[Clinical efficacy and relative factors of dendritic cell-based tumor vaccination for prostate cancer: a systematic review and meta-analysis].

OBJECTIVE: To evaluate the efficacy and safety of dendritic cell (DC)-based vaccines in the treatment of prostate cancer, and investigate the factors that influence the clinical benefit rate (CBR) of the vaccines. METHODS: Based on pre-determined search criteria, we searched the Medline database for randomized controlled trials on DC-based vaccines immunotherapy of prostate cancer. We systematically analyzed the identified studies using RevMan 5.0 and SPSS 17.0 softwares. RESULTS: Ten randomized controlled trials involving 179 prostate cancer patients were identified and subjected to meta-analysis. The CBR of the DC vaccines for prostate cancer was 54.2% , and the objective response rate was 7.7%. Most adverse effects were local reactions at the injection site, fever and flu-like symptoms. The prostate cancer patients achieved cellular immune response (OR = 31.12, 95% CI = 5.52-175.6, P < 0.01) and reduction of log PSA slope (OR = 4.38, 95% CI = 1.17-16.35, P = 0.03) after administration of DC vaccines, which was positively correlated with CBR. The dose of DC vaccines had a significant correlation with CBR (OR = 5.98, 95% CI = 1.45-24.62, P = 0.01), but not the age of the patients (P = 0.53). Besides, density-enriched DCs achieved a higher CBR, while the route of administration had no effect on CBR. CONCLUSION: DC-based vaccines are effective, safe and well-tolerated in the treatment of prostate cancer. DC-mediated cellular immune response has a significant effect on CBR and can be used as an important index for the assessment of vaccines. More multi-centered randomized controlled trials of higher quality and larger sample size are needed to provide more valid evidence.