Liquid-based cytology versus conventional cytology for detection of uterine cervical lesions: A prospective observational study

Objective: Liquid-based cytology (LBC) and conventional cytology (CS) are routine diagnostic techniques in cervical cytology, but few studies have compared their diagnostic performances with each other and with histologic diagnosis. This study aimed to compare the diagnostic performances of these techniques in subjects with abnormal cervical cytology of atypical cells of undetermined significance (ASC-US) or worse. Methods: A total of 312 patients diagnosed with ASC-US or worse were enrolled in this prospective study in Japan from 2013 to 2014. LBC and CS samples were prepared by a split-sampling technique and evaluated blindly. The results were classified using the Bethesda System 2001. Colposcopy and biopsy were conducted simultaneously or within 4 weeks of cytology-specimen collection in all cases. Diagnostic performance was calculated in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detection of CIN2 or worse, with a cut-off ASC-US or worse. Results: There was one unsatisfactory CS sample and the remaining 311 cases were evaluated. The sensitivities of LBC and CS were 100.0% and 98.8%, specificities were 17.2% and 23.8%, PPVs were 56.1% and 57.9% and NPVs were 100.0% and 94.7%, respectively. LBC had slightly higher sensitivity and NPV for detection of CIN2, but there was no significant difference between the two methods. Conclusions: There was no significant difference in the diagnostic performances of LBC and CS in patients with ASC-US or worse. LBC may therefore be an alternative approach to CS for cervical cancer screening.