Effectiveness and safety of chemotherapy with cytokine-induced killer cells in non-small cell lung cancer: A systematic review and meta-analysis of 32 randomized controlled trials.

Background Aims: Cytokine-induced killer (CIK) cells are the most commonly used cellular immunotherapy for multiple tumors. To further confirm whether chemotherapy with CIK cells improves clinical effectiveness and to reveal its optimal use in non-small cell lung cancer (NSCLC), we systematically reevaluated all relevant studies.

Methods: We collected all studies about chemotherapy with CIK cells for NSCLC from the Medline, Embase, Web of Science, China National Knowledge Infrastructure Database (CNKI), Chinese Scientific Journals Full-Text Database (VIP), Wanfang Data, China Biological Medicine Database (CBM), Cochrane Central Register of Controlled Trials (CENTRAL), Chinese clinical trial registry (Chi-CTR), World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and U.S. clinical trials. We evaluated their quality according to the Cochrane evaluation handbook of randomized controlled trials (RCTs) (version 5.1.0), extracted the data using a standard data extraction form, synthesized the data using meta-analysis and finally rated the evidence quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results: Thirty-two RCTs with 2250 patients were included, and most trials had unclear risk of bias. The merged risk ratios values and their 95% confidence intervals of meta-analysis for objective response rate, disease control rate, 1- and 2-year overall survival rates, 1- and 2-year progression-free survival rates were as following: 1.45 (1.31-1.61), 1.26 (1.16-.37), 1.42 (1.23-1.63), 2.06 (1.36-3.12), 1.93 (1.38-2.69) and 3.30 (1.13-9.67). Compared with chemotherapy alone, all differences were statistically significant. CIK cells could increase the CD3 T cells, CD3 CD4 T cells, NK cells and the ratio of CD4/CD8 T cells. The chemotherapy with CIK cells had a lower risk of hematotoxicity, gastrointestinal toxicity, liver injury and a higher fever than that of chemotherapy alone. The evidence quality was "moderate" to "very low."

Conclusions: The available moderate evidences indicate that chemotherapy with CIK cells, especially autologous CIK cells, can significantly improve the tumor responses, 1- and 2-year overall and progression-free survival rates in patients with advanced NSCLC. This treatment does have a high risk of fever. The optimal use may be treatment with one or two cycles and in combination with vinorelbine and cisplatin, paclitaxel and cisplatin, or docetaxel and cisplatin.