Cytologic detection of cervical abnormalities using liquid-based compared with conventional cytology: a randomized controlled trial.
OBJECTIVE
To compare test positivity rates of liquid-based and conventional cytology.


METHODS
This study was a cluster randomized controlled trial with family practice as the unit of randomization, performed within the Dutch national cervical screening program. Women aged 30-60 years (n=89,784) recruited from 246 family practices were included. One-hundred twenty-two practices (49,222 individuals) were randomly assigned to the experimental arm, and 124 practices (40,562 participants), to the conventional arm. Inclusion was performed during a 3-year period between April 2003 and July 2006. Cytologic test positivity rates of liquid-based compared with conventional cytology was compared in terms of crude and adjusted odds ratios, applying a per-protocol analysis.


RESULTS
Crude ratios of the odds of test positivity rates of liquid-based compared with conventional cytology for atypical squamous cells of undetermined significance or more severe, low-grade squamous intraepithelial lesion or more severe, and high-grade squamous intraepithelial lesion or more severe were 0.95 (95% confidence interval [CI] 0.82-1.10), 1.00 (95% CI 0.83-1.20), and 0.97 (95% CI 0.77-1.22), respectively. Liquid-based cytology resulted in fewer unsatisfactory tests (odds ratio 0.30, 95% CI 0.23-0.38). The results did not change when the odds ratios were adjusted for age, study site, study period, and urbanization level. Of 128 women screened with liquid-based cytology, one unsatisfactory preparation is avoided.


CONCLUSIONS
This study found no statistically significant difference in cytologic test positivity rates between liquid-based and conventional cytology. However, liquid-based cytology resulted in significantly fewer unsatisfactory tests.


BACKGROUND
Nederlands Trial Register, www.trialregister.nl, NTR1032


METHODS
I.
Siebers
Albertus G
AG
From the Department of Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands; PAMM Laboratories, Eindhoven, the Netherlands; Scientific Institute of Public Health, Brussels, Belgium, and European Cooperation on Development and Implementation of Cancer Screening and Prevention Guidelines, International Agency for Research on Cancer, Lyon, France; and Department of Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
Klinkhamer
Paul J J M
PJJM
Arbyn
Marc
M
Raifu
Amidu O
AO
Massuger
Leon F A G
LFAG
Bulten
Johan
J
D000328:Adult; D005260:Female; D016591:Histocytological Preparation Techniques / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D009426:Netherlands; D002578:Uterine Cervical Dysplasia / Q000473:pathology*; D002583:Uterine Cervical Neoplasms / Q000473:pathology*; D014626:Vaginal Smears / Q000379:methods*