Liquid-based versus conventional cytology of oral brush biopsies: a split-sample pilot study.

OBJECTIVE: The aim of this prospective split sample study was to evaluate the applicability of liquid-based cytology (LBC) of oral brush biopsies for detection of oral cancer.

METHODS: Two different preparation techniques were investigated: the conventional transfer procedure to glass slides and the LBC preparation method. The obtainments of epithelial cells were performed five times with a nylon brush and transferred onto five glass slides. Additionally, the brushes, which were normally discarded, were stored in a fixative solution. Conventional slides and respective thin layers from a total of 113 cases were reviewed with both techniques.

RESULTS: Thin layers showed excellent morphology on a clear background, which allowed an accurate diagnosis. In contrast, the conventional glass slides showed significantly more blood contamination and cell overlapping. The sensitivity of conventional cytological diagnosis was 96.3%, the specificity archived 90.6%, the positive predictive value was 96.3% and the negative predictive value scored 90.6%. The sensitivity of the cytological diagnosis using thin layers archived 97.5%, the specificity was 68.8%, the positive predictive value revealed 88.76% and negative predictive value was 91.7%.

CONCLUSION: Our findings indicate that in oral cytology, LBC may replace other types of wet-fixed preparations using the full amount of collected cells, resulting in enhanced specimen quality archiving comparable values of diagnostic accuracy.

CLINICAL RELEVANCE: LBC facilitates the cell collection due to simpler handling and less transfer errors by dentists and may improve the overall diagnostic accuracy of oral brush biopsies in future.