Twenty-One Studies Evaluating Cytyc's ThinPrep(R) Imaging System Featured at National Scientific Meeting.

TORONTO -- Cytyc Corporation (Nasdaq: CYTC), a leading provider of surgical and diagnostic products targeting cancer diagnostics and women's health, today announced that twenty-one scientific abstracts evaluating the performance of the ThinPrep([R]) Imaging System were published in the special programs supplement of the journal Cancer Cytopathology, distributed this week at the 54th Annual Scientific Meeting of the American Society of Cytopathology (ASC) in Toronto. The studies show a variety of benefits including improved disease detection compared

to manual screening, evaluation of specimen adequacy, detection of glandular abnormalities, and impact on overall quality and productivity.

The studies were conducted at a variety of institutions including private laboratories, hospital centers, and academic institutions. A representative sample of the range of topics and institutions included the following:

Researchers from Fletcher Allen Health Care, the University of Vermont, presented data evaluating the effectiveness of the ThinPrep Imaging System in low risk screening population. The study by Papillo et al., compared cytologic interpretation rates for two, six-month periods before and after implementation of the ThinPrep Imaging System. The authors reported statistically significant increases in the detection of low-grade (LSIL) and high-grade and more severe (HSIL+) squamous intraepithelial lesions. The authors also reported that follow-up validation showed there was no loss of specificity with the increased detection.

Travers et al., of the Physicians Laboratory, Ltd. in Sioux Falls, South Dakota, evaluated the impact of the ThinPrep Imaging System on the detection of cytologic abnormalities. The study compared the detection rates of 35,553 ThinPrep([R]) Pap Test slides processed with the ThinPrep Imaging System to detection rates of 25,636 manually screened ThinPrep slides from similar time periods. The authors reported statistically significant increases in the detection of all categories of abnormalities, including a 50 percent increase in HSIL detection. Cytologic-histologic correlation did not change significantly for HSIL cases, suggesting that the increase in HSIL detection with the Imager was not due to false positive diagnoses.

Sabo et al., from the Cleveland Clinic Foundation, Ohio, evaluated the detection of endocervical adenocarcinoma in situ (AIS) using the ThinPrep Imaging System. The study evaluated the overall performance of the ThinPrep Imaging System for the identified known AIS cases and the presence of atypical endocervical cells in the Imager selected 22 fields of view (FOV). The authors concluded that the ThinPrep Imaging System effectively assisted in the detection of endocervical AIS. The authors also added that there were no false negative Pap tests in this series.

A combined study conducted at Magee Women's Hospital of UPMC in Pittsburgh, Pennsylvania, and the Cleveland Clinic Foundation, in Cleveland, Ohio, explored the impact of the ThinPrep Imaging System as both a quality tool and productivity tool at large academic cytology laboratories. Productivity measures included slides screened per hour and turnaround time, while quality measures include abnormality detection rates and laboratory false negative rates. The author reported improvements in both quality and productivity as well as an observable decrease in false negative rate at one of the institutions with the ThinPrep Imaging System. The authors concluded, "In these two academic centers, the impact of the ThinPrep Imaging System as a quality tool was more prominent than its impact as a productivity tool."

A multi-institutional study by Linder et al. examined the impact of the ThinPrep Imaging System at ten institutions, representing private, hospital, and academic laboratories in the United States. The authors evaluated individual laboratory detection rates as well as pooled data comparing manually screened ThinPrep Pap Tests versus Imaged ThinPrep slides. Overall, more than one million Pap diagnoses were included: 579,750 manual versus 597,290 in the Imager cohort. The aggregate data from all sites yielded a significant 22.7 percent increase in the detection of HSIL with the ThinPrep Imaging System.

"These data underscore the value of the ThinPrep Imaging System over manual screening and other cervical screening methods," said Ellen Sheets, M.D., Cytyc's chief medical officer. "It is particularly gratifying that so many of these institutions choose to share their data in scientific forums like this. In total, more than 40 studies related to the ThinPrep System, including the 21 focusing on the ThinPrep Imaging System, were included in the Cancer Cytopathology supplement of abstracts for this meeting."

Cytyc Corporation is a leading provider of best-in-class medical technology that enables physicians and laboratories to improve patients' lives throughout the world. Cytyc provides diagnostic and minimally invasive surgical products targeting cancer and women's health. The ThinPrep([R]) System is the most widely used method for cervical cancer screening in the United States. The ThinPrep System consists of the ThinPrep([R]) 2000 Processor, ThinPrep([R])3000 Processor, ThinPrep([R]) Imaging System, and related reagents, filters, and other supplies. The ThinPrep System also provides the platform from which the Company launched its expansion into breast cancer risk assessment with the FirstCyte([R]) Breast Test. The NovaSure([R]) Impedance Controlled Endometrial Ablation System, or the NovaSure([R]) System, is an innovative endometrial ablation device to treat menorrhagia, or excessive menstrual bleeding. The MammoSite([R]) Radiation Therapy System is a single-use device for the treatment of breast cancer that positions radiation sources directly into the post-lumpectomy site to optimize radiation treatment delivery while minimizing damage to healthy tissue. The GliaSite([R]) Radiation Therapy System is for the treatment of malignant brain tumors.

Cytyc is traded on The Nasdaq Stock Market under the symbol CYTC. Cytyc, ThinPrep, FirstCyte, NovaSure, MammoSite, and GliaSite 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 timelines, management of growth, product diversification, and organizational change, entry into new market segments domestically and new markets internationally, 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 in the United States and abroad, 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 those under the heading "Risk Factors" in its 2005 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.