Anal Pap Screening in Gay and Bisexual Men

Greater Surveillance Needed in MSM as Anal Cancer Rates Soar

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Photo Credit: David Goehring

For decade, women have had the benefit of a test that helps detect cervical cancer in the early stages of infection. The technology, known as the Pap smear, has saved countless lives by ensuring the early detection and intervention, dramatically reducing the incidence of death in women.

Today, the technology has been expanded to enable the early detection of anal cancer in gay and bisexual men, as well as at-risk women.

What is an Anal Pap Smear?

The anal Pap smear is a test similar to the vaginal Pap smear insofar as a small sample of cells is collected from the anus and rectum. They are then examined under the microscope to identify any structural changes in the cells. These changes are often identified as precursors to anal cancer, a type of cancer which disproportionately affects gay and bisexual men.

The Link Between HPV and Cancer

Anal cancer and cervical cancer are both associated with the human papillomavirus (HPV), the virus of which can cause genital warts that are easily spread from person to person through sexual intercourse.

Gay and bisexual men with HIV are especially at risk because they are at higher risk for persistent HPV infection, which can manifest with a 40-fold increase in the risk of anal cancer compared to the general U.S. population. And unlike other sexually transmitted diseases, condoms are not entirely effective in preventing the spread of the virus.

Studies show that the incidence of anal cancer is much higher in men who have sex with men (MSM) who are HIV positive, with current evidence indicating that

  • 35 of every 100,000 MSM will develop anal cancer.
  • 8 of every 100,000 women will get cervical cancer,

Generally speaking, HIV infection itself is associated with a high risk for the development of many types of cancer, both HIV-associated and non-HIV associated.

The Anal Pap Procedure

The anal Pap smear is very quick, painless and simple. Using a Dacron swab, the clinician collects cell samples from the anal canal by swabbing all surfaces of the anus and rectum. These cell samples are then sent to a lab where technicians prep the samples and examine them under a microscope to identify any cellular changes which may indicate cancer. Generally within a few days, the physician will have the results and be able to discuss them with you.

To ensure an accurate test, guidelines suggest that patients adhere that certain precautions be taken 24 hours before an anal Pap smear is performed:

  • Do not have receptive anal intercourse
  • Do not put any creams, lubricants or medications into your anus
  • Do not insert sex toys or other objects into your anus
  • Do not douche or take enemas

How Often Do You Need an Anal Pap?

Sue Goldie, MD, MPH, the author of a anal PAP study at the Harvard School of Public Health found that screening gay and bisexual men every three years would identify many cases of anal cancer early—when they can most often be treated successfully.

Some clinicians, however, recommend yearly anal Pap smears for MSM, particularly those with HIV. For their part, neither the Centers for Disease Control and Prevention (CDC) nor the U.S. Preventive Services Task Force (USPSTF) currently offer any recommendations regarding routine anal Pap screening in either men or women.

In addition to MSM, any persons with a history of anogenital and vulvovaginal condylomas (warts) should be regularly screened. See what a genital wart looks like.

If the Pap smear is abnormal, the cells in the anal canal will develop abnormal, pre-malignant changes called intraepithelial neoplasms. These changes gradually worsen and, if left untreated, can develop into an invasive cancer.

If abnormal changes are noted, further investigations are performed and, if indicated, surgical laser excision may be used to remove affected tissue.

U.S. Department of Veteran Affairs. "Anal Dysplasia and HIV: Primary Care for Veterans with HIV." October 8, 2011; Washington, D.C.; accessed February 9, 2016.

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