Hello, Human papilloma virus (HPV) is the most common sexually transmitted disease. Infection sometimes causes genital warts and/or warts on or around the anus and inside the rectum. Sometimes HPV has no visible symptoms. HPV is associated with a variety of cancers - most significantly cervical and "anal squamous cell carcinoma" which is basically cancer of the anus.
It's been known for some time that sexually transmitted HPV can cause cervical cancer in womencalled cervical squamous cell carcinoma (CSCC).
There are many subtypes of HPV. CSCC is usually associated with subtypes 16 and 18. The incidence of cervical carcinoma has been dramatically lowered since the association between HPV and cervical cancer was discovered and understood. This discovery led to the determination that regular pap smears (a test where cells from the lining of the cervix are sampled and tested in a laboratory) can detect HPV infection before the development of cancer and subsequent treatment involving the removal of affected tissue can prevent the development of cervical cancer.
Studies have shown that men who have sex with men (and women who engage in anal sex) can also develop HPV infection - as well as a kind of carcinoma similar to cervical cancers, called anal squamous cell carcinoma (ASCC). HPV can also be spread digitally from cervical infection in women and by use of contaminated sex toys in men and women. More women than men develop anal cancer, and it is as common in men now as it was in women before routine screening for cervical cancer with pap smears.
There is now evidence that anal pap smears can detect anal HPV infection. Although the research is limited, many clinicians feel that anal pap smears can detect early infections and thereby prevent the development of anal cell carcinoma with treatment of the infected areas.
An anal pap smear is a simple procedure that involves sweeping a small moist Dacron swab around the anus a few centimeters in from the opening of the anus (anal verge) where anal mucosa and skin meet, gathering cells. This sample is then sent to a lab for what is called for a cytological examination. This test looks for evidence of HPV infection and cells that look as if they may already be progressing toward the development of ASCC.
Those for whom such screening is felt appropriate are:
People with HIV (men and women). Gay men and MSM who are sexually active particularly with multiple partners and engage in anal intercourse. Women with cervical cancer, evidence of HPV infection, or who have had anal intercourse Others who are immunosuppressed such as transplant recipients.
Studies that have tried to determine the appropriate frequency of screening suggest that people with HIV should be screened once a year. Other people at risk should be screened every 2-3 years.
Anal pap smears are a recent practice and have not become a routine standard of care. There are no official guidelines that recommend this except for the clinical guidelines published by the New York AIDS Institute. This is a new idea in prevention and has not been extensively studied. It is based on the idea that what we know about cervical cancer and its relationship to HPV may well mirror anal cancer and its relationship to HPV.
Screening with anal pap smears is reasonable as it is generally an easy procedure, and there is treatment available for both precancerous HPV infection as well as early forms of cancer.
While anal pap smears are done to prevent the development of anal cancer or find it early (when treatment is easier and most effective) the mainstay for detection of anal carcinoma is still an old fashioned rectal examination that looks for any abnormal masses in the anal area.
An unanswered question, but one which is now under study is whether all young men and women should have a vaccine to prevent HPV infection prior to becoming sexually active. Such a vaccine is now recommended for young women.
Download a fact sheet on HPV in men
