“…Cancer is a fundamental scientific and societal problem, and in the past several decades, intensive research has been focused on understanding the complexity of cancer progression, developing new therapies, and formulating optimal treatment protocols. While much work has been done in the mathematical community on tumor modeling (e.g., see the reviews [3,6,7,9,46,47]), to date there has been little work in modeling tumor growth in realistic, heterogeneous tissues on large spatial scales. The methods we present in this paper will provide the foundation for a biologically-detailed millimeter-to-centimeter-scale model of tumor growth in heterogeneous tissues with realistic features (e.g., mechanically soft and hard regions, bone, and inhomogeneous nutrient delivery) [33,35,39].…”