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.

Antiretroviral Therapy

Antiretroviral or ARV is used to treat HIV virus. A combination of ARV used to treat HIV - Antiretroviral therapy. Patients tend to take 3 or more combinations of ARV medication called the combination therapy. Currently the main treatment for HIV is through Antiretroviral therapy.

Antiretrovirals aim to inhibit the process which the virus resorts to kill T lymphocytes. More than 20 antiretroviral drugs have been approved to treat HIV. Some Antiretroviral drugs have been combined into one single pill known as a fixed dose combination. Different dosage of medicine is prescribed for different people depending on the severity of the infection in the blood.

ART medication cannot cure or treat HIV; however it helps in preventing the growth of the virus and reduces the risk of transmitting it to others. This prevents the virus from multiplying and slows down the virus and thereby HIV. Having less HIV in the body gives the immune system of the body a chance to recover and fight infections.

Significant advances have been made in this therapy since its introduction in 1987. ART involves ingesting a combination of HIV medicines on a daily basis as prescribed by the physician. If left untreated HIV can develop into AIDS. If only one drug is taken, HIV will become resistant to the drug very soon and the drug will stop working. Hence a combination of drugs is used. ART is often a lifelong treatment that is currently helping numerous HIV affected people lead a better quality of life. The effectiveness of the treatment largely depends on the adherence of medicine intake schedule.

When to start ART depends on the patients' need and condition. A blood test called the CD4 count is taken to measure the number of CD4 cells in a sample of blood. CD4 cells are infection-fighting cells in the immune system of the human body. HIV attacks and destroys these CD4 cells, thus making it difficult for the body to fight infection. A low or dropping CD4 count indicates that HIV is advancing and damaging the immune system. Under the guidance of a physician when the patient begins ART, the CD4 count begins to improve which indicates that the immune system in the body is recovering.

Physicians also may order a blood test to check and measure HIV by checking the viral load in the blood i.e. the amount of the virus in the bloodstream. ART aims at reducing the viral load in the blood to an extent that it can't be traced any longer while testing. HIV virus though present in the blood will be very low - not sufficient to cause any symptoms.

Combination ARV therapy is also available and is known as highly active ART or HAART. With the availability of HAART, HIV-1 infection is manageable as a chronic disease in patients. Antiretroviral drugs are used in combinations of three or more classes of drugs, called Combination Therapy. This therapy helps prevent drug resistance in patients. Six classes of drugs, Antiretroviral agents, exist currently:

• Chemokine receptor antagonists (CCR5 antagonists) such as maraviroc.
  
• Fusion inhibitors (FIs) such as enfuvirtide.
  
• Integrase inhibitors (INSTIs) such as dolutegravir and raltegravir.
  
• Nucleoside reverse transcriptase inhibitors (NRTIs) such as abacavir, emtricitabine and tenofovir.
  
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs) such as efavirenz, etravirine, and nevirapine.
  
• Protease inhibitors (PIs) such as atazanavir, darunavir, andritonavir.

Each class targets a different step in the life cycle of the virus. Each of these drug classes includes more than 25 HIV medicines that are approved to treat HIV infection. ART regimen includes three or more Antiretroviral from at least two different classes.

Drugs have to be taken at the right time and in the right way for the drugs to work well. The regimen requires plenty of discipline. The drugs may cause side effects in a few. If patients stop taking the drug, they may develop resistance to the drug and thereby will stop responding to the treatment when continued at a later stage.

Few of the commonly reported side effects include loss of appetite, fatigue, depression, mood changes, weight gain, sleep disturbance and metabolic disturbance. ART is available for pregnant women so that they don't pass on the virus to the fetus in the womb. Post delivery, the mother is advised not to breast feed the baby as she may pass the HIV virus through this to the baby. Though ART is not a complete cure for HIV, it serves the purpose to:

• Reduced HIV viral load in the blood.
  
• Enhanced quality living for patients inflicted with HIV.
  
• Lesser damage to the immune system.
  
• Reduced transmission of HIV in the society.

Though ART is considered to be a great regimen in handling HIV, it has few limitations such as:

• Strict adherence to medication regimen; few tablets need to be taken at the same time of the day, everyday.
  
• Expensive medicines have to be continued life long.
  
• Side effects
  
• Virus cannot be eradicated completely from the body.
  
• Relapse is possible on discontinuation of drugs.
  

CD4 Count Test

The CD4 Count Test is an indicator of the working of the immune system. By measuring the number of CD4 T lymphocytes or CD4 cells in the blood, it helps to predict and assess the progression of HIV. This count helps in planning antiretroviral therapy or ART. Monitoring the CD4 count through regular blood tests helps to determine the efficacy of the ART and whether the patient is at risk for other infections.

The CD4 lymphocytes are WBC that play a vital role in infection protection. HIV virus tag on to CD4 cells to propagate and spread the infection within the body. Thus an infected person will notice a reduced count of CD4 cells (less than 200 cells/mm3) when the normal range of CD4 cells is from 500 cells/mm3 to 1,200 cells/mm3.

Successful ART results in reduced CD4 count and lesser viral load in the blood. CD8 cells are another type of WBC that work against infections in the body including HIV.