New Studies Published in Peer-Reviewed Journals Support Significantly Improved Performance of ThinPrep Pap Test.

Business Editors and Health/Medical Writers

BOXBOROUGH, Mass.--(BW HealthWire)--Nov. 7, 2001

Cytyc Corporation (Nasdaq:CYTC) today announced that two studies, recently published in prestigious ob/gyn journals, highlight the significantly improved performance of the ThinPrep(R) Pap Test(TM).

A major study by Dr. Jerome Belinson, section head of gynecologic oncology at the Cleveland Clinic Foundation, and others, appears in the current issue of the journal Gynecologic Oncology. The study, conducted in Shanxi Province, China, evaluated a number of techniques for the detection of cervical neoplasia. All patients underwent HPV testing, fluorescence spectroscopy, the ThinPrep Pap Test, a visual inspection diagnosis, and colposcopy with multiple biopsies. The authors report that the ThinPrep Pap Test had a 94% sensitivity for the detection of cervical intraepithelial neoplasia and a 100% sensitivity for cancer. The study compared the performance of the various tests with respect to sensitivity and specificity using the receiver operating characteristic (ROC) analysis. The authors report that, based on the ROC analysis, the ThinPrep Pap Test performed significantly better than the other procedures.

Another important study, recently published in the American Journal of Obstetrics and Gynecology, concluded that the ThinPrep Pap Test improves diagnosis of low-grade (LSIL) and high-grade squamous intraepithelial lesions (HSIL) compared to the conventional Pap smear. The article also demonstrated improved sample adequacy with the ThinPrep method.

The study, titled "Liquid-based cervical cytologic smear study and conventional Papanicolaou smears: A metaanalysis of prospective studies comparing cytologic diagnosis and sample adequacy," by Bernstein et al., evaluated the cytologic diagnosis and sample adequacy of the ThinPrep Pap Test compared with that of the conventional Pap smear. The authors used computerized databases and references from published articles to identify prospective trials that compared the ThinPrep Pap Test and conventional smears. The searches were conducted for literature published in English between January 1990 and April 2000. The authors identified twenty-five publications that met inclusion criteria for this review.

The results of the metaanalysis showed that the ThinPrep Pap Test was "significantly better than the conventional smear" for the diagnosis of low-grade (LSIL) and high-grade squamous intraepithelial lesions (HSIL). The analysis of the pooled data also showed that "the overall adequacy was significantly improved in the ThinPrep group in all trials."

"The superior performance of the ThinPrep Pap Test continues to be validated in the published literature," said Patrick J. Sullivan, Cytyc's president and chief executive officer. "We are particularly pleased that these studies were published in prestigious medical journals after rigorous peer-review. It is also noteworthy that in 1941 the American Journal of Obstetrics and Gynecology, currently the most cited ob/gyn journal, published the original paper by Drs. Papanicolaou and Traut that changed the course of cervical cancer diagnosis and treatment."

Cytyc Corporation develops, manufactures, and markets the ThinPrep(R) System for medical diagnostic applications. The ThinPrep System consists of the ThinPrep(R) 2000 Processor, ThinPrep(R) 3000 Processor, and related reagents, filters, and other supplies.

Cytyc(R) and ThinPrep(R) are registered trademarks and ThinPrep(R) Pap Test(TM) is a trademark 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 regarding product development and performance, 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 proprietary technology, risks associated with competition and competitive pricing pressures, 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 2000 Form 10-K 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.