Cytokine-induced killer cells/dendritic cells-cytokine induced killer cells immunotherapy combined with chemotherapy for treatment of colorectal cancer in China: a meta-analysis of 29 trials involving 2,610 patients

PURPOSE: To systematically evaluate the efficacy and safety of Cytokine-induced killer cells/dendritic cells-cytokine induced killer cells (CIK/DC-CIK) immunotherapy in treating advanced colorectal cancer (CRC) patients. RESULTS: 29 trials including 2,610 CRC patients were evolved. Compared with chemotherapy alone, the combination of chemotherapy with CIK/DC-CIK immunotherapy significantly prolonged the overall survival rate (OS) and disease-free survival rate (DFS) (1–5 year OS, P < 0.01; 1-, 2-, 3- and 5-year DFS, P < 0.01). The combined therapy also improved patients’ overall response, disease control rate and life quality (P < 0.05). After immunotherapy, lymphocyte subsets percentages of CD3(+), CD3(−)CD56(+), CD3(+)CD56(+) and CD16(+)CD56(+) (P < 0.01) and cytokines levels of IL-2 and IFN-γ (P < 0.05) were increased, while CD4(+), CD8(+) and CD4(+)CD25(+) and IL-6 and TNF-α did not show significant change (P > 0.05). MATERIALS AND METHODS: Clinical trials reporting response or safety of CIK/DC-CIK immunotherapy treating advanced CRC patients and published before September 2016 were searched in Cochrane Library, EMBASE, PubMed, Wanfang and CNKI database. Research quality and heterogeneity were evaluated before analysis. Pooled analyses were performed using random or fixed-effect models. CONCLUSIONS: The combination of CIK/DC-CIK immunotherapy and chemotherapy prolong CRC patients’ survival time, enhanced patients’ immune function and alleviates the adverse effects caused by chemotherapy.