Abstract: Predictive Factors of Cytokine Induced Killer Cell Treatment forMetastatic Renal Cell CarcinomaYan GAO1, Shui CAO1, Xiubao REN1, Jinpu YU2, Naining ZHANG1, Jing ZHANG1Correspondence to: Xiubao REN, E-mail: rwziyi@yahoo.com1Department of Biotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China2Department of Immunology, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, ChinaAbstract Objective: To analyze the efficacy of cytokine induced killer cells (CIK) for metastatic renal cell carcinoma (MRCC).Methods: In this study, 48 MRCC patients received at least two cycles of CIK therapy. The clinical therapeutic effect was observed andthe progression-free survival (PFS) time was determined. Kaplan-Meier analysis and Cox proportional hazards regression were per-formed respectively to analyze clinical features and baseline biochemical parameters associated with PFS. Results: Of the 48 cases, 2had PR, 30 had SD, and 16 had PD. PR+SD accounted for 66.7%. The overall median PFS was 7 months. Multivariate analysis identi-fied the number of metastatic sites and baseline platelet (PLT) counts as independent prognostic factors for PFS ( P = 0.034 and 0.046,respectively ). The stratified analysis of the 33 cases that had only one metastatic site showed that metastatic sites may not have an im-pact on the effect of CIK administration. Conclusions: Administering CIK is safe and effective in the treatment of MRCC. Havingmore than one site of metastasis and high PLT counts are independent negative prognostic factors for PFS.Keywords Cytokine induced killer (CIK); Metastatic renal cell carcinoma (MRCC); Predictive factors