PURPOSETo observe the efficacy and side effects of adjuvant dendritic cells' (DCs) vaccine combined with cytokine-induced killer cell (CIK) therapy after renal cell carcinoma (RCC) surgery (RCCS).METHODSDCs vaccine and CIK that loaded the autologous tumor cell lysate were prepared in vitro. Four hundred and ten RCC patients were recruited, and the study group was given DCs-CIK immunotherapy, while the control group was given IFN-α therapy.RESULTSDisease progression (recurrence, metastasis or death) showed significant differences between the two groups in clinical stage I and II patients, as well as in highly and moderately differentiated disease (p<0.05), while there was no significant difference between the two groups in patients with poorly differentiated disease (p>0.05). The 3- and 5-year overall survival rates of the DCs-CIK group (96% and 96%, respectively) exhibited significant difference compared to the IFN-α group (83% and 74%, respectively (p<0.01). Progression-free survival (PFS) between the two groups was significantly different (p<0.01). Tumor stage and DCs-CIK treatment were independent factors concerning prognosis of RCC (p<0.05). There was no severe toxicity observed in the DCs-CIK treatment group.CONCLUSIONSAdjuvant post-RCCS DCs-CIK treatment prolonged PFS and reduced mortality, showing better overall activity compared to interferon treatment.