Cancer begins when there’s a change in the coding information in cells that tells them when to grow and replicate.
The code is read from the deoxyribonucleic acid (DNA) that’s found in all human cells. A change to the code is known as a mutation, and it can alter the instructions that control cell growth.
This means that cells carry on growing instead of stopping when they should. This results in the cells reproducing in an uncontrollable manner and producing a lump of tissue that’s known as a tumour.
The human herpesvirus 8 (HHV-8)
Kaposi’s sarcoma is caused by a virus called the human herpesvirus 8 (HHV-8), which is also known as the Kaposi’s sarcoma-associated herpesvirus (KSHV).
It is thought that HHV-8 contains genetic material that interferes with the normal workings of cells, causing them to reproduce uncontrollably.
HHV-8 doesn’t cause Kaposi’s sarcoma in everyone who develops the virus. The virus only seems to cause Kaposi’s sarcoma in people with:
- a weakened immune system – this is thought to be the reason why people develop HIV or AIDS-related Kaposi’s sarcoma and transplant-related Kaposi’s sarcoma
- an inherited (genetic) vulnerability to HHV-8 – this is thought to be the reason why people develop either classic Kaposi’s sarcoma or ‘endemic’ African Kaposi’s sarcoma
Although HHV-8 was first identified in 1994, there’s still no firm evidence as to how the virus is spread.
One method of transmission of HHV-8 appears to be through unprotected anal sex. This is because rates of HHV-8 in some European and North American countries show that the virus is almost always more widespread in men who have sex with men.
However, this doesn’t explain how many heterosexual African men and women and their children acquire this common infection with HHV-8. Therefore HHV-8 may be passed on by some other means, e.g. through saliva. This means that the virus could be spread by kissing.
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Overview - Causes of Kaposi"s sarcoma
