Liquid-based Pap Test

Abstract: Objective To confirm the accuracy of the ThinPrep Pap Test (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) on the basis of histologic diagnosis by biopsy and the detection of human papillomavirus (HPV) DNA in mass screening. Study design A total of 1,997 women residing in Xiangyuan County, Shanxi Province, P.R.C., an area with a high incidence of cervical carcinoma, were enrolled in this study. We collected exfoliative cervical samples from all subjects into a liquid buffer (Preserv-Cyt [Cytyc]) and utilized for both cytologic screening using the ThinPrep Pap Test and HPV DNA testing. Subsequent colposcopic biopsies were taken on all subjects. All the tests were performed in an independent and blinded fashion. We compared the ThinPrep Pap test with colposcopic biopsy and HPV test. Results High grade squamous intraepithelial lesions (HSIL) (CIN 2/3) were identified in 74 (3.7%) of 1,993 women adequately assessed, and there were 12 cases of squamous cell carcinoma (SCC). The false negative rate of ThinPrep cytology was 3.2% for biopsy-confirmed CIN 3 and 9.3% for CIN 2. Twenty-seven (87%) of the 31 women with biopsy-confirmed CIN 3 and 12 (100%) of 12 with biopsy-confirmed SCC had a diagnosis of either HSIL or greater abnormalities on ThinPrep cytology. In addition, the HPV DNA detection rates offered a good correlation between cytology and biopsy. Conclusion The ThinPrep Pap performed extremely well in this primary screening trial. We found a good correlation between ThinPrep cytology and colposcopic biopsy on detection of HSIL and SCC; cervical specimens collected in ThinPrep liquid buffer serve as a direct test for HPV as well.

Abstract: Over a 10-year period the Pap program at our community hospital laboratory progressed from the use of 100% conventional smears to predominantly ThinPrep (TP) and then to nearly 100% SurePath (SP). During this period the annual Pap volume grew from less than 20,000 to nearly 50,000. This retrospective review focuses on improvements in high-grade squamous intraepithelial lesion (HSIL) detection rates and specimen adequacy rates during the 10-year period. The laboratory database was used to identify 310,080 Pap test records between 1995 and 2004 inclusive. Pap type differences in HSIL detection rates and specimen adequacy rates were examined using the Cochran-Mantel-Haenszel test, with year as the stratification variable. The Breslow-Day test was used to evaluate the consistency of differences across the years. The overall results are summarized below in tabular format. Results of Combined 10-Year Data for Total Number of Cases, HSIL Rate, and Unsatisfactory Specimen Rate by Pap Method are given: [table: see text]. HSIL detection rates were significantly higher for liquid-based Pap tests compared with conventional smears (P < 0.0001). In addition, SP was associated with higher HSIL detection rates than TP with an estimated common odds ratio (OR) of 1.37 (95% confidence interval (CI), 1.10 - 1.71; P = 0.005), and higher specimen adequacy compared with TP or conventional Pap methods (P < 0.0001).

Abstract: Objective To evaluate the direct-to-vial efficacy of the SurePath Pap test (TriPath Imaging, Burlington, North Carolina, U.S.A.) in a community hospital laboratory and to assess its impact on productivity, as measured by Pap test turnaround times (TATs). Study design A total of 8,771 SurePath Pap tests were compared to 5,055 conventional Pap smears collected and processed over the same 12-month period. SurePath histologic correlation rates were compared to historical correlation rates for conventional Pap smears. Pap test TATs for 3 months prior to implementing SurePath were compared to TATs for the last 3 months of the study, which included an approximate 70:30 ratio of SurePath to conventional Pap tests. Laboratory staffing was unchanged, and mean monthly accessions were relatively constant. Results SurePath showed statistically significant improvements in the detection of low grade (LSIL) (196%) and high grade (HSIL) (243%) squamous intraepithelial lesions (SILs) relative to conventional Pap smears. The atypical cells of undetermined significance (ASCUS) rate remained nearly constant with SurePath, while the ASCUS/SIL ratio decreased by 68%. Unsatisfactory rates declined 81%. Histologic correlation rates with SurePath increased over those of conventional Pap smears. Pap test mean TATs improved 73% with SurePath. Conclusion Sure-Path detected significantly more cases of LSIL and HSIL than conventional smears without compromising specificity. The ASCUS/SIL ratio and unsatisfactory rate declined dramatically. Pap test TATs also improved markedly with SurePath.