Tumor vascular responses to antivascular and antiangiogenic strategies: looking for suitable models

Antiangiogenic and vascular disrupting agents are in the current cancer therapeutic armamentarium. A better understanding of the intricate mechanisms ruling neovessel survival within tumors during or after treatment is needed. Refinement of imaging and a growing knowledge of molecular biology of tumor vascularization provide new insights. It is necessary to define suitable methods for monitoring tumor response and appropriate tools to analyze data. This review compares most commonly used preclinical models, considering their recent improvements, and describes promising new approaches such as microfluidics, real-time electrical impedance based technique and noninvasive imaging techniques. The advantages and limitations of the in vitro, ex vivo and in vivo models are discussed. This review also provides a critical summary of emerging approaches using mathematical modeling.