Neoadjuvant immunotherapy for resectable hepatocellular carcinoma: a systematic review and meta-analysis

OBJECTIVE: Immune checkpoint inhibitors have initiated a new era in hepatocellular carcinoma (HCC) treatment. For improving the prognosis of patients with resectable HCC and reducing postoperative recurrence, immunotherapy is being developed in the neoadjuvant setting. However, the efficacy and safety of neoadjuvant immunotherapy remain unclear. MATERIALS AND METHODS: PubMed, Embase, Medline, and Cochrane Library databases were systematically searched for the clinical trials of neoadjuvant immunotherapy for resectable HCC. A single-arm meta-analysis was conducted to calculate the odds ratio and 95% confidence interval (CI), and statistical transformation was performed to obtain the pooled rate P(t) and its CI. Subgroup analyses were performed according to the type of combination therapy. RESULTS: 81 patients from four studies were included in this meta-analysis. In patients with resectable HCC, the pooled major pathological response (MPR) rate and pathological complete response (pCR) rate for neoadjuvant immunotherapy were 0.23 (95% CI, 0.14-0.36) and 0.19 (95% CI, 0.10-0.30), respectively. The pooled objective response rate (ORR) was 0.18 (95% CI, 0.10-0.28), comparable to the results of immunotherapy for advanced HCC. The overall treatment-related adverse events (TRAE) rate was 0.80 (95% CI, 0.68-0.89), but the grade >= 3 TRAE rate was low at 0.21 (95% CI, 0.13-0.33). The pooled surgical resection rate and surgical delay rate were 0.95 (95% CI, 0.85-0.98) and 0.05 (95% CI, 0.02-0.16), respectively. Subgroup analyses revealed no significant differences in clinical outcomes between immunotherapy combinations. CONCLUSIONS: This meta-analysis provides preliminary evidence of the efficacy and safety of neoadjuvant immunotherapy for HCC, suggesting that it is a promising perioperative treatment option. Conclusive evidence supporting its use requires additional data from large-scale clinical trials.