In the United States, the rate for anal cancer in the general population is 1 case per 100,000 people; among HIV-negative men who have sex with men the rate increases to 35 cases per 100,000 people.
For HIV-positive gay and bisexual men, the rate is estimated to be between 75 to 115 cases per 100,000 people. It seems to affect those of us who have lived longer with HIV, have had detectable HIV viral load for a few years, have had anal warts (debatable) and/or had lower CD4 cells in our HIV infection.
There is good evidence that HPV causes many cases of anal cancer. More than 100 subtypes of HPV have been found. The subtype known as HPV-16 is often found in anal cancer lesions and is also found in some anal warts. Another type, HPV-18, is found less often. Most anal warts are caused by HPV-6 and HPV-11. Warts containing HPV-6 or HPV-11 are much less likely to become cancerous than those containing HPV-16. Some reports show that many HIV+ long term survivors have been exposed to many HPV genotypes, including the oncogenic (cancer producing) ones.
There are really no guidelines yet about how to diagnose and treat anal dysplasia. The University of California in San Francisco is leading the way in studying different methods of detection. They are researching three forms of tests: an anal Pap smear (where the doctor swabs an area of the anus to remove surface cells), a high resolution anoscopy (where a doctor uses a special microscope to look at the anus), and a biopsy (where the doctor scrapes away an area of the anus to remove surface cells).
The good news is that a 5-year study designed by Dr. Joel Palefsky and his team is now enrolling patients to study the long term effect of performing high resolution anoscopies (HRA) and infrared coagulation (IRC) in HIV+ men and women with dysplasia versus not performing the IRC to determine if IRC is an effective way to prevent progression to cancer.
I had the pleasure and honor to interview Dr. Palefsky, one of the world’s experts on HPV infection in HIV+ people, and Jeff Taylor, the nation’s top HPV/HIV activist. I think everyone will agree with me that this video includes most of the information needed to proactively prevent and/or treat HPV related anal cancer as we age with HIV. You can also find out information on how to volunteer to be monitored in Dr. Palefsky study.