How often should people who have anal sex get screened for anal cancer?
Executive summary
People with HIV are the clearest group for whom repeated anal‑cancer screening is now recommended: federal and specialist guidance calls for at least annual symptom assessment and digital anorectal exam (DARE), with additional lab‑based screening and high‑resolution anoscopy (HRA) for older or higher‑risk patients [1] [2]. International expert consensus (IANS) identifies several high‑risk groups (people with HIV, certain women with prior HPV‑related disease, transplant recipients) and recommends tailored screening strategies using anal cytology, high‑risk HPV testing, co‑testing, and HRA where capacity exists [3] [4].
1. Why frequency matters: risk levels and the ANCHOR result
Screening frequency is tied to risk. People with HIV—especially men who have sex with men (MSM)—have anal cancer incidence rates far above the general population (for example, MSM with HIV ~85 per 100,000 person‑years), a level that drove recommendations to screen this group actively [2] [5]. The ANCHOR trial showed that treating high‑grade precancer (HSIL) lowers progression to anal cancer in people with HIV, which underpins more frequent surveillance and intervention in this population [5] [6].
2. Federal and clinic guidance: annual assessment as the baseline
A U.S. federal expert panel and state HIV clinical guidelines now recommend that all adults with HIV be assessed at least yearly for anal symptoms and undergo DARE; older or higher‑risk people with HIV should receive lab‑based screening (anal cytology and/or high‑risk HPV testing) with referral to HRA for abnormal results [1] [2]. Where HRA is unavailable, continued symptom assessment and DARE remain advised [1].
3. International consensus: rules for who to screen and with what tools
The International Anal Neoplasia Society (IANS) issued consensus guidelines that identify risk thresholds and recommend screening in groups with substantially elevated incidence. IANS endorses multiple acceptable strategies—anal cytology, hrHPV testing including HPV16 genotyping, and co‑testing—and suggests shared decision‑making for some groups (for example, people ≥45 years with prior cervical/vaginal HSIL or cancer or persistent HPV16) if HRA capacity exists [3] [4].
4. Practical frequency recommendations emerging from societies
Although exact intervals vary by guideline and resource availability, clinical practice commonly uses annual assessment for people with HIV and considers annual cytology/HRA‑driven programs for higher‑risk subgroups; for others at elevated but lower risk, some providers suggest screening every 2–3 years [1] [7]. Systematic reviews of recent society recommendations show heterogeneity in target groups and screening intervals, reflecting evolving evidence and local capacity [8] [9].
5. Capacity and tradeoffs: HRA availability shapes frequency and method
IANS and federal guidance both stress that recommended screening approaches depend on having access to diagnostic capacity—HRA, pathology, and treatment—because screening without ability to diagnose and treat precancer is of limited value. Where HRA is limited, programs may prioritize symptom/DARE and targeted lab testing rather than routine HRA for everyone [3] [1].
6. Who else might be screened—and why the picture is mixed
Beyond people with HIV, IANS and some societies include other high‑risk groups: women with prior vulvar HSIL or cancer, transplant recipients, and people with persistent high‑risk HPV findings or perianal warts; these groups may be considered for screening, often with shared decision‑making, and typically at older ages (≥45) when incidence rises [3] [4]. However, not all organizations make universal recommendations for these groups, and guidance emphasizes tailoring to local resources [8].
7. What the evidence gaps and disagreements are
Recent systematic reviews document multiple recommendations but also heterogeneity—different societies advocate differing target populations, methods, and intervals—which reflects ongoing uncertainty and the practical limits of implementing HRA‑based programs broadly [8] [9]. Some sources note that only a minority of jurisdictions have established standard, statewide screening programs [10].
8. Bottom line for people who have anal sex
Available sources do not issue a single, universal screening interval strictly based on sexual practice alone; instead, frequency is determined by measured risk factors—most importantly HIV status, prior HPV‑related disease, and age. For people with HIV: annual assessment and DARE is the clear minimum, with additional lab screening and HRA as indicated [1] [2]. For others with specific HPV‑related histories or transplant status, individualized discussion and risk‑based screening (possibly every 1–3 years) are advised where resources permit [3] [7].
Limitations: guidance and evidence are evolving; recommendations depend on local HRA/treatment capacity and differing society thresholds [8] [3].