SummaryThe aim of this six-centre, split-sample study was to compare ThinPrep fluid-based cytology to the conventional Papanicolaou smear. Six cytopathology laboratories and 35 gynaecologists participated. 5428 patients met the inclusion criteria (age > 18 years old, intact cervix, informed consent). Each cervical sample was used first to prepare a conventional Pap smear, then the sampling device was rinsed into a PreservCyt vial, and a ThinPrep slide was made. Screening of slide pairs was blinded (n = 5428). All non-negative concordant cases (n = 101), all non-concordant cases (n = 206), and a 5% random sample of concordant negative cases (n = 272) underwent review by one independent pathologist then by the panel of 6 investigators. Initial (blinded) screening results for ThinPrep and conventional smears were correlated. Initial diagnoses were correlated with consensus cytological diagnoses. Differences in disease detection were evaluated using McNemar's test. On initial screening, 29% more ASCUS cases and 39% more low-grade squamous intraepithelial lesions (LSIL) and more severe lesions (LSIL+) were detected on the ThinPrep slides than on the conventional smears (P = 0.001), including 50% more LSIL and 18% more high-grade SIL (HSIL). The ASCUS:SIL ratio was lower for the ThinPrep method (115:132 = 0.87:1) than for the conventional smear method (89:94 = 0.95:1). The same trend was observed for the ASCUS/AGUS:LSIL ratio. Independent and consensus review confirmed 145 LSIL+ diagnoses; of these, 18% more had been detected initially on the ThinPrep slides than on the conventional smears (P = 0.041 360-366 © 2001 Cancer Research Campaign doi: 10.1054/ bjoc.2000.1588, available online at http://www.idealibrary.com on http://www.bjcancer.com Linder and Zahniser, 1997;Roberts et al, 1997; Bolick and Heuman, 1998;Corkill et al, 1998;Dupree et al, 1998;Papillo et al, 1998; Carpenter and Daveu, 1999;Diaz-Rosario and Kabawat, 1999;Guidos and Selvaggi, 1999;Wang et al, 1999; Yeoh et al, 1999; Weintraub and Morabia, 2000).This study, conducted in France, is the first formal multilaboratory, large-scale evaluation of the ThinPrep Pap Test in the European setting.
METHODS
Study organization6 laboratories in France participated in the study, each laboratory obtaining cervical samples from 5 to 8 participating gynaecologists and their patients. A total of 35 gynaecologists participated in the study.Before the study commenced, the 6 laboratory directors (4 cytopathologists and 2 cytologists) and their participating staff were trained to interpret ThinPrep slides, and also to use the Bethesda System for reporting the screening results (Kurman and Solomon, 1994). The study protocols and forms were reviewed and approved by the local Ethics Committee.Patients were recruited sequentially in the participating gynaecologists' practices, from March 1998 to September 1998. According to the inclusion criteria, female patients aged 18 and older, attending regular cervical cancer screening, and who voluntarily gave their informed consen...
