Clinical applications of dendritic cells–cytokine-induced killer cells mediated immunotherapy for pancreatic cancer: An up-to-date meta-analysis

Purpose: This study aimed to systematically evaluate the efficacy and safety of dendritic cells–cytokine-induced killer (DC–CIK) cells immunotherapy in treating pancreatic cancer (PC) patients. Methods: Data were collected from published articles of clinical trials. Databases including Web of Science, EMBASE, PubMed, Cochrane Library, Wanfang, and CNKI were searched. The main outcome measures in this research included the overall response rate (ORR), disease control rate (DCR), overall survival (OS), patients’ quality of life (QoL), immune function, and adverse events. Comparative analysis was conducted between DC–CIK immunotherapy and chemotherapy (combined therapy) and chemotherapy alone. Results: This analysis covered 14 trials with 1,088 PC patients involved. The combined therapy showed advantages over chemotherapy alone in ORR (odds ratio [OR] =1.69, 95% confidence interval [CI] =1.20–2.38, P=0.003), DCR (OR =2.33, 95% CI =1.63–3.33, P,0.00001), OS (1-year OS, OR =3.61, 95% CI =2.41–5.40, P,0.00001; 3-year OS, OR =2.65, 95% CI =1.56–4.50, P=0.0003) and patients’ QoL (P,0.01) with statistical significance. After immu­notherapy, lymphocyte subsets’ percentages of CD3+ (P,0.00001), CD4+ (P=0.01), CD3+CD56+ (P,0.00001), and cytokine levels of IFN-γ (P,0.00001) were significantly increased, and the percentages of CD4+CD25+CD127low (P,0.00001) and levels of IL-4 (P,0.0001) were sig­nificantly decreased, whereas analysis on CD8+ (P=0.59) and CD4+/CD8+ ratio (P=0.64) did not show a significant difference. Conclusion: The combination of DC–CIK immunotherapy and chemotherapy is effective for PC treatment, indicated by prolonging the PC patients’ survival time, which benefit from reconstructed immune function of patients.