The changing face of cervical screening. Challenges for the future

It is early 2005 and cytology professionals have turned their full attention to the looming issues of mandated proficiency testing. Concerns abound regarding the cost, the validity of the test(s), and the consequences not only for individuals but laboratories and the profession itself. While we are all trying to connect to teleconferences and list serves to answer our questions regarding proficiency testing, the ThinPrep Imaging system (TIS), the automated cytology screening device manufactured by Cytyc Corporation (Boxborough, MA) is rapidly introducing a new approach to cytology screening in the United States. At the time of this editorial, the location-guided screening system produced by TriPath Imaging has yet to obtain FDA approval, so the comments in this article will be limited to the ThinPrep Imaging System. Many of the issues that will be raised, however, will apply to any automated screening system that is introduced in the future. A multi-center clinical trial examined the performance of the TIS in comparison to our traditional manual review for 10,742 Pap tests. This trial showed equivalence between the two methodologies. The clinical trial data also demonstrated a statistically significant, increased sensitivity for the detection of ASCUSþ and a greater specificity for the diagnosis of high-grade squamous intraepithelial lesions (HSIL). These results were obtained while almost doubling cytotechnologist productivity by decreasing 10-fold the number of Fields of View (FOV) necessary to sign out most negative Pap tests. After careful consideration of the new technology, clinical trial data and potential advantages of the TIS, the cytology laboratory at the Cleveland Clinic Foundation made the decision to adopt the TIS for cervical screening. In October 2003, the TIS was fully implemented in our laboratory at the Cleveland Clinic Foundation and the first clinical case was signed out. Since that time, over 100,000 ThinPrep Pap Tests have been analyzed on the TIS and signed out by cytotechnologists and cytopathologists. What advantages has this provided for our laboratory? The most obvious advantage has been the improved Pap Test turn-around-time. In a laboratory that traditionally had turnaround-times (TAT) ranging from 3 days to 3 wk depending on the time of year, number of technologists on vacation, etc., we have been able to consistently maintain a TAT of two to three days or even less. In a clinical laboratory setting, it is difficult to prove that there is increased detection of abnormalities. One concern regarding TIS performance was the detection of glandular abnormalities, but in a limited series of biopsy-proven adenocarcinomas, abnormal cells were identified on all the ThinPrep Pap Tests. In the majority of cases, the correct diagnosis could be rendered after a review of the 22 FOV. Indeed, one would predict that the good performance of the TIS in accurately identifying abnormal cells combined with less cytotechnologist fatigue would lead to an increased overall detection rate and an improvement in laboratory false-negative rates. With success stories such as ours in the initial implementation in a clinical laboratory, the number of laboratories adopting this technology has far exceeded the expectations of many involved. At the end of 2004, 158 TIS systems had been placed in cytology laboratories across the United States. Of these systems, 144 have been fully implemented and are generating clinical revenue. Assuming that each TIS is screening on average 50,000 Pap Tests/yr, approximately 7.9 million cervical smears will be analyzed using this technology. A rough estimate of the number of cytotechnologists routinely looking at Pap Tests on the TIS in 2005 (assuming around 8000 pap tests/technologist/yr) would be around 1000. *Correspondence to: Andrea E. Dawson, M.D., Cleveland Clinic Foundation, Cleveland, OH. E-mail: dawsona@ccf.org Received 3 March 2005; Accepted 20 April 2005 DOI 10.1002/dc.20302 Published online in Wiley InterScience (www.interscience.wiley.com).