Kaposi Sarcoma

Of the seven types of Sarcomas, the incidence of Kaposi Sarcoma, a type of skin cancer is found to be more prevalent in persons with immune deficiency disease like AIDS. The rate of Kaposi Sarcoma is reported to be 20 times more. It is estimated that 15% of HIV infected persons will develop Kaposi Sarcoma. The weakened immune system is unable to fight the Kaposi Sarcoma Herpes Virus. Thanks to HAART (highly active anti-retrovirus therapy), the incidence rate has decreased.

Sarcoma is a rare type of cancer. The malignant tumors occur in the body's connective tissues - the tissues that support, connect and bind various parts of the body. Muscles, fat, fibrous tissues, nerves, blood vessels, cartilage, bones and joint tissues are all connective tissues.

Sarcomas fall into three broad categories.

Soft tissue cancers

• Benign (non cancerous)
  
• Malignant (cancerous)

Primary bone cancer

Gastro-intestinal stromal tumors

Kaposi Sarcoma is a soft tissue sarcoma, malignant in nature.

Kaposi Sarcoma causes

Human herpes virus 8 (HHV8) also called Kaposi Sarcoma associated herpes virus (KSHV), a virus causes the infection. Though as many as 1 in 20 people may have this virus sans any symptom, certain groups of people are vulnerable to its effect and develop Kaposi Sarcoma. Mostly, people whose immune system isn't working properly either due to a medical condition or medication (immunosuppressive medications) can develop Kaposi sarcoma. The weakened immune system allows the HHV8 to multiply to high levels in the blood thus increasing the chance of developing Kaposi Sarcoma.

Kaposi Sarcoma symptoms

The first symptom is the lesion appearing on the skin. It can be bluish-red, or brown or purple spots or lesions on the skin, flat or as a slightly raised bump, linear or in a symmetrical distribution. In fact, the appearance of the lesion indicates the possibility of the person being infected with HIV or the condition it causes, namely, AIDS. Kaposi Sarcoma can also affect internal organs which can lead to a range of symptoms, depending on the organ that is affected.

Skin lesions

The lesions can appear anywhere on the body but in most cases the lesions appear on the face (ears, mouth and tip of the nose), legs and feet and the genital area. It could occur in a single area in the beginning. These can merge to form a large tumor.

Lymph nodes: Swollen lymph nodes are the symptoms of Kaposi Sarcoma affecting the lymph nodes.

Arms and legs: If Kaposi Sarcoma affects the lymph vessels, there is buildup of fluid in the arms and legs. This condition is called lymphoedema.

Lung problems: Kaposi Sarcoma affecting the lungs can lead to breathlessness and coughing up blood.

Digestive system: Nausea, vomiting, stomach pain and diarrhea are symptoms related to Kaposi Sarcoma affecting the digestive system.

HIV related Kaposi Sarcoma: Being HIV positive or having AIDS increases the risk factor of HIV-related Kaposi Sarcoma. Compared to women, men have higher chances as also gay and bisexual men who are HIV positive are at risk of HIV related Kaposi Sarcoma.

Classic Kaposi Sarcoma: A rare condition, classic Kaposi Sarcoma affects middle-aged and elderly men of Mediterranean or Ashkenzi Jewish descent. There is a high possibility of being born with a pre-existing genetic vulnerability to the HHV-8 virus.

Endemic African Kaposi sarcoma: This type is a common cancer in parts of Africa with high levels of HIV. In most cases, the reason is either undiagnosed HIV infection or a pre-existing genetic vulnerability to HHV-8 virus.

Transplant related Kaposi Sarcoma: After an organ transplant, a strong immune system can reject the new organ. In order to weaken the immune system thereby preventing the rejection of new organ, medications (immunosuppressant) are used. This makes the person vulnerable to HHV-8 virus infection.

Tests for diagnosis of Kaposi Sarcoma

For a definitive diagnosis, a small amount of tissue is removed for examination under the microscope. If the biopsy results confirm, further tests are required to know the spread to internal organs. X-ray, Endoscopy, Bronchoscopy, CT scan and photography are the diagnostic tests that reveal the spread of cancer - staging of the cancer.

Kaposi Sarcoma staging

For all cancer types, staging determines the treatment options and the patient's survival outlook. With regard to Kaposi Sarcoma, the staging is largely influenced by the person's weakened immune system and the presence of AIDS related infections. For Kaposi Sarcoma staging, doctors use the AIDS Clinical Trial Group system. Three factors are considered under the AIDS Clinical Trial Group system while categorizing patients in good risk group and poor risk group.

