Definition
Kaposi's sarcoma (KS) is a form of cancer. It can cause lesions on the skin, mucus membranes, or internal organs such as the gastrointestinal tract and lungs.
KS can be classified according to the group of people that it affects:
- Classic—usually affects men of Mediterranean descent
- Endemic—usually affects people living in equatorial Africa
- Transplant-related (acquired)—affects people who have received an organ transplant and have a suppressed immune system
- AIDS-related (epidemic)—affects people with HIV infection
Causes
Cancer occurs when cells in the body divide without control or order. If cells keep dividing, a mass of tissue forms. This mass is called a growth or tumor. Malignant tumors can invade and destroy nearby tissue. Some types of cancer will eventually 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 also have a weakened immune system.
Risk Factors
Factors that may increase your chance of getting KS include:
- Having an HIV infection
- Use of medication that suppresses the immune system.
Symptoms
KS lesions may develop anywhere on the body. They tend to be raised blotches or nodules which may be purple, brown, red, or pink.
Lesions in the lungs can also breathing problems.
Diagnosis
The doctor will ask about your symptoms and medical history. A physical exam will be will be done If you have skin lesions, the doctor may base the diagnosis on this. If you have bleeding, pain, or weight loss, you may need more tests to find out if you have KS.
Tests may include:
Treatment
Talk to your doctor about the best treatment plan for you. Treatment depends on the type of KS, how much it has spread, and how well a persons immune system if functioning. Treatments include one or more of the following:
Local Therapy
Local therapy is useful if there are a few lesions together in a small area. Treatments may include:
- Topical retinoid gel—Applied directly to the lesion. It shrinks the lesion over the course of 1-2 months.
- Cryosurgery—Liquid nitrogen is used to freeze and kill the abnormal cells. After the area thaws, the dead tissue falls off. More than one freezing may be needed to remove the growth completely.
These treatments do not prevent new lesions from developing.
Surgery
Surgery is an option if there are a few, small lesions. Surgery may include:
- Simple excision—A surgical knife is used to cut out the lesion.
- Curettage and electrodesiccation—A curette is an instrument with a sharp, spoon-shaped end. It is used to scoop out the affected area. A small electric current will help to control bleeding. It will also kill any cancer cells remaining around the edge of the wound.
Photodynamic Therapy
A special medication is applied to the skin to make it sensitive to light. The skin is later exposed to a special. The sensitivity to the light kills the cancer cells.
Radiation Therapy
High-energy radiation is used to kill cancer cells. The number of treatments depends on the size and location of the lesions. It can also be used to treat pain and swelling. Different types of radiation therapy may include:
- Electron-beam—Shallow penetration used to treat skin lesions
- Photon—Deeper penetration used to treat mouth or throat lesions
Radiation therapy schedules may vary, but it is generally done over a period of several weeks.
Antiretroviral Therapy
This therapy is used to combat HIV and restore immune function. In some patients, it may be very effective against KS.
Chemotherapy
Chemotherapy is the use of drugs to kill cancer cells. It may be given in many forms, including pill, injection, and via a catheter. The drugs enter the bloodstream and travel through the body killing mostly cancer cells. Some healthy cells are also killed.
In some cases, the agents can be injected directly into a lesion.
Immunotherapy
This is the use of the body's own immune system. They are used to increase or restore the body's natural defenses against cancer. Immunotherapy of KS is done with interferon.