['Antiangiogenic therapy has become the most important treatment modality for patients with advanced hepatocellular carcinoma (HCC). In this study, the authors investigated levels of alpha-fetoprotein (AFP) as a potential biomarker for treatment efficacy of antiangiogenic therapy.', 'Patients with advanced HCC who had been enrolled in 3 prospective phase 2 clinical trials that evaluated either sorafenib, bevacizumab, or thalidomide in combination with a potentially antiangiogenic, metronomic, oral 5-fluoropyrimidine as first-line systemic therapy were included. An early AFP response was defined as a decline >20% from baseline after 2 to 4 weeks of treatment. AFP response was analyzed for its association with treatment efficacy and survival outcome.', 'Seventy-two patients were included for early AFP response evaluation, and 12 of those patients (17%) were classified as early AFP responders. Early AFP responders, compared with nonresponders, had a significantly improved overall response rate (33% vs 8%; P=.037) and a significantly improved disease control rate (83% vs 35%; P=.002), which was defined as the percentage of patients who had an objective response plus stable disease for a minimum of 8 weeks. AFP responders, compared with nonresponders, also had longer median progression-free survival (PFS) (7.5 months vs 1.9 months; P=.001) and longer median overall survival (OS) (15.3 months vs 4.1 months; P=.019). In a multivariate analysis, AFP response remained a significant independent predictor of better PFS and OS.'] Does early alpha-fetoprotein response predict treatment efficacy of antiangiogenic systemic therapy in patients with advanced hepatocellular carcinoma?