Drug cocktails used to control the AIDS virus may also work to prevent cervical cancer, U.S. researchers reported on Tuesday.

It is not clear whether the drugs have a direct effect on precancerous lesions or if they allow the immune system to naturally battle them, the researchers report in this week’s issue of the Journal of the National Cancer Institute.

But it marks one more benefit of the drug cocktails called highly active antiretroviral therapy, or HAART, which do not cure HIV infection but can help control it.

The human immunodeficiency virus can allow the spread of a range of infections as it destroys the body’s immune cells. Among its effects is an increased risk of abnormalities in the cervix called squamous intraepithelial lesions.

Doctors believe these lesions, which can progress to cancer, are caused by human wart virus or human papillomavirus. HIV infection also raises the risk of HPV infection and both can be sexually transmitted.

Usually the lesions clear on their own. But they are more likely to progress to cancer in women infected with HIV.

Linda Ahdieh-Grant of Johns Hopkins University and colleagues analyzed data from 2,000 women taking part in a study of HAART.

Before women started HAART, the lesions regressed in none. After women started HAART the regression rate was 12.5 percent.

“These findings underscore the importance of ensuring that women who are immunosuppressed have full access to antiretroviral therapy,” Ahdieh-Grant and colleagues wrote.

“It should be emphasized, however, that HIV-infected women on HAART must still receive careful gynecologic follow-up and close routine monitoring.”

Pap smears look for the abnormalities associated with the precancerous lesions. Cervical cancer is easily prevented but kills rapidly if left to progress on its own.