Objective: The objective of this study was to compare the sensitivity of cervical cytology using conventional smears and SurePath liquid-based cytology (LBC).
Design: Prospective randomised evaluation of diagnostic test.
Setting: A single institution colposcopy clinic.
Population: Women attending first visit colposcopy appointments were offered entry into the study.
Methods: Cervical cytology samples from 913 women of age 16-75 years were randomly processed as SurePath LBC or conventional smears. Conventional smears were taken for 453 women and a SurePath LBC taken for 451 women. Cytology results were correlated with colposcopic findings and histology from colposcopic biopsies, treatment and follow up.
Main outcome measures: To compare the sensitivity of SurePath LBC and conventional smears for histologically proven abnormality. Other outcome measures include a comparison of their sensitivity for high-grade abnormalities and their satisfactory rate.
Results: Accounting for all randomised samples, there was a trend towards improved sensitivity for SurePath LBC (79.1 versus 73.7%, P = 0.1). However, excluding unsatisfactory cytology (and samples not taken) eliminated this trend; the sensitivity for both LBC and conventional smears for any epithelial abnormality was 81%. With a threshold of atypical squamous cells of uncertain significance (ASC-US), both SurePath LBC and conventional smears had a sensitivity of 92% for high-grade lesions. SurePath LBC was less likely to be reported as unsatisfactory (2.7 versus 9.1%, P < 0.0001).
Conclusions: In this context, with a threshold of ASC-US, both SurePath LBC and conventional smears offer high sensitivity for the detection of CIN2/3, but SurePath LBC is less likely to be reported as unsatisfactory.