Accuracy of Liquid-Based Pap Tests

Autor: Mithra Baliga, Michael D Hughson, Ming Guo, Shawn Liu, Leanne Martin, Lulin Hu
Rok vydání: 2005
Předmět:
Zdroj: Acta Cytologica. 49:132-138
ISSN: 1938-2650
0001-5547
DOI: 10.1159/000326120
Popis: Objective To evaluate the diagnostic performance of a liquid-based Pap test, the ThinPrep Pap test (TP) (Cytyc Corp., Roxborough, allassachusetts, U.S.A.), by comparing concurrent TP and cervical biopsy results on 782 patients who were referred for colponcopy because of previously abnormal conventional Pap smears (CPs). Study Design The ability of TP diagnoses of atypical cells of undetermined significance (ASC-US) and squamous intraepithelial lesions (SILs) to predict biopsy diagnoses of cervical intraepithelial neoplasm (CIN) was analyzed using X 2 and McNemar tests. Results The rate of agreement between diagnoses of SIL by TP and CEN by biopsy was 74.7%. ASC-US accounted for 16.0% of TP diagnoses. ASC-US had biopsy diagnoses of CIN 1 in 60% and CYN 2/3 in 12.8% of cases. For TP diagnosis of low grade SIL, biopsy diagnoses of CIN 2/3 were found in 13.5% of cases. For TP diagnoses of ASC-US and higher, the proportions of TP and cervical biopsies in comparable diagnostic categories were statistically significant (p < 0.001), with TP having sensitivity of 89.4%) and positive predictive value of 89.7% for the detection of CYN. The false positive rate for TP was 8.1%, but rescreening confirmed the presence of abnormal cells in 51 of 63 (81.0%) cases of ASC-US or higher having negative biopsies. TP bad a false negative late of 8.3% and negative predictive value of 61.3%. Rescreening shoved that most (77.6%) of the false negative TP specimens failed to have abnormal cells on the slides. Conclusion For patients having previously detected cervical abnormalities by CP, concurrent TP demonstrated the following: (1) that it has high diagnostic accuracy for SIL, (2) that ASC-US was diagnostically equivalent to LSIL, and (3) that false negative TP for SIL can be attributed primarily to sampling rather than cytotechnologists' screening errors.
Databáze: OpenAIRE
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