Kaposi's sarcoma is a specific type of cancer that involves the vascular tissues of the skin or other organs and tissues.
Kaposi's sarcoma, or KS, usually begins in certain vascular tissue. Blotches may be visible on the skin or in the skin cells of the mouth. These cells undergo cancerous changes and begin to grow uncontrollably. For people with intact immune systems, the cancer grows slowly, if at all, and rarely spreads.
The disease becomes very aggressive if the person has an impaired immune system. Human immunodeficiency virus (HIV) infections and drugs given after organ transplant suppress the immune system. Until AIDS became widespread, KS was rarely seen. KS is common in people with AIDS.
A person usually will find an abnormal thickened purplish growth on the skin or on the mucous membranes inside the mouth. Any area of the skin can be affected. The growth may not cause any pain or discomfort. Inside the mouth or throat, it may be large enough to interfere with swallowing or breathing. Kaposi's sarcoma may also involve the gastrointestinal and respiratory systems.
People with HIV infection are at very high risk for KS. After organ transplant, people are given powerful drugs to prevent rejection of the new organ. Those people are also at risk. KS is otherwise very rare, but may be seen in a lesser form in elderly men of Mediterranean origin.
In an individual with HIV infection, it is possible to test for HHV-8, and if positive, to treat with antiviral medications specific for HHV-8.
It is important to identify KS early in HIV-positive persons. This means skin areas and mouth should be regularly inspected by the person at risk and by a healthcare professional to find the lesions while they are still small. KS has been less prevalent since HAART (highly active antiretroviral therapy) has been used to treat people with AIDS.
If cancer is suspected, it must be confirmed by examining the abnormal tissue in the pathology laboratory. This can mean removing a piece of the tissue with a biopsy. Sometimes the whole tumor is removed, which is known as a resection. Additional studies such as specialized X-rays and blood tests may be performed to measure the extent of the disease, which is known as staging the disease.
If cancer is not successfully treated, it will spread in people with compromised immune systems. The spread of the cancer can destroy tissue around and press on other structures. If the cancer spreads to organs like the lungs, it will cause death.
HHV-8 is a transmissible infection, though the means of transmission are still being studied. Sexual transmission is believed to occur. Therefore, as with other sexually transmitted infections, safer sex practices can reduce, but not eliminate, the risk of acquiring HHV-8.
Treatment for KS may involve chemotherapy (doxorubicin, daunorubicin, paclitaxel, vinorelbine), radiation, or immunotherapy. Aliretinoin topical gel may be used, or vinblastine injected into the KS lesions. Angiogenesis inhibitors may be used. Other local treatments involve laser therapy or cryotherapy.
Occasionally, a combination of treatments is used. Effectively treating underlying AIDS, if present, is also important. As the AIDS is treated, the KS lesions usually regress with decreased risk of new KS lesions. The goal may be to control the cancer and reduce pressure from the tumor on other structures. New therapeutic regimens are being studied. However, KS is not likely to be cured.
The side effects of treatment depend on the specific therapy. Generally, treatment is designed to control the cancer and relieve symptoms. If the person with KS also has other medical conditions such as AIDS or has undergone organ transplant, those conditions may affect the person's well-being. Every effort is made to minimize side effects and maintain quality of life.
The person will be monitored closely for recurrence and progression.
The lesion will be observed for changes. All other skin areas will also be observed because new KS lesions can develop. If organs such as the lungs are involved then X-rays will be used to follow the person's progress. The frequency will depend on the person's condition and the extent of the cancer.
Miles, S.A.; Aboulafia, D.M.;&Mitsuyasu, R.I. (1997). AIDS-related maligancies in Cancer: Principles and Practice of Oncology. 5th Edition DeVita, V.T. (ed). J.B. Lippincott:Phildephia. Pp.2445-2448.