Canadian AIDS Treatment Information Exchange (CATIE) TreatmentUpdate48, Vol. 4, No. 8 - March 1994
Sean Hosein

As the immune systems of people with HIV/AIDS break down a number of complications appear, such as Kaposi's sarcoma, commonly called 'KS'. In the early years of the AIDS epidemic doctors thought that KS was a form of cancer. More recent research suggests that KS lesions are made up of an overgrowth of blood vessels. KS lesions on the skin or other parts of the body do not usually kill people. Lesions in the lungs can be dangerous resulting in "cough, shortness of breath and [blocking the ability to breathe]."

SPREAD AND GROWTH

In the early 1980s KS was common in North America in men with HIV/AIDS but a decade later it has become much less common. Researchers are not sure what causes KS; some think it is spread by a microorganism such as a virus but this has not been formally proven. In general, KS occurs more in men than in women. Some researchers think that there are growth factors such as hormones that help lesions grow and spread. The state of the immune system probably plays a role in the spread of lesions. Damaging the immune system with drugs such as Prednisone and cyclosporin can allow KS lesions to grow. When patients stop taking these drugs, the immune system may recover and the lesions disappear. In very rare cases doctors have noticed that KS can disappear without treatment.

STANDARD TREATMENTS

Therapies normally used against KS include anticancer agents and/or radiation. Anticancer agents such as Adriamycin (doxorubicin), bleomycin, vinblastine and vincristine have not cured KS. They may (or may not) reduce the spread of lesions. Many intravenous anticancer agents can cause side effects such as bone marrow toxicity, increased risk of infections and reduced quality of life. Sometimes these drugs are used only as a last resort. There are at least 2 ways to use these drugs so that their side effects may be reduced:

* liposomal and cancer agents * injecting drugs directly into lesions (called intralesional injections)

Liposomes are tiny spheres of fat. Anticancer drugs can be put inside the spheres. When infused into patients the spheres tend to move to the lesions where they release their contents. In this way the toxicity can be reduced. Data provided by drug companies making, selling and/or promoting these liposomal drugs suggest that liposomal anticancer therapy is a major improvement over the regular, 'free', form of the drug. Data released by doctors not working for or affiliated with these companies suggest that, overall, these drugs ultimately do not improve survival and can still cause side effects in some patients while leaving others free from toxicity. See the reference from the Lancet on page 13.

Injecting chemotherapy directly into a lesion also spares the body from the toxicity of these drugs. Intralesional treatment does have the small risk of nerve damage and loss of hair at the injection site. See the reference from the Lancet on page 13 for details. Although less toxic than intravenous chemotherapy, intralesional therapy does not, of course, affect other lesions on the skin or inside the body.

RADIATION

Sending a beam of radiation at lesions can damage them and provide relief from some symptoms such as fluid build-up in the feet or face. Like chemotherapy, radiation does not cure KS. Radiation can cause some skin and tissue surrounding the lesion to temporarily become tender and inflamed. Spraying cold liquid nitrogen onto skin lesions can destroy them but this does nothing to lesions inside the body.

DRUGS THAT AFFECT THE IMMUNE SYSTEM

Doctors are experimenting on their patients with KS using interferon-alpha with or without AZT, chemotherapy or radiation. Patients given intravenous interferon-alpha and doxorubicin may become more sensitive to radiation. These combinations of drugs may temporarily reduce the number and/or size of lesions in some patents, but they are not a cure. Side effects from interferon-alpha treatment include "fever, [fatigue and loss of energy]} liver damage (increased blood levels of liver enzymes) and decreasing levels of white blood cells [because of damage to the bone marrow]." Interferon-alpha can also be injected directly into lesions. In the next section we report some current research on new therapies for KS.

REFERENCES:

1. Myskowski PL. Kaposi's sarcoma: where do we go from here? Archives of Dermatology 1993;129:1320-1323.

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Copyright © 1994 - TreatmentUpdate. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the Editor, The Canadian AIDS Treatment Information Exchange, 555 Richmond St. West, Suite 505, Box 1104, Toronto, ON, M5V 3B1 • Phone: 416-203-7122 • Toll Free: 1-800-263-1638 • Fax: 416-203-8284  http://www.catie.ca