Performance of a new, liquid-based cervical screening technique in the clinical setting of a large French laboratory

OBJECTIVE: To compare the performance of liquid-based cytology with the CYTO-screen System(R) (SEROA(R)) with that of conventional smears through a secondary analysis of a large database covering the activity of an independent French laboratory during the period 1998-2002. STUDY DESIGN: The study was performed with a retrospective, comparative, historical design on 2 subgroups of women having been screened by gynecologists who switched from conventional smears to the CYTO-screen System(R) in the period 1998-2002. The first cohort population consisted of women who had at least 4 subsequent screening tests over the period with half conventional and half with the CYTO-screen System(R). A control group consisted of smears collected by gynecologists who fully maintained activity with a conventional method over the same period. The second group consisted of women who had their first screening test performed over the study period by gynecologists who modified their technique. Specimen adequacy, endocervical cell content and epithelial cell abnormality detection rates were compared between the groups. RESULTS: As compared with the conventional smear, the CYTO-screen System(R) showed a reduction in unsatisfactory reports, especially in the second group of first-screened (0.14% versus 1.3%, P < .0001). The rate of atypical squamous cells of undetermined significance increased significantly after the switch to the CYTO-screen System(R) (2.5% versus 1.3%, P = .004) and in the second group of first-screened women (2.05% versus 1.4%, P = .0014), with higher histologic confirmation in both situations. There was a nonsignificant increase in the detection rates of low and high grade squamous intraepithelial lesions after the switch to the CYTO-screen System(R) and in the second group of first-screened women. CONCLUSION: The CYTO-screen System(R) gives higher-quality specimens and has a higher detection rate for squamous intraepithelial lesions, but that rate was significant only for atypical squamous cells of undetermined significance.