Author Affiliation: Breast Oncology Program, University of Michigan Comprehensive Cancer Center, Ann Arbor.
In 1971, Folkman1 proposed that malignancies could only grow to a significant size, or metastasize to other organs, by stimulating new blood vessel growth. This process, designated angiogenesis or neovascularization, is now accepted as necessary for cancers to extend beyond the in situ state and metastasize to distant sites.2 Tumor-induced angiogenesis requires a complex interplay between the cancer cell and surrounding stroma at the primary cancer site and at the metastasis site, including recruitment of bone marrow–derived, circulating endothelial cell precursors.3
Hayes DF. Bevacizumab Treatment for Solid TumorsBoon or Bust?. JAMA. 2011;305(5):506–508. doi:10.1001/jama.2011.57