Anal cytology as a predictor of anal intraepithelial neoplasia in HIV‐positive men and women

Abstract

Human immunodeficiency virus (HIV)-infected individuals have increased risk of anal intraepithelial neoplasia (AIN) and squamous cell carcinoma (SCC). Cytologic screening is invaluable in the detection of cervical neoplasia, therefore many clinicians have adopted anal cytology as part of anal cancer screening in patients at high-risk for anal neoplasia. The purpose of this study is to determine whether anal cytology is a valuable screening test for identifying AIN in HIV+ patients. The cohort included 228 HIV+ patients who underwent anal cancer screening with collection of 318 anal cytology specimens between January 2006 and December 2009. Of this group, 74 (32.5%) patients had associated anal biopsies within a 6-month period, with a total of 89 comparison cases. The anal cytology samples were classified using the 2001 Bethesda System terminology. The sensitivity of anal cytology in detecting ASC-US, AIN 1-3 or SCC was 93%. Cytology was 88% sensitive for detecting low-grade AIN (AIN 1), but only 20% sensitive for detecting high-grade AIN (AIN 2-3) or SCC. Atypical squamous cells of undetermined significance cases were distributed evenly between low- and high-grade AIN, with two cases having normal histology. Only six cases had negative cytology, all of which were associated with AIN on biopsy, for a false negative rate of 7%. Anal cytology is a good predictor of AIN, as confirmed by the high degree of sensitivity. However, there is poor correlation between the cytological and histological grade of AIN. Cytology underestimates the grade of dysplasia compared to the corresponding biopsy.

Histopathologic and Cytologic Follow-Up in High Risk Male Patients with Unsatisfactory Anal Cytology

“…Anal cytology is known to underestimate the grade of AIN on biopsy; however follow-up of unsatisfactory anal Pap smears has not been extensively studied [3,10]. Unsatisfactory anal cytology rate of 17.8% in our study is similar to that reported by Morency et al [13].…”

“…However, in people living with HIV/AIDS it is the fourth most common cancer. The incidence of anal cancer in HIV-infected MSM is estimated at 131 per 100,000 personyears and surpasses the rate of cervical cancer in women prior to the initiation of screening [3,4]. The incidence of AIN has not decreased since highly active antiretroviral therapy (HAART) therapy began [5].…”

Oncogenic human papillomavirus is not helpful for cytology screening of the precursor lesions of anal cancers in Taiwanese men who are infected with human immunodeficiency virus

“…The sensitivity of anal cytology to detect AINs of any grade ranges between 68 % by self-collection and 70 % as collected by clinicians in one report [36] and 83 % in another [37], and the sensitivity for identifying high-grade AINs is reported to be 33-39 % [36]. In HIV-positive patients, the sensitivity is as low as 20 % [38] and as high as 84 % [33]. Berry et al [39] demonstrated differences in the sensitivity of anal cytology between HIV-positive and HIV-negative patients.…”

Screening for Anal Cancer in Women

“…97 Many studies have found poor correlation between grade of the cytology report and grade diagnosed on subsequent biopsy. 46,84,97,109-111 This may reflect the difficulty of thorough anal canal cytologic sampling, the skill of the anoscopist and the inherent limitations of HRA and HRA-guided biopsy. 110,112 …”