Kaposi Sarcoma

Kaposi sarcoma (KS) is a rare type of sarcoma (cancer arising from bone or soft tissue) that develops in the lining of blood and lymph vessels. More specifically, it develops from endothelial cells, which are responsible for regulating inflammatory response and controlling the passage of certain substances from the blood into the tissues.

KS is always associated with an infection with the human herpes virus 8 (HHV-8), which is also known as the Kaposi sarcoma-associated herpesvirus (KSHV). It is similar to the Epstein-Barr virus (EBV), which is also known as human herpes virus 4 (HHV-4), and is known to affect four distinct populations.

KS is slightly more common in men, and is frequently found in people with suppressed immune systems. However, anyone can develop this disease.

Types of Kaposi Sarcoma

There are four types of KS, which are categorised by the populations they affect.

Classic (Mediterranean) Kaposi Sarcoma

Classic KS generally affects older men of Mediterranean or middle/east European descent. This type may result from being a carrier of HHV-8 that has been activated by the natural age-related immune system decline. The classic subtype is often slow-growing, and generally appears as lesions on the legs, ankles and/or feet.

Epidemic (AIDS/HIV) Kaposi Sarcoma

Epidemic KS, also known as AIDS-related or HIV-associated Kaposi sarcoma, is the most common type of Kaposi sarcoma. This type develops in patients who have been diagnosed with the human immunodeficiency virus (HIV) and/or acquired immunodeficiency syndrome (AIDS). It is frequently found in men who engage in sexual intercourse with other men. It may also be found in children, as a possible result of saliva transmission from parent to child.

Endemic (African) Kaposi Sarcoma

Endemic KS is frequently found in equatorial Africa (countries along the equator in Africa). This type is often found in children and young adults, and may be linked to saliva transmission from parent to child. Common health concerns in some African populations, such as malaria, certain chronic infections, and malnutrition, may contribute to the development of this disease.

Iatrogenic (transplant-related) Kaposi Sarcoma

Iatrogenic KS is most commonly found in patients who take immune-supressing drugs after an organ transplant to decrease the risk of organ rejection. This type tends to be a milder form than other types of KS, and is usually easier to manage.

Treatment

If KS is detected, it will be staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.

Cancers can be staged using the TNM staging system:

T (tumour) indicates the size and depth of the tumour.
N (nodes) indicates whether the cancer has spread to nearby lymph nodes.
M (metastasis) indicates whether the cancer has spread to other parts of the body.

This system can also be used in combination with a numerical value, from stage 0-IV:

Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advanced or metastatic cancer.

Cancers can also be graded based on the rate of growth and how likely they are to spread:

Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.

Once your tumour has been staged and graded, your doctor may recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.

Treatment is dependent on several factors, including type of KS, location, stage of disease and overall health.

Classic Kaposi Sarcoma Treatment

Classic KS is usually low-grade and slowly metastasises (if it does at all). As such, the treatment options for this type usually include:

Surgery, potentially including:
- Simple excision (removal of lesion and some surrounding skin).
- Curettage and electrodesiccation (involves scraping the lesions off with a long, thin instrument with a sharp looped edge (curette), and then treating the area with an electric needle (electrode) to destroy any remaining cancer cells).
Chemotherapy.
Radiation therapy.
Cryotherapy.
Photodynamic therapy.
Clinical trials.
Palliative care.
Complimentary therapies.

Epidemic Kaposi Sarcoma Treatment

Epidemic KS can be treated in a few different ways, including:

Anti-AIDs drug combinations, potentially including the highly active antiretroviral therapy drug (HAART).
Radiation therapy.
Cryotherapy.
Photodynamic therapy.
Chemotherapy.
Clinical trials.
Palliative care.
Complementary therapies.

Endemic Kaposi Sarcoma Treatment

Treatments for Endemic KS are generally the same as classical treatment options. However, as this type of cancer is frequent in poorer countries, treatment options available may be limited. Treatment options may include:

Surgery, potentially including:
- Simple excision (removal of lesion and some surrounding skin).
- Curettage and electrodesiccation (involves scraping the lesions off with a long, thin instrument with a sharp looped edge (curette), and then treating the area with an electric needle (electrode) to destroy any remaining cancer cells).
Chemotherapy.
Radiation therapy.
Cryotherapy.
Photodynamic therapy.
Clinical trials.
Palliative care.
Complimentary therapies.

