2015 Antineoplastics

DRUGS THAT INTEREFERE WITH ANGIOGENESIS

  • all tissues (including tumors) secrete substances that promote or inhibit angiogenesis (the formation of new blood vessels) - more than 35 angiogenesis stimulators and 18 suppressors have been described so far

  • once a group of cancer cells reaches a certain size (~1-2 mm in diameter), it must develop a blood supply in order to grow, because diffusion is no longer adequate to supply the cells with oxygen and nutrients and to take away wastes

  • some tumours secrete substances that inhibit angiogenesis at other tumour sites which leads to the clinical phenomenon whereby:
    • a patient has a primary tumour, and there is no evidence that the primary tumour has metastasized
    • a surgeon removes the primary tumour
    • some weeks later, metastases of the tumour appear throughout the patient's body.
    • the speed of the appearance of the secondary tumours indicates that they were present all along, but were too small to be detected (this is one of the justifications for chemotherapy as an adjunct to surgery for the treatment of solid cancers)

  • another concern is rebound angiogenesis: rapid growth of cancer when an angiogenesis inhibitor is stopped
    • this was first described in animal models, but of most concern is observations in patients with gliomas, where there is rapid, aggressive regrowth of the tumours after BEVACIXIMAB treatment is stopped
Email: Dr. Janet Fitzakerley | ©2015 University of Minnesota Medical School Duluth | Last modified: 11-apr-15 9:39 AM