Kaposi's Sarcoma - Causes

A variety of factors appear to lead to the development of KS:

• Genetic background. People with classic and African KS appear to possess an abnormal gene. Genes are chemical substances in the body that determine a person's physical and biological characteristics.
• Sex hormones. KS occurs far more often in men than in women. This suggests that sex hormones may have something to do with how the disease develops.
• Immune suppression. In many cases, the immune system may be strong enough to defend the body against KS. When the immune system is weakened, however, it loses that ability. People who are taking immunosuppressant drugs are, therefore, at risk for KS. So are people with AIDS, whose immune systems are often very badly damaged.
• Infectious agents that are sexually transmitted. Gay and bisexual men and intravenous drug users are all at high risk for AIDS. But gay and bisexual men are ten times more likely to develop KS than are intravenous drug users. That suggests that KS may be caused by some agent that is transmitted sexually. Further support for this idea comes from the fact that the rate of KS cases among gay and bisexual men has dropped dramatically as safer sex practices have become more widespread.

Researchers have already found viruses they think may cause KS. One of the most likely candidates is called human herpes virus 8. This virus belongs to the same family that causes cold sores and shingles. The virus has been found in samples of KS taken from patients with the disease. Additional studies are still needed to confirm this theory.