Limb-Saving Treatment for Peo... Health Article

Although melanoma is the rarest form of skin cancer, it is becoming more and more common. According to the American Academy of Dermatology, 1 in 62 Americans today have a lifetime risk of developing invasive melanoma. That is a 2000% increase from 1930.

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. About 50% of all melanomas occur in the arms or legs. In less than 10% of these cases, when the melanoma is at an advanced stage, removing the arm or leg may be the best treatment. This may seem drastic, but about 33% of these people will be cured after surgery. Still, amputation is not performed very often because the chance of recurrence is still high.

For a special group of people, though, there may be another treatment option. These people may have a lot of melanoma in their arms or legs but nowhere else in their body. For them, a procedure called isolated limb perfusion (ILP) offers hope. This procedure helps prevent amputation and shrinks the tumor. It also relieves symptoms such as pain and swelling.

What Is ILP?

ILP is a very special procedure, first developed more than 35 years ago. It combines surgery and drug treatment. First, the surgeon temporarily cuts off the circulation to the affected arm or leg. Isolating the limb prevents high doses of chemotherapy drugs from affecting other organs. Then, he or she exposes an artery and vein and inserts a tube into it. The doctor uses these tubes to move blood and inject high doses of anticancer drugs throughout the limb. The surgeon uses a tube called a catheter 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, it is mixed with oxygen and chemotherapy drugs.

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 anti-cancer 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 2 to 3 hours.

Since 1969, the anticancer drug Alkeran (melphalan) has been an option for an aggressive form of melanoma that occurs in the arms and legs, called “in transit.” Research shows that this drug shrinks the tumor in half in about 70% to 85% of people who take it. The tumor disappears in 40% to 50% of people who take the drug. However, the tumors come back in many of these people.

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 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.

To improve ILP, doctors have tried adding other agents. Adding something to stimulate the immune system seems promising and doctors need to test it further. TNF-a (tumor necrosis factor alpha) is a naturally produced protein that helps the immune system fight cancer. Scientists can make this protein in a lab and give it to patients to try to modify their bodies’ response to the tumor. Research also shows that TNF-a destroys tumor blood vessels and increases the amount of melphalan taken into the tumor. When given throughout the body, though, TNF-a does not work as well as melphalan. In a study done by the American College of Surgeons Oncology group, adding TNF to melphalan did not improve the results. And it has serious side effects, including potentially life-threatening drops in blood pressure. TNF is no longer used in ILP in this country.

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