The number of cancers and the types of cancers among people living with AIDS in the U.S. have changed dramatically during the 15-year period from 1991-2005, according to an article published online April 11th in the Journal of the National Cancer Institute.
It is known that HIV-infected patients face an increased risk of Kaposi sarcoma, non-Hodgkin lymphoma, and cervical cancer--the AIDS-defining cancers--and that the incidence of these cancers dropped when highly active anti-retroviral therapy (HAART) became available in the mid-1990s. People living with HIV and AIDS are also known to have an elevated risk of certain other cancers, including lung, anal, and liver cancer, and Hodgkin lymphoma. These are known among AIDS researchers as non-AIDS-defining cancers.
To estimate the numbers of AIDS-defining and non-AIDS-defining cancers in people with AIDS in the U.S., researchers from the National Cancer Institute (NCI) in Bethesda, Md, and the Centers for Disease Control and Prevention (CDC) in Atlanta, led by Meredith S. Shiels, Ph.D., at the NCI, used data from the U.S. HIV/AIDS Cancer Match Study and from the CDC. They evaluated data from three calendar periods: 1991-1995 (pre-HAART); 1996-2000 (early-HAART); and 2001-2005 (late-HAART).
As expected, the researchers found that the number of AIDS-defining cancers overall dropped markedly from the pre-HAART (34,587 cases) to the late-HAART period (10,325 cases). In contrast, the non-AIDS-defining cancers increased three-fold between the early period (3,193 cases) and the late period (10,059 cases). In fact, since 2003, fewer than half of the all cancers have been AIDS-defining cancers.
Also, to estimate cancer burden in people with HIV but not AIDS, the authors used data from 34 states from 2004-2007 and found lung cancer to be the most common malignancy in the HIV-only population, comprising 20% of all cancers.
Aging and increased survival are largely responsible for the patterns observed, according to the authors. From 1991 to 2005, the AIDS population in the U.S. increased fourfold, primarily because of an increase in patients aged 40 years or older who are living longer because of HAART. Particularly as the number of older people living with AIDS has grown, the burden of cancer has shifted, resulting in a new and serious public health issue, according to the authors.
"The growing burden of non-AIDS-defining cancers highlights the need for cancer prevention and early detection among HIV-infected people," the authors write. They suggest various strategies, such as smoking cessation to help prevent lung cancer; prevention and treatment of hepatitis B and C infections to reduce the risk of liver cancer; and further evaluation of screening tests for anal cancer.
The authors note that cancer treatments must be tailored to people with HIV. "As individual centers may see few cancers in HIV-infected people, multicenter consortia are needed to comprehensively evaluate cancer treatment protocols in this population," they write.