According to new research, women who have HIV acquire cancer-causing forms of the human papillomavirus (HPV) that are not included in the HPV vaccines Cervarix and Gardasil.
“People with issues in their immune system such as HIV will be at risk of acquiring HPV, as well, and the current vaccine may not fully protect them,” study author Elizabeth Blackman, MPH, research specialist at Fox Chase Cancer Center, was quoted as saying.
“Protecting the immune system, however, may prevent other disease,” Blackman said. Women who were taking HIV medications for at least four years were less likely to carry the cancer-causing forms of HPV. Treating HIV may also protect women from the consequences of HPV.
There are more than 40 different types of HPV that can infect the genital areas, with at least 15 of them considered “high risk.” This means that they can cause changes in cells that can lead to cancer. About 4,000 women in the U.S. die every year from cervical cancer, which usually stems from HPV infection.
HPV is very common; practically every sexually active person will acquire it at some point. Blackman says that most cases do not lead to cancer because a healthy immune system can normally clear the virus on its own. “However, if your immune system is compromised, such as in HIV, you will not be able to fight off the infection. Over time, persistent infection with HPV can lead to cancer,” Blackman said.
The study tested 176 HIV-positive women living in the Bahamas with the presence of high-risk forms of HPV. Three-quarters of the women tested carried the high-risk forms of HPV and close to 30 percent had precancerous cervical cells. Current vaccines for HPV prevent infections from 16, and 18, the most common types that make up 70 percent of cervical cancer in the world.
Blackman and her team found that many HIV-positive women in the Bahamas who had precancerous cervical cells carried HPV types 16 and 18, but also had infections with HPV types 52 and 58, that are high-risk but not protected by the current vaccines.
Women taking highly active retroviral therapy (HAART) to treat HIV were less likely to have high-risk forms of HPV, suggesting that controlling the immune system may curb additional infections.
“If women take medications for a long enough time, their immune system may prevent other diseases from developing,” Blackman said.
SOURCE: Presentation at the AACR, April 2013