Comparison of Quality between Conventional and Thin- Prep Cytology in Investigation of Patients with Epithe- Lial Ovarian Cancer

The liquid-based cytology (ThinPrep) is an alternative to the long-used conventional cytology that received Food and Drug Administration approval in 1996. The purpose of the current study was to determine the diagnostic cytomorphologic criteria of ThinPrep cytology and a comparison of the accuracy of conventional and ThinPrep cytology in investigation of patients with epithelial ovarian cancer. We investigated the advantages of liquid-based cytology and the potential role of the DNA ploidy in investigation of patients with the ovarian cancer. One hundred and five consecutive body cavity fluids (32 ascitic fluids, 42 free peritoneal fluids and 31 peritoneal washings) were diagnosed cytologically by both the conventional and the ThinPrep methods. The differences between ThinPrep and conventional cytology were evaluated for a variety of parameters including cellularity, cytologic morphology, specimen preparation, screening time, cytologist preference, and the impact on final diagnosis. Consequently, DNA ploidy analysis was performed on the ThinPrep specimens. The estimation of DNA ploidy was based on such parameters as the DNA index, the ploidy balance, the degree of aneuploidy, the degree of hyperploidy and the proliferation index . According to our findings, results through the TP method were considerably improved compared with those of the conventional method. Sensitivity was improved to 90.47%, negative predictive value to 72.41% and diagnostic accuracy to 92.37%. Furthermore, these findings were in excellent correlation with the final clinical diagnosis (p >0.05). According to the results of DNA ploidy analysis, 64 cases were aneuploids (60.95%), while 41 cases were euploids (39.04%). Furthermore, with the addition of the DNA ploidy analysis in our material, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were improved to 97.62%, 100%, 100%, 91.3% and 98.09%, respectively. ThinPrep method was found to provide better cytological details, significantly improved the diagnostic accuracy of the cytological diagnosis of ovarian cancer, reduced the screening time, and permitted the valuable application of current techniques of static DNA cytometry. Furthermore, the additional application of DNA ploidy further improved the diagnostic accuracy, confirming the fact that there are changes in submicroscopical level, which are difficult to be recognized with the simple microscopical examination. Based on these findings of automatic cytology, it is possible to improve our diagnostic criteria.