Acceptability of High-Resolution Anoscopy for Anal Cancer Screening in HIV-infected Patients

JO Lam; GM Barnell; M Merchant; CG Ellis; MJ Silverberg


HIV Medicine. 2018;19(10):716-723. 

In This Article

Abstract and Introduction


Objectives: HIV-infected individuals are at increased risk of anal cancer. Screening for anal cancer precursors using high-resolution anoscopy (HRA) may be clinically beneficial. In this study, we examined patient tolerability of this procedure.

Methods: The acceptability of HRA was evaluated among HIV-infected patients who completed a first-time HRA between July 2008 and December 2013 at Kaiser Permanente Northern California. We reviewed electronic medical records to identify lack of HRA acceptability, which was defined as receipt of HRA with sedation, dispensation of opioid analgaesia, and/or an urgent care visit following HRA, and to evaluate factors associated with patients not returning for a recommended repeat HRA (proxy for HRA acceptability). HRA acceptability was also assessed via a survey mailed to patients who completed HRA between January 2014 and August 2014. Logistic regression was used to model lack of acceptability of initial HRA and likelihood of not returning for a repeat HRA.

Results: Of 1857 HIV-infected patients, 94 were prescribed opioids and one had an urgent care visit. Lack of HRA acceptability was more likely in patients with pre-existing anal conditions [e.g. warts or fissure; adjusted odds ratio (aOR) 4.02; 95% confidence interval (CI) 2.4–6.7], those who had ever smoked (aOR 1.6; 95% CI 1.0–2.5) and women (aOR 5.3; 95% CI 1.6–17.5). Fifty per cent of patients returned for a repeat HRA, with younger patients less likely to return (per 10–year age interval, aOR 0.8; 95% CI 0.7–0.9). Of 48 survey respondents, 91.7% reported acceptable pain levels and all reported willingness to return for a repeat HRA.

Conclusions: HRA was generally well tolerated and may be an acceptable screening approach for patients at high risk of anal cancer.


Anal cancer is rare in the general population, with an annual incidence between one and two cases per 100 000 in the USA and most other settings,[1,2] but disproportionately affects people with HIV infection (PWH), who experience an approximately 28–fold increased risk.[3] HIV-infected men who have sex with men (MSM) have the highest incidence of disease (131 cases per 100 000 annually)[4] and account for an estimated 83% of the excess cases among PWH.[5] In fact, the rates of anal cancer among HIV-infected MSM are several fold higher than cervical cancer rates among women before the widespread adoption of routine Papanicolaou (Pap) screening.[6,7] Furthermore, like cervical dysplasia, anal dysplasia is typically asymptomatic and patients often present clinically at advanced stages of disease, resulting in poor prognosis.[8]

Given that anal cancer has been described to arise from a dysplastic precancerous phase,[9,10] early detection and treatment of squamous intraepithelial lesions (SILs) may reduce anal cancer incidence,[11] although the practicality and utility of implementing such a screening strategy have been debated. Currently, no established national guidelines exist for early detection and prevention of anal cancer,[12] even in high-risk groups. However, based on the model for cervical cancer screening and prevention, health care practitioners experienced in the care of PWH often recommend patients with abnormal anal cytology for further evaluation using high-resolution anoscopy (HRA), an out-patient procedure which consists of magnified visual examination of the anus with biopsy of suspicious lesions for pathological diagnosis, and treatment of these same lesions as needed.

Although HRA is, in principle, analogous to cervical colposcopy,[10] visualization of the anal canal is considerably more complicated given the convoluted physiology and multiple mucosal folds of the anal tract.[13] Complications of biopsy may include bleeding, infection and pain.[13] For HRA to be successful as a cancer prevention strategy, it needs to be both effective and tolerable to the target patient population. While previous studies have examined the clinical utility and performance of HRA,[11,14–21] few have documented patient experience with HRA, including the tolerability of discomfort during the procedure and postprocedure pain, as well as patient willingness to undergo routine or follow-up HRA.[14,22,23]

Using both electronic health record (EHR)–based and patient survey-based measures, we evaluated the acceptability of HRA among HIV-positive patients who received their first HRA procedure as part of an anal cancer screening programme in a large integrated health care system. Given that the tolerability of an HRA procedure could significantly impact patient compliance with screening, we also evaluated potential predictors of patients not returning for a recommended repeat HRA.