amfAR, The Foundation for AIDS Research

Thai MSM Clinic Conducts Innovative Studies of Anal Cancer and HIV

February 2010—Among HIV-positive men who have sex with men (MSM), the risk of anal cancer associated with human papillomavirus (HPV) is twice the level of those who are HIV negative, according to research conducted in the US. Unlike many cancers, anal cancer is potentially preventable, but many MSM are unaware of their risk of acquiring HPV and do not know to seek Pap smear screening.

In Asia, where very little research has been done on this issue, anal cancer among HIV-positive MSM has been largely overlooked and untreated. That has now begun to change, thanks to an ongoing study conducted by the Thai Red Cross AIDS Research Center in Bangkok.

In 2008, this TREAT Asia Network site established an anonymous MSM sexual health clinic providing screening and treatment for sexually transmitted infections, anal Pap smear testing, treatment of abnormal anal Pap smears, and risk reduction counseling. Funding from amfAR's MSM Initiative allowed investigators to offer the Pap smears free of charge and facilitated the purchase of a high-resolution anoscope, which allowed researchers to better evaluate patients with abnormal Pap smears.


Brochures about sexual health for MSM. (Photo: Thai Red Cross).

Analyzing the results of their early testing, researchers found that a high percentage of MSM had abnormal results—and at a much younger age than in the US (30 years and under, compared to 40-45 years in the US). In addition, HIV-positive MSM showed significantly higher rates of precancerous lesions (dysplasia) than those without HIV (18 percent versus five percent).

These findings led investigators, under the guidance of Nittaya Phanuphak, M.D., to propose additional research to better characterize the problem of anal dysplasia and HPV infection among MSM. "Recognizing this as an emerging issue for HIV-positive MSM in Asia," said TREAT Asia director Annette Sohn, M.D., "we were able to help obtain funding for the next phase of their research through the US National Institutes of Health's IeDEA program" (Click here to read more about TREAT Asia’s cancer research efforts.)

The first round of this new support sponsored a study of the clinical epidemiology of anal cancers among MSM. The second phase, which began in December 2009, involves basic biomedical research looking at biomarkers to provide scientific clues about how to better identify MSM with pre-cancerous anal lesions and why some men are developing persistent infection with HPV and disease progression. "We are hoping to see some interesting preliminary results from this stage of the project, which could lead to its further expansion," Dr. Nittaya indicated.

"This is an innovative study for the region, and clearly necessary in light of Asia's MSM-driven epidemic," said Dr. Sohn. "These researchers are taking the science to a higher level that will teach us how to manage patients more comprehensively."