Iatrogenic Kaposi Sarcoma Treatment

Patients with Iatrogenic KS may simply involve stopping or switching the immune-supressing drugs taken after their transplant, if possible to do so. Other treatment options may include:

Surgery, potentially including:
- Simple excision (removal of lesion and some surrounding skin).
- Curettage and electrodesiccation (involves scraping the lesions off with a long, thin instrument with a sharp looped edge (curette), and then treating the area with an electric needle (electrode) to destroy any remaining cancer cells).
Radiation therapy.
Cryotherapy.
Photodynamic therapy.

Chemotherapy is not generally given to patients with Iatrogenic KS.

For more information on the treatment options, please refer to the Rare Cancers Australia Treatment Options page.

Risk factors

KS is caused by an infection with HHV-8, which is most common in men who have sexual intercourse with other men and/or individuals with a HIV infection. It is also associated with transmission via saliva or insect bites, genetic factors, hormonal factors and immunodeficiency.

Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.

Early symptoms

KS can develop externally or internally. Symptoms that may be indicative of external KS lesions include:

Lesions on the skin, which can be described as:
- Purple, red or brown in colour.
- Flat (patches), slightly raised (plaques) or bumps (nodules)
- Often appearing on the lower extremities (legs, ankles, feet), but can also develop on the face, in the pelvic region or on other parts of the body.
Lesions in the lower extremities accompanied by painful swelling of the legs, ankles and/or feet.

KS lesions can also develop internally, in areas such as the mouth, throat, eye/eyelids, gastrointestinal tract and/or the lungs. Symptoms that may be indicative of internal KS lesions include:

Lesions in the mouth, throat or eyelids that are not itchy or painful.
Shortness of breath, caused by a lesion in the lung blocking an airway.
Abdominal pain and diarrhoea, caused by lesions in the stomach and/or intestines.
Coughing up blood, caused by bleeding lesions in the lung.
Bloody stools, caused by bleeding lesions in the intestines.
Anaemia.
Fatigue.

Not everyone with the symptoms above will have cancer, but see your GP if you are concerned.

Diagnosis/diagnosing

If your doctor suspects you have KS, they will order a range of diagnostic tests to confirm the diagnosis, and refer you to a specialist for treatment.

Physical examination

Your doctor will collect your overall medical history, as well as your lifestyle/health habits, and current symptoms. Following this, they may examine your body to check for any abnormalities.

Imaging & blood tests

The doctor will take images of your body using magnetic resonance imaging (MRI), a computed tomography scan (CT scan), x-ray and/or ultrasound, depending on where it is suspected the cancer is. The doctor may also look at other parts of the body and looks for signs of metastasis. Additionally, a blood test may be taken to assess your overall health and help guide treatment decisions.

Endoscopy

An endoscopy is a surgical procedure that involves inserting a long, flexible tube with a light and small camera through oesophagus and into the stomach. You will be given a sedative or anaesthetic throughout the procedure. You will be asked to fast for several hours prior to the procedure. An endoscopy is often done as a day surgery. Your doctor will discuss the risks and any possible complications prior to the procedure.

Throughout the procedure, your doctor may also perform an endoscopic ultrasound to guide the needle during a biopsy, or to check for signs of cancer metastasis.

Bronchoscopy

A bronchoscopy is a day procedure that examines the trachea and lungs. A long, thin tube with a light and camera attached (bronchoscope) is inserted through the mouth or nose and into trachea and lungs to check for any abnormalities.

Biopsy

Once the location of the cancer has been identified, the doctor will perform a biopsy to remove a section of tissue using a needle. Once a sample has been removed, it will be sent to a lab and analysed for cancer cells.

Prognosis (Certain factors affect the prognosis and treatment options)

While it is not possible to predict the exact course of the disease, your doctor may be able to give you a general idea based on the rate and depth of tumour growth, susceptibility to treatment, age, overall fitness, and medical history. Generally, early-stage KS has a better prognosis and survival rate. However, if the cancer is advanced and has spread, the prognosis may not be as good and there may be a higher risk of cancer recurrence. It is very important to discuss your individual circumstances with your doctor to better understand your prognosis.

References

^{Some references are to overseas websites. There may be references to drugs and clinical trials that are not available here in Australia.}