IGFBP)-2 has been reported in several cancers. Objective: We aimed to assess the roles of plasma IGF-II and IGFBP-2 levels as diagnostic and prognostic biomarkers and the impact of loss of imprinting (LOI) of IGF-II on the survival of colorectal cancer (CRC). Design: We conducted a case control and prospective cohort study for diagnostic and prognostic values, respectively. Patients and Setting: Plasma levels of IGF-II and IGFBP-2 were measured in 162 patients with CRC before surgery, in paired 15 patients after curative surgery , in 24 patients with advanced colon polyps, and in 114 healthy controls between 2003 and 2006 in National Taiwan University Hospital. Results: The area under the curve values of using IGFBP-2 as a diagnostic marker for advanced colon polyp and CRC were 0.654 [95% confidence interval (CI) = 0.547-0.76; P = 0.017] and 0.815 ( 95% CI = 0.766-0.864; P