Kaposi sarcoma (KS) is a cancer that causes patches of abnormal tissue to grow under the skin, in the lining of the mouth, nose, and throat, in lymph nodes, or in other organs. These patches, or lesions, are usually red or purple. They are made of cancer cells, blood vessels, and blood cells.

KS is caused by infection with human herpesvirus-8 (HHV-8). Most people infected with HHV-8 don't get KS. It usually happens in:

• People with weak immune systems, due to HIV/AIDS, drugs taken after an organ transplant, or another disease
• Older men of Jewish or Mediterranean descent
• Young men in Africa

The skin lesions may not cause symptoms. But they can spread to other parts of the body, especially in people with HIV/AIDS. If they spread to the digestive tract or lungs, they can cause bleeding. Lesions on the lungs can also make it hard to breathe.

Treatment depends on where the lesions are and how bad they are. Options include radiation therapy, surgery, chemotherapy, and biologic therapy. People with HIV/AIDS also take HIV/AIDS medicines.

Kaposi sarcoma is a disease in which malignant lesions (cancer) can form in the skin, mucous membranes, lymph nodes, and other organs.

Kaposi sarcoma is a cancer that causes lesions (abnormal tissue) to grow in the skin; the mucous membranes lining the mouth, nose, and throat; lymph nodes; or other organs. The lesions are usually purple and are made of cancer cells, new blood vessels, red blood cells, and white blood cells. Kaposi sarcoma is different from other cancers in that lesions may begin in more than one place in the body at the same time.

Human herpesvirus-8 (HHV-8) is found in the lesions of all patients with Kaposi sarcoma. This virus is also called Kaposi sarcoma herpesvirus (KSHV). Most people with HHV-8 do not get Kaposi sarcoma. People with HHV-8 are more likely to develop Kaposi sarcoma if their immune system is weakened by disease, such as human immunodeficiency virus (HIV), or by drugs given after an organ transplant.

There are several types of Kaposi sarcoma. The two types discussed in this summary include:

• Classic Kaposi sarcoma.
• Epidemic Kaposi sarcoma (HIV-associated Kaposi sarcoma).

Kaposi sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8 (HHV-8), can cause Kaposi sarcoma. KSHV can also cause primary effusion lymphoma and multicentric Castleman disease.

KSHV is most commonly spread through saliva. It can also be spread through organ or bone marrow transplantation, and there is some evidence that it can be spread by blood transfusion, although this risk is minimized by practices followed in the United States such as blood storage and removal of white cells.

KSHV infection is generally limited to certain populations, and the way KSHV is spread varies among these populations. In sub-Saharan Africa and certain regions of Central and South America, where KSHV infection is relatively common, it is believed to spread by contact with saliva among family members. In Mediterranean countries (Italy, Greece, Israel, Saudi Arabia), where KSHV infection is present at intermediate levels, it is thought to spread by contact among children and by ill-defined routes among adults. Finally, in regions where KSHV infection is uncommon, such as the United States and Northern Europe, it appears to be mostly transmitted sexually, especially among men who have sex with men.

Most people infected with KSHV do not develop cancer or show any symptoms, although those who also have HIV infection or are immunosuppressed for other reasons are more likely to develop KSHV-caused diseases. There is no vaccine to prevent KSHV infection and no therapy to treat infection. Men who have sex with men may be advised to avoid oral–anal contact (including use of saliva as a personal lubricant). And people who are infected with HIV can lower their risk of KSHV-related complications by using antiretroviral therapy.

Classic Kaposi sarcoma is found most often in older men of Italian or Eastern European Jewish origin.

Classic Kaposi sarcoma is a rare disease that gets worse slowly over many years.

Signs of classic Kaposi sarcoma may include slow-growing lesions on the legs and feet.

Patients may have one or more red, purple, or brown skin lesions on the legs and feet, most often on the ankles or soles of the feet. Over time, lesions may form in other parts of the body, such as the stomach, intestines, or lymph nodes. The lesions usually don't cause any symptoms but may grow in size and number over a period of 10 years or more. Pressure from the lesions may block the flow of lymph and blood in the legs and cause painful swelling. Lesions in the digestive tract may cause gastrointestinal bleeding.

Another cancer may develop.

Some patients with classic Kaposi sarcoma may develop another type of cancer before the Kaposi sarcoma lesions appear or later in life. Most often, this second cancer is non-Hodgkin lymphoma. Frequent follow-up is needed to watch for these second cancers.

