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A Snapshot of Kaposi Sarcoma

Incidence and Mortality

Kaposi sarcoma (KS) is a soft tissue sarcoma that can occur on the skin; the mucous membranes lining the mouth, nose and throat; lymph nodes; and other organs. "Classic" KS is rare and found mainly in older men of Italian or Eastern European Jewish origin. Immunosuppressed individuals are also at increased risk for KS. The incidence of KS rose sharply in the 1980s, with the emergence of acquired immunodeficiency syndrome (AIDS). In the United States, infection with human immunodeficiency virus (HIV), which causes AIDS, is by far the greatest risk factor for KS.

KS is caused by the Kaposi sarcoma-associated herpes virus (KSHV). Most people infected with KSHV do not develop KS or show any symptoms, but in people with weakened immune systems the infection can lead to KS. The incidence of KS began to fall in the late-1980s, with the introduction of the first effective therapies against HIV.  The subsequent introduction, in the mid-1990s, of highly active antiretroviral therapy (HAART), which partially restores immune system function, led to a dramatic drop in the incidence of KS. Incidence has continued to fall, by 1.7% annually, since 1998. Men have a much higher incidence than women, particularly among those between the ages of 25 and 59. Incidence is highest in African Americans.

Standard treatments for KS include radiation therapy, surgery, chemotherapy, and biological therapy. New treatments for KS, including targeted therapies, are currently being tested in clinical trials.

Line graphs showing U.S. Kaposi Sarcoma Incidence per 100,000 by race and ethnicity between 1991-2011 and incidence per 100,000 by race and age. In 2011, African Americans have the highest incidence, followed by Hispanics and whites. Insufficient data available for time trend analysis American Indian/Alaska Natives or Asians/Pacific Islanders.   Incidence data not available before 1992 for Hispanics. Kaposi sarcoma incidence is higher for African Americans aged 20-64 compared to whites.  Starting at age 65,

Source: Surveillance, Epidemiology, and End Results (SEER) Program and the National Center for Health Statistics. Additional statistics and charts are available at the SEER Web site.

Examples of NCI Activities Relevant to Kaposi Sarcoma

  • The Kaposi Sarcoma Working Group, part of the AIDS Malignancy Consortium, supports studies to evaluate the safety, side effects, and effectiveness of potential treatments and preventive medicines for KS and develops comprehensive procedures for evaluating KS response data and correlating these data with patient outcomes.
  • The Office of HIV and AIDS Malignancy coordinates and prioritizes HIV/AIDS-related research throughout NCI and oversees research programs in HIV/AIDS and HIV-associated cancers.
  • The Infections and Immunoepidemiology Branch conducts multidisciplinary research on infectious agents and cancer, including KS and other HIV/AIDS-associated malignancies. Projects include a case-control study examining associations between environmental exposures, including smoking, and the risk of KS; studies of KSHV transmission and prevalence; and studies exploring the genomic integrity of KS.
  • The Cancer Etiology Branch supports research on biological, chemical, and physical agents that are known or possible carcinogens. One program area—HIV- and AIDS-Associated Malignancies—supports investigations of the role of HIV, KSHV, and other viruses as etiologic agents of AIDS-associated cancers and how their interactions affect carcinogenesis and cancer progression.
  • The Center of Excellence in HIV/AIDS and Cancer Virology facilitates and communicates advances in antiviral and immunologic approaches for preventing and treating HIV infection, AIDS-related malignancies, and cancer-associated viral diseases.
  • The intramural HIV and AIDS Malignancy Branch conducts laboratory and clinical research in AIDS-related malignancies, HIV disease, and viral-induced tumors to understand the pathogenesis of and explore new treatments for HIV-associated tumors. Ongoing projects include studies to understand the resistance of HIV to anti-HIV drugs and to develop novel HIV drugs and treatments, including protease inhibitors that are effective against drug-resistant disease.
  • The AIDS and Cancer Virus Program is a multidisciplinary program that consists of seven research teams that work together to improve our understanding of AIDS-associated viruses and to facilitate improved diagnosis, prevention, and treatment of HIV infection, AIDS, and AIDS-associated tumors.

Selected Advances in Kaposi Sarcoma Research

Pie chart of NCI Kaposi Sarcoma Research Portfolio.  Percentage of total dollars by scientific area.  Fiscal year 2013.  Biology, 15%.  Etiology/causes of cancer, 42%.  Prevention, 3%.  Early detection, diagnosis, and prognosis, 6%.  Treatment, 27%.  Cancer control, survivorship, and outcomes research, 4%.  Scientific model systems, 3%.

Source: NCI Funded Research Portfolio. Only projects with assigned common scientific outline area codes are included. A description of relevant research projects can be found on the NCI Funded Research Portfolio Web site.


  • In a mouse model of KSHV-induced Kaposi sarcoma, tumorigenesis was found to be driven by a viral G protein-coupled receptor that activates the kinase IKKε, triggering an inflammatory pathway that causes tumor formation. Published June 2013. [PubMed Abstract]
  • Lymphoma cells infected with Epstein Barr virus (EBV) and KSHV release exosomes (small vesicles) that contain different proteins, some of which are known to be pro-tumorigenic. These exosomes may allow these oncogenic viruses to modulate the tumor microenvironment; they may also provide diagnostic markers specific for EBV- and KSHV-associated malignancies. Published July 2013. [PubMed Abstract]
  • The AIDS Malignancy Consortium’s phase II trial of imatinib in AIDS-associated KS found that 30 percent of patients showed long-term clinical benefit and remained on imatinib for the entire year of the trial, suggesting that imatinib may be an alternative therapy for some patients with AIDS-associated KS. Published December 2013. [PubMed Abstract]
  • Researchers characterized a mouse model of KSHV infection in humans that includes robust KSHV infection via transmission routes that occur during natural infection in humans and should be useful studying the infection and pathogenesis of KSHV in vivo. Published February 2014. [PubMed Abstract

Trends in NCI Funding for Kaposi Sarcoma Research

NCI’s investment1 in KS research was $21.8 million in fiscal year (FY) 2013. In addition to the funding described in the graph, NCI supported $11 million in KS research in FYs 2009 and 2010 using funding from the American Recovery and Reinvestment Act.

Bar graph of NCI Kaposi Sarcoma Research Investment in 2009-2013: Fiscal year (FY) 2009, $25.2 million Kaposi Sarcoma Funding of $4.97 billion Total NCI Budget. FY 2010, $22.4 million Kaposi Sarcoma Funding of $5.10 billion Total NCI Budget.  FY 2011, $24.5 million Kaposi Sarcoma Funding of $5.06 billion Total NCI Budget.    FY 2012, $22.9 million Kaposi Sarcoma Funding of $5.07 billion Total NCI Budget.  FY 2013, $21.8 million Kaposi Sarcoma Funding of $4.79 billion Total NCI Budget.

Source: NCI Office of Budget and Finance.

Additional Resources for Kaposi Sarcoma

  • 1 The estimated NCI investment is based on funding associated with a broad range of peer-reviewed scientific activities. For additional information on research planning and budgeting at the National Institutes of Health (NIH), see About NIH.
  • Posted: November 5, 2014