Quest Diagnostics Incorporated , a leading provider of cancer screening and diagnostic testing, information and services, today announced that it has begun to offer InSure™, an FDA-cleared fecal immunochemical test to detect the presence of blood in stool samples. The test is intended to help physicians screen for colorectal cancer at an early stage in patients who are at average risk. Earlier this year, Quest Diagnostics and Enterix Inc., a privately held colorectal cancer screening company, announced that they had entered into an agreement for Quest Diagnostics to offer InSure.

"InSure meets the critical need for a broad-based colorectal cancer screening test," said Joyce Schwartz, M.D., Vice President and Chief Laboratory Officer of Quest Diagnostics. "It is sensitive, specific and easy for patients to use."

"Increasing compliance with screening guidelines is the key to reducing the number of cases of colorectal cancer, which is a preventable disease," noted Jack Mandel, Ph.D., M.P.H., Chairman of the Department of Epidemiology at the Emory University Rollins School of Public Health and lead investigator for the definitive clinical trial of guaiac-based fecal occult blood tests. "InSure offers physicians a screening tool that has been shown to have greater compliance than guaiac-based fecal occult blood tests."

InSure is a more effective alternative to guaiac-based fecal occult blood testing because it is specifically designed to detect human hemoglobin only from lower gastrointestinal bleeding, from sources such as the colon and rectum, without requiring the patient to observe dietary and medicinal restrictions. In addition, studies indicate that InSure provides 87% sensitivity(1) for colorectal cancer detection and 97.8% specificity.

The American Cancer Society's 2003 guidelines for colorectal cancer screening cite immunochemical tests' advantages over guaiac-based fecal occult blood tests. Based on a recent review(2) of various colorectal cancer screening technologies by The American Cancer Society's (ACS) Colorectal Cancer Screening Advisory Group, the ACS's Recommendations for Screening and Surveillance for the Early Detection of Adenomatous Polyps and Colorectal Cancer for 2003 now include the statement: "In comparison with guaiac-based tests for the detection of occult blood, immunochemical tests are more-patient friendly, and are likely to be equal or better in sensitivity and specificity." The Group also noted that " ... recent studies of InSure combined with previously published reports on the performance of immunochemical tests for stool occult blood provide a persuasive argument that these tests offer enhanced specificity in colorectal cancer screening compared with guaiac-based testing."

The new InSure technology provides uncomplicated specimen collection that is easy for patients to use at home. Unlike other colorectal cancer screening technologies, InSure is non-invasive and it requires no handling of fecal matter. To date, guaiac-based fecal occult blood testing has been the cornerstone