http://www.healthology.com/emb_player/main_embed.asp?f=cancer&c=cancer_m...
printed summary of webcast.
Summary:
Molecular targeted therapies may become a revolutionary change in the treatment of cancer. Listen as experts describe how these drugs are being used today and what may lie ahead.
Transcript:
ANNOUNCER: Researchers have learned a great deal in recent years about how some cancers develop. That knowledge is beginning to pay off, with the development of new medicines that narrowly target those processes.
PAUL BUNN, MD: So in the last 30 years since the war on cancer started with the National Cancer Act, we've made a lot of basic science advances that define how a cancer cell is different from a normal cell. The proteins and the genes that make it different are the targets, so we have new therapies now that are designed to inhibit these genes and proteins associated with cancer. So that's what people mean by molecularly targeted therapy: therapy that's targeted towards genes and proteins that are different on cancer cells compared to normal human cells.
ANNOUNCER: What's different in the cancer cell are abnormalities in the biochemical circuits that control cell growth and death. The "switches" in these circuits can be in the nucleus of the cell: in its body or on the surface.
ROMAN PEREZ-SOLER, MD: Signaling pathways are basically switches on the surface of the cell that are turned on and off. If you turn them on, the cell grows and divides. If you are a tumor and you turn it on, what happens is then that the tumor grows.
So you attack the signaling pathways by going to the surface of the cell and blocking the switch, or you can just go inside all that circuit and block it somewhere inside.
ANNOUNCER: Another approach in "targeted" therapy is called angiogenesis inhibition, which deprives the cancer of its blood supply.
PAUL BUNN, MD: When you block blood vessel formation the tumor will shrink and die because it doesn't get oxygen.
ANNOUNCER: The various types of molecular targeted therapy can be very effective. Often with few side effects.
ROMAN PEREZ-SOLER, MD: The excitement is the higher degree of specificity, which basically means therapeutic effect with fewer side effects, and probably more therapeutic effect. Because as we really attack the pathway that is the secret of that cell, we basically very specifically harm that cell without damaging the rest of the body.
ANNOUNCER: Chemotherapy, in contrast, affects many types of normal cells, causing side effects such as hair loss, nausea and vomiting. And what's often most serious, low blood counts. Targeted drugs have side effects too. But they are usually quite mild.
PAUL BUNN, MD: Many of the targeted therapies may cause diarrhea. Some of them cause skin rash. Some of them cause fatigue. But generally these side effects are (a) mild, and (b) are reversible by either discontinuing the drug for a short period of time or lowering the dose.
ANNOUNCER: Many targeted therapies are being studied only in the lab, or in clinical trials. But quite a few of the drugs are already being used in clinical practice.
PAUL BUNN, MD: The list of cancers treated with molecularly targeted drugs is long and growing, all the way from leukemia to solid tumors, such as breast cancer, colon cancer, lung cancer, and every day literally we're adding to the list of cancers that are going to be treated with molecularly targeted drugs.
ANNOUNCER: Sometimes targeted therapies are used alone. More commonly, they're used in combination with traditional chemotherapy.
PAUL BUNN, MD: Tarceva combined with gemcitabine is better than either alone in pancreas cancer. Herceptin combined with chemotherapy is better than chemotherapy alone for HER-2 positive breast cancer. All the angiogenesis agents have been shown to be better in combination with chemotherapy than by themselves, so that is most often true, but not always.
ANNOUNCER: In some cancers, such as several types of lymphoma, targeted therapy can increase the likelihood of a cure. In other cases, the newer drugs delay the progression of a fatal disease. As doctors and researchers continue to learn more about how cancer develops, they say more and better targeted drugs will become available. They payoff in improved treatment is likely to be significant.
PAUL BUNN, MD: So the promises of molecular targeted therapy and personalized medicine using specific therapies for a specific patient's tumor, are that we will cure many more patients with early stage disease and that patients that have advanced disease that can't be cured will have a product life.
DAVID GARFIELD, MD: In all the years I've been in oncology, these past few years have been the most exciting. We were stuck with chemotherapy for years. The progress was slow and arduous. But now we're finding that these molecular targeted therapies work in a dramatic fashion, very quickly. For reasons that we understand, whereas we didn't understand the chemotherapy before, we're able to combine molecular targeted therapies and get a better response and so these are very, very fine times for us. The fruits of our labors over the last many decades are finally coming to fruition.