An Agent-Based Model of Avascular Tumor Growth

We propose a simplified agent-based model of avascularized tumor. It involves a tissue in which blood vessels introduce nutrients that diffuse. Cells move, proliferate and die according to an individual quantity of "energy" and free space for their offspring. They can transition to a "cancerous" type and an intermediate "mutated" type, where they behave normally but can be affected by cancerous neighbors. We are interested in finding the key parameters that can lead a majority of cancerous cells to be replaced by normal ones. First, we give a brief overview of previous tumor growth models, especially in avascular tissues. Then, we describe in detail the agents and rules of our model, commenting on the choices made. Next, we conduct a parameter space exploration, varying in particular the influence of neighbors, the division probability and mutation probability. Results show a marked phase transition between domains of high cancerous cell density and high mutated cell density. We also analyze the importance of certain rules in our model by "rule knockout" and find that energy-dependency of division and space for offspring are essential, while type-specific division probabilities are not. Finally, we discuss the overall relevance of the model and possible future improvements.