ABLATION TECHNOLOGIES REVIEWED
Today there are many ablation technologies to fight cancer. Before, we were mainly limited to performing radiofrequency ablation procedures which basically consisted of putting a needle into the tumor. Radio waves were sent into the needle, these heat the tumor and then died.
Likewise, there was cross cryoablation, this procedure consisted of placing a needle in the tumor and freezing it. In my early days of radiofrequency ablation and cryoablation procedures, there were patients who had multiple lesions, the treatments were done at different stages, and it was common that there were areas that could not be treated, however, some lesions disappeared without having the opportunity to treat them. Hence, we realized that ablation had the ability to create an immune response.
Nevertheless, it is a limited procedure, so we are constantly looking for ways to improve. What are the issues? An interesting aspect is that when the cancer is in an advanced stage and the ablation is done, in fact, partial ablations are done, without trying to ablate the tumor completely. If you start the procedure by killing a large amount of the tumor, then all those parts of the tumor, seen by the immune system, become suppressive and the immune system shuts down. In addition, much of the normal tissue begins to be damaged.
Therefore, when a tumor is ablated, a part of normal tissue is obtained around it, as if it were a surgery. Otherwise, with ablation for advanced-stage disease, killing that normal tumor can confuse the immune system. Moreover, having normal tissue dead, you’re also going to get a release of certain factors like TGFbeta and Vega, which are immunosuppressive. We know that by blocking Vega when we block TGF beta with the combined inflation we can significantly enhance the immune response. Nowadays, different procedures are carried out, for example, the intriguing immune therapy that consists of an injection into the tumor, there is also the pulsed electric field, which is a new technique.
Williams, J. (2019, 15th October) The Immunotherapy Revolution. (pp. 56-65)