You have been invited to participate in this research study because you answered an invitation from your doctor to take part in an anal cancer screening program for human immunodeficiency virus (HIV)-positive men who have sex with men (MSM), or have taken part in an existing screening program. You received this invitation from your doctor either through the mail or in-person in the clinical setting. With your recruitment letter you were randomly selected to either receive or not receive an educational brochure to accompany your invitation.
Human papillomavirus (HPV) is the most common viral sexually transmitted infection (STI) in the world, and is the most common cause of anal cancer. The most common HPV types that cause cancer are types 16 and 18 and it may be useful to test for them. Anal cancer is a cancer of the anus which occurs when healthy cells in the area have become abnormal. These abnormal cells then proceed to grow and destroy healthy cells. HPV is the same virus that causes cancer of the cervix in women. HPV starts out as an infection that may not cause any changes in the tissues; at a later stage, there may be abnormal changes in the tissues (called dysplasia or pre-cancer); some dysplasia can progress to cancer. In HIV-positive MSM, the rates of anal HPV infection are very high and the rates of anal cancer are over 100 times the rate in the general population. Unfortunately, by the time men present with symptoms that suggest anal cancer, the cancer is often quite advanced and not easily treated. Thus, it is best to try to detect pre-cancerous changes so that anal cancer can be prevented.
Despite this evidence regarding anal cancer, there is no agreement on how best to detect and manage the anal pre-cancers in MSM. There are no routine screening programs or guidelines and there is no consensus on how best to diagnose these changes in the anus. There are only a handful of physicians in Canada trained to do detection and treatment of HPV-related pre-cancers in MSM. However, physicians working on this study are trained in anal cancer screening and treatment.
You are being invited to participate because HPV-related cancers and pre-cancers are frequent in HIV-positive MSM and there is a need to screen for them. If you agree to participate in this screening study, you will have an anal Pap smear to screen for high-grade (precancerous) anal disease. You will be enrolled with approximately 3,000 other MSM. If your Pap smear shows moderate to severely abnormal cells, called high-grade squamous intraepithelial lesion (HSIL), you will be offered a special anoscopy called High Resolution Anoscopy (HRA). An anoscopy is an exam of the rectum and anus with a small tube inserted into the anus. Approximately 300 men will have HSIL cytology and they will be enrolled in the treatment phase of the study. A subset of men whose Pap smear indicates only low grade (mildly abnormal cells) squamous intraepithelial lesions (LSIL), whose Pap is abnormal, those with a repeat unsatisfactory for diagnosis result, or whose Pap is normal will be randomized and also be invited to have HRA. The purpose of this research study is to improve decisions about which HIV-positive MSM should have HRA.
The purpose of this research study is to optimize decision making about which HIV-positive MSM should be sent to HRA.