Anal Cancer Screening for People Living with HIV

Anal cancer is a type of cancer that starts in the anus, which is the opening at the end of the body where stool (poo) leaves. Most anal cancers are caused by a virus called human papillomavirus (HPV) when the infection stays in the body for a long time. (Spindler et al., 2024)

Anal cancer can often be prevented. Most anal cancers develop after a long-lasting infection with HPV, like high-risk HPV types. Before cancer forms, changes can happen in the cells of the anus. These are called precancerous cell changes. Finding and treating these changes early can lower the chance of developing anal cancer. Prevention focuses on regular screening for people at higher risk, follow-up testing when needed, and treating early cell changes before cancer starts or catching cancer in its earlier stages. Taking action early is important because these changes may not cause symptoms at first. (Spindler et al., 2024)

People living with HIV have a higher risk of anal cancer because their immune system may have a harder time fighting infections like HPV. HPV is a very common virus, and some types can cause cancer if they stay in the body for a long time. The International Anal Neoplasia Society (IASN) recommends regular anal cancer screening for people with conditions, including people living with HIV. Screening helps find changes early when treatment works best.

Anal cancer screening can find early cell changes before they turn into cancer. These early changes are not cancer yet, but they can become cancer over time if they are not treated. Finding and treating these changes early can lower the chance of getting anal cancer by more than half. (Palefsky et al., 2022; Stier et al., 2024)

People living with HIV have a much higher chance of getting anal cancer than people without HIV. They are more likely to develop anal cancer than the general population because HIV can weaken the immune system. Screening can find early cell changes before they turn into cancer. These early changes are called high-grade squamous intraepithelial lesions (HSIL), which means cells that are not cancer yet but can turn into cancer if they are not treated. HSIL is easier to treat when found early. (Palefsky et al., 2022)

Anal cancer screening looks for abnormal cells before cancer starts. It is different from colonoscopy, which is used to check for colon cancer. Instead, anal cancer screening is more like a Pap test used to check for cervical cancer. Research shows that finding and treating these early changes can help prevent anal cancer from developing. (Stier et al., 2024)

Early changes in the anus may not cause any symptoms. This is why regular screening is important, even if you feel fine. Sometimes, people may notice symptoms like these (Hong et al., 2025):

These symptoms do not always mean cancer, but they should be checked by a doctor or nurse as soon as possible.

Some other health problems, like hemorrhoids, small tears in the skin (anal fissures), or cancers of the rectum or colon, can cause similar symptoms. Because these problems can feel alike, a doctor or nurse needs to examine you to find out what is causing the symptoms.

Anal cancer screening is recommended for people living with HIV:

These recommendations are based on higher rates of anal cancer in people living with HIV compared to people without HIV. Anal cancer is more often found in people who are immunocompromised or people whose bodies have a harder time fighting infections, such as people living with HIV, and those who are middle‑aged or older.

(Clifford et al., 2020; Stier et al., 2024)

Anal cancer often does not cause noticeable symptoms until it is at an advanced stage, making regular screening essential for people at higher risk. Your doctor or nurse can help determine when screening should begin and how often if should be repeated, based on your personal risk factors and medical history.

People living with HIV may not always be asked about anal cancer screening during regular health visits. If you think screening might be right for you, it is okay to bring it up with your doctor or nurse.

If your doctor or nurse talks to you about screening, they will explain why it may be helpful and what the test is like. You can ask questions such as:

Your doctor or nurse may also ask you questions about your health, any symptoms you have, and other risk factors. This helps them decide if screening is right for you.

If you are not sure how to bring it up, you could say:

Screening can find early cell changes before they turn into cancer, when treatment works best. Screening is often done once a year, but the timing may be different for each person. Your doctor or nurse can help decide the best screening plan for you.

To learn more about the Anal Pap test, visit the Chicago Colon and Rectal Clinic website for additional information and a visual reference.

For a step-by-step educational demonstration of the Anal Pap test performed by a physician with a patient, refer to the IANS Anal Cytology collection video. Please note that this video includes real patients.

(Hirsch et al., 2025)

If either test shows changes that are not normal, your doctor or nurse may send you to a specialist for high resolution anoscopy (HRA) or biopsy to examine the area more closely.

To learn more, see the IANS DARE video, which shows a doctor performing the procedure on a real patient for educational purposes.

If your results are normal, your doctor or nurse may suggest having screening again each year. This can depend on your health and past test results. (Hirsch et al., 2025)

If the results show changes that are not normal, your doctor or nurse may send you to a specialist for more tests. The specialist may use a test called high resolution anoscopy (HRA) to look closely inside the anus. They may also take a very small tissue sample, called a biopsy, if needed. (Spindler et al., 2024)

Biopsy results are reported along a range, including:

Some screening tests can find HSIL. SIL means early cell changes that are not cancer but could turn into cancer over time. Treating HSIL can greatly lower the chance of getting anal cancer. (Hirsch et al., 2025)

Treatment depends on what works best for each person. Options may include: (Palefsky et al., 2022; Hirsch et al., 2025)

Treating HSIL early has been shown to lower the chance of anal cancer by more than half. (Spindler et al., 2024)

Screening results can be normal or abnormal.

If anal cancer is diagnosed, your healthcare team will talk with you about next steps. Treatment plans are made for each person and are based on different factors, such as:

Your doctor or nurse will explain your treatment options, answer your questions, and help you make decisions that are right for you.

(Hirsch et al., 2025)