Patients with human immunodeficiency virus (HIV) are at risk of developing epidemic Kaposi sarcoma (HIV-associated Kaposi sarcoma).

Acquired immunodeficiency syndrome (AIDS) is caused by HIV, which attacks and weakens the body's immune system. A weakened immune system is unable to fight infection and disease. People with HIV have an increased risk of infection and cancer.

A person with HIV and certain types of infection or cancer, such as Kaposi sarcoma, is diagnosed as having AIDS. Sometimes, a person is diagnosed with AIDS and epidemic Kaposi sarcoma at the same time.

The use of drug therapy called highly active antiretroviral therapy (HAART) reduces the risk of epidemic Kaposi sarcoma in patients with HIV.

HAART is a combination of several drugs used to lessen the damage to the immune system caused by HIV infection. Treatment with HAART reduces the risk of epidemic Kaposi sarcoma, although it is possible to for a person to develop epidemic Kaposi sarcoma while taking HAART.

For information about AIDS and its treatment, see the AIDSinfo website.

Signs of epidemic Kaposi sarcoma can include lesions that form in many parts of the body.

The signs of epidemic Kaposi sarcoma can include lesions in different parts of the body, including any of the following:

• Skin.
• Lining of the mouth.
• Lymph nodes.
• Stomach and intestines.
• Lungs and lining of the chest.
• Liver.
• Spleen.

Kaposi sarcoma is sometimes found in the lining of the mouth during a regular dental check-up.

In most patients with epidemic Kaposi sarcoma, the disease will spread to other parts of the body over time.

Tests that examine the skin, lungs, and gastrointestinal tract are used to diagnose Kaposi sarcoma.

The following tests and procedures may be used:

• Physical exam and health history: An exam of the body to check general signs of health, including checking skin and lymph nodes for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.
• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body. This is used to find Kaposi sarcoma in the lungs.
• Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.

  One of the following types ofbiopsies may be done to check for Kaposi sarcoma lesions in the skin:

  • Excisionalbiopsy: A scalpel is used to remove the entire skin growth.
  • Incisionalbiopsy: A scalpel is used to remove part of a skin growth.
  • Corebiopsy: A wide needle is used to remove part of a skin growth.
  • Fine-needle aspiration (FNA) biopsy: A thin needle is used to remove part of a skin growth.

  An endoscopy or bronchoscopy may be done to check for Kaposi sarcoma lesions in the gastrointestinal tract or lungs.

  • Endoscopy for biopsy: A procedure to look at organs and tissues inside the body to check for abnormal areas. An endoscope is inserted through an incision (cut) in the skin or opening in the body, such as the mouth. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of disease. This is used to find Kaposi sarcoma lesions in the gastrointestinal tract.
  • Bronchoscopy for biopsy: A procedure to look inside the trachea and large airways in the lung for abnormal areas. A bronchoscope is inserted through the nose or mouth into the trachea and lungs. A bronchoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue samples, which are checked under a microscope for signs of disease. This is used to find Kaposi sarcoma lesions in the lungs.

After Kaposi sarcoma has been diagnosed, tests are done to find out if cancer cells have spread to other parts of the body.

The following tests and procedures may be used to find out if cancer has spread to other parts of the body:

• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the lung, liver, and spleen, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
• PET scan (positron emission tomography scan): A procedure to find malignant lesions in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant lesions show up brighter in the picture because they are more active and take up more glucose than normal cells do. This imaging test checks for signs of cancer in the lung, liver, and spleen.
• CD34 lymphocyte count: A procedure in which a blood sample is checked to measure the amount of CD34 cells (a type of white blood cell). A lower than normal amount of CD34 cells can be a sign the immune system is not working well.

There are different types of treatment for patients with Kaposi sarcoma.

Different types of treatments are available for patients with Kaposi sarcoma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Six types of standard treatment are used to treat Kaposi sarcoma:

Treatment of epidemic Kaposi sarcoma combines treatment for Kaposi sarcoma with treatment for acquired immunodeficiency syndrome (AIDS). The six types of standard treatment used to treat Kaposi sarcoma include:

HAART

Highly active antiretroviral therapy (HAART) is a combination of several drugs used to lessen the damage to the immune system caused by human immunodeficiency virus (HIV) infection. For many patients, HAART alone may be enough to treat epidemic Kaposi sarcoma. For other patients, HAART may be combined with other standard treatments to treat epidemic Kaposi sarcoma.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy:

• External radiation therapy uses a machine outside the body to send radiation toward the area of the body with cancer.
• Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer.

