Kaposi's sarcoma (KS) is most common in individuals affected with acquired immunodeficiency syndrome (AIDS) and those living in the Mediterranean region.1 In the United States, non-AIDS related KS make up a small 1%of all cancers, and the greatest concentration occurs in the rain forest of Central Africa which makes up 5% of all tumors.2 Most patients in the U.S. are older than age 60, and the peak age in Africa is 25-45 years. The typical American patient occurs generally in the ankle, then arms. Visceral organs are involved in less than 5% of patients, mostly in the gastrointestinal tract. The disease can also arise in kidney transplant patients because of immunosuppressive therapy.
Etiology:
Most common malignancy in AIDS patients, these patients are 20,000 times more likely to develop KS.2 Human immunodeficiency virus (HIV) has led to occurrence of KS in children.1
Signs & Symptoms:
Patients with KS who do not have acquired immunodeficiency syndrome (AIDS) are known as having classic KS.2 The ankle region is the most common site of onset, followed by the arms. Kaposi’s sarcoma patients with AIDS are more likely to develop epidemic KS. The legs are most commonly involved in epidemic KS, followed by the tip of the nose and around the eyes and ears. Visceral lesions occur in most patients, and can involve any organ.
Diagnostic Procedures:
Diagnosis involves inspection of all visible skin and mucosal surfaces. In addition, any patient with gastrointestinal symptoms should undergo endoscopic evaluation due to the the high risk of visceral KS.2
Histology:
The histology of KS has spindle cell and vasular elements.2 The neoplatic element is in the spindle shaped cells. Reprinted from inPractice, 2013.3
Lymph node drainage:
This cancer can develop anywhere in the body. Therefore, there are not certain lymph nodes that are commonly involved in the disease. However, tumors can develop in the lymph nodes.4 Radiation treatment does not involved any local lymph nodes to the disease.
Metastatic spread:
CNS5
Heart
Thoracic duct
Urinary system
Breast
Grading:
The grading of KS is low grade with limited ability to metastasize.5
Staging:
There is no official staging system for KS, but several different systems such as the ACTG classification system and the modified Mituyasu can be used.6
The AIDS Clinical Trials Group (ACTG) Classification System
Tumor (T): Extent of tumor
T0 (good risk): KS is confined to skin and/or lymph nodes and/or demonstrates minimal oral disease (roof of mouth); the KS lesions in the mouth are flat rather than raised
T1 (poor risk): KS lesions are widespread; one or more of the following is present:
Edema (swelling) due to the tumor
Extensive oral KS: nodular lesions (raised) and/or lesions in areas of the mouth besides the palate
Lesions of KS are in organs other than the lymph nodes (eg, lungs, intestine, liver)
Immune system (I): Status of the immune system, as measured by CD4 cell levels
I0 (good risk): CD4 cell count is ≥200/µL (normal range, 600-1500/µL); more recent studies have used counts of either 150 or 100
I1 (poor risk): CD4 cell count is < 200/µL; more recent studies have used counts of either 150 or 100
Systemic illness (S): Extent of involvement within the body or systemic illness
S0 (good risk): No systemic illness present; all of the following are true:
No history of opportunistic infections or thrush (thrush is a fungal infection in the mouth, and opportunistic infections are infections that rarely cause problems in healthy people but more commonly affect people with suppressed immune systems)
None of the following B symptoms is present: unexplained fever, night sweats, >10% involuntary weight loss, diarrhea persisting for >2wk
And this is true: Karnofsky performance status score of ≥70 (ie, you are up and about most of the time and able to take care of yourself)
S1 (poor risk): Systemic illness present; 1 or more of the following is true:
History of opportunistic infections or thrush
One or more B symptoms is present
Karnofsky performance status score < 70
Other HIV-related illness is present, such as neurologic disease or Lymphoma
Modified Mituyasu staging system
Stage I: Represents localized nodular KS, with >15 cutaneous lesions or involvement restricted to 1 bilateral anatomic site and few, if any, gut nodules
Stage II: Includes both exophytic destructive lesions and locally infiltrative cutaneous lesions as locally aggressive KS
Stage III: Generalized lymphadenopathic KS has widespread lymph node involvement, with or without skin lesions, but with no visceral involvement
Stage IV: Disseminated visceral KS has widespread KS, usually progressing from stage II or stage III, with involvement of multiple visceral organs
Radiation side effects:
Irradiation of KS can cause skin changes, nausea, vomiting, and fatigue.7 Radiation can also reduce blood cell counts causing anemia and increasing the risk of infection due to low white blood cells. When using photon radiation for the treatment of KS lesions in the mouth or throat, the irradiated areas can become painful and open sores can develop. “If chemotherapy and radiation are given at the same time, the side effects are worse.”
Prognosis:
The survival rate for KS is low in countries with Highly Active Antiretroviral Therapy (HAART) and often can see death within 6 months.[2]
The survival rate based on years after diagnosis:
64.9%
41.5%
31.0%
26.4%
23.5%
22.1%
21.0%
20.3%
19.6%
19.2% [2]
Treatments:
For patients with advanced disease systemic chemotherapy has been a common modality.
Doxorubicin, bleomycin, and vincristine have shown to benefit patients with KS.
Liposomal drugs such as daunorubicin and doxorubicin have become a common treatment and have a similar treatment rate as adriamycin, bleomycin, and vinblastine.
Surgery is rarely used for palliation, and cryotherapy is occasionally used for smaller lesions.
Radiation therapy
Used for palliation/to stop bleeding and swelling.
A superficial x-ray or electron treatment with the use of bolus is commonly used.
The treatments are taken to 30 Gray (Gy) in 10 fractions.
If the patient also has AIDS, a one fraction 8 Gy treatment will be given.[2]
Reprinted from inPractice, 2013.3
The AIDS Clinical Trials Group (ACTG) Classification System
Modified Mituyasu staging system
The survival rate based on years after diagnosis:
- Doxorubicin, bleomycin, and vincristine have shown to benefit patients with KS.
- Liposomal drugs such as daunorubicin and doxorubicin have become a common treatment and have a similar treatment rate as adriamycin, bleomycin, and vinblastine.
Surgery is rarely used for palliation, and cryotherapy is occasionally used for smaller lesions.Radiation therapy
Bone marrow 250 cGy; aplasia, pancytopenia
Retina 5500 cGy; blindness
Lens 500 cGy; blindness
Heart 4500 cGy; pericarditis
Lung 3000 cGy; pneumonitis
Intestine 4500 cGy; ulcer, peforation, hemorrhage