Types of Kaposi’s sarcoma and their causes

There are four main types of KS:

The first, called classic KS, develops without any weakened immunity, like many other types of cancer. It is very rare and is usually only found in older men of Mediterranean or Jewish descent. This type of KS is usually only found in the skin, particularly on the lower legs and feet. As it is a slow-growing cancer people with early stage classic KS may not need any treatment.

The second type of KS, endemic or African KS, is found in parts of equatorial Africa. It develops more quickly than classic KS and can affect men, women and children of all ages. Like all forms of KS it is more common in men than women.

The third type of KS usually occurs in people who have a weakened or damaged immune system. People who have had organ transplants, such as a kidney transplant, take medication which suppresses their immune system and reduces the risk of rejection of the donated organ. Although rare, KS can occur in transplant patients who are taking these immunosuppressant drugs. This form of KS may improve if the immunosuppressant drugs are reduced or stopped.

The fourth type of KS, AIDS-related KS, is the commonest and most quickly developing form of the disease. During the normal course of AIDS, the immune system becomes weaker and as it does the risk of developing KS increases. Research shows that there are other risk factors involved in developing AIDS-related KS.

Infection with the herpes virus (Human Herpes Virus 8), has been linked to the development of all forms of KS. It seems likely that the virus is passed on through sexual transmission.