The enhancement of immune response against tumor antigens has shown some 
efficacy when used as a single mode of systemic treatment in patients with late 
stage disease. Novel strategies of active immunotherapy could be more effective 
in patients with less advanced disease who receive standard therapies supporting 
concomitant stimulation of the immune system. Radio-Frequency Ablation (RFA) is 
a minimally invasive technique which is used as standard local therapy of 
primary and metastatic liver tumors. Tumor ablation by RFA induces effects 
important for boosting anti-tumor immune responses. Tumor cell necrosis 
generates a permanent immunogenic source of tumor antigens. These antigens can 
be uptaken, processed and presented by dendritic cells for effective 
immunization without requirement for ex vivo antigen loading. Further immune 
activation can be originated by RFA through induction of heat shock proteins on 
tumor cells, acute phase response which causes the release of pro-inflammatory 
cytokines, and mobilization of antigen presenting cells and effector 
lymphocytes. Thus, RFA can facilitate immune responses to tumor antigens driven 
by active immunotherapy. On the other hand, immunotherapy is expected to 
eradicate residual disease after RFA and prevent tumor recurrences. The 
combination of RFA and active immunotherapy may well have synergistic effects 
for cancer treatment.