Angiogenesis, the formation of new blood vessels, is a process controlled by certain chemicals produced in the body. Although this formation may help in normal wound healing, cancer can grow when these new blood vessels are created. Angiogenesis provides cancer cells with oxygen and nutrients, allowing the cancer cells to multiply, invade nearby tissue and spread to other areas of the body (metastasize).
A chemical that interferes with the signals to form new blood vessels is referred to as an angiogenesis inhibitor.
Sometimes called anti-angiogenic therapy, this treatment may prevent the growth of cancer by blocking the formation of new blood vessels.
There are many compounds being studied that interfere with the formation of new blood vessels. Research has shown that many factors stimulate new blood vessel growth. Using a drug that blocks just one factor may not be enough to prevent the growth of a cancer. Also, because these drugs block new blood vessel formation, the old ones are still there and the tumors may not shrink. Because of this possibility, there is a tend toward combining anti-angiogenesis drugs with standard chemotherapy.
Bevacizumab (Avastin) became the first anti-angiogenesis drug to be approved for treating cancer. The FDA approved it for use along with chemotherapy in patients with metastatic colorectal cancer. A clinical trial found that people who received bevacizumab plus chemotherapy lived an average of about five months longer than people who got chemotherapy alone. Bevacizumab can help some people live longer, but it is not expected to be a cure.