Introduction

There is growing interest in anal cancer screening strategies. However, cytological/molecular evaluation of anal samples is challenging. We aimed to determine the feasibility of detecting, in anal liquid-based cytologies, the expression of biomarkers involved in the cell cycle disturbance elicited by human papillomavirus (HPV). The accuracy of this approach in the identification of high-grade squamous intraepithelial lesions/anal intraepithelial neoplasia grade2-3 (HSIL/AIN2-3) was also evaluated. 215 anal cytologies from men having sex with men living with human immunodeficiency virus were evaluated.

Methods

For this cross-sectional study, anal cytology samples, collected in the Anal Cancer Prevention Unit from January to December 2016 from men who have sex with men living with HIV, were retrieved from the Department of Pathology of the Hospital Clinic. Patients showing concordant cytological and anoscopy-directed biopsy diagnosis were selected: 70 with negative cytology and HPV test, 70 with low-grade SIL (LSIL/AIN1) cytology and biopsy, and 75 with cytology and biopsy of HSIL/AIN2-3. CDKN2A/p16, MKI67 and TOP2A mRNA expression was analyzed. HPV detection was performed with Xpert HPV Assay (Cepheid, Sunnyvale, CA). The data were analyzed with the SPSS program (Version 24.0).

Results

The mRNA expression was significantly higher in HSIL compared with LSIL and negative samples for the three biomarkers: TOP2A (p= 0.043 and p=0.030, respectively), MKI67 (p=0.011 and p<0.001, respectively) and CDKN2A/p16 (p=0.011 and p<0.001, respectively). The specificity for HSIL/AIN2-3 detection for a sensitivity established at 70% was 44.7% (95%confidence interval [CI] 36.5-53.2) for TOP2A and MKI67 and 54.5% (95%CI 46.0-62.8%) for CDKN2A/p16.

Conclusions

mRNA detection of cell biomarkers in anal liquid-based cytology is feasible. Further studies are warranted to confirm if strategies based on mRNA detection have any role in anal cancer screening.

This work was supported by the Instituto de Salud Carlos III (ICSIII)-Fondo de Investigación Sanitaria and ERDF ‘One Way to Europe’ (grants PI15/00546 and PI17/00772).