For people with HIV

Anal cancer is caused by HPV, a common virus that most people get at some point. In most people, the infection clears by itself. In some, it remains and can slowly cause changes in the cells of the anal canal. These changes can be found and treated long before they become cancer. Some groups, including people with HIV, have a higher risk. Today there is no screening for anal cancer in Sweden. SANCA studies whether screening would work, and how it should be designed.

• Women with HIV aged 45 and older who attend the HIV clinic at Karolinska University Hospital, Södersjukhuset or Sahlgrenska University Hospital.
• From 2027: transgender and non-binary people with HIV aged 18 and older at the same clinics.

• You take a simple swab from the anus and, where relevant, from the vagina yourself. It takes a few minutes and is done at your regular visit.
• You give a blood sample, usually together with your regular blood tests.
• You answer a questionnaire on your own phone, through a QR code.
• If your HPV test is negative, you are offered a new test after one year.

A positive HPV test does not mean you have cancer. Most people with HPV never get cancer. If the test shows HPV in the anus, you are offered an examination of the anal canal with a flexible instrument that is approximately 1 cm in diameter about 5-7 cm into the anal canal. To reduce any discomfort, an anesthetic cream is used. If the examination finds precancerous changes, they are removed during the same procedure or at a later visit. If the test shows HPV in the vagina, you are referred to a gynaecologist according to routine care. If you are treated for precancerous changes, you are also offered HPV vaccination.

Your information is stored under a study number, not your name or personal identity number. The key linking the study number to you is kept at your hospital, not by the researchers. Data are stored on a secure server at Karolinska Institutet, and only researchers working with the analyses have access. Results are only published at group level, so no individual can be identified. The study has been approved by the Swedish Ethical Review Authority (decision numbers 2025-03075-01, 2025-07071-02 and 2026-01005-02).

You decide whether to take part. You can stop at any time, without giving a reason and without it affecting your care. If you want to stop, or want to know what information about you is stored, speak to your HIV clinic or the study's research nurse.

If you take part, you are tested for anal HPV, and precancerous changes can be found and treated early. That is a direct benefit, and it is not available as routine care today. The study also has a longer-term benefit: the results will help decide how anal cancer screening should be offered in Sweden to people at high risk.