What is the role of Avastin in cancer treatment?

Avastin, also known as bevacizumab, is a monoclonal antibody that specifically targets vascular endothelial growth factor (VEGF). VEGF is a key protein involved in the process of angiogenesis, which is the formation of new blood vessels. By binding to VEGF, Avastin inhibits its interaction with receptors on endothelial cells, effectively blocking the signaling pathways that promote the growth of new blood vessels.

The inhibition of VEGF activity leads to the starvation of tumors for oxygen and nutrients, which are essential for their growth and survival. As a result, Avastin can effectively reduce tumor vascularization and hinder the ability of the cancer to expand. This mechanism is significant in treating various types of cancer, as tumors often depend on the development of their own blood supplies to thrive and metastasize.

In contrast, direct killing of cancer cells, promoting angiogenesis, or enhancing tumor growth would not align with the established function of Avastin. The primary therapeutic action of Avastin is to disrupt the blood supply to tumors by targeting VEGF, leading to decreased tumor size and rejuvenated therapeutic efficacy when combined with other treatments.