Microwave tumour coagulation plus in situ treatment with cytokine-microparticles: induction of potent anti-residual tumour immunity.

After local microwave coagulation and subsequent intra-tumoural injection of microparticles encapsulating interleukin-2 and granulocyte-macrophage colony-stimulating factor, the anti-tumour efficacy against subcutaneous Lewis lung carcinoma in syngeneic mice was evaluated. This treatment elicited a potent systemic anti-tumour immunity that protected treated mice from re-challenge with the same tumour cells and caused the distal tumours in a bilateral tumour model to be rejected. Cytotoxicity assay indicated that both T- and natural killer cells acted as the effector cells in the anti-tumour immunity. These data highlight the feasibility of microwave-pre-treated in situ cancer vaccination for clinical use.