Anal cancer screening: who is offered it, the tests, and what results mean
Anal cancer is not common in the United States, so screening the general public is not widely recommended. (ACS, 2025) The International Anal Neoplasia Society (IANS) recommends screening for higher-risk groups, starting at ages and times that depend on the group. (IANS, 2024)
What screening looks for
Most anal cancers are related to HPV infection. (MedlinePlus, anal cancer) Similar to cervical cancer, anal cancer is preceded by high-grade squamous intraepithelial lesions (HSIL), a precancerous growth also known as anal intraepithelial neoplasia (AIN) 2 or 3. (ANCHOR, 2022) The rate of anal cancer is substantially higher among people living with HIV than in the general population. (ANCHOR, 2022) MedlinePlus lists a weakened immune system, from conditions such as HIV or from medicines needed after an organ transplant, and a history of vulvar, vaginal or cervical cancer among the things that make anal cancer more likely. (MedlinePlus, anal cancer)
Who is offered screening, and from when
IANS based its 2024 guidelines on anal cancer rates by age in each risk group. Its recommendations: (IANS, 2024)
| Group | When IANS says to start |
|---|---|
| Men who have sex with men (MSM) and transgender women with HIV | Start at age 35. (IANS, 2024) |
| Other people with HIV | Start at age 45. (IANS, 2024) |
| MSM and transgender women without HIV | Start at age 45. (IANS, 2024) |
| Solid organ transplant recipients | Start 10 years after the transplant. (IANS, 2024) |
| People with a history of vulvar precancer or cancer | Start within 1 year of that diagnosis. (IANS, 2024) |
| Age 45 or older with a history of cervical or vaginal HSIL or cancer, perianal warts, persistent (more than 1 year) cervical HPV16, or autoimmune conditions | Could be considered, with shared decision-making, where there is enough capacity for high-resolution anoscopy. (IANS, 2024) |
ACS lists men who have sex with men (regardless of HIV status), people who have had penile, cervical, vaginal or vulvar cancer, anyone with HIV, and anyone who is immunocompromised (such as after an organ transplant or with long-term steroids) as people at increased risk who might benefit from screening. Some experts also recommend screening for anyone with a history of anal warts and for women older than 45 who are HPV-16 positive. (ACS, 2025)
The tests
- Anal cytology (anal Pap test): much like a Pap test for cervical cancer. The anal lining is swabbed, and the cells that come off on the swab are looked at closely in the lab. (ACS, 2025)
- High-risk HPV test: IANS lists anal cytology, high-risk HPV testing (including genotyping for HPV16) and HPV-cytology co-testing as screening strategies that show acceptable performance. (IANS, 2024)
- Digital rectal exam (DRE): the doctor inserts a gloved, lubricated finger into the anus to feel for unusual lumps or growths. A DRE can find some anal cancers early. (ACS, 2025)
- Anoscopy and high-resolution anoscopy (HRA): an anoscopy is an exam of the anus and lower rectum using a short, lighted tube called an anoscope. High-resolution anoscopy adds a magnifying device called a colposcope. (MedlinePlus, anal cancer) If an abnormal area is seen during the anoscopy, a biopsy may be done at that time. (NCI, diagnosis)
For more on the matching cervical tests and their result terms, see Pap and HPV test results.
What results mean in general terms
- Abnormal screening test: IANS sets out which screening results should lead to high-resolution anoscopy and which to a follow-up screening test. (IANS, 2024) In the ANCHOR trial, areas that looked like HSIL or cancer on high-resolution anoscopy were biopsied. (ANCHOR, 2022)
- HSIL (AIN 2 or 3) on biopsy: a precancerous growth. In a meta-analysis cited by the ANCHOR investigators, the risk of progression from anal HSIL to cancer was estimated at 265 per 100,000 person-years. (ANCHOR, 2022)
- The ANCHOR trial: in 4,446 people with HIV aged 35 or older with biopsy-proven anal HSIL, the rate of progression to anal cancer was 57% lower with HSIL treatment than with active monitoring. (ANCHOR, 2022)
How often to repeat screening is not settled: the anal Pap test has not been studied enough to know how often it should be done, or whether finding AIN early lowers anal cancer risk, and there is no widespread agreement on the best schedule. (ACS, 2025)
MedlinePlus, signs and symptoms of anal cancer may include: (MedlinePlus, anal cancer)
- Bleeding from the anus or rectum
- A lump near the anus
- Pain or pressure in the area around the anus
- Itching or discharge from the anus
- A change in bowel habits, such as narrower stools, having to go more often, or bowel incontinence
Where they differ:
- IANS (international, 2024): screening for the risk groups in the table, starting at 35 for men who have sex with men and transgender women with HIV and at 45 for other people with HIV. (IANS, 2024)
- MedlinePlus (US): adults with HIV should get anal cancer screening every year, including a digital rectal exam, with anoscopy or high-resolution anoscopy if anything unusual is found. (MedlinePlus, anal cancer)
- ACS (US): screening the general public is not widely recommended; some experts recommend an anal Pap test every year for at-risk people with HIV and every 2 to 3 years for at-risk people without HIV, but there is no widespread agreement on the schedule or exactly which groups benefit. (ACS, 2025)
- NCI (US): studies suggest that using anoscopy to screen for anal cancer could reduce deaths from the disease in people who are HIV positive. (NCI, prevention)
- USPSTF (US): anal cancer screening is an inactive topic; a draft research plan was posted on December 8, 2022, and the Task Force will not move to an evidence review at this time. (USPSTF)
- UK NSC (UK): the recommendation is archived because anal cancer is overwhelmingly confined to high-risk groups, which puts that population outside the committee's remit. (UK NSC)
For HIV testing itself, see HIV test results; for other checks by age, see sexual health screenings by age.
Your doctor decides what your result means for you.
This page does not give treatment advice. If you have an abnormal result, see after an abnormal screening result for questions to ask.
Questions people ask
Who should get anal cancer screening?
Screening the general public is not widely recommended. The IANS 2024 guidelines recommend screening for higher-risk groups: people with HIV (from 35 or 45 depending on the group), men who have sex with men and transgender women without HIV (from 45), solid organ transplant recipients (from 10 years after transplant) and people with a history of vulvar precancer or cancer. (ACS, 2025) (IANS, 2024)
What is an anal Pap test?
Anal cytology, also called an anal Pap test, is much like a Pap test for cervical cancer: the anal lining is swabbed and the cells are looked at closely in a lab. It can be followed by a digital rectal exam or an anoscopy. (ACS, 2025)
What does HSIL mean on an anal test?
HSIL (high-grade squamous intraepithelial lesion) is a precancerous growth, also known as anal intraepithelial neoplasia (AIN) 2 or 3. Anal cancer is preceded by HSIL, similar to cervical cancer. (ANCHOR, 2022)
How often is anal cancer screening done?
There is no widespread agreement on the best schedule. ACS says some experts recommend an anal Pap test every year for at-risk people with HIV and every 2 to 3 years for at-risk people without HIV. MedlinePlus says adults with HIV should get anal cancer screening every year. (ACS, 2025) (MedlinePlus, anal cancer)
Does the USPSTF recommend anal cancer screening?
No. The USPSTF lists anal cancer screening as an inactive topic: a draft research plan was posted in December 2022, and the Task Force decided not to move to an evidence review at this time. (USPSTF)