Read about Kaposi's sarcoma, the different types and how it might be treated.
What it is
Kaposi's sarcoma (KS) is a rare type of cancer that develops from cells called endothelial cells. KS growths are called lesions or tumours. External lesions on the skin are the most common. But it can also involve internal organs such as the lymph nodes, lung, bowel, liver and spleen.
KS develops in a different way to many other types of cancers. Most cancers begin in one place in the body and may then spread to other places. KS can start in several areas of the body at the same time.
The causes of Kaposi's sarcoma
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. So it is thought that there are other factors involved. Scientists agree that having a weakened immune system or certain types of infections 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
These nodules or 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 giving the appearance of patchwork. 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. So you might have some swelling of your arms and legs called lymphoedema. KS cells block the flow of lymph fluid through the lymphatic system. So tissue fluid backs up and causes swelling. It can be very painful and uncomfortable.
There is no cure for lymphoedema, but treatment can help to control it and relieve the symptoms. The earlier it is picked up and treated, the easier it is to control. So do let your doctor know if you have any swelling that you think may be lymphoedema.
Diagnosing Kaposi's sarcoma
The only way to definitely tell if you have a Kaposi’s sarcoma is to examine a tissue sample (biopsy) under a microscope.
You can usually have a biopsy with a local anaesthetic if the lesion is on the skin.
These tests are more invasive if your doctor thinks you have KS inside your body. For example, you would need a bronchosopcy if your doctor thinks you may have KS in the lungs. You might have an endoscopy if your doctor thinks you may have KS in your digestive system.
You have these tests under a local or general anaesthetic, depending on your situation. You might also have sedation to help you relax.
Types and treatment of Kaposi's sarcoma
Which treatment you have 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 appearance of the lesions.
You might not need treatment if your KS is in the early stages. You might have radiotherapy if the lesions are large and in very visible areas on the body. Or your doctor may suggest freezing the areas with liquid nitrogen or removing them with a small operaition.
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 who have weakened or damaged immune systems For example, people who have had an organ transplant operation. These people need to take drugs to stop their bodies rejecting the donated organ. These drugs suppress the immune system.
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.
The treatment you have depends very much on how well you are and whether or not you can cope with the side effects of treatment. You might have treatment with chemotherapy or interferon. The side effects of interferon can be quite severe.
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).
It can be difficult coping with a diagnosis of cancer, particularly if it is a rare type.