Kaposi's Sarcoma

Definition

Kaposi's sarcoma (KS) is a rare form of cancer. It starts in cells that line blood and lymph vessels. It commonly appears on the skin. But it can also affect the inside of the body such as the lungs, digestive tract, or lymph nodes.

KS is grouped by the people it affects:

• Classic—usually affects older people of Mediterranean descent
• Endemic—usually affects people living in equatorial Africa
• Transplant-related (iatrogenic)—affects people who have a weak immune system after having an organ transplant
• AIDS-associated (epidemic)—affects people who have HIV infection

Causes

Cancer occurs when cells in the body divide without control or order. If cells keep dividing, a growth or tumor forms. Malignant tumors are cancerous. They can invade and destroy nearby tissue. Some types of cancer spread to other parts of the body.

KS is caused by an infection with a specific virus. The virus is called human herpes virus 8 or Kaposi sarcoma herpesvirus (KSHV). Most people infected with the virus will not get KS. KS most often develops in people who have the virus and a weak immune system.

Risk Factors

Things that raise the risk of KS are:

• Having HIV infection
• Using medicine that weakens the immune system

Symptoms

KS tumors may develop anywhere on the body. They tend to be raised blotches or lumps which may be purple, brown, red, or pink.

Skin Lesions

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KS spots in the lungs can also cause breathing problems. Those in the stomach and intestines can cause belly pain or loose stools (poop).

Diagnosis

The doctor will ask about symptoms and past health. A physical exam will be done. The exam will focus on the skin and inside the mouth. This may be enough for the doctor to suspect KS. If there is bleeding, pain, or weight loss, the doctor may do more tests to look for KS.

Tests may include:

• Biopsy
• CT scan
• Bronchoscopy
• Endoscopy

Treatment

Treatment depends on the type of KS, how much it has spread, and how well a person's immune system is working.

Any underlying immune system problems will need treatment. This may involve:

• Giving anti-HIV drugs to those who have HIV or AIDS
• Stopping, lowering, or changing medicines—in those with weak immune systems from certain medicines

If there are a few KS tumors together in a small area, treatment may be:

• Medicated gel or creams—put on the tumors to shrink them.
• Cryosurgery—liquid nitrogen applied directly to freeze and kill the abnormal cells.
• A simple excision—surgery to cut the tumor out.
• Curettage and electrodesiccation—the tumor is scraped off with a special instrument.
• Photodynamic therapy—a drug on the skin and a special light destroy the cancer cells.

Other treatments for KS may include:

• Radiation therapy—applied to the area to destroy the cancer cells. The number of treatments depends on the size and location of the tumors. It can also be used to treat pain and swelling. Different types of radiation therapy may include:
  • Electron-beam—Shallow exposure used to treat skin lesions
  • Photon—Deeper exposure used to treat mouth or throat lesions
• Chemotherapy (chemo)—drugs given by pill, injection, or IV to kill cancer cells. Sometimes a small amount of a chemo drug is injected right into the tumors.
• Immunotherapy—drugs that help the immune system fight the cancer.

Prevention

Steps to prevent HIV infection can help lower the risk of some KS.