Does liquid-based technology really improve detection of cervical neoplasia? A prospective, randomized trial comparing the ThinPrep Pap Test with theconventional Pap Test, including follow-up of HSIL cases

OBJECTIVE: To compare the sensitivity, specificity and specimen adequacy of the ThinPrep Pap Test (TP) with the conventional Pap Test (CV) in a low-ri sk population with subsequent follow-up of HSIL cases. STUDY DESIGN: A prospective, randomized, controlled design was chosen to co mpare the TP with CV. Cytologic diagnosis and specimen adequacy were evalua ted and compared with histology data ill high grade squamous intraepithelia l lesion (HSIL) cases. Fifteen gynecologists in private practice, all train ed in colposcopy, participated hi the trial, Cytologic diagnosis, specimen adequacy and follow-up of the cytologic HSIL cases were compared in the two groups. In total, 1,999 patients were included, 997 in the TP group and 1, 002 in the CV group. Randomization assignments were designated on cytology case report forms, which were placed in scaled envelopes. Each envelope had a sequential randomization number on the outside to allow tracking and aut hentication of randomization assignments. RESULTS: Comparison of results between CVs and TPs revealed no statisticall y significant differences in all diagnostic categories, ranging from "withi n normal limits" to HSIL. Specimen adequacy, however, was superior with CVs (P < .001). The cytologic diagnosis of HSIL correlated with the histologic diagnosis in 91 % of the TP group and 100% of the CV group. CONCLUSION: Because there was no statistically significant difference in se nsitivity and specificity of the two techniques, improved detection of cerv ical abnormalities and better specimen adequacy might not be a consequence of utilizing liquid-based preparations but of a better sampling technique. Removing mucus and cellular debris from the cervical surface with a cellulo se swab before sampling cells With a proper Sampling device results in the same sensitivity and specimen adequacy and is much less expensive than the liquid-based technique.