Meta-analysis of chemotherapy and dendritic cells with cytokine-induced killer cells in the treatment of non-small-cell lung cancer

Background: Non-small-cell lung cancer (NSCLC) is one of the most fatal cancers, which leads to large number of people dead. Followed by surgery, chemotherapy and radiotherapy, chemotherapy combined dendritic cells with cytokine-induced killer cells (DC-CIK) immunotherapy has been applied in NSCLC for some time, but little consistent beneficial results are provided. So, it is essential to weigh the pros and cons of the new therapeutic method. Methods: We searched the randomized controlled trials of NSCLC mainly by PubMed database. Terms combination of "cytokine-induced killer cells", "tumor" and "cancer" were used. After evaluating the heterogeneity of selected studies, then we performed the meta-analysis. Pooled risk ratios (RRs) were estimated and 95% confidence intervals (CIs) were calculated using a fixed-effect model. Sensitivity analysis was also performed. Results: Six eligible trials were enrolled. Efficiency and safety of chemotherapy followed by DC-CIK immunotherapy (experimental group) and chemotherapy alone (control group) were compared. 1-year overall survival (OS) (P=0.02) and progression free survival (PFS) (P=0.005) in the experimental group were significantly increased compared with the control. Disease control rate (DCR) (P=0.006) rose significantly in experimental group. However, no significant differences between the two groups were observed in 2-year OS (P=0.21), 2-year PFS (P=0.10), overall response rate (ORR) (P=0.76) and partial response (PR) (P=0.22). Temporary fever, anemia, leukopenia and nausea were the four major adverse events (AEs) treated by chemotherapy. The incidence of anemia, leukopenia and nausea in the experimental group was obviously lower than the control group. Temporary fever rate was higher in experimental group than that in the control, but could be alleviated by taking sufficient rest. Conclusions: Chemotherapy combined with DC-CIK immunotherapy showed superiority in DCR, 1-year OS and PFS, and no more AEs appeared, however, there was no significant improvement in ORR, PR, 2-year OS and PFS. As a whole, the combination therapy is safer but modest in efficacy for advanced NSCLC patients.