Kaposi’s sarcoma is a rare type of cancer that can affect both the skin and internal organs.
The most common initial symptom of Kaposi’s sarcoma is the appearance of red or purple patches on the skin. The patches then grow into lumps known as nodules.
Kaposi’s sarcoma can also damage the internal organs, which can lead to a range of symptoms, depending on which organs are affected. Possible symptoms include:
- bleeding gums
- coughing up blood
- feeling sick (nausea)
- being sick (vomiting)
- stomach pain
- stomach swelling
- leg swelling
Read more about the symptoms of Kaposi’s sarcoma.
Unlike most types of cancer, the cause for Kaposi’s sarcoma has been identified. The condition is caused by a virus known as the human herpesvirus type 8 (HHV-8). The virus is also sometimes referred to as the Kaposi's sarcoma associated herpes virus (KSHV).
HHV-8 is a relatively common virus. As many as 1 in 20 people possibly have the virus in their body. In most cases, HHV-8 doesn't cause any noticeable symptoms. The majority of people with the virus won't go on to develop Kaposi’s sarcoma.
However, certain groups of people who are vulnerable to the effects of HHV-8 (see below) go on to develop Kaposi’s sarcoma. These are usually people whose immune system isn't working properly, either because they have another condition (a cancer or infection) or, they have received an organ transplant and have been given medication to allow the transplant to work.
Read more about the causes of Kaposi’s sarcoma.
Types of Kaposi’s sarcoma
There are four main types of Kaposi’s sarcoma, which are outlined below.
HIV-related Kaposi’s sarcoma
Kaposi’s sarcoma often affects people whose immune systems have been severely weakened by HIV.
During the 1980s, as many as 1 in 5 people with HIV or AIDS developed Kaposi’s sarcoma.
However, following advancements in treatment during the mid 1990s for HIV, particularly the introduction of a range of medications known as highly active antiretroviral therapy (HAART), the number of people with HIV who were affected by Kaposi’s sarcoma fell by about 90%.
Endemic African Kaposi’s sarcoma
Endemic African Kaposi’s sarcoma is common in parts of Africa and is one of the most widespread types of cancer in that region, accounting for 1 in every 10 cases of cancer in Africa. The condition is particularly widespread in:
- the Congo (both the Democratic Republic of the Congo and the Republic of the Congo)
Many people from sub-Saharan Africa are also infected with HIV as well as HHV8. Therefore, it's highly likely that many cases of so-called ‘endemic’ African Kaposi’s sarcoma were and are, in fact, due to undiagnosed HIV infection.
‘Endemic’ African Kaposi’s sarcoma that's not HIV-related is thought to develop as a result of a pre-existing genetic vulnerability to the virus that causes it.
Classic Kaposi’s sarcoma
Classic Kaposi’s sarcoma is a rare condition that accounts for only 1 in every 500 cases of cancer in England. The condition mainly affects middle-aged and elderly men of Mediterranean or Ashkenazi Jewish descent.
Ashkenazi Jews are people who are descended from Jewish communities that lived in Central and Eastern Europe. Most Jewish people in England are Ashkenazi Jews.
It is thought that people who develop classic Kaposi’s sarcoma were born with a pre-existing genetic vulnerability to the HHV-8 virus.
Transplant-related Kaposi’s sarcoma
Transplant-related Kaposi’s sarcoma is an uncommon complication of organ transplants. In England, an estimated 1 in every 200 people who have an organ transplant develop Kaposi’s sarcoma.
Following an organ transplant, medication is usually taken that weakens the immune system (immunosuppressants) and prevents the body rejecting the new organ. However, when a person’s immune system is weakened, they're more vulnerable to the HHV-8 virus.
Kaposi’s sarcoma can be treated using a combination of anti-HIV medication (if HIV-infected), chemotherapy, radiotherapy and surgery. HIV-related Kaposi’s sarcoma is usually a sign that a person’s HIV is being poorly controlled. So if they're not receiving HAART, this should be started. If they're on treatment, this may need to be reviewed to ensure that their HIV is well-controlled.
Read more about the treatment of Kaposi’s sarcoma.
In England, the outlook for people with Kaposi’s sarcoma is usually relatively good when compared to other types of cancer.
Provided people with HIV-related Kaposi’s sarcoma get access to HAART early on in their HIV disease, their outlook will also be relatively good, and the condition will often go into remission (the symptoms will go away). If not, chemotherapy and radiotherapy can also relieve symptoms.
Classic Kaposi’s sarcoma is a very slow-growing form of cancer that often has no impact on a person’s natural lifespan.
Provided people with HIV- or AIDS-related Kaposi’s sarcoma get access to HAART, their outlook will also be relatively good, and the condition will often go into remission (the symptoms go away).
Transplant-related Kaposi’s sarcoma can usually be successfully treated by adjusting a person’s dosage of immunosuppressants.
Due to the relatively good outlook, deaths due to Kaposi’s sarcoma are now very rare. For example, during 2009, there were only seven deaths as a result of Kaposi’s sarcoma in England and Wales. However, it's important to realise that a complete cure for all types of Kaposi’s sarcoma isn't always possible, and there's a chance that the condition could reoccur in the future.