What Are These Therapies and How Do They Work?
A talk by Dr. Rakesh Jain
Rakesh K. Jain, PhD, is a professor of tumor biology at Harvard Medical School in Boston, and the director of the Steele Laboratory of Tumor Biology at Massachusetts General Hospital, where he has worked since 1991. He specializes in tumor biology, drug delivery and in vivo imaging.
In April 2006, as part of the AACR’s Scientist↔Survivor Program, Jain spoke to a group of patient advocates about drugs that interfere with the formation of new blood vessels, a process called angiogenesis. Angiogenesis is required for a healthy tissue to grow, but because blood vessels deliver oxygen and nutrients to nourish tumors, the process is equally necessary for a tumor to grow. Scientists have believed that the development of effective anti-angiogenic drugs might prevent the growth of these vessels and help starve a tumor to death. In fact, doctors have found that these agents improve the survival by several months of many patients who take them in combination with traditional chemotherapy.
But there’s more to the story. In his lecture, Jain explains that today’s anti-angiogenic agents don’t completely choke off a tumor’s blood supply in patients—the drugs are much too toxic for patients to take them at the high doses necessary to kill a tumor’s blood vessels entirely. Jain discusses a counterintuitive idea: Anti-angiogenic agents may kill many tumor blood vessels, but improve the structure of the blood vessels that remain behind. Those improved, or normalized, blood vessels allow chemotherapy and radiation treatments to be more effective.
Jain’s lecture is presented here, in an adapted form, edited for the Survivors and Advocates website.
Please click on the links in the outline below to read Jain's talk:
2—Tumor Blood Vessels
3—New Ideas About Angiogenesis
4—Normalization of Blood Vessels
5—Showing Normalization by Anti-Angiogenic Drugs in Patients
June 25, 2007