HIV Infection and Cancer Risk (Fact Sheet)

Has the introduction of antiretroviral therapy changed the cancer risk of people infected with HIV?

The introduction of highly active antiretroviral therapy (HAART), also called combination antiretroviral therapy (cART), starting in the mid-1990s greatly reduced the incidence of certain cancers in HIV-infected patients, especially Kaposi sarcoma and non-Hodgkin lymphoma.² The likely explanation for this reduced incidence is that cART lowers the amount of HIV circulating in the blood, thereby allowing partial restoration of immune system function to fight the viruses that cause many of these cancers.

Although the risk of these AIDS-defining cancers among people infected with HIV is lower than in the past, it is still much higher than among people in the general population.¹⁵ This persistently high risk may reflect the fact that cART does not completely restore immune system functioning. Also, many people infected with HIV are not aware they are infected, have had difficulty in accessing medical care, or for other reasons are not receiving adequate antiretroviral therapy.

The introduction of cART has not reduced the incidence of all HIV-related cancers, and in fact there has been an increase in non–AIDS-defining cancers. For example, the incidence of liver and anal cancer may be increasing among HIV-infected individuals.^2,15

An important factor contributing to the increase in non–AIDS-defining cancers is that as cART has reduced the number of deaths from AIDS, the HIV-infected population has grown in size and become older. The fastest growing proportion of HIV-infected individuals is the over-40 age group. These individuals are now developing cancers common in older age and also have an increased cumulative risk of developing HIV-associated cancers.

What can people infected with HIV do to reduce their risk of cancer or to find cancer early?

Taking cART as indicated based on current HIV treatment guidelines lowers the risk of Kaposi sarcoma and non-Hodgkin lymphoma and increases overall survival.

The risk of lung, oral, and other cancers can be reduced by quitting smoking. Because HIV-infected people have a higher risk of lung cancer, it is especially important that they do not smoke.

The higher incidence of liver cancer among HIV-infected people appears to be related to more frequent infection with hepatitis virus (particularly HCV in the United States) than among HIV-uninfected people.^12,16 Therefore, HIV-infected individuals should know their hepatitis status.

In addition, if HIV-infected people currently have viral hepatitis, they should discuss with their health care provider whether antiviral treatment is an option for them.^9,16–19 Some drugs may be used for both HBV-suppressing therapy and cART.¹⁶

Because HIV-infected women have a higher risk of cervical cancer, it is important that they be screened regularly for this disease. In addition, the Centers for Disease Control and Prevention (CDC) recommends vaccination against human papillomavirus (HPV) for women and men with HIV infection up to age 26 years. Cervical cancer screening guidelines that incorporate results of a Pap test and an HPV DNA test are evolving, and women should discuss screening options with their healthcare provider.²⁰

Some researchers recommend anal Pap test screening to detect and treat early lesions before they progress to anal cancer.²¹ However, it is not clear if this type of screening benefits all HIV-infected people or if treating such lesions prevents anal cancer. These questions are being addressed in an NCI-funded trial called the Anal Cancer/HSIL Outcomes Research (ANCHOR) Study. This study is currently enrolling men and women with HIV to undergo anal Pap testing and then be randomly assigned to receive either treatment or observation (no treatment). The goal is to determine whether treatment of anal lesions prevents anal cancer in HIV-infected people with anal lesions.

KSHV is secreted in saliva, and transmission of this virus may occur through deep kissing, through the use of saliva as a lubricant in sex, or through oral–anal sex. Reducing contact through these routes may reduce the chance of being infected with KSHV.

READ FULL ARTICLE From National Cancer Institute