Evolutionarily Stable Strategies in Oncology
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2795450/
Theoretically, the idea of steady states in evolutionary game theory can further be applied to understanding certain cancer dynamics. Further, McEvoy claims that the application of game theory and equilibrium states to cancer dynamics will allow for the potential manipulation of cancer growth by predicting and affecting improved survival by changing the strategies and payoffs of the resulting cancer ‘game’. The research linked above relates the simplified interactions between malignant cells and normal cells in a multiple myeloma model to the players and strategies in popular game theory models such as the Hawk-Dove game.
Logically, the Hawk-Dove game can be applied to the cancer ‘game’ where the aggressive hawks are similar in nature to malignant cells, and therefore passive doves are comparable to normal cells. As the game is an evolutionary model, the payoffs in the matrix correspond to the fitness of the cells.
The article outlines multiple hypotheticals and their outcomes given varying values of the fitness of cells. For example, two malignant cells interacting with one another, the payoff will result in 1 for the both of them. Two normal cells interacting will receive 2 apiece, and a mixed interaction between a malignant and a normal cell will receive 4, 0 respectively. In this situation, the resulting evolutionarily stable strategy will be that the whole population turns into malignant cells, despite the value of the initial fraction of cells that were malignant in the beginning, as long as the fraction is not 0.
However, by lowering the payoffs slightly, the steady state of the game can be changed significantly. If instead the interaction between two malignant cells resulted in -1 for the both of them, the end result would become ⅓ of normal cells and subsequently ⅔ malignant cells.
Although such applications to game theory seem promising, there are many limiting factors, or simply problems that were not factored into the ‘game’. For example, the simplified approach given above do not account for the fact that malignant cells cannot rationally choose- in other words, cells are not rational players, and this lack of rationality may limit the applicability of game theory to oncology.