Objective: To review published and other available data comparing the effectiveness of liquid-based cytology preparations in detecting epithelial cell abnormalities in cervicovaginal (gynecologic) cytology as compared to the conventional Papanicolaou test.
Study design: Available split-sample data comparing liquid-based gynecologic cytology preparations with the conventional cervical cytologic test were collated from published studies, unpublished studies reported on at professional meetings or in the press, and from Food and Drug Administration Premarket Clinical Trials on ThinPrep and AutoCyte PREP. Data were stratified with regard to use of newer preparatory instrument models, use of varying collection devices and different split-sample protocols.
Results: Available data from split-sample studies of liquid-based methods showed overall increased detection of epithelial cell abnormalities. Results have varied considerably from study to study and appear to be influenced by collection protocol methods and probably by collection devices' different delivery of cellular material in split-sample studies, first to the conventional smear and second to the liquid-based medium. Newer preparatory instrument models may also enhance detection.
Conclusion: Liquid-based gynecologic cytology preparations increase detection of epithelial cell abnormalities, as compared to the conventional, single-slide cervical cytologic smear, based on available data from split-sample studies. The true potential impact of these methods in enhancing detection of epithelial cell abnormalities awaits accumulation of data from direct-to-vial studies, especially data on detection of biopsy-confirmed high grade squamous intraepithelial lesions from a wide variety-of clinical practice settings.