ThinPrep Pap Test for Diagnosis of Cervical Cancer in Early Stages

Abstract

Background: Cervical cancer is one of the world’s deadliest forms of cancer and Pap smear is the most popular screening test for diagnosis in early stages. The aim of our study was to assess potential screening rule of ThinPrep Pap test. Methods: In this cross sectional, study Cervical samples were collected from all women who referred to a pathology center for Papanicolaou test and all samples were prepared with ThinPrep process. To assess validity, biopsy was selected as gold standard. 131 women who had ThinPrep Pap test and biopsy were considered for the analysis. The participants were selected purposeful. Three thresholds were used to define test positivity: 1) Atypical squamous cells of undetermined significance (Asc-us) 2) Low grade squamous intraepithelial lesion (LSIL) 3) High grade squamous intraepithelial lesion (HSIL) and worse. Inter and intra observer reliability were evaluated using kappa (simple and weighted) as well as Fleiss kappa and validity were assessed by the well-known validity estimates for qualitative variables. Results: Intra observer reliability was moderate for pathologists with low and moderate experience (kappa was 0.44 and 0.46 respectively) and was good for experienced pathologist [kappa (WK) = 0.64]; however, inter observer reliability was poor (Fliess kappa=0.12). For diagnosis of ASCUS and worse, the sensitivity was 96.3% and for diagnosis of HSIL and worse the sensitivity and specificity were 86.6% and 95.1%, respectively. Conclusion: ThinPrep pap is an acceptable screening test for diagnosis of cervical cancer in early stages. However, experience and specialty have effect on reliability’s results.

Keywords

• thinprep- papanicolaou- validity- inter and intra observer reliability