Kaposi’s sarcoma is a rare type of cancer that affects the skin, mouth and occasionally the internal organs.
What are the causes of Kaposi’s sarcoma?
Kaposi’s sarcoma is caused by the HHV-8 virus, sometimes called Kaposi’s sarcoma – associated herpes virus (KSHV). The virus can be controlled by a healthy immune system but can cause Kaposi’s sarcoma in people who have a compromised immune system, as happens with people affected by HIV and those who are taking immunosuppressant drugs following an organ transplant. 94% of Kaposi’s sarcoma cases in the UK are caused by both HHV-8 and HIV infection, the remaining 6% are caused by HHV-8 with no HIV present.
Types of Kaposi’s sarcoma
There are four main types of Kaposi’s sarcoma. Your treatment will depend on the type you have, where in the body it is, your age and general health and well-being.
- Epidemic or Aids-related Kaposi’s sarcoma
- Classic Kaposi’s sarcoma
- Endemic or African Kaposi’s sarcoma
- Acquired Kaposi’s sarcoma, sometimes called transplant Kaposi’s sarcoma
Epidemic or Aids-related Kaposi’s sarcoma
This is the most common type of Kaposi’s sarcoma. It affects people whose immune systems have been weakened by HIV.
If you are diagnosed with early stage Kaposi’s sarcoma and you have an untreated HIV infection, you will be given highly active antiretroviral therapy (HAART). HAART reduces the level of HIV in your body to improve your immunity. On this treatment Kaposi’s sarcoma often gets better and sometimes disappears, this can take a number of months. If your skin lesions are causing you distress during this time radiotherapy may be offered to shrink them.
If you are diagnosed with advanced Kaposi’s sarcoma you will usually be given chemotherapy as well as HAART. If you are already receiving anti-HIV treatment when Kaposi’s sarcoma is diagnosed or if your condition progresses, then chemotherapy is usually given.
Classic Kaposi’s sarcoma
This a rare condition that mainly affects middle-aged and elderly men of Mediterranean descent and men descended from Jewish communities in Eastern and Central Europe, called Ashkenazi Jews. Most Jewish people in the UK are Ashkenazi Jews.
It is thought that people who develop Classic Kaposi’s sarcoma have a pre-existing genetic vulnerability to the HHV-8 virus.
This is a slow-growing cancer and generally does not cause any problems, so it does not usually need to be treated. Radiotherapy is sometimes used to treat large or very visible skin lesions.
Endemic or African Kaposi’s sarcoma
This type is common in parts of Africa accounting for 1 in 10 cases of cancer in the continent.
It is thought that this type of Kaposi’s sarcoma is caused by a pre-existing genetic vulnerability to the HHV-8 virus.
The main treatment for this type of Kaposi’s sarcoma is chemotherapy.
Acquired Kaposi’s sarcoma, sometimes called transplant Kaposi’s sarcoma
This is a rare condition that affects some people following an organ transplant. The drugs they need to suppress their immune system reduces the risk of their body rejecting the donated organ; however, as their immune system is weakened they develop Acquired Kaposi’s sarcoma.
This type of Kaposi’s sarcoma can sometimes be controlled or stopped by switching the immunosuppressant drugs. If that doesn’t work you may be given chemotherapy or radiotherapy.
Signs and symptoms
The first symptom of Kaposi’s sarcoma (KS) is usually skin lesions. These can range in colour from pink to brown, brown-red or reddish purple. KS can appear as a raised or slightly raised bump or a flat area on the skin. The lesions can develop quickly. Although there may be a single area at first, it’s possible for more than one to appear. Often the lesions merge to form a larger tumour. Any part of the skin can be affected, including the inside of the mouth.
Occasionally, KS can also affect other parts of the body such as the lungs, liver, stomach, bowel and lymph nodes (glands). When this happens, the symptoms will depend on the part of the body that’s affected. These can include:
- If the lymph nodes are affected by Kaposi’s sarcoma they may become swollen
- Swelling in the arms and legs caused by damage to lymph vessels
- Digestive complaints
- Kaposi’s sarcoma in the lungs can cause breathlessness and a cough
Types of diagnostic scans
The earlier sarcoma is diagnosed the better the chances of successful treatment. Sarcomas are usually found by a patient when a lump appears on the leg, arm or trunk. They can also be found during an investigation of other symptoms or during a routine operation.
A specialist doctor will diagnose sarcoma through a series of tests. These may include:
- Physical examination – looking at and feeling any lump
- A scan – taking pictures of the inside of the body using ultrasound, x-ray, CT, EUS, PET or MRI
- A biopsy – taking and testing a tissue sample
Types of diagnostic scans and tests
Uses x-radiation to take images of dense tissues inside the body such as bones or tumours.
A scan that uses sound waves to create images from within the body.
The Computer Tomography (CT) scan takes a number of x-rays to make a 3D image of an affected area.
The Endoscopic Ultrasound Scan (EUS) uses a tube-like instrument called an endoscope with an ultrasound scanner attached. This is put inside the body to look inside the gut to investigate GIST tumours.
The Positron Emission Tomography (PET) scan shows up changes in tissues that use glucose as their main source of energy – for example the brain or heart muscle. It involves an injection of a very small amount of a radioactive drug into the body. The drug travels to places where glucose is used for energy and shows up cancers because they use glucose in a different way from normal tissue.
Magnetic Resonance Imaging (MRI) uses magnets to create an image of the tissues of the body.
Examination of a tissue sample by a pathologist under a microscope to identify disease.
Laboratory analysis of a blood sample.
Understanding the diagnosis
Identifying the stage and grade of a cancer means your doctor can advise on the best course of treatment for you. It also describes the cancer in a common language which is useful when your doctor is discussing your case with other doctors or healthcare professionals.
Unlike other types of sarcoma, Kaposi’s sarcoma is not usually treated under a sarcoma multidisciplinary team (MDT). You will usually be treated under the most appropriate MDT for the type of sarcoma you have and the location in the body that is affected; for example, a dermatology (skin) MDT.
After treatment, you will have regular follow-up appointments for several years. You should receive a follow-up schedule from your sarcoma clinical nurse specialist. The usual practice will include:
- A chance to discuss symptoms
- An examination to look for any signs of the sarcoma returning. This may include an MRI or ultrasound if required after examination
- A chest x-ray to rule out any secondary cancers occurring in the lungs
Sarcoma cancer can reappear in the same area after the treatment of a previous tumour; this is called a local recurrence.
If the cancer does reappear, it is important to get treated as quickly as possible. This could involve further surgery and/or radiotherapy; your treatment will be assessed on an individual basis. It is useful to check for recurrences yourself through self-examination: your doctor or sarcoma clinical nurse specialist can tell you what to look for.
If you are worried about your cancer returning contact your doctor or nurse; they may decide to bring forward the date of your follow up appointment to investigate your concerns.
What if my cancer spreads to another part of my body?
A recurrence of sarcoma may be accompanied by cancer in other parts of the body. This is called metastasis or secondary cancer. Some people are diagnosed with sarcoma because their metastases have been discovered before their primary sarcoma tumour. In sarcoma patients, these secondary cancers may appear in the lungs, which is why a chest x-ray is taken at follow-up appointments.
Secondary cancers may also appear in the liver or brain. Treatment for secondary cancer may involve surgery, radiotherapy or chemotherapy as appropriate; your treatment will be assessed on an individual basis.