Enhanced local dendritic cell activity and tumor-specific immunoresponse in combined radiofrequency ablation and interleukin-2 for the treatment of human head and neck cancer in a murine orthotopic model.

BACKGROUND Radiofrequency ablation (RFA) is a minimally invasive tumor destruction technique and can provide the antigen source initiating tumor immunity. However, induced immune response is weak and requires additional immunotherapy for optimized RFA treatment against cancer. METHODS A murine orthotopic model of head and neck squamous cell carcinoma (HNSCC) was established to investigate the efficacy and mechanism of an RFA + interleukin-2 (IL-2) combination adenoviral gene therapy among 6 groups. Tumor volume change, apoptosis, in situ macrophage recruitment, cytotoxic T lymphocyte (CTL) activity, migration of dendritic cells into the regional lymph nodes, and systemic antitumor immunity were examined. RESULTS RFA + IL-2 therapy induced the highest levels of macrophage recruitment and dendritic cell migration resulting in enhanced CTL activity, increased tumor apoptosis, enhanced systemic antitumor immunity, and the best inhibition of tumor growth among all groups. CONCLUSION RFA + IL-2 combination therapy generates potent tumor immunity to suppress tumor growth in HNSCC.