Highly active antiretroviral therapy (HAART), a combination of drugs used to treat HIV infection, can help prevent cancers that are associated with AIDS, new research shows. In contrast, HAART doesn’t seem to reduce the risk of non-AIDS related cancers in HIV-infected patients.

A type of skin cancer called Kaposi’s Sarcoma and an immune system cancer called non-Hodgkin lymphoma are among the cancers that are seen much more often in AIDS patients than in the general population.

While several studies have tied AIDS to various cancers, Dr. Gary M. Clifford of the International Agency for Research on Cancer in Lyon, France, and colleagues note, there is little information on the effect of HAART.

They used data from Swiss HIV and cancer registries to determine the effect of HAART use, cigarette smoking and other behavioral factors on cancer risk in 7,304 patients with HIV infection.

The researchers report their findings in the Journal of the National Cancer Institute.

As expected, Kaposi sarcoma and non-Hodgkin lymphoma were much more common among patients with HIV infection than among the general population. However, some non-AIDS-related cancers were also more common among patients with HIV infection, such as cervical cancer and liver cancer.

Lung and mouth cancers were also more common among patients with HIV infection. However, this may have been because smoking, a risk factor for both cancers, was more common among HIV-infected patients.

HAART reduced the risk of Kaposi sarcoma and non-Hodgkin lymphoma, the researchers found, but had no effect on rates of other cancers.

Still, even with HAART, rates of Kaposi sarcoma and non-Hodgkin lymphoma in HIV patients are 20-times higher than in the general population, Drs. Eric A. Engels and James J. Goedert of the National Cancer Institute note in a related editorial, and it’s unclear whether these cases are due to the failure of HAART or other causes.

SOURCE: Journal of the National Cancer Institute, March 16, 2005.