What is angiogenesis?
Angiogenesis, the formation of new blood vessels, is a process controlled by certain chemicals produced in the body. Although this may help in normal wound healing, cancer can grow when these new blood vessels are created. New blood vessels near the cancer cells provide them with oxygen and nutrients. This allows the cancer cells to multiply, invade nearby tissue, and spread to other areas of the body (metastasize).
What are angiogenesis inhibitors and how do they work?
A chemical that interferes with the signals to form new blood vessels is referred to as an angiogenesis inhibitor. Scientists have studied the effect of angiogenesis inhibitors on certain kinds of tumors and cells.
Sometimes called antiangiogenic therapy, this treatment may prevent the growth of cancer by blocking the formation of new blood vessels. In some animal case studies, angiogenesis inhibitors have caused cancer to shrink and resolve completely. In human studies, angiogenesis inhibitor therapy may stabilize the tumor and prevent it from growing further, and in some cases the size of the tumor has been reduced, and in a few cases, the tumor has resolved and has become clinically undetectable.
Thalidomide has been identified as having mild activity as an angiogenesis inhibitor in myelodysplastic syndrome and sometimes in kidney cancer. A newer version of this medication is lenalidomide (Revlimid), which has fewer side effects than thalidomide.
Another medication, bevacizumab (Avastin®), has been approved by the US Food and Drug Administration (FDA) to aid in the treatment of colorectal, lung, and some other cancers. Two newer additions to antiangiogenesis therapy include sunitnib (Sutent®) and sorafenib (Nexavart®). Many other angiogenesis inhibitors are now being studied as well.
Angiogenesis inhibitors have different side effects from most conventional cancer chemotherapy medications because they work very differently. Rather than killing healthy cells along with cancer cells, as many chemotherapy drugs do, angiogenesis inhibitors only prevent new blood vessels from forming. Though the side effects are generally less and milder than with conventional chemotherapy medications, some of the side effects can be serious and include high blood pressure, intestinal bleeding and poor wound healing.