Efficacy and security of tumor vaccines for hepatocellular carcinoma: a systemic review and meta-analysis of the last 2 decades

Background Tumor vaccines for hepatocellular carcinoma (HCC) is an area of intense interest. Tremendous clinical trials have been conducted globally, but the efficacy and security of tumor vaccines are elusive. The aim of our study was to evaluate the efficacy and security of tumor vaccines. Methods All relevant studies were identified in PubMed, EMBASE, Web of science and Cochrane Library databases. Objective response rate (ORR), median overall survival (OS), or median progression-free survival (PFS) and 95% CI were meta-analyzed based on the random-effects model. The individual-level data of OS, PFS were pooled by conducting survival analysis. All observed adverse events were collected. Results 31 studies containing 35 eligible cohorts with 932 HCC patients were included. The pooled ORR were 7% (95% CI 3-14%), while ORR of dendritic cell (DC) vaccine (19%, 95% CI 11-29%) were highly significant than ORR of peptide vaccine (1%, 95% CI 0-5%). The pooled median OS and PFS were 13.67 months (95% CI 8.20-22.80) and 6.19 months (95% CI 2.97-12.91), respectively. The pooled median OS (DC vaccine: median OS = 21.77 months, 95% CI 18.33-25.86; Peptide vaccine: median OS = 10.08 months, 95% CI 5.23-19.44) and PFS (DC vaccine: median PFS = 11.01 months, 95% CI 5.25-23.09; Peptide vaccine: median PFS = 1.97 months, 95% CI 1.53-2.54) of DC vaccine were also longer than that of peptide vaccine. HBV-related HCC may acquire more benefits from tumor vaccines than HCV-related HCC. In almost all studies, the observed toxicities were moderate even tiny. Conclusions Tumor vaccines for HCC, especially DC vaccine, are safe and worth exploring. More high-quality prospective studies are warranted.

Automated summary

The study evaluated the efficacy and security of tumor vaccines for hepatocellular carcinoma (HCC). The results showed that tumor vaccines, especially DC vaccine, are safe and worth exploring. DC vaccine had a higher objective response rate (ORR) and longer median overall survival (OS)/progression-free survival (PFS) compared to peptide vaccine. HBV-related HCC may benefit more from tumor vaccines. However, more high-quality prospective studies are needed to further validate the efficacy and safety of tumor vaccines.