Anal Cancer Screening in High-Risk Populations: A Review of the Clinical Utility, Diagnostic Accuracy, Cost-Effectiveness, and Guidelines


Project Status:
Project Line:
Health Technology Review
Project Sub Line:
Summary with Critical Appraisal
Project Number:


  1. What is the clinical utility of cytology-based anal cancer screening techniques in high-risk populations?
  2. What is the comparative diagnostic accuracy of cytology-based anal cancer screening techniques versus digital rectal exam or standard anal scope in high-risk populations?
  3. What is the cost-effectiveness of cytology-based anal cancer screening techniques in high-risk populations?
  4. What are the evidence-based guidelines for anal cancer screening in high-risk populations?

Key Message

This review was comprised of one systematic review of evidence-based guidelines, one non-randomized study, one diagnostic test accuracy study, and two economic evaluations regarding cytology-based anal cancer screening techniques in high-risk populations.Evidence of limited quality from one non-randomized study indicated that a population of adults with a confirmed diagnosis of HIV who underwent a structured anal cancer screening program (which consisted of digital rectal examination and annual cytological testing) had decreased incidence of invasive anal squamous cell carcinoma compared to those who were not screened. One diagnostic test accuracy study suggested that screening with standard anoscopy was significantly less likely to detect high-grade intraepithelial neoplasia than screening with anal cytology. The two economic evaluations concluded that the use of cytology-based screening techniques may be cost-effective in high-risk populations. The findings of one economic evaluation suggested that screening women with a new diagnosis of cervical cancer using a combination of human papillomavirus testing and anal cytology may be cost-effective for the prevention of deaths due to anal cancer, depending on willingness-to-pay and time horizons. The second economic evaluation demonstrated screening women with a previously detected cervical intraepithelial neoplasia using anal cytology was 95% likely to be cost-effective at a willingness-to-pay threshold of C$45,500 per life-year gained.As for evidence-based guidelines, the systematic review identified two guidelines that made specific recommendations regarding the provision of anal cancer screening in-high risk populations. One guideline recommends the use of digital rectal examination with or without a Papanicolaou test every one to three years in HIV-positive men who have sex with men (the strength of the recommendation was not reported). The second guideline recommends that an annual digital anal examination may be useful to detect masses on palpation that could be anal cancer (moderate strength recommendation; the target population was not specified). Both of these recommendations were based on expert opinion.The limitations of the available literature, such as the current lack of randomized controlled trials, and of this report should be considered when interpreting the results.