Kaposi Sarcoma Treatment (PDQ®): Treatment - Health Professional Information [NCI]

General Information About Kaposi Sarcoma

Epidemiology

Kaposi sarcoma (KS) was first described in 1872 by the Hungarian dermatologist, Moritz Kaposi. From that time until the HIV and AIDS epidemic, KS remained a rare tumor. Classic KS is most commonly seen in Europe and North America in older men of Italian or Eastern European Jewish ancestry,[1] and endemic KS is most commonly seen in sub-Saharan Africa. The disseminated, fulminant form of KS associated with HIV disease is referred to as AIDS-associated KS to distinguish it from classic and endemic KS. Transplant-related KS (also sometimes called iatrogenic KS) is seen in patients receiving chronic immunosuppression therapy, such as after organ transplant.[2,3]

Histopathology

Although the histopathology of the different types of KS is essentially identical, the clinical manifestations and course of the disease differ dramatically.[2] Human herpesvirus 8 (HHV8), also known as Kaposi sarcoma-associated herpesvirus, was identified in KS tissue biopsies from almost all patients with classic, endemic, AIDS-associated, and transplant-related KS but was absent from noninvolved tissue.[2]

Classic Kaposi Sarcoma

Classic KS is considered a rare disease. It occurs more often in men, at a ratio of approximately 10 to 15 men to 1 woman. In North American and European populations, the usual age at onset is between 50 and 70 years. Classic KS tumors usually present with one or more asymptomatic red, purple, or brown patches, plaques, or nodular skin lesions. The disease is often limited to single or multiple lesions usually localized to one or both lower extremities, especially involving the ankles and soles.

Classic KS most commonly runs a relatively benign, indolent course for 10 to 15 years or more, with slow enlargement of the original tumors and the gradual development of additional lesions. Venous stasis and lymphedema of the involved lower extremity are frequent complications. In long-standing cases, systemic lesions can develop along the gastrointestinal tract, in lymph nodes, and in other organs. The visceral lesions are generally asymptomatic and are most often discovered only at autopsy, though clinically, gastrointestinal bleeding can occur. As many as 33% of patients with classic KS develop a second primary malignancy, which is most often non-Hodgkin lymphoma.[4]

Endemic Kaposi Sarcoma

Endemic KS refers to KS diagnosed in patients, typically children and younger adults, living in sub-Saharan Africa. This classification was based on several reports from the 1950s of KS in this younger HIV-negative cohort in human herpesvirus–endemic African countries. Prior to the AIDS epidemic, the estimated incidence for endemic KS was highest (>6 per 1,000 person-years) in Uganda, Tanzania, Cameroon, and Congo. The etiology behind endemic KS is unclear but may possibly be related to saliva-sharing practices, chronic infection, and malnutrition.[3]

The clinical presentation of endemic KS varies and differs between children and adults. Whereas adults present with disease that resembles classic KS, children can have more aggressive disease, including diffuse lymphadenopathy, significant lymphedema, and visceral dissemination.[3]

AIDS-Associated Kaposi Sarcoma

The use of antiretroviral therapy for patients with AIDS-associated KS has been associated with a sustained and substantial decline in KS incidence in multiple large cohorts.[5,6,7] Antiretroviral therapy has delayed or prevented the emergence of drug-resistant HIV strains, profoundly decreased viral load, led to increased survival, and lessened the risk of opportunistic infections.[8] KS can still appear during antiretroviral therapy with complete suppression of HIV; most cases in the United States occur in patients with high CD4 counts receiving ongoing antiretroviral therapy.[9]

The disease often progresses in an orderly fashion from a few localized or widespread mucocutaneous lesions that may involve the skin, oral mucosa, and lymph nodes to more numerous lesions and generalized skin disease that involves visceral organs, such as the gastrointestinal tract, lung, liver, and spleen. Most patients with HIV disease who present with mucocutaneous KS lesions feel healthy and are usually free of systemic symptoms, as compared with HIV patients who first develop an opportunistic infection. AIDS-associated KS presents at sites that are much more varied than those seen in other types of this neoplasm. While most patients present with skin disease, KS involvement of lymph nodes or the gastrointestinal tract may occasionally precede the appearance of the cutaneous lesions.

Transplant-Related Kaposi Sarcoma

Transplant-related KS (also called iatrogenic KS) is diagnosed in patients who are therapeutically immunosuppressed, such as after an organ transplant. In fact, solid-organ transplant recipients are 200-fold more likely to develop KS than the general population. Risk factors include male sex, older age, higher levels of immune suppression, and living in HHV8-endemic areas.[3]

Transplant-related KS typically yields cutaneous lesions, though mucosal and visceral disease can occur. The lesions commonly occur within the first several months of immunosuppression therapy and regress with changes or reductions in immunosuppression.[3]

References:

1. Ruocco E, Ruocco V, Tornesello ML, et al.: Kaposi's sarcoma: etiology and pathogenesis, inducing factors, causal associations, and treatments: facts and controversies. Clin Dermatol 31 (4): 413-422, 2013 Jul-Aug.
2. Uldrick TS, Whitby D: Update on KSHV epidemiology, Kaposi Sarcoma pathogenesis, and treatment of Kaposi Sarcoma. Cancer Lett 305 (2): 150-62, 2011.
3. Cesarman E, Damania B, Krown SE, et al.: Kaposi sarcoma. Nat Rev Dis Primers 5 (1): 9, 2019.
4. Safai B, Good RA: Kaposi's sarcoma: a review and recent developments. Clin Bull 10 (2): 62-9, 1980.
5. Portsmouth S, Stebbing J, Gill J, et al.: A comparison of regimens based on non-nucleoside reverse transcriptase inhibitors or protease inhibitors in preventing Kaposi's sarcoma. AIDS 17 (11): F17-22, 2003.
6. Carrieri MP, Pradier C, Piselli P, et al.: Reduced incidence of Kaposi's sarcoma and of systemic non-hodgkin's lymphoma in HIV-infected individuals treated with highly active antiretroviral therapy. Int J Cancer 103 (1): 142-4, 2003.
7. Grabar S, Abraham B, Mahamat A, et al.: Differential impact of combination antiretroviral therapy in preventing Kaposi's sarcoma with and without visceral involvement. J Clin Oncol 24 (21): 3408-14, 2006.
8. Lodi S, Guiguet M, Costagliola D, et al.: Kaposi sarcoma incidence and survival among HIV-infected homosexual men after HIV seroconversion. J Natl Cancer Inst 102 (11): 784-92, 2010.
9. Yanik EL, Achenbach CJ, Gopal S, et al.: Changes in Clinical Context for Kaposi's Sarcoma and Non-Hodgkin Lymphoma Among People With HIV Infection in the United States. J Clin Oncol 34 (27): 3276-83, 2016.