CTN 292A: Screening for high-grade anal dysplasia in HIV+ MSM

About The Study

The purpose of this research study is to develop an effective method for determining which HIV-positive men who have sex with men (MSM) should receive a high-resolution anoscopy (HRA) examination to check for abnormal changes in the anal canal (anal dysplasia, or pre-cancer). This study looks to optimize decision making about HIV-positive MSM, through validation of the proposed anal cancer screening algorithm. Participants found to have high-grade dysplasia, described below, will be invited to enroll in CTN 292B which will compare the effectiveness of a surgical treatment versus observation alone for the condition.

About The Disease

HPV is the most common sexually transmitted infection (STI) in the world and is the most common cause of anal cancer. HPV begins as an infection that may not cause any changes in the tissues, but can lead to anal dysplasia, a form of pre-cancer, and in some cases cancer. Pre-cancer is when there are abnormal cells or lesions that have the potential to turn cancerous. In HIV-positive men, the rates of anal HPV infection are very high, and these infections tend to persist longer in these men. As a consequence of the high HPV rates and higher persistence rates, the rates of anal cancer are much higher in HIV-positive men, particularly in men who have sex with men (MSM), compared to the general population. Unfortunately, there has not been enough research done for healthcare professionals to agree on a universal standard for screening for anal HPV, so anal dysplasia can be difficult to manage if detected.

Healthcare professionals are also unsure if treating dysplasia in anal tissues makes a difference in cancer rates. However, women with similar lesions in the cervix do benefit from treatments that get rid of the abnormal cells, usually through a process called ablation (removal of the upper layers of cells with an instrument that burns the area). Similar treatments are offered to men but there is no strong evidence to show that they make a difference in the long-term.

Study Approach

The research team will recruit participants for the trial using an invitation from participating clinics that provide care to HIV-positive MSM. Three thousand MSM will receive an HPV test and an anal Pap smear to screen for signs of anal pre-cancer. Some of these participants will then be offered a high-resolution anoscopy (HRA) to check for more serious abnormal changes in the anal tissues.

By combining anal Pap smear and HPV testing, researchers will analyze the ability of these tests to identify individuals who need further testing. As mentioned, participants found to have high-grade dysplasia will be invited to participate in a treatment clinical trial, CTN 292B.