NCI Study Shows Improved Accuracy of Cytyc's ThinPrep Pap Test.

Business Editors/Health/Medical Writers

BOXBOROUGH, Mass.--(BUSINESS WIRE)--Dec. 5, 2003

Cytyc Corporation (Nasdaq: CYTC) today announced that a recently published study, evaluating a variety of cervical cancer screening techniques, reported that combining an additional screening technique with liquid-based cytology (LBC) did not improve accuracy. The ThinPrep(R) Pap Test was the exclusive LBC method used in the study.

The study by Ferreccio et al., and conducted in Costa Rica as part of the ongoing Guanacaste Project, included more than 8,500 patients from a region at high risk of cervical cancer. The study evaluated the sensitivity and specificity of conventional Pap smears, cervicography, human papillomavirus (HPV) testing, and the ThinPrep Pap Test. The cytology was collected using a split-sample protocol wherein the conventional Pap smear was collected first and then only the residual material was rinsed in the ThinPrep vial. HPV DNA testing was performed by PCR and Hybrid Capture(R)technologies during the ongoing study. However, the basis for this report was a masked re-testing of the specimens using PCR, which the authors describe as a more sensitive test for HPV DNA. Colposcopic examinations and biopsy were used as the reference standard of disease.

Results of this split-sample study showed that the ThinPrep Pap Test had a sensitivity of 85.7 percent, specificity of 87.8 percent, and a negative predictive value of 99.8 percent. The authors noted that while the ThinPrep Pap Test and HPV DNA testing were the most accurate techniques, "Combining them, there was a marginally significant gain in accuracy compared with the use of HPV testing alone, and a nonsignificant improvement compared with liquid-based cytology alone." The study also found that combining the conventional Pap and ThinPrep cytology was actually less accurate than the ThinPrep Pap Test alone. The authors concluded, "Adding another technique to liquid-based cytology as interpreted in this project did not additionally improve screening performance."

"I have found that the improved performance of the ThinPrep Pap Test is remarkably consistent," said Martha Hutchinson, M.D., Ph.D., one of the study's co-authors. "It should be noted that not only did the study employ a split-sample protocol, which is biased against ThinPrep, but we also used an early prototype of the ThinPrep(R) 2000 Processor to process the slides. It is clear to me that well-prepared cervical cytology remains the tried and true method for cervical cancer screening."

The study, entitled, "A Comparison of Single and Combined Visual, Cytologic, and Virologic Tests as Screening Strategies in a Region at High Risk of Cervical Cancer," appeared in the journal Cancer Epidemiology, Biomarkers & Prevention (Vol. 12, 815-823, September 2003). The study was supported by the National Cancer Institute (NCI).

Cytyc Corporation designs, develops, manufactures, and markets the ThinPrep(R) System for use in medical diagnostic applications primarily focused on women's health. The ThinPrep System is widely used for cervical cancer screening and is the platform from which the Company has launched its expansion into breast cancer risk assessment with the FirstCyte(R) Breast Test. The ThinPrep System consists of the ThinPrep(R) Pap Test, ThinPrep(R) 2000 Processor, ThinPrep(R) 3000 Processor, ThinPrep(R) Imaging System, and related reagents, filters, and other supplies. Cytyc is traded on The Nasdaq Stock Market under the symbol CYTC.

Cytyc, ThinPrep, and FirstCyte 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 the Company's financial condition, operating results and future economic performance, and management's expectations regarding 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 proprietary technology, uncertainty of product development efforts, product acceptance, management of growth, risks associated with litigation, competition and competitive pricing pressures, risks associated with the FDA regulatory approval processes and any healthcare reimbursement policies, and other risks detailed in the Company's filings with the Securities and Exchange Commission, including under the heading "Certain Factors Which May Affect Future Results" in its 2002 Annual Report on Form 10-K and its most recent Quarterly Report on Form 10-Q filed with the Commission. The Company cautions readers not to place undue reliance on any such forward-looking statements, which speak only as of the date they were made. The Company disclaims any obligation to publicly update or revise any such statements to reflect any change in Company 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.

Hybrid Capture(R) is a trademark of Digene Corporation.