['Patients with liver cirrhosis or hepatocellular carcinoma (HCC) have decreased serum insulin-like growth factor (IGF)-1 levels. We evaluated whether IGF-1 levels were associated with the outcomes of patients with advanced HCC treated with systemic antiangiogenic therapy.', 'The study was based on patients with advanced HCC who were enrolled in two clinical trials evaluating first-line combination antiangiogenic therapy. Serum samples were collected before treatment and four to six weeks after the start of treatment. The levels of IGF-1, IGF-2, and IGF-binding protein-3 (IGFBP3) were analyzed for their associations with treatment outcomes.', 'A total of 83 patients were included in the study. Patients who had high (≥the median level) baseline IGF-1 levels had significantly higher disease control rate (DCR) than patients who had low (<the median level) levels (71% vs. 39%, P = 0.003). The levels of posttreatment IGF-1, and pre- or posttreatment IGF-2 and IGFBP3 were not associated with DCR. Patients with high baseline IGF-1 levels, compared with patients with low levels, had significantly longer progression-free survival (PFS; median, 4.3 vs. 1.9 months, P = 0.014) and overall survival (OS; median, 10.7 vs. 3.9 months, P = 0.009). The high baseline IGF-1 level remains an independent factor associated with favorable PFS and OS in multivariate analysis.'] Do serum insulin-like growth factor-1 levels predict outcomes of patients with advanced hepatocellular carcinoma receiving antiangiogenic therapy?