  Tumour cells have to acquire a number of capabilities if a neoplasm is to
become a cancer. One of these key capabilities is increased motility which is
needed for invasion of other tissues and metastasis. This paper presents a
qualitative mathematical model based on game theory and computer simulations
using cellular automata. With this model we study the circumstances under which
mutations that confer increased motility to cells can spread through a tumour
made of rapidly proliferating cells. The analysis suggests therapies that could
help prevent the progression towards malignancy and invasiveness of benign
tumours.
