July 31 (HealthDay News) -- As their immune system weakens, people with AIDS are at increased risk for human papillomavirus (HPV)-related cancers, a new study has found.

It was known that people with AIDS had a greater risk for HPV-associated cancers of the anus, cervix, penis, vagina, vulva and oropharynx. However, the extent to which AIDS-related weakening of the immune system played a role wasn't clear, the researchers pointed out.

For this study, researchers at the U.S. National Cancer Institute analyzed cancer registry data on almost 500,000 people diagnosed with AIDS between 1980 and 2004. They found that people with AIDS had a statistically significant higher risk for all HPV-related cancers.

"Given that individuals currently infected with HIV may obtain little benefit from available HPV vaccines…our results underscore the need for effective screening for cervical cancer and anal cancer among persons with HIV infections or AIDS," the researchers wrote.

The study was published online July 31 in the Journal of the National Cancer Institute.

While it does offer new evidence of the link between HIV/AIDS and HPV-related cancer, the study doesn't actually prove a biological connection, Dr. Howard D. Strickler, of the Department of Epidemiology and Population Health at Albert Einstein College of Medicine, wrote in an accompanying editorial.

SOURCE: Journal of the National Cancer Institute, news release, July 31, 2009