Angiogenesis, the formation of new blood vessels, is a process controlled by certain chemicals produced in the body. A chemical which signals this process to stop is referred to as an angiogenesis inhibitor.

Cancer spreads by the formation of new blood vessels, which supply the cancer cells with oxygen and nutrients, helping the cells to grow, invade nearby tissue, and spread to other areas of the body (metastasize).

Scientists are studying ways to stop angiogenesis, in the hope that angiogenesis inhibitors will be able to prevent the growth of cancer by blocking the formation of new blood vessels. In animal studies, angiogenesis inhibitors have prevented the growth of new blood vessels, causing the cancer to shrink and go away completely, in some cases. Research studies in humans are being conducted to learn whether the idea will be applicable to human cancers. Patients with cancers of the breast, prostate, pancreas, lung, stomach, ovary, cervix, and others are being studied. If the research studies demonstrate that angiogenesis inhibitors are both safe and effective for cancer treatment in humans, these agents would then need to be approved by the US Food and Drug Administration (FDA) in order for them to be available for widespread use.