Abstract: Objective To investigate the efficacy and safety of maintenance therapy with autologous cytokineinduced killer cells（CIK） in patients with medium and advanced non-small cell lung cancer（NSCLC） after firstline treatment.
MethodsA total of 112 medium and advanced NSCLC patients with therapeutic effect of SD or above after firstline treatment were selected and assigned to treatment group（n=56） and control group（n=56） at random. The treatment group accepted maintenance therapy with autologous CIK cells after the firstline treatment. T lymphocyte subpopulations in peripheral blood were measured and the side effects were estimated according to NCI-CTC 4.0 version. Then， patients of both groups were followed up. Results The statuses of T lymphocyte subpopulation were improved after the therapy with autologous CIK cells and no side effects of grade 3-4 occurred. The median progressionfree survival（PFS） of treatment group was 8.6 months， higher than 7.5 months of control group（P＜0.05）. The median overall survival（OS） in treatment group and control group were 19.2 and 18.6 months without significant difference（P＞0.05）. In treatment group， the median PFS in patients with therapeutic effect ≥50％ PR-CR was 11.5 months， higher than 7.9 months in patients with ＜50％ PR-SD and the difference was significant（P＜0.05）， but no difference was observed on the median OS between both subgroups（P＞005）. In control group, there was no significant difference on the median PFS and OS between patients with therapeutic effect ≥50％ PR-CR or ＜50％ PR-SD（P＞0.05）. In the cases whose therapeutic effect ≥50％ PR-CR， the median PFS was 11.5 months in treatment group， higher than 8.8 months in control group with significant difference（P＜0.05）， but no difference was observed on the median OS between both groups（P＞0.05）.
Conclusion Maintenance therapy with autologous CIK cells in patients with medium and advanced NSCLC after firstline treatment improves the immune function and enhances the ability of antitumor effect by natural immunity with a prolonged PFS and welltolerated toxicity.