Tumor growth is a multifactorial process that surely emerges from molecular and genetic abnormalities, but also depends strongly on cell-cell and cell-extracellular matrix macroscopic
regulations and interactions. Numerous models have been developed to understand the mechanisms controlling solid tumor morphogenesis: While the earliest efforts were focusing on cell
proliferation kinetics, modulated by the availability of supplied nutrients, new approaches emphasize the crucial role of several biophysical processes, including local matrix
remodeling, active cell migration and traction, and reshaping of the host tissue blood vessel network. In this talk a brief review over a number of representative models will be given,
in particular those predicting the emergence of invasive behavior through growth instabilities at the tumor-host interface. Then the focus will be put on the analysis of vascular
remodeling during tumor growth within a theoretical model including angiogenesis, cooption and regression of blood vessels. The physical mechanisms determining the morphological and
hydrodynamical characteristics of the emerging tumor vasculature are analyzed and implications for blood borne drug delivery are discussed.