Immunotherapy of DC-CIK cells enhances the efficacy of chemotherapy for solid cancer: a meta-analysis of randomized controlled trials in Chinese patients.

Objective: Professional antigen-presenting dendritic cells (DCs) and cytokine-induced killer (CIK) cells, components of anti-cancer therapy, have shown clinical benefits and potential to overcome chemotherapeutic resistance. To evaluate whether DC-CIK cell-based therapy improves the clinical efficacy of chemotherapy, we reviewed the literature on DC-CIK cells and meta-analyzed randomized controlled trials (RCTs).

Methods: We searched several databases and selected studies using predefined criteria. RCTs that applied chemotherapy with and without DC-CIK cells separately in two groups were included. Odds ratio (OR) and mean difference (MD) were reported to measure the pooled effect.

Results: Twelve reported RCTs (826 patients), which were all performed on Chinese patients, were included. Combination therapy exhibited better data than chemotherapy: 1-year overall survival (OS) (OR=0.22, P<0.01), 2-year OS (OR=0.28, P<0.01), 3-year OS (OR=0.41, P<0.01), 1-year disease-free survival (DFS) (OR=0.16, P<0.05), 3-year DFS (OR=0.32, P<0.01), objective response rate (ORR) (OR=0.54, P<0.01), and disease control rate (DCR) (OR=0.46, P<0.01). Moreover, the levels of CD3(+) T-lymphocytes (MD=-11.65, P<0.05) and CD4(+) T-lymphocytes (MD=-8.18, P<0.01) of the combination group were higher.

Conclusions: Immunotherapy of DC-CIK cells may enhance the efficacy of chemotherapy on solid cancer and induces no specific side effect. Further RCTs with no publishing bias should be designed to confirm the immunotherapeutic effects of DC-CIK cells.