Experimental data demonstrates that simultaneous injection of cancer cells at two distinct sites can result in one large and one small tumour. This data has previously been explored mathematically to examine the role of systemic inhibition in this phenomenon. Here, we hypothesize that unbalanced inflammation may be the cause of the growth rate separation. We develop a mathematical model for immune recruitment and competition between two cancer sites to explore the role in tumour-promoting inflammation in the observed growth phenomenon. Due to the experimental set-up, immune predation may be neglected, focusing the model on tumour-promoting immune actions only. I will present a new mathematical model with localized immune

recruitment and competition between the two cancer sites using a multi-compartment ODE system. I will discuss the process of determining parameter values from data fitting and then present numerical simulations to explore our hypothesis.