Limb-Saving Treatment for People with Melanoma: Isolated Limb Perfusion
Although melanoma is less common than some other forms of skin cancer, it is becoming more and more common.
Melanoma can occur at any site on the skin. It is more common on the chest, back, head, and neck in men. It is more common on the arms and legs in women.
For those people who have a lot of melanoma in their arms or legs, but nowhere else in their body, a special treatment option called isolated limb perfusion (ILP) may be used. This procedure may help prevent amputation and shrink the tumor. It may also relieve symptoms, such as pain and swelling.
What Is ILP?
ILP was first developed several decades ago. It combines surgery and drug treatment. First, the surgeon temporarily stops the blood circulation to the affected arm or leg. Isolating the blood supply of the limb prevents high doses of chemotherapy drugs from getting into the body and affecting other organs. Then, he or she puts in two small tubes called catheters--one in an artery and one in a vein. The doctor uses these catheters to move blood and anticancer drugs (chemotherapy) throughout the limb. The doctor also uses one of the catheters to withdraw blood from the limb, which is transferred to a machine called a pump-oxygenator. This machine is like the one used in heart bypass surgery. There, the blood is mixed with oxygen and chemotherapy drugs. (Melphalan is the most common chemotherapy drug used.)
Chemotherapy drugs move through the limb for up to 90 minutes. During this time, blankets keep the limb warm. The drugs are also warmed as they move through the pump-oxygenator. This appears to help the anticancer drugs work better. At the end of the procedure, the drugs are flushed out of the limb and normal circulation is re-established. The entire procedure takes about two to three hours.
The main advantage of ILP is that it allows high doses of the chemotherapy drug to be given to the affected limb, but spares the rest of the body from the side effects of the treatment. Side effects from ILP are largely limited to local effects, such as limb swelling.
Problems with ILP
ILP has a few drawbacks. For one, it is major surgery. Also, it does not affect any cancer that has spread beyond the limb. Lastly, while response rates with this procedure are good, the overall long-term survival rates with ILP and melphalan alone are not much better than those of people treated in other ways.
Doctors continue to look for ways to improve ILP. One method that is being studied as an alternative to ILP is called isolated limb infusion (ILI). In ILI, high doses of chemotherapy are injected into an artery or vein of the affected limb while the blood is temporarily stopped with a tourniquet. It is believed that this type of infusion may kill more cancer cells and cause less damage to healthy tissue. So far, results have been good, but more research is needed.