title: p16(INK4a) is superior to high-risk human papillomavirus testing in cervical cytology for the prediction of underlying high-grade dysplasia.
abstract: BACKGROUND
  The primary goal of this study was to compare the clinical performance of an optimized and rigorously controlled immunocytochemical (ICC) assay for p16(INK4a) to high-risk (HR) human papillomavirus (HPV) detection by polymerase chain reaction (PCR) as diagnostic adjuncts for cytology specimens from colposcopy patients.
  
  
  METHODS
  : The study included 403 cervical cytology specimens collected within 3 months of colposcopy. The colposcopic impression and cervical biopsy diagnosis served as the standards for correlation with cytological, p16(INK4a), and HPV data. p16(INK4a) was evaluated using an immunoperoxidase-based assay that was linear over 4 logs for the detection of HeLa-spiked positive control cytology specimens, using a threshold for positive test results that was based on receiver operating characteristic curve analysis. HR-HPV was detected by multiplex PCR using genotype-specific primers.
  
  
  RESULTS
  : In all combined diagnostic categories (negative for intraepithelial lesion and malignancy, atypical glandular cells, atypical squamous cells of undetermined significance, atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion, low-grade squamous intraepithelial lesion, and high-grade squamous intraepithelial lesion), the p16(INK4a) ICC and HR-HPV assays, respectively, had sensitivity of 81.7% and 83.3% (P = .81) and specificity of 78.1% and 50.9% (P < .001) for the detection of underlying > or =grade 2 cervical intraepithelial neoplasia (CIN) lesions on biopsy. Furthermore, the positive predictive value of p16(INK4a) ICC was greater than that of HR-HPV for patients with biopsies > or =CIN-2 (41.2% and 24.2%, respectively, P = .001).
  
  
  CONCLUSIONS
  : This p16(INK4a) immunocytochemical assay has superior specificity but similar sensitivity to HR-HPV testing to predict underlying high-grade dysplastic lesions in patients who are referred for colposcopy. The determination of the overall performance characteristics of p16(INK4a) immunocytochemistry, as an independent test or in combination with HPV testing in low-risk screening populations, however, will require subsequent large-scale prospective clinical trials.
authors.affiliation: Department of Pathology, Stony Brook University Medical Center, Stony Brook, New York 11794-8691, USA.
authors.forename: Panduka
authors.initials: P
authors.lastname: Samarawardana
authors.forename: Donna L
authors.initials: DL
authors.lastname: Dehn
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Singh
authors.forename: Douglas
authors.initials: D
authors.lastname: Franquemont
authors.forename: Chesney
authors.initials: C
authors.lastname: Thompson
authors.forename: Loretta
authors.initials: L
authors.lastname: Gaido
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Torkko
authors.forename: Petra
authors.initials: P
authors.lastname: Homer
authors.forename: Stephanie
authors.initials: S
authors.lastname: Burke
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Titmus
authors.forename: Vipul
authors.initials: V
authors.lastname: Nayi
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Shroyer
mesh_terms: D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000032:analysis*; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D006801:Humans; D027383:Papillomaviridae / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D011230:Precancerous Conditions / Q000175:diagnosis*; D012306:Risk; D012680:Sensitivity and Specificity; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis* / Q000473:pathology / Q000821:virology
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D004279:DNA, Viral