Evolutionary game theory and oligometastatic patient: considering the role of interventional oncology.

The possible role of evolutionary game theory (EGT), to pursue a tailored therapeutic strategy, has recently gained widespread interest within the clinical setting of oncological patients. The potentially revolutionary shift of paradigm suggested by EGT points to the fact that, for metastatic patients, the optimal therapeutic strategy should be aimed at reducing the survival fitness of tumor cells compared with normal cells, thus allowing natural selection to help control the overall tumor burden, instead of trying to kill all tumor cells. A specific subset of metastatic patients, the so-called oligometastatic patients, has not been adequately considered so far in the light of EGT theoretical approach. A modern and comprehensive definition of oligometastatic patient should consider at least three main parameters: the total number of lesions, the timing of their appearance and their biological heterogeneity. A valid therapeutic option for oligometastatic patients could be to integrate together both systemic and local therapies, such as interventional oncology. The potential advantage of implementing interventional oncology in the clinical practice, for example in oligorecurrent or oligoprogressive patients, could be to delay or even to avoid unnecessary shifts in systemic therapies. Another important point to consider is the potential role that the treatment of a single metastatic site may have in terms of immune system activation towards other untreated metastatic sites; such phenomenon is known as abscopal effect.