Kaposi's sarcoma (KS) is a rare type of soft tissue sarcoma. A soft tissue sarcoma is a type of cancer.
What is it?
Kaposi's sarcoma (KS) develops in cells of the inner lining of lymph or blood vessels. It is most commonly found on the skin, but it can also affect the inside of the body, such as lymph nodes, lungs, bowel, liver and spleen. KS growths are also called lesions or tumours.
KS develops in a different way to other types of cancer. Most cancers begin in one place in the body an may then spread to other parts of the body (metastasise). Ks can start in several areas of the body at the same time.
A main cause of KS is a virus called the human herpes virus 8 (HHV8). The virus infects the cells and it is thought that this causes them to become cancerous. Mostly HHV8 is a sexually transmitted virus and is a common infection. It can also pass in blood between drug users who share needles.
Not everyone infected with HHV8 gets KS. It is thought that there are other factors involved. Scientists agree that having a weakened immune system or certain types of infection along with HHV8, also play a part in a person developing KS.
Signs and symptoms
The signs and symptoms are different, depending on whether you have external KS on the skin, or KS inside the body. Lesions on the skin are more common than internal lesions inside of the body.
Kaposi's sarcoma of the skin
Lesions on the skin usually start out very small and flat. They do not cause any pain or itching and seem harmless. They look quite like a bruise, but do not lose their colour when pressed, as a bruise does.
As they grow, they might start to stick up above the surrounding skin and grow into each other. The lesions might be in different colours such as brown, blue, red or deep purple.
KS in the skin might grow very slowly and show no changes for a few months. But some grow more quickly, with new areas appearing weekly.
Internal Kaposi's sarcoma
Internal KS lesions can grow in the lymph nodes and body organs, such as the lungs, liver and spleen. The symptoms you have depend on which organs are affected.
The most common type of KS is related to AIDS. In AIDS related KS it is common for disease to be in the lymph nodes, KS cells can block the flow of lymph (tissue fluid) through the lymphatic system. This build up of fluid can cause swelling in the arms or legs. This is called lymphoedema.
Lymphoedema can be very painful and uncomfortable. Unfortunately there is no cure for this condition. But treatment can help to control and relieve it. The earlier this is picked upand treated, the easier it is to control. So do let your doctor know if you have any swelling that you think might be lymphoedema.
Kaposi's sarcoma (KS) is usually diagnosed with a biopsy. This means that you have a tissue sample (biopsy) taken. A specialist doctor (pathologist) then looks at the cells under a microscope.
The way you have the biopsy depends on where in your body the lesion is.
You usually have a biopsy with a local anaesthetic if the lesion is on the skin. A local anaesthetic numbs the area.
Lesions in the lung
You might have a bronchoscopy to collect a biopsy from a lung lesion.
Lesions in the digestive system
You might have an endsocopy or colonoscopy to biopsy lesions in the digestive system.
Types and treatment of Kaposi's sarcoma
Your treatment depends on:
- the type of KS
- the size and location of the lesions
- how severe it is
- your general health
There are four types of Kaposi's sarcoma.
This type of KS is very rare and is only found on the skin, mainly on the lower legs and feet. It is most common in older men of Jewish, middle Eastern or Mediterranean origin. It is a slow growing cancer and does not usually cause any problems apart from the appearence of the lesions.
You might not need treatment if your KS is in the early stages, You might have treatment if the lesions are large and in very visible areas of the body.
Treatment can include freezing the area with liquid nitrogen (cryotherapy) or removing them with a small operation. Or you might have radiotherapy to the lesions.
Endemic or African KS
This type of KS is found in parts of Africa where HHV8 infection is common. It is faster growing than classic KS.
It is more common in men, but women and children of all ages may develop it. You might have radiotherapy or chemotherapy for this type of KS.
Transplant related KS
This type of KS is very rare and is most common in people with lowered immunity. This includes people who have had a stem cell or organ transplant. These people need to take drugs to stop their bodies rejecting the new organ or stem cells. These drugs supress the immune system. They are called immunosuppressive drugs or immunosupressents.
Reducing or changing the immunosuppressive drugs usually improves it. If that doesn't help, it may be necessary to treat the KS with radiotherapy or chemotherapy.
AIDS related KS
This is the most common type of KS. It tends to grow faster than the other types. Your immune system is weakened if you have AIDS and this increases your risk of developing KS.
You might have treatment with chemotherapy or a type of immunotherapy called interferon. The side effects can be quite severe. Your choice of treatment will depend on your general health.
Foscarnet is an anti herpes drug that doctors are testing for this type of KS.
Treatment for advanced KS
Usually you have chemotherapy if the KS has spread throughout your body. Treatment at this stage is palliative, which means it is used to treat symptoms rather than offer a cure. You usually have 2 or more of these drugs:
- doxorubicin (Adriamycin)
- paclitaxel (Taxol)
Newer chemotherapy drugs are now available to treat KS that is no longer being controlled by standard chemotherapy. These are liposomal drugs. They are wrapped up in a fatty covering called liposome. This makes the drug work better and causes less severe side effects.
Examples include doxorubicin liposome (Doxil or Caelyx) and daunorubicin liposome (DaunoXome).
Coping with a diagnosis of a rare cancer can be especially difficult, both practically and emotionally. Being well informed about your sarcoma and its treatment can make it easier to make decisions and cope with what happens.
Sarcoma UK provides support and information for people affected by soft tissue and bone sarcoma.
The Rare Cancer Alliance offer support and information to people affected by rare cancers.
Talking to other people who have the same thing can also help.
Our discussion forum Cancer Chat is a place for anyone affected by cancer. You can share experiences, stories and information with other people who know what you are going through.