Few clinical studies have confirmed the role of cytokine-induced killer cells (CIKs) in the maintenance therapy of advanced lung cancer patients. We investigate effectiveness and tolerability of CIKs as a maintenance therapy in the treatment of advanced lung cancer patients.

70 patients with advanced lung cancer (stage IIIB to IV) admitted to the First Affiliated Hospital of Third Military Medical University in Chongqing from Nov. 2011 to Jan. 2015 and treated with CIKs were enrolled as a CIKs group (T group), and another 70 advanced lung cancer patients treated with optimal supportive care during the same period were enrolled as a control group(C group). The changes of immune system, response rate, disease control rate, overall survival, and side effects were compared between the two groups. Furthermore, the factors that might influence the efficacy of CIKs therapy were evaluated.

Compared with the healthy people, the ratios of CD3⁺, CD4⁺ and CD8⁺ T cells significantly decreased (P<0.05) in lung cancer patients. After CIKs treatment, the ratios of CD3⁺ and CD4⁺ T cells and CD4⁺/CD8⁺ significantly increased (P<0.05). The response rate (RR) and disease control rate (DCR) were 34.3% and 80.0% in the CIKs group, which were significantly higher than those in the control group (11.4% and 54.3%, both P<0.05). Besides, the median PFS was significantly improved in the CIKs group than that in control group (6 months vs. 4 months, P<0.05). Although median OS was 28 months in CIKs group while 22 months in control group, no significant difference was observed (P>0.05). However, The 2-year, 3-year survival rates were 56.8% and 21.6% in the CIK group, respectively, which were significantly improved compared to that in the control group (both P<0.05). KPS score significantly increased in the CIKs group (P=0.001). 6 patients suffered from transient fever or chills in the process of CIKs transfusion, and no other side effect was observed. Furthermore, we also found that TNM stage, tumor size, metastasis in vital organs and KPS score were all factors associated with efficacy of CIKs treatment.

CIKs treatment, as a maintenance therapy, is safe and effective for advanced lung cancer patients, and can also improve the immune imbalance, RR, DCR, PFS, OS and quality of life of the lung cancer patients.