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.
