Efficacy of cytokine-induced killer cell infusion as an adjuvant immunotherapy for hepatocellular carcinoma: a systematic review and meta-analysis

Ruili Yu,1 Bo Yang,2 Xiaohua Chi,3 Lili Cai,4 Cui Liu,5 Lei Yang,6 Xueyan Wang,1 Peifeng He,7 Xuechun Lu2 1Department of Allergy, Beijing Shijitan Hospital, Affiliated to Capital Medical University, 2Department of Geriatric Hematology, Chinese PLA General Hospital, 3Department of Pharmacy, Chinese PLA Rocket Force General Hospital, 4Department of Geriatric Laboratory Medicine, 5Department of Geriatric Ultrasound, 6Medical Department, Nanlou Clinic, Chinese PLA General Hospital, Beijing, 7School of Medical Information Management, Shanxi Medical University, Taiyuan, People’s Republic of China Abstract: This study was designed to evaluate the efficacy and safety of cytokine-induced killer (CIK) cell-based immunotherapy as an adjuvant therapy for hepatocellular carcinoma (HCC). Published studies were identified by searching Medline, Cochrane, EMBASE, and Google Scholar databases with the keywords: cytokine-induced killer cell, hepatocellular carcinoma, and immunotherapy. The outcomes of interest were overall survival, progression-free survival, and disease-free survival. Eight randomized controlled trials (RCTs), six prospective studies, and three retrospective studies were included. The overall analysis revealed that patients in the CIK cell-treatment group had a higher survival rate (pooled hazard ratio (HR) =0.594, 95% confidence interval [CI] =0.501–0.703, P<0.001). Patients treated with CIK cells in non-RCTs had a higher progression-free survival rate (pooled HR =0.613, 95% CI =0.510–0.738, P<0.001). However, CIK cell-treated patients in RCTs had progression-free survival rates similar to those of the control group (pooled HR =0.700, 95% CI =0.452–1.084, P=0.110). The comparison between pooled results of RCTs and non-RCTs regarding the progression-free survival rate did not reach statistical significance. Patients in the CIK cell-treatment group had lower rates of relapse in RCTs (pooled HR =0.635, 95% CI =0.514