Tumor tissue and tumor-feeding vasculature

Tumor tissue and tumor-feeding vasculature refers to the integrated system of malignant cells and the specialized, aberrant blood vessel network that supports tumor growth and survival [Jain, Science, 2005]. Unlike normal physiological vessels, tumor-feeding vasculature is characterized by rapid, disorganized angiogenesis, leading to leaky, tortuous vessels with high interstitial fluid pressure and a lack of pericyte coverage [Carmeliet & Jain, Nature, 2011]. This complex environment is a critical focus for oncology therapeutics, primarily through two mechanisms: anti-angiogenic agents and vascular disrupting agents (VDAs). Anti-angiogenic agents, such as Bevacizumab, block signaling molecules like VEGF to prevent new vessel growth [Ferrara et al., Nature Reviews Drug Discovery, 2004]. In contrast, VDAs like Combretastatin A-4 phosphate target the cytoskeleton of existing tumor endothelial cells to induce rapid vascular collapse and subsequent tumor necrosis [Tozer et al., Nature Reviews Cancer, 2005]. While these therapies aim to starve the tumor of oxygen and nutrients, the heterogeneous nature of the tumor microenvironment often leads to therapeutic resistance and suboptimal drug penetration [NIH NCI Dictionary]. Clinical management of drugs hitting this system requires careful monitoring for systemic vascular toxicities, such as hypertension, hemorrhage, and thromboembolism [FDA Labeling]. Overall, this "target" represents a physiological compartment rather than a single molecular entity, necessitating a multi-faceted therapeutic approach.

Other names

Tumor microenvironmentTumor neovasculatureTumor-associated blood vesselsTumor stroma

Inhibition of pro-angiogenic signaling (e.g., VEGF/VEGFR pathway) and physical disruption of established tumor endothelial cell integrity.