INTRODUCTION Physical and mathematical models can be very useful in many subelds of biomedicine and, in particular, in oncology. Physical models, based on a comparison with well-known phenomena, which present formal analogies with some aspects of tumoral development, may be extremely helpful, since they may suggest new mechanisms to be tested and analyzed. Mathematical and computational models allow researchers to vary the details of the proposed model or their parameters, for example, by adding new ingredients and/or eliminating ineective ones. us, it becomes possible to perform virtual experiments of selected therapies and to predict or optimize the outcome of suggested therapeutic protocols. e current relevance of physical, mathematical, and computational modeling

CONTENTS Introduction 237 Model: Cancer Growth 238 Model: Malignant Neoplasias 243 Discussion: What Next? 249 Acknowledgments 249 References 250

is due to a combination of related factors (Deisboeck et al. 2007, 2009; Liu et al. 2006; Kitano, 2002; Hornberg et al. 2006; Coey 1998).