Kaposi sarcoma

What is Kaposi sarcoma?

Kaposi sarcoma is a cancer that develops from the cells that line lymph or blood vessels. It usually appears as tumours on the skin, mucosal surfaces such as inside the mouth, lymph nodes or the digestive tract.

The different types of Kaposi sarcoma are defined by the different populations it develops in, but the changes within the cells are very similar.

The most common type of Kaposi sarcoma is AIDS-related. This type of sarcoma develops in people who are infected with HIV, the virus that causes AIDS. The virus can be present in the body for a long time, often many years, before causing major illness. The disease known as AIDS begins when the virus has seriously damaged the immune system, which results in certain types of infections or other medical complications. When HIV damages the immune system, people who also are infected with a certain virus (the Kaposi sarcoma herpes virus) are more likely to develop Kaposi sarcoma. When Kaposi sarcoma occurs in someone infected with HIV, that person officially has AIDS (and is not just HIV positive). Another sarcoma, Endemic (African) Kaposi sarcoma occurs in people living in Equatorial Africa. This type usually affects the lymph nodes and other organs and can progress quickly.

Can Kaposi sarcoma be prevented?

Kaposi sarcoma is caused by the Kaposi sarcoma herpes virus (KSHV). There are no vaccines at this time to protect people against KSHV. For now, preventing Kaposi sarcoma depends on reducing the chance of becoming infected with KSHV and reducing the chance that people who are infected with KSHV will develop sarcoma.

What are the signs and symptoms of Kaposi sarcoma?

Kaposi sarcoma usually appears first on the skin, forming purple, red, or brown patches (not raised above the surrounding skin), plaques (flat areas that are slightly raised), or nodules (bumps) that are called lesions. The skin lesions of Kaposi sarcoma most often develop on the legs or face, but they can also appear in other areas. Lesions can also develop on mucous membranes such as those inside the mouth. The lesions are usually not painful or itchy. Some lesions on the legs or in the groin area might block the flow of fluid out of the legs. This can lead to painful swelling in the legs and feet. Kaposi sarcoma lesions can also sometimes appear in other parts of the body. Lesions in the lungs might block part of an airway and cause shortness of breath. Lesions that develop in the intestines can cause abdominal pain, diarrhea, or bleeding from the rectum.

How is Kaposi sarcoma diagnosed?

Tests and procedures used to diagnose mouth cancer include:

  • Physical exam: If your doctor suspects you might have Kaposi sarcoma, you will be asked about your medical history to learn about illnesses, operations, your sexual activity, and other possible exposures to KSHV and HIV. The doctor will ask you about your symptoms and about any skin tumours you have noticed.
  • Biopsy: To be sure that a lesion is caused by Kaposi sarcoma, the doctor will need to take a small sample of tissue from the lesion and send it to a lab to be analysed. This is called a biopsy. A specially trained doctor called a pathologist can often diagnose KS by looking at the cells in the biopsy sample under a microscope.

Additional imaging tests such as an x-ray or endoscope may also be done if Kaposi sarcoma is suspected to have spread to other types of the body.

For AIDS-related Kaposi sarcoma, the outlook (or staging) is influenced by the presence of other AIDS-related problems as it is by the spread of Kaposi sarcoma. For this reason, staging of Kaposi also considers factors such as how much the immune system is damaged and the presence of AIDS-related infections.

What are my treatment options?

Treatment for Kaposi sarcoma is more effective than it was a couple of decades ago. Choices about the best treatment options for each patient are based on the function of the immune system as well as the number, location, and size of the lesions. The patient’s general health is also a major factor. The presence and severity of other serious health problems can make some treatments a poor choice.

For patients with immune system problems, the most important treatment is keeping the immune system healthy and any related infections under control. Some of the other treatments used for Kaposi sarcoma are:

  • Local therapy: Local treatment only affects certain Kaposi sarcoma lesions (or areas of lesions). This type of treatment is often used to treat a few skin lesions in one spot to help a person look or feel better. Local therapy is most useful when there are just a few lesions in a very visible area (such as the face). The drawbacks of local therapy are that it does not treat lesions anywhere else and it can’t keep new lesions from developing.
  • Radiation therapy: Radiation therapy uses high-energy radiation to kill cancer cells. When the radiation is delivered from outside the body it is called external beam radiation therapy. This is the type of radiation therapy used to treat lesions of Kaposi sarcoma. Radiation therapy is often effective as a type of local therapy to treat lesions on or near the surface of the body. Radiation is used to reduce symptoms like pain or swelling. It is also used for skin lesions that look bad and are in places that can easily be seen.
  • Chemotherapy: Chemotherapy is the use of drugs to treat cancer. When the drugs are given into a vein or by mouth, they enter the bloodstream to reach all areas of the body. This is a type of systemic treatment. It is useful to treat cancer that has spread to many areas of the body.

For some people with Kaposi sarcoma, treatment may completely remove or destroy the cancer.  For others, the cancer never goes away completely. These people may get regular treatments with chemotherapy, radiation therapy, or other therapies to try to help keep the cancer in check.

Even if your treatment ends, your doctors will still want to watch you closely. Talk with your doctor about what kind of follow-up schedule you should follow.

” Courtesy of the Aga Khan Hospital”