Application of CytoPath®Easy Vials in Cervical Cancer Screening: Self-Sampling Approach

Abstract

Context: CytoPath®Easy kit (DiaPath S.p.A.) offers a major advantage compared to other commercially available kits available for the screening of cervical cancer, as it does not require additional equipment for sample processing. Using this methodology, collected epithelial cells are immersed in a preservative liquid before setting as a thin layer on a slide via gravity sedimentation.

Aims: To evaluate the suitability of the CytoPath®Easy kit for the processing of cervical samples, detection of pre-neoplastic lesions, and nucleic preservation and extraction for HR-HPV diagnosis.

Materials and methods: A total of 242 self-sampled cervical specimens were utilized, with 192 collected in CytoPath®Easy vials and 50 collected and processed using the ThinPrep^TM for comparative analysis. The samples underwent processing, Papanicolaou staining, and microscopic evaluation for morphological parameters. The extracted nucleic acids were assessed for purity and integrity, and the detection of high-risk human papillomavirus (HR-HPV) was carried out using the Alinity^m HR HPV system kit (Abbott Laboratórios Lda).

Results: Both methods demonstrated effective performance, enabling the morphological assessment of the cervical epithelium. Statistical analysis indicated that ThinPrep^TM yielded significantly better results in terms of cellularity. Conversely, CytoPath®Easy exhibited superior performance in terms of the quantity of extracted DNA and its degree of purification. Concerning the time consumed during processing, both methods were comparable, with the CytoPath®Easy methodology standing out for its cost-effectiveness, as it does not necessitate additional instruments and consumables.

Conclusions: The novel CytoPath®Easy methodology proves effective in preserving both nucleic acids and cell morphology characteristics, two crucial features for cervical cancer screening.

Keywords: Cervical cytology; HR-HPV; nucleic acids; pre-neoplastic lesions.

Figure 1

Microscopic evaluation of cell features analyzed after sample processing using each methodology, Papanicolaou staining, and mounting. Global characteristics of the cell imprint are observed in (a) (ThinPrep^TM) and (d) (CytoPath®Easy) at a low magnification field (100x); background, cellularity, and cell morphology preservation characteristics, as well as nuclear detail, hematoxylin color and cytoplasmic differentiation are observed at high magnification–400x (b, c (ThinPrep^TM), e and f (CytoPath®Easy))

Figure 2

Graphic representation of global characteristics scores-cellularity, imprint thickness/cell overlap, presence of undesirable background, and preservation of cell morphology. Results showed both CytoPath®Easy and ThinPrep^TM provide similar results, although significant statistical differences were observed in cellularity

Figure 3

Graphic representation of staining properties. Similar mean values were found with regard to nuclear detail, hematoxylin color, nuclear differentiation, cytoplasmic staining, and differentiation

Figure 4

Graphic representation of results obtained by a spectrophotometric reading of DNA extracted from ThinPrep^TM and CytoPath®Easy samples. A260/280, A260/A230, and DNA yield were quantified and compared. Significant differences were observed on A260/A230 (P < 0.0001). NanoDrop 1000 spectrophotometer reader reveals a bigger concentration of extracted DNA from CytoPath®Easy vials

Figure 5

Representative image of electrophoresis gel (1.5% agarose) running samples of both methodologies- ThinPrep^TM and CytoPath®Easy, captured on a UV light reader