Anal Pap Screening Guidelines for HIV-Negative Men
Current guidelines do not recommend routine anal Pap smear screening for HIV-negative men due to insufficient evidence supporting its effectiveness in reducing anal cancer morbidity and mortality. 1
Risk Assessment for Anal Cancer in HIV-Negative Men
The risk of anal cancer varies significantly based on specific risk factors:
- General population: 1-2 cases per 100,000 person-years 1
- HIV-negative MSM: 14 cases per 100,000 person-years 1
- HIV-positive MSM: 80-131 cases per 100,000 person-years 1, 2
Key Risk Factors in HIV-Negative Men
- History of receptive anal intercourse 1, 2
- Previous HPV-related genital dysplasia or cancer 2
- Presence of genital warts 2
- History of immunosuppression (non-HIV related) 3
Current Screening Recommendations
Digital Anorectal Examination (DARE)
- For HIV-negative MSM with history of receptive anal intercourse: Annual DARE may be useful to detect masses on palpation 1
- DARE is acceptable to patients and has a low risk for adverse outcomes 1
- No specific guidelines exist for initiation age or examination intervals 1
Anal Cytology (Anal Pap)
- Not routinely recommended for HIV-negative men in the general population 1, 4
- Data are insufficient to support routine anal cancer screening with anal cytology among HIV-negative men 1
- Some clinical centers perform anal cytology for high-risk populations (primarily HIV-positive individuals and MSM with history of receptive anal intercourse) 1
Considerations for Selective Screening
If considering anal Pap testing for high-risk HIV-negative MSM, important limitations to consider:
- Sensitivity of anal cytology in HIV-negative males ranges from 26-47% 3
- Specificity ranges from 81-92% 3
- Health centers should only initiate cytology-based screening if referrals to high-resolution anoscopy (HRA) and biopsy are available 1
Prevention Strategies
HPV Vaccination
- Recommended for all males aged 9-21 years 1
- Males aged 22-26 years should also be vaccinated if not previously vaccinated 1
- HPV vaccination is highly effective in preventing infection with HPV subtypes responsible for approximately 70% of anal cancers 1
- No therapeutic effect on pre-existing anal dysplasia 1, 2
Management of Abnormal Findings
If anal cytology is performed and abnormal results are found:
- Referral for high-resolution anoscopy (HRA) is recommended 1
- Biopsy of any abnormal areas should be performed 1
- Treatment should be based on biopsy results 1, 2
Research Gaps
- More evidence is needed regarding the natural history of anal intraepithelial neoplasia in HIV-negative men 1
- Optimal screening methods and target populations remain undefined 1, 4
- Ongoing clinical trials are investigating whether treatment of high-grade squamous intraepithelial lesions (HSIL) reduces anal cancer incidence 1
Conclusion
While anal cancer screening with anal Pap tests is being studied in high-risk populations, current guidelines do not support routine screening for HIV-negative men. Annual digital anorectal examination may be considered for HIV-negative MSM with a history of receptive anal intercourse, but more research is needed before broader screening recommendations can be made.