What is angiogenesis?
Angiogenesis is the formation of new blood vessels. The process is controlled by certain chemicals produced in the body. The word comes from 2 Greek words, angio meaning blood vessel and genesis meaning beginning. 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 called an angiogenesis inhibitor. Scientists have studied the effect of angiogenesis inhibitors on certain kinds of tumors and cells. Several of the angiogenesis inhibitors are also effective in treating an eye disease, macular degeneration.
Sometimes called antiangiogenic therapy, this treatment may prevent the growth of cancer by blocking new blood vessels from forming. Angiogenesis inhibitor therapy may stabilize the tumor and prevent it from growing further. Or it may reduce the size of the tumor. More than a dozen medicines with antiangiogenic properties are available in the U.S.
Some other cancer drugs are known to act in similar ways. Thalidomide and lenalidomide have been identified as having mild activity as angiogenesis inhibitors.
An angiogenesis inhibitor medicine, bevacizumab, has been approved by the FDA to aid in the treatment of glioblastoma, colorectal cancer, non-small cell lung cancer, liver (hepatocellular) carcinoma, neuroendocrine tumors, and metastatic renal cell cancer. Other antiangiogenesis therapies include sunitinib, sorafenib, pazopanib, and everolimus. Many other angiogenesis inhibitors are now being studied as well.
Angiogenesis inhibitors have different side effects from most conventional cancer chemotherapy medicines because they work very differently. Many chemotherapy medicines kill healthy cells along with cancer cells. But angiogenesis inhibitors only prevent new blood vessels from forming. The side effects from angiogenesis inhibitors are generally less and milder than with conventional chemotherapy medicines. But some of the side effects can be serious and include:
- High blood pressure
- Intestinal bleeding
- Clots in the arteries (which may lead to stroke or heart attack)
- Poor wound healing
Angiogenesis inhibitors might also affect a developing unborn baby and are not recommended for pregnant women or women who may become pregnant.