• The extent of the tumor
  
• The status of the immune system as measured by the number of certain immune cells (CD4 cells) present in the blood
  
• Systemic illness

These factors have two subgroups. After assessing the features, the type of Kaposi Sarcoma, doctors discuss the most suitable treatment option.

Kaposi Sarcoma treatment

Kaposi Sarcoma is incurable but can be controlled with treatment. The stage, the type of Kaposi Sarcoma, the number of lesions, age and general health are considered by the doctors before determining the appropriate treatment option. It could be chemotherapy, immunotherapy, antiviral drugs or radiation therapy. There are possible side effects for each of these treatment options.

Chemotherapy: Chemo drugs can be given into a vein or by mouth to enter the blood stream to reach all areas of the body. Chemotherapy is a treatment option when the cancer has spread to many areas of the body. Chemo drugs cannot be given for long periods as it can weaken the immune system. Particularly for HIV infected patients, there is a need to strengthen the immune system. In such cases, combined antiretroviral therapy can be used along with chemo drugs. Drug interaction is taken into account before prescribing the combined therapy. After tests indicate control of Kaposi sarcoma, chemo drugs may be stopped and the treatment may continue with combined antiretroviral therapy alone.

Immunotherapy: Transplant related Kaposi Sarcoma is usually treated using immunosuppressant medications or immunotherapy. The aim is to strengthen the immune system so as to fight the HHV-8 while ensuring the body doesn't reject the transplanted organ. Alternatively, radiotherapy or chemotherapy may also be considered.

cART: Combination antiretroviral therapy (cART) involves the use of several different medications called antiretroviral therapy to lower HIV levels in the blood by slowing down the rate at which the virus can multiply.

Radiotherapy: If Kaposi Sarcoma spreads and affects the internal organs, symptoms such as breathlessness and swelling of the arms and legs cause immense distress. Radiotherapy is chosen as a treatment option as the high-energy rays destroy cancer cells cautiously without harming the healthy cells in the body.

Surgery: If the lesions are small, after injecting local anesthetic to numb the area, surgery is performed to remove the lesion.

Cryotherapy: Cryotherapy involves freezing small lesions with liquid nitrogen.

Retinoic acid gel: Retinoic acid is applied directly to the skin several times a day on the small lesions. After few weeks of application, significant improvement can be noticed.

Ophthalmoscope

An ophthalmoscope is used to examine the retina and vitreous. Ophthalmoscopy aids visualization of the inside of the back of the eye including the retina, optic disc, choroid and blood vessels. It is often part of a routine eye examination. A direct ophthalmoscope is used for viewing the central retina. It is hand-held and powered with a light source. The instrument has to be adjusted constantly to focus on different structures within the eye. The light can be intense and disturbing. An indirect ophthalmoscope aids in examining the entire retina. This instrument is attached to the doctor's head and allows a clear view of the retina with a special lens. The patient may feel uncomfortable due to the intense light and pressure from the instrument.

Ophthalmoscopy is useful in detecting any changes in the retina due to diseases such as eye disease, diabetes, arteriosclerosis, high blood pressure or macular degeneration. Cataracts and other eye problems can be detected with an ophthalmoscope.

The patient's eyes are dilated so as to allow a good view of the insides of the eye. Some patients develop allergic reaction, vomiting, nausea and dizziness. This test is conducted in a darkened room where the patient is asked to look ahead at a distant spot. The eyes must be held steady without blinking. The ophthalmoscopy procedure may take just about 5 - 10 minutes.

PET scan

PET - Positron Emission Tomography scan is a non-invasive test that aids in imaging the cellular functions and body tissues. It helps in observing the blood flow, oxygen use, and glucose metabolism. A PET scan is of immense help in the diagnosis of cancer, heart disease and brain disorders. The PET scan has been of particular help in the diagnosis of brain tumors, head and neck cancer and esophageal cancer. Since the PET scan reveals metabolic changes in the cells, it aids in early detection of certain conditions such as epilepsy. A PET scan involves injection of a small amount of radioactive tracer drug such as FDG-18. After an hour when the radioactive tracer has spread to the body, the scan is taken. The tracer emits tiny positively charged particles (positrons) that produce signals. A PET scan produces three-dimensional color images from the images taken by a camera that records the tracer as it travels through the body. It is often combined with a CT scan to study a particular body area. Lactating mothers must not breast feed their babies for a few hours after the PET scan.