Comparison of nylon‐flocked swab and Dacron swab cytology for anal HSIL detection in transgender women and gay, bisexual, and other men who have sex with men

Abstract

Background An anal histological high‐grade squamous intraepithelial lesion (hHSIL) is an anal cancer precursor. Experts recommend Dacron swab anal cytology as a primary screen for anal hHSILs, especially among human immunodeficiency virus–infected and –uninfected men who have sex with men (MSM). Studies have shown that Dacron cytology inaccurately predicts anal hHSILs and results in unnecessary diagnostic procedures. Nylon‐flocked (NF) swabs have been shown to trap pathogens and cells well. Thus, this study compared test characteristics of anal cytology using NF and Dacron swab collection protocols to predict anal hHSILs. Methods A single‐visit, randomized clinical trial compared NF and Dacron swab anal cytology specimens to predict high‐resolution anoscopy and biopsy–diagnosed anal hHSILs. Data for 326 gay men, bisexual men, other MSM, and male‐to‐female transgender women contributed descriptive and tabular statistics with which unadjusted and fully adjusted logistic regression models were constructed. The models estimated the odds of hHSILs, test accuracy (area under the curve [AUC]) and sensitivity, and specificity as well as the positive and negative predictive values of abnormal NF and Dacron cytology for predicting hHSILs. Results In the fully adjusted model, the sensitivities for NF and Dacron cytology were nearly equal (48% vs 47%), but the specificity was higher with NF cytology (76% vs 69%). Comparisons of the areas under receiver operating characteristic curves showed that NF cytology alone predicted hHSILs better than the covariate model (AUC, 0.69 vs 0.63; P = .02), but NF and Dacron cytology comparisons showed no statistically significant differences (AUC, 0.69 vs 0.67; P = .3). Conclusions NF cytology and Dacron cytology provide modest sensitivity, but NF cytology has higher specificity and accuracy, and this is important for lowering the costs of population‐based screening.

A systematic review and meta‐analysis of cytology and HPV‐related biomarkers for anal cancer screening among different risk groups

“…Briefly, 4717 articles were identified, after removal of duplicates (n = 863), 3748 were excluded based on title/abstract review. Of the remaining 106 articles, 39 were included after full‐text review (Table 1; Supplemental Material) 12‐50 . Most studies reported data for PLWH (n = 29), 12,13,15,16,18‐34,36‐39,41,43,47,50 a majority were among MSM LWH (n = 18) 12,13,15,16,21,25‐27,29,31‐34,36,38,39,47,50 .…”

Cytology in Anal Cancer Screening: Practical Review for Clinicians

“…However, the study had a very small sample size and no correlation between cytology and histology was reported. A study by Wiley et al [26] (n = 58 MSM) suggested that flocked swabs were better able to predict histological anal HSIL; however, in a more recent study with a larger sample (326 subjects) [27], the sensitivity in predicting anal HSIL was similar between brushes. Thus far, studies have consistently failed to show that flocked nylon swabs are better than Dacron swabs.…”

“…They are approved for use in the endocervical canal of women only [24] and can be uncomfortable in the anal canal. Several studies have compared Dacron swabs and flocked nylon swabs [25][26][27] in terms of the number of cells collected and the performance of anal cytology compared with histology.…”

A eficácia no rastreio do câncer anal através da avaliação retrospectiva de resultados de citologia anal relacionados a dados demográficos e infecções virais intercorrentes

“…Diversos países já têm estudos comparando diferentes métodos de rastreio em grupos populacionais distintos [50][51][52][53][54][55][56] , contudo, muitos viéses ainda são encontrados devido ao grande número de dados clínicos, laboratoriais e comportamentais.…”