1. To appreciate the extent of potentially beneficial and harmful systemic effects of “focal” interventional oncologic therapy.
2. To gain awareness of the molecular mechanisms that cause such systemic effects with an eye toward potentiating them for clinical benefit.
3. To learn how immuno-oncologic techniques can be combined with both percutaneous and transcatheter interventional oncologic therapies to potentially achieve better clinical outcomes.
Image-guided cancer therapies have matured and gained sufficient clinical acceptance to the point that the relatively new discipline of interventional oncology has joined surgery, radiation, and chemotherapy as the fourth pillar of cancer care. Percutaneous thermal ablation using energy sources, including radiofrequency and microwave to produce heat and cryoablation to produce freezing, is a prominent interventional oncologic technique commonly used to treat a wide range of focal primary and metastatic tumours in the liver, kidney, lung, bone, and elsewhere. Although it has been asserted that tumour ablation is a local therapy, recent research suggests that it can induce systemic effects largely via cytokines and other growth factors. On the one hand, these factors can produce potentially unwanted “off-target” tumorigenesis that, in some cases, may lead to unintended increased cancer progression. Such human-made iatrogenesis could be viewed as an opening of Pandora’s Box. On the other hand, there is ever increasing research documenting that ablation can activate the immune system to induce widespread distant anti-tumoral effects. Leveraging these “abscopal” effects to achieve synergy in combination with recently developed immuno-oncologic therapeutics can be viewed as a Holy Grail. Given this potential double-edged sword, further molecular biologic research is necessary to better understand the mechanisms behind these processes. This will afford better insight as to which pathways are activated in individual patients and ultimately allow us to develop rational strategies to accentuate and more consistently induce positive immune effects, while simultaneously eliminating negative tumorigenic effects to benefit our patients and discipline.