Systemic conversion therapies for initially unresectable hepatocellular carcinoma: a systematic review and meta-analysis

Abstract Background Systemic conversion therapy provides patients with initially unresectable hepatocellular carcinoma (HCC) the chance to salvage radical liver resection and superior survival outcomes, but the optimal conversion strategy is unclear. Methods A systematic literature search was conducted on PubMed, EMBASE, Web of Science, Scopus, and the Cochrane Library between 2007 and 2024 focusing on studies reporting conversion therapy for HCC. The treatment groups were divided into Tyrosine kinase inhibitors (TKI), TKI plus loco-regional therapy (LRT), TKI plus anti-PD-1 therapy (TKI + PD-1), TKI + PD-1 + LRT, immune checkpoint inhibitors (ICI) plus LRT, and Atezolizumab plus bevacizumab (A + T) groups. The conversion to surgery rate (CSR), objective response rate (ORR), grade ≥ 3 treatment-related adverse events (AEs), overall survival (OS) and progression-free survival (PFS) were analyzed. Results 38 studies and 4,042 patients were included. The pooled CSR were 8% (95% CI, 5-12%) in TKI group, 13% (95% CI, 8-19%) in TKI + LRT group, 28% (95% CI, 19-37%) in TKI + PD-1 group, 33% (95% CI, 25-41%) in TKI + PD-1 + LRT group, 23% (95% CI, 1-46%) in ICI + LRT group, and 5% (95% CI, 3-8%) in A + T group, respectively. The pooled HR for OS (0.45, 95% CI, 0.35–0.60) and PFS (0.49, 95% CI, 0.35–0.70) favored survival benefit of conversion surgery. Subgroup analysis revealed that lenvatinib + PD-1 + LRT conferred higher CSR of 35% (95% CI, 26-44%) and increased ORR of 70% (95% CI, 56-83%). Conclusions The current study indicates that TKI + PD-1 + LRT, especially lenvatinib + PD-1 + LRT, may be the superior conversion therapy with a manageable safety profile for patients with initially unresectable HCC. The successful conversion therapy favors the superior OS and PFS compared with systemic treatment alone. Trial registration International prospective register of systematic reviews (PROSPERO) (registration code: CRD 42024495289).