Tumor Hypoxia and Malignant Progression

Publisher Summary This chapter discusses tumor hypoxia and malignant progression. Hypoxic (or anoxic) areas arise as a result of an imbalance between the supply and the consumption of oxygen. Whereas in normal tissues or organs the O2 supply matches the metabolic requirements, in locally advanced solid tumors the O2 consumption rate of neoplastic as well as stromal cells may outweigh an insufficient oxygen supply and result in the development of tissue areas with very low O2 levels. Major pathogenetic mechanisms involved in the emergence of hypoxia in solid tumors are (a) severe structural and functional abnormalities of the tumor microvessels (b) a deterioration of the diffusion geometry, and (c) tumor-associated and/or therapy-induced anemia leading to a reduced O2 transport capacity of the blood. This chapter discusses current information from experimental and clinical studies, which illustrates the interaction between tissue hypoxia and the phenomenon of malignant progression. Evidence, characterization and pathogenesis of tumor hypoxia, and the role of hypoxia in malignant progressionare discussed.