New Drug Cuts Blood Supply to Cancer


2004-3-9

This is the VOA Special English Health Report.

There is an expression that describes the traditional three stepsthat doctors use to treat cancer: "cut, burn and poison." Cut outthe growth. Burn the cancerous cells with radiation. Poison thosethat remain with chemotherapy drugs.

More than thirty years ago, a young American doctor proposedanother way. Doctor Judah Folkman thought cutting the blood supplyto cancers could block their growth. For a long time, many otherscientists dismissed this theory.

But, last month, the United States Food and Drug Administrationapproved the first drug that works the way he proposed. The drug iscalled Avastin. The Genentech company developed it to lengthen thelives of people with colon cancer that has spread in the body. Itdoes not cure the disease, however.

To test the drug, some patients received both Avastin andchemotherapy chemicals. Others received only chemotherapy. Thepeople who had both generally survived for twenty months. That wasabout five months longer than those on chemotherapy alone.

Avastin is a genetically engineered protein. It connects with aprotein in the body that helps blood vessels grow. That protein isknown as V.E.G.F., vascular endothelial growth factor. Blocking thisgrowth factor can interfere with the supply of blood to the cancerand starve the cells.

Avastin is designed to target the weak places in cancer cells. Itdoes not damage normal tissue. Chemotherapy drugs kill cancer cells,but usually also kill other cells. This can cause infections alongwith stomach and intestinal problems.

Today, Judah Folkman is a professor at the Harvard Medical Schoolin Cambridge, Massachusetts. During the nineteen-sixties he workedat the Bethesda Naval Hospital in Bethesda, Maryland. Doctor Folkmanthought that cancers put out some kind of material that made newblood vessels form. He thought it might be possible to develop newtreatments if the vessel growth could be blocked. Today other drugsare also being tested to see if they can stop the formation of bloodvessels.

Avastin is one of three new drugs approved for colon cancer inthe past two years. But some doctors also note that these newmedicines cost a lot more than older treatments.

This VOA Special English Health Report was written by JerilynWatson.