Continuum models of avascular tumor growth
In this chapter we review existing continuum models of avascular tumor growth, explaining how they are inter-related and the biophysical insight that they provide. The models range in complexity and include one-dimensional studies ofradially-symmetric growth, and two-dimensional models of tumor invasion in which the tumor is assumed to comprise a single population of cells. We also present more detailed, multiphase models that allow for tumor heterogeneity. The chapter concludes with a summary of the different continuum approaches and a discussion of the theoretical challenges that lie ahead.