For Immediate Release

MARLBOROUGH, Mass., (Nov 08, 2005) - Cytyc Corporation, a leading women's health company, today announced that twelve studies evaluating the performance of the ThinPrep(R) Imaging System were presented this week at the 53rd Annual Scientific Meeting of the American Society of Cytopathology (ASC) in San Diego. The studies reported on a range of implementation and performance criteria including validation protocols, disease detection and impact on workload.

The studies were conducted at a variety of institutions including private laboratories, hospital centers and academic institutions. Two studies conducted at Magee-Womens Hospital of University of Pittsburgh Medical Center reported on increases in diagnostic rates and improved sensitivity and specificity with the ThinPrep Imaging System. University of Texas Southwestern Medical Center also presented two studies; one focusing on the validation protocol which provided preliminary evidence of improved sensitivity and positive predictive value with the ThinPrep Imager and a second that reports on biopsy correlation for the Atypical Squamous Cells, cannot exclude HSIL (ASC-H) diagnostic category. Metropolitan Pathology, a large private laboratory in Denver, Colorado also presented two studies. One study included more than 80,000 slides processed with the ThinPrep Imager and reported that "High-grade Squamous Intraepithelial Lesions (HSIL) cases detected with Imager assistance are more likely to have had a false negative smear in the past." The second study reported that "the false negative rate has dropped by half" with implementation of the ThinPrep Imaging System.

Brigham and Women's Hospital and Harvard Medical School Department of Pathology presented a study reporting "a 7.75-fold decrease in the FNF (false negative fraction) with the implementation of the ThinPrep Imaging System." A study conducted at SUNY Upstate Medical Center compared cell yield of HSIL and LSIL (Low-grade Squamous Intraepithelial Lesions) located by cytotechnologists using the ThinPrep Imaging System and reported no significant difference. An in house validation of the ThinPrep Imaging System conducted at Yale University reported a false-negative rate "well below standard false negative rate." Columbia University Medical Center reported "a 25% increase in the overall abnormal (Atypical Squamous Cells of Undetermined Significance, or ASC-US, and above) rate" with implementation of the ThinPrep Imaging System. A study by LDS Hospital, Salt Lake City, Utah, reported increased detection of ASC-US not associated with increase detection of high-risk human papillomavirus (HPV). Finally, the Cleveland Clinic Foundation presented a study concluding that ThinPrep Imager assisted screening "effectively detected atypical glandular cells in Pap tests from patients with adenocarcinoma involving the cervix."

"This meeting has resulted in over 30 presentations on the ThinPrep method," said James Linder, M.D., Cytyc's chief medical officer. "In addition to the 12 presentations that demonstrated the improved performance of cervical cancer screening by cytotechnologists using the ThinPrep Imaging System compared to manual screening, there were other papers describing the benefits of the ThinPrep method for cervical screening, urine cytology, improved glandular disease detection and molecular testing. We are gratified that our customers are able to conduct these investigations to validate the many benefits of ThinPrep technology."