Combined immunotherapy with dendritic cells and cytokine-induced killer cells for malignant tumors: A systematic review and meta-analysis

A new strategy of adoptive and passive immunotherapy involves combining dendritic cells (DCs) with a subset of natural killer T lymphocytes termed cytokine-induced killer (CIK) cells. The objective of this systematic review and meta-analysis was to evaluate the safety and efficacy of DC-CIK therapy vs. placebo, no intervention, conventional treatments, or other complementary and alternative medicines for malignant tumors.We searched PubMed, Medline, Embase, Cochrane, Wangfang, Weipu, CNKI databases and reference lists of articles. We selected randomized controlled trials of DC-CIK therapy vs. placebo, no intervention, conventional treatments, or other complementary and alternative medicines in patients with all types and stages of malignant tumor. Primary outcome measures were overall survival and treatment response. Secondary outcome measures were health-related quality of life (HRQoL) assessment, progression free survival (PFS), and adverse events.Six trials met our inclusion criteria. There was evidence that chemotherapy+DC-CIK increased the 2-year (RR 2.88, 95% CI 1.38 to 5.99, P=0.005) and 3-year (RR 11.67, 95% CI 2.28 to 59.69, P=0.003) survival rates and progression free survival (RR 0.64, 95% CI 0.34 to 0.94, P<0.0001) in patients with non-small cell lung cancer compared to those treated with chemotherapy alone. DC-CIK therapy appears to be well-tolerated by cancer patients and to improve post-treatment patient health related quality of life.DC-CIK immunotherapy is a safe and effective treatment for patients with malignant tumors. Further clinical trials to provide supportive evidence for the routine use of DC-CIK therapy in clinical practice are warranted.