What are the anal cancer screening recommendations for Human Immunodeficiency Virus (HIV)-positive women?

Anal Cancer Screening Recommendations for HIV-Positive Women

Annual digital anorectal examination (DARE) is recommended for HIV-positive women to detect early anal cancer, while routine anal cytology screening lacks sufficient evidence for universal recommendation but may be considered for those with additional risk factors. 1

Risk Assessment for HIV-Positive Women

HIV-positive women have a significantly elevated risk of anal cancer compared to the general population:

• Incidence rate of 20-30 cases per 100,000 person-years in HIV-positive women versus 1-2 cases per 100,000 person-years in the general population 1, 2
• Risk is further increased in women with:
  • History of abnormal cervical Pap test results 1
  • History of receptive anal intercourse 1
  • Previous HPV-related genital dysplasia/cancer (6-63 cases per 100,000 person-years) 1, 2
  • Presence of genital warts 1

Recommended Screening Approach

Primary Screening Method:

• Annual digital anorectal examination (DARE) to detect masses on palpation 1, 2
  • Simple, low-risk procedure with high acceptability to patients 1
  • Essential clinical tool for detection of lesions in the anal area 1

Additional Screening for Higher-Risk Subgroups:

Anal cytology (anal Pap test) should be considered for HIV-positive women with:

• History of abnormal cervical Pap test results 1
• History of receptive anal intercourse 1
• Previous HPV-related genital dysplasia or cancer 2
• Presence of genital warts 1

Management of Abnormal Findings

If abnormal findings are detected through DARE or anal cytology:

1. Referral for high-resolution anoscopy (HRA) with biopsy of suspicious lesions 1, 2
2. Targeted biopsy of anal lesions suspicious for anal intraepithelial neoplasia (AIN) to exclude invasive disease 1
3. Treatment based on biopsy results 1, 2

Important Considerations and Caveats

• Health centers that initiate cytology-based screening programs should only do so if referrals to HRA and biopsy are available 1
• Sensitivity and specificity of anal cytology to detect high-grade squamous intraepithelial lesions (HSIL) are limited (sensitivity 55%-89% and specificity 40%-67%) 1, 2
• Female patients with AIN should be screened for synchronous cervical, vulvar, and vaginal intraepithelial neoplasia 1, 2
• Recent evidence from a Northern Italian cohort study shows that despite high prevalence of anal HPV infection and associated abnormalities in HIV-positive women, screening uptake was notably low (45.3% refused testing) 3
• Older age, lower nadir CD4 counts, and previous history of cervical HPV-related disease were identified as significant risk factors for HSIL and anal cancer 3

Prevention Strategies

• HPV vaccination is recommended for all females aged 9-26 years 1
• HPV vaccination appears to offer protective benefits against high-risk HPV infections even in HIV-positive individuals 3
• Vaccination has no therapeutic effect on preexisting cervical or anal dysplasia 1

Emerging Evidence and Future Directions

The International Anal Neoplasia Society (IANS) recently developed consensus guidelines recommending:

• Screening initiation at age 45 years for people with HIV (other than MSM and transgender women) 4
• Anal cytology, high-risk HPV testing (including genotyping for HPV16), and HPV-cytology co-testing as acceptable screening strategies 4

The ongoing Anal Cancer HSIL Outcomes Research (ANCHOR) study is investigating whether treating HSIL affects anal cancer incidence, which may provide more definitive evidence for screening recommendations in the future 5.