BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality, with a rapidly changing landscape of treatments. In the past 20 years, numerous randomized controlled trials (RCTs) have aimed at improving outcomes across disease stages. We aimed to analyze the current evidence and identify potential factors influencing response to therapies. METHODS: We conducted a systematic review of phase III RCTs (2002-2020) across disease stages. A meta-analysis was designed to examine the relationship between etiology and outcome after systemic therapies with either tyrosine-kinase inhibitor (TKI)/antiangiogenic or immune checkpoint inhibitor (ICI) therapy. RESULTS: Out of 10,100 studies identified, 76 were phase III RCTs. Among them, a rigorous screening algorithm identified 49 with high quality including a total of 22,113 patients undergoing adjuvant (n = 7) and primary treatment for early (n = 2), intermediate (n = 7), and advanced (first-line, n = 21; second-line, n = 12) stages of disease. Nine of these trials were positive, 6 treatments have been adopted in guidelines (sorafenib [2 RCTs], lenvatinib, atezolizumab+bevacizumab, regorafenib, cabozantinib and ramucirumab), but 2 were not (adjuvant CIK cells and sorafenib plus hepatic arterial infusion with FOLFOX). Meta-analysis of 8 trials including 3739 patients revealed ICI therapy to be significantly more effective in patients with viral hepatitis compared with nonviral-related HCC, whereas no differences related to etiology were observed in patients treated with TKI/anti-vascular endothelial growth factor. CONCLUSIONS: Among 49 high-quality RCTs conducted in HCC during 2002-2020, 9 resulted in positive results. A meta-analysis of systemic therapies suggests that immunotherapies may be more effective in viral etiologies.