HPV Testing for Anal Warts
HPV testing is not recommended for routine diagnosis or management of visible anal warts, as it would not alter clinical management of the condition. 1
Diagnosis of Anal Warts
- Visual examination is the primary and sufficient diagnostic method for genital/anal warts, which are predominantly caused by HPV types 6 and 11 (low-risk types) 2, 1
- Biopsy is indicated only in specific circumstances:
- The application of acetic acid is not a specific test for HPV infection and is not recommended as a screening procedure 2
Management of Anal Warts
- First-line treatments for anal warts include:
- Cryotherapy with liquid nitrogen
- TCA or BCA 80-90% applied only to warts
- Surgical removal 2
- Intra-anal warts should be managed in consultation with a specialist 2
- Many persons with warts on the anal mucosa may also have warts on the rectal mucosa, warranting inspection of the rectal mucosa by digital examination, standard anoscopy, or high-resolution anoscopy 2
HPV Testing and Anal Cancer Risk
- While HPV testing is not recommended for visible anal warts, certain high-risk populations may benefit from anal cancer screening due to increased risk:
- Men who have sex with men (MSM) with HIV infection (80-131 cases per 100,000 person-years)
- Men with HIV infection (40-60 cases per 100,000 person-years)
- Women with HIV infection (20-30 cases per 100,000 person-years)
- MSM without HIV infection (14 cases per 100,000 person-years) 2
- The presence of perianal warts has been associated with an increased risk of anal HPV 16 detection and anal dysplasia, particularly in HIV-positive MSM 3
- Studies have found that HSIL (high-grade squamous intraepithelial lesion) may be detected in approximately 14.5% of biopsies from intra-anal warts 4
Screening Considerations in High-Risk Groups
- An annual digital anorectal examination (DARE) might be useful to detect masses in persons with HIV infection and possibly in MSM without HIV with a history of receptive anal intercourse 2
- Data are insufficient to recommend routine anal cancer screening with anal cytology in the general population or even in high-risk groups 2
- Some clinical centers perform anal cytology for high-risk populations followed by high-resolution anoscopy (HRA) for abnormal results, but sensitivity and specificity of anal cytology to detect HSIL are limited (sensitivity 55-89% and specificity 40-67%) 2
Important Counseling Points
- HPV infection is very common, with most sexually active adults acquiring HPV at some point 2
- The types of HPV that cause genital warts (types 6 and 11) are different from the high-risk types that can cause cancer 2
- Treatment targets visible warts but does not eliminate the virus itself 2
- Recurrence is common (approximately 30%), regardless of treatment method 1
- Correct and consistent condom use might reduce but does not eliminate transmission risk 2
Special Considerations
- In immunocompromised patients, particularly those with HIV:
- Warts may be larger or more numerous
- Response to therapy may be poorer
- Recurrence rates may be higher
- Risk of squamous cell carcinomas arising in or resembling genital warts is increased 2
- HPV vaccination (Gardasil) is recommended for prevention and protects against HPV types 6 and 11 (which cause 90% of genital warts) as well as types 16 and 18 (which cause most HPV-related cancers) 2, 5
Common Pitfalls to Avoid
- Using HPV DNA testing for screening in men, partners of women with HPV, adolescent females, or for conditions other than cervical cancer 2
- Assuming HPV infection indicates sexual infidelity, as the virus can remain dormant for long periods 2
- Using acetic acid soaks as a screening test for subclinical HPV infection due to high false-positive rates 1