Twelve Studies Evaluating Cytyc's ThinPrep(R) Imaging System Presented at National Scientific Meeting.

SAN DIEGO, Calif. -- Cytyc Corporation (Nasdaq: CYTC), 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."

Cytyc Corporation is a leading women's health company that designs, develops, manufactures, and markets innovative and clinically effective products. Cytyc products cover a range of women's health applications, including cervical cancer screening, breast cancer risk assessment, treatment of excessive menstrual bleeding, and treatment of breast cancer.

Cytyc is traded on The Nasdaq Stock Market under the symbol CYTC. Cytyc and ThinPrep are registered trademarks of Cytyc Corporation.

Forward-looking statements in this press release are made pursuant to the provisions of Section 21E of the Securities Exchange Act of 1934. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements relating to Cytyc's future financial condition, operating results and economic performance, and management's expectations regarding key customer relationships, future growth opportunities, product acceptance and business strategy, constitute forward-looking statements. These statements are based on current expectations, forecasts and assumptions that are subject to risks and uncertainties, which could cause actual outcomes and results to differ materially from those statements. Risks and uncertainties include, among others, dependence on key personnel and customers as well as reliance on proprietary technology, uncertainty of product development efforts and product acceptance, management of growth and product diversification, entry into new market segments, risks associated with litigation, the effective integration of acquired businesses and technologies, competition and competitive pricing pressures, risks associated with the FDA regulatory approval processes and healthcare reimbursement policies, introduction of technologies that are disruptive to Cytyc's business and operations, the impact of new accounting requirements and governmental rules and regulations, as well as other risks detailed in Cytyc's filings with the Securities and Exchange Commission, including under the heading "Certain Factors Which May Affect Future Results" in its 2004 Annual Report on Form 10-K and its most recent Quarterly Report on Form 10-Q filed with the Commission. Cytyc cautions readers not to place undue reliance on any such forward-looking statements, which speak only as of the date they were made. Cytyc disclaims any obligation to publicly update or revise any such statements to reflect any change in its expectations or events, conditions, or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements.