Cervical biopsy-based comparison of a new liquid-based thin-layer preparation with conventional Pap smears

• Published in: Diagnostic cytopathology 2004-04, Vol.30 (4), p.220-226
• Main Authors: Mattosinho de Castro Ferraz, Maria da Gloria, Nicolau, Sérgio Mancini, Stávale, João Norberto, Focchi, José, Castelo, Adauto, Dôres, Gerson Botacini, Mielzynska-Lohnas, Iwona, Lorincz, Attila, Rodrigues de Lima, Geraldo
• Format: Article
• Language: English
• Subjects: Biopsy; cervical cancer screening; Cervical Intraepithelial Neoplasia - diagnosis; cervicovaginal cytology; Cross-Sectional Studies; Cytological Techniques; Female; Humans; Papanicolaou Test; Predictive Value of Tests; Reproducibility of Results; Sensitivity and Specificity; test performance; UCM liquid-based cytology; Uterine Cervical Neoplasms - diagnosis; Vaginal Smears
• ISSN: 8755-1039; 1097-0339
• DOI: 10.1002/dc.10409

The objective of this study is to compare the diagnostic efficacy of universal collection medium (UCM) liquid‐based cytology (LBC) (Digene Corp., MD) and the conventional Pap smear in a comparative study, using histologic results as the gold standard. This was a cross‐sectional study. Conventional Pap smears and UCM LBC specimens, obtained from women in a low socioeconomic outpatient population referred to a tertiary center for gynecologic care, were compared. For the purpose of this study, when cervical specimens were collected for cytology, all women underwent colposcopy and biopsy was done if a cervical abnormality was observed. Cytologic evaluation of UCM LBC and conventional Pap smears were carried out separately, masked to the results of the other method. Agreement beyond chance between the two cytologic methods was ascertained by means of the unweighted κ statistic. Sensitivity, specificity, and predictive values with 95% confidence intervals were calculated for both methods. McNemar's test was used to determine the level of association between the two cytology procedures. A total of 800 women were evaluated. Assessment of the overall agreement between the two cytologic methods yielded a κ of 0.777 (P < 0.0001). After adjustment for histologic diagnosis, the computed κ in each stratum was as follows: normal = 0.733; CIN 1 = 0.631; CIN 2/3 = 0.735; cancer = 0.652. The sensitivity and specificity of UCM LBC for detection of cervical intraepithelial lesions and cancer were 75.3% and 86.4%, respectively, not statistically different from the 81.8% and 85.2% seen with the conventional method. This study demonstrates that the UCM LBC method is as accurate as the conventional Pap smear cytology in detecting cervical intraepithelial lesions and cancer even so the UCM samples were systematically prepared from a second sampling of the cervix. Diagn. Cytopathol. 2004;30:220–226. © 2004 Wiley‐Liss, Inc.