Objective: To eliminate the disadvantages and inherent bias of split-sample studies by evaluating the relative performance of monolayers and conventional cervical cytologic smears in a single laboratory through evaluation of two large and similar, randomly derived patient groups from the same geographical and demographically similar population.
Study design: Two randomly created large patient groups from the same population were evaluated using conventional microscopic screening. One group was tested using the conventional smear. The other was evaluated using only the new liquid-preservative-based CytoRich preparation (AutoCyte, Inc., Elon College, North Carolina, U.S.A.) with the intended direct-tovial cell collection method. Results were then compared statistically as to disease detection and sample adequacy.
Results: Age comparisons between the two groups demonstrated equivalency. Specimen adequacy was greatly improved in the group tested with the CytoRich monolayer preparation. The monolayer group also demonstrated a significant reduction in ambiguous atypical squamous cells of undetermined significance/atypical glandular cells of undetermined significance diagnoses and a threefold increase in the detection of squamous intraepithelial lesion and cancer.
Conclusion: Routine use of homogeneous monolayer preparations as a total replacement for the conventional smear can be expected to dramatically improve specimen adequacy and sensitivity of the conventional smear alone. Direct-to-vial use of the new monolayer preparation generated significantly better results than those shown in any of the earlier split-sample trials.