#Source [Angiogenesis in Cancer - PMC](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1993983/) # Abstract: New growth in the vascular network is important since the growth, as well as metastatic spread, of cancer cells depends on an adequate supply of oxygen and nutrients and the removal of waste products. New blood and lymphatic vessels form through processes called [angiogenesis](../../4.%20Lions%20&%20Tigers%20&%20Bears%20(Pathways%20&%20Drivers)/Angiogenesis.md) and lymphangiogenesis, respectively. [Angiogenesis](../../4.%20Lions%20&%20Tigers%20&%20Bears%20(Pathways%20&%20Drivers)/Angiogenesis.md) is regulated by both activator and inhibitor molecules. More than a dozen different proteins have been identified as angiogenic activators and inhibitors. Levels of expression of angiogenic factors reflect the aggressiveness of tumor cells. The discovery of angiogenic inhibitors should help to reduce both morbidity and mortality from carcinomas. Thousands of patients have received antiangiogenic therapy to date. Despite their theoretical efficacy, antiangiogeic treatments have not proved beneficial in terms of long-term survival. There is an urgent need for a new comprehensive treatment strategy combining antiangiogenic agents with conventional cytoreductive treatments in the control of cancer. # Conclusion: Cancer cells require access to blood vessels for growth and [metastasis](../../4.%20Lions%20&%20Tigers%20&%20Bears%20(Pathways%20&%20Drivers)/Metastasis.md). The discovery of angiogenic inhibitors provides hope for reducing the mortality and morbidity from carcinomas. There has been a modest positive outcome with the use of antiangiogenic drugs based on some clinical trials ([Cobleigh et al 2003](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1993983/#b12); [Yang et al 2003](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1993983/#b93)), but no long-term survival benefits have been documented as yet ([Mayer 2004](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1993983/#b57)). However, when used in combination with [chemotherapy](../../3.%20Treatments/3.6%20%20Standard%20care/Chemotherapy.md) or [radiation therapy](../../3.%20Treatments/3.6%20%20Standard%20care/Radiation%20therapy.md), these drugs tend to increase survival ([Hurwiz et al 2004](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1993983/#b34)).