What Is Kaposi Sarcoma?
Kaposi sarcoma (KS) is a rare type of cancer that develops in cells that line blood vessels and lymphatic vessels. Cancerous lesions usually appear on the skin and on mucous membranes, such as inside the mouth and throat, but they can also develop in the lymph nodes, lungs and digestive tract. Kaposi sarcoma lesions can be flat patches, raised patches or bumps and may be red, purple or brown. They commonly appear on the face, legs and feet.
The lesions are usually painless, but those on the legs or in the groin area may cause painful swelling of the legs and feet.
If KS has affected the lungs, you may cough up blood or have trouble breathing. If it has affected the digestive tract, it may cause pain and bleeding that can lead to anemia.
What Causes Kaposi Sarcoma?
People with KS are infected with a virus called human herpesvirus-8, or HHV-8, also called Kaposi sarcoma-associated herpesvirus. Normally, the virus doesn’t cause any symptoms, and most people who have it never develop KS because their immune system keeps it in check. But HHV-8 can lead to KS in people whose immune systems are compromised..
Who Gets Kaposi Sarcoma?
There are four types of Kaposi sarcoma, and each one occurs in different patient populations.
Epidemic (AIDS-associated) Kaposi sarcoma. This is the most common type in the United States. It occurs in people who have AIDS. KS can also develop in people who are HIV-positive. When this happens, it is a sign that the HIV has progressed to AIDS.
Classic (Mediterranean) Kaposi sarcoma. Most people who develop this form of KC are older and of Mediterranean, Eastern European or Middle Eastern descent. Men are more commonly affected than women. Lesions tend to develop on the legs, ankles and soles of the feet.
Endemic (African) Kaposi sarcoma. This type of KS occurs in people living in Africa, where rates of HHV-8 infection are higher and certain conditions that weaken the immune system, such as malaria and malnutrition, are more common. Endemic KS tends to occur in people under age 40 and is more likely to affect the lymph nodes and other organs.
Iatrogenic Kaposi sarcoma. People who take immunosuppressant medication due to an organ transplant may develop this type of KS.
Kaposi Sarcoma Treatment
Your doctor will determine which treatment is best depending on the type of kaposi sarcoma, the location and number of tumors, your overall health and whether you’re experiencing any other symptoms.
Treating immunodeficiency is key for people who have AIDS-associated or iatrogenic KS. For those with HIV or AIDS, a combination therapy called highly active antiretroviral therapy (HAART) is used. It may be the only treatment necessary to shrink the lesions and keep them under control.
Doctors may treat people with iatrogenic KS by stopping, lowering or switching their immunosuppressant medications.
If you have only a few lesions in one spot (which is not usually the case in AIDS-associated KS), especially if they are in a highly visible area, such as your face, the lesions may be treated to shrink them or get rid of them altogether. Treatments include:
- Topical gels and creams
- Excision (cutting the lesions out)
- Electrodesiccation and curettage (scooping out the lesion with a sharp, spoon-shaped tool and cauterizing the remaining cancer cells)
- Local chemotherapy (injecting a chemotherapy drug into the lesion)
- Photodynamic therapy (applying a topical drug and then activating it with a special light)
- Radiation therapy
Radiation therapy may also be used to reduce symptoms such as pain and swelling and to treat lesions in the mouth or throat.
If you have lesions throughout your body, intravenous chemotherapy may be necessary.
Immunotherapy using biologic drugs is also used to treat KS.
Kaposi Sarcoma Prevention
There is no vaccine for HHV-8. Since most KS cases in the U.S. develop in people with HIV and AIDS, the best way to reduce your risk of KS is to avoid becoming infected with HIV. You can do this by:
- Getting tested for HIV and encouraging your partner to do so before having sex
- Using condoms when you have sex, especially vaginal and anal sex
- Limiting your number of sex partners
- Taking pre-exposure prophylaxis (PrEP) drugs if you’re at high risk of contracting HIV
- Refraining from injecting drugs or from sharing needles if you do inject drugs