title: Accuracy of liquid based versus conventional cytology: overall results of new technologies for cervical cancer screening: randomised controlled trial.
abstract: OBJECTIVE
  To compare the accuracy of conventional cytology with liquid based cytology for primary screening of cervical cancer.
  
  
  METHODS
  Randomised controlled trial.
  
  
  METHODS
  Nine screening programmes in Italy.
  
  
  METHODS
  Women aged 25-60 attending for a new screening round: 22 466 were assigned to the conventional arm and 22 708 were assigned to the experimental arm.
  
  
  METHODS
  Conventional cytology compared with liquid based cytology and testing for human papillomavirus.
  
  
  METHODS
  Relative sensitivity for cervical intraepithelial neoplasia of grade 2 or more at blindly reviewed histology, with atypical cells of undetermined significance or more severe cytology considered a positive result.
  
  
  RESULTS
  In an intention to screen analysis liquid based cytology showed no significant increase in sensitivity for cervical intraepithelial neoplasia of grade 2 or more (relative sensitivity 1.17, 95% confidence interval 0.87 to 1.56) whereas the positive predictive value was reduced (relative positive predictive value v conventional cytology 0.58, 0.44 to 0.77). Liquid based cytology detected more lesions of grade 1 or more (relative sensitivity 1.68, 1.40 to 2.02), with a larger increase among women aged 25-34 (P for heterogeneity 0.0006), but did not detect more lesions of grade 3 or more (relative sensitivity 0.84, 0.56 to 1.25). Results were similar when only low grade intraepithelial lesions or more severe cytology were considered a positive result. No evidence was found of heterogeneity between centres or of improvement with increasing time from start of the study. The relative frequency of women with at least one unsatisfactory result was lower with liquid based cytology (0.62, 0.56 to 0.69).
  
  
  CONCLUSIONS
  Liquid based cytology showed no statistically significant difference in sensitivity to conventional cytology for detection of cervical intraepithelial neoplasia of grade 2 or more. More positive results were found, however, leading to a lower positive predictive value. A large reduction in unsatisfactory smears was evident.
  
  
  BACKGROUND
  Current Controlled Trials ISRCTN81678807 [controlled-trials.com].
authors.affiliation: Unit of Cancer Epidemiology, Centre for Cancer Prevention, Via S Francesco da Paola 31 10123 Turin, Italy. guglielmo.ronco@cpo.it
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Ronco
authors.forename: Jack
authors.initials: J
authors.lastname: Cuzick
authors.forename: Paola
authors.initials: P
authors.lastname: Pierotti
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Cariaggi
authors.forename: Paolo
authors.initials: P
authors.lastname: Dalla Palma
authors.forename: Carlo
authors.initials: C
authors.lastname: Naldoni
authors.forename: Bruno
authors.initials: B
authors.lastname: Ghiringhello
authors.forename: Paolo
authors.initials: P
authors.lastname: Giorgi-Rossi
authors.forename: Daria
authors.initials: D
authors.lastname: Minucci
authors.forename: Franca
authors.initials: F
authors.lastname: Parisio
authors.forename: Ada
authors.initials: A
authors.lastname: Pojer
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Schiboni
authors.forename: Catia
authors.initials: C
authors.lastname: Sintoni
authors.forename: Manuel
authors.initials: M
authors.lastname: Zorzi
authors.forename: Nereo
authors.initials: N
authors.lastname: Segnan
authors.forename: Massimo
authors.initials: M
authors.lastname: Confortini
mesh_terms: D000328:Adult; D003584:Cytological Techniques / Q000379:methods / Q000592:standards*; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000592:standards*; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D002583:Uterine Cervical Neoplasms / Q000517:prevention & control* / Q000821:virology; D014626:Vaginal Smears / Q000592:standards; D002578:Uterine Cervical Dysplasia / Q000517:prevention & control* / Q000821:virology