The added value of digital imaging to reflex cytology for triage of high-risk human papillomavirus positive self-sampled material in cervical cancer screening: A prospective cohort study

Abstract

Objective: Cytology performed directly on hrHPV-positive self-samples (reflex cytology) is feasible and for women with abnormal cytology, an additional cytology test at the general practitioner could be omitted. The aim of this study is to assess the added value of digital imaging (ThinPrep® Imaging System) on the clinical utility of reflex cytology by reducing screening error. Design: A secondary analysis of a prospective cohort study. Setting: One of five Dutch screening laboratories. Population: Women tested hrHPV-positive on self-samples between December 2018 and August 2019. Methods: Self-samples were used for reflex cytology with and without digital imaging. The follow-up data (cytological and histological results within 1 year of follow-up) were obtained through the Dutch Pathology Registry (PALGA). Main outcome measures: Test performance of the reflex cytology was determined by comparing it with physician-collected follow-up results. Results: The sensitivity for detecting abnormal cells by reflex cytology on self-samples increased significantly from 26.3% (42/160; 95% confidence interval [CI] 19.6–33.8) without digital imaging to 35.4% (56/158; 95% CI 28–43.4) with digital imaging (P < 0.05) without compromising specificity. Importantly, 41.7% of women with ≥CIN2 (35/84) and 45.6% with ≥CIN3 (26/57) were detected by reflex cytology with digital imaging on hrHPV-positive self-samples. Conclusion: Digital imaging is of added value to reflex cytology on hrHPV-positive self-samples with a 9% increase in sensitivity. If reflex cytology on self-samples analysed with digital imaging had been implemented in the screening programme, 35.4% of the hrHPV-positive women with abnormal cytology on additional physician-collected samples could have been referred directly for colposcopy.