FOLFOX regimen plus dendritic cells–cytokine-induced killer cells immunotherapy for the treatment of colorectal cancer: a meta-analysis

PURPOSE: To systematically investigate the efficacy and safety of the combination of FOLFOX (oxaliplatin, 5-fluorouracil, and leucovorin) regimen and cocultured dendritic cells and cytokine-induced killer cells (DC-CIK) immunotherapy for the treatment of colorectal cancer (CRC). METHODS: Publications reporting the clinical trials’ responses or safety of FOLFOX regimen combined with DC-CIK immunotherapy in treating CRC patients were searched in PubMed, Embase, Cochrane Library, China National Knowledge Internet, and Wanfang databases. Trials meeting the selection criteria were analyzed. The overall survival (OS), overall response rate (ORR), disease control rate (DCR), tumor markers, immune function, and adverse events were evaluated. RESULTS: Ten trials including 881 CRC patients were analyzed in this meta-analysis. The combined therapy showed advantages over FOLFOX treatment-alone in 2-year OS (odds ratio [OR] =2.77, confidence interval [CI] =1.58–4.86, P=0.0004), ORR (OR =1.85, CI =1.34–2.56, P=0.0002), and DCR (OR =2.54, CI =1.76–3.67, P<0.00001), with statistical significance. After immunotherapy, lymphocyte subset percentages of CD3(+) (P=0.0006) and CD4(+) (P=0.01), CD4(+)/CD8(+) ratio (P=0.0003), and levels of cytokines IFN-γ (P=0.003) and IL-2 (P=0.01) were significantly increased, whereas analysis of CD8(+), CD3(−)CD56(+), CD3(+)CD56(+), CD4(+)CD25(+), IL-6, and TNF-α did not show any significant difference (P>0.05). Moreover, the level of carcinoembryonic antigen was also decreased significantly upon immunotherapy (P<0.00001). CONCLUSION: The combination of FOLFOX regimen and DC-CIK immunotherapy was safe and effective for CRC patients.