The way the radiation therapy is given depends on the type of the cancer being treated. Certain types of external radiation therapy are used to treat Kaposi sarcoma lesions. Photon radiation therapy treats lesions with high-energy light. Electron beam radiation therapy uses tiny negatively charged particles called electrons.

Surgery

The following surgical procedures may be used for Kaposi sarcoma to treat small, surface lesions:

• Local excision: The cancer is cut from the skin along with a small amount of normal tissue around it.
• Electrodesiccation and curettage: The tumor is cut from the skin with a curette (a sharp, spoon-shaped tool). A needle-shaped electrode is then used to treat the area with an electric current that stops the bleeding and destroys cancer cells that remain around the edge of the wound. The process may be repeated one to three times during the surgery to remove all of the cancer.

Cryosurgery

Cryosurgery is a treatment that uses an instrument to freeze and destroy abnormal tissue. This type of treatment is also called cryotherapy.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, tissue, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy).

In electrochemotherapy, intravenous chemotherapy is given and a probe is used to send electric pulses to the tumor. The pulses make an opening in the membrane around the tumor cell and allow the chemotherapy to get inside.

The way the chemotherapy is given depends on where the Kaposi sarcoma lesions occur in the body. In Kaposi sarcoma, chemotherapy may be given in the following ways:

• For local Kaposi sarcoma lesions, such as in the mouth, anticancer drugs may be injected directly into the lesion (intralesional chemotherapy).
• For local lesions on the skin, a topical agent may be applied to the skin as a gel. Electrochemotherapy may also be used.
• For widespread lesions on the skin, intravenous chemotherapy may be given.

Liposomal chemotherapy uses liposomes (very tiny fat particles) to carry anticancer drugs. Liposomal doxorubicin is used to treat Kaposi sarcoma. The liposomes build up in Kaposi sarcoma tissue more than in healthy tissue, and the doxorubicin is released slowly. This increases the effect of the doxorubicin and causes less damage to healthy tissue.

Immunotherapy

Immunotherapy is a treatment that uses the patient's immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body's natural defenses against cancer. This cancer treatment is a type of biologic therapy. Interferon alfa and interleukin-12 are biologic agents used to treat Kaposi sarcoma.

New types of treatment are being tested in clinical trials.

This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied.

Targeted therapy

Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells. Targeted therapies usually cause less harm to normal cells than chemotherapy or radiation therapy do. Monoclonal antibody therapy and tyrosine kinase inhibitors (TKIs) are types of targeted therapy being studied in the treatment of Kaposi sarcoma.

• Monoclonal antibodies are immune system proteins made in the laboratory to treat many diseases, including cancer. As a cancer treatment, these antibodies can attach to a specific target on cancer cells or other cells that may help cancer cells grow. The antibodies are able to then kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells. Bevacizumab is a monoclonal antibody that may be used to treat Kaposi sarcoma.

• TKIs block signals needed for tumors to grow. Imatinib mesylate is a TKI that may be used to treat Kaposi sarcoma.

Treatment for Kaposi sarcoma may cause side effects.

Patients may want to think about taking part in a clinical trial.

For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.

Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Patients can enter clinical trials before, during, or after starting their cancer treatment.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Follow-up tests may be needed.

Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests.

Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.

Treatment for single skin lesions may include the following:

• Radiation therapy.
• Surgery.

Treatment for skin lesions all over the body may include the following:

• Radiation therapy.
• Chemotherapy.
• Electrochemotherapy.

Treatment for Kaposi sarcoma that affects lymph nodes or the gastrointestinal tract usually includes chemotherapy with or without radiation therapy.

Treatment for epidemic Kaposi sarcoma may include the following:

• Surgery, including local excision or electrodesiccation and curettage.
• Cryosurgery.
• Radiation therapy.
• Chemotherapy using one or more anticancer drugs.
• Biologic therapy using interferon alfa or interleukin-12.
• Targeted therapy using imatinib or bevacizumab.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis and treatment options depend on the following:

• The type of Kaposi sarcoma.
• The general health of the patient, especially the patient's immune system.
• Whether the cancer has just been diagnosed or has recurred (come back).