Phase II/III Study of Radiofrequency Ablation Combined with Cytokine-Induced Killer Cells Treating Colorectal Liver Metastases

Abstract

Purpose: This phase II/III, non-randomized clinical trial aimed to determine the efficacy and safety of the combination of radiofrequency ablation (RFA) and cytokine-induced killer (CIK) cells transfusion for patients with colorectal liver metastases (CRLMs). Experimental Design: A total of 60 eligible patients with CRLMs were enrolled and divided into Group A (RFA alone, n = 30) and Group B (RFA plus CIK, n = 30), and following enzyme-linked immunosorbent spot assay was performed in 8 patients with CEA > 50 ng/mL pre-RFA and 7 days post-RFA and CIK treatment, respectively. Results: The median progression-free survival (PFS) times of Group A and Group B were 18.5 months and 23 months, respectively (P = 0.0336). The 3-year progression-free rates were 13.3% in Group A and 20.3% in Group B, respectively. The median overall survival time was 43 months in Group A, and not reached in Group B. The 3-year survival rates were 64.6% in Group A and 81.0% in Group B, respectively (P = 0.1187). Among the 8 patients with CEA > 50ng/mL, 6 had increase of circulating CEA-specific T cells after RFA (P = 0.010). After CIK cell therapy, the number of CEA-specific T cells increased in all the 8 patients comparing with that pre-treatment (P = 0.001) and in 7 patients comparing with that post-RFA (P = 0.028). Conclusions: We firstly confirm that the combination of RFA and CIK cells boosts CEA-specific T cell response and shows to be an efficacious and safe treatment modality for patients with CRLMs.