Abstract. We propose a descriptive 2D Hybrid Cellular Automaton model that simulates the growth behavior of a tissue with cancerous cells. We combine a
set of hallmarks of cancer (Hanahan and Weinber, 2000) with the effect of acidification of the cell surroundings by the production of acid by tumorous cells and model some aspects of the communication in living tissues. The dynamics of the growth is determined to obey a power law. We conclude that the model predicts a cancer growth rate between the exponential Gompertzian growth and a laboratory evidence of linear growth.