Antiretroviral therapy may prevent excess risk of some cancers in people with HIV

In people infected with human immunodeficiency virus (HIV), highly active anti-retroviral therapy (HAART) may prevent most excess cases of Kaposi sarcoma and non-Hodgkin lymphoma, according to a new study in the March 16 issue of the Journal of the National Cancer Institute.

Studies of people with acquired immunodeficiency syndrome (AIDS) have reported increased risks of several cancers, including Kaposi sarcoma, non-Hodgkin lymphoma, and to a lesser extent, anal cancer, invasive cervical cancer, and Hodgkin lymphoma. However, less well understood are the associations of these cancer risks with the use of HAART, with immune status and with behavioral risk factors such as smoking.

To estimate excess cancer risk in people infected with HIV and investigate the modifying effects of the use of HAART and behavioral factors on this cancer risk, Gary M. Clifford, Ph.D., of the International Agency for Research on Cancer, based in Lyon, France, and colleagues analyzed data from the Swiss HIV Cohort Study and Swiss cancer registries on more than 7,300 people infected with HIV.

People with HIV in the study had a highly elevated risk of Kaposi sarcoma and non-Hodgkin lymphoma. They also had an increased risk of anal cancer, Hodgkin lymphoma, cervical cancer, liver cancer, cancer of the lip, mouth, and pharynx, and non-melanoma skin cancer. People who used HAART had lower risks of Kaposi sarcoma and non-Hodgkin lymphoma compared with those who did not use HAART. HAART use did not decrease, however, the risk of Hodgkin lymphoma or other cancers. Whilst cancers of the lung, lip, mouth, and pharynx were associated with an elevated risk in people infected with HIV, no cases of such cancers occurred among non-smokers.

"In conclusion, HAART treatment may prevent excess risk of [Kaposi sarcoma] and non-Hodgkin lymphoma, but not that of Hodgkin lymphoma or other cancers," the authors write. "Focusing on ways to encourage persons infected with HIV to quit smoking would be effective in reducing lung cancer in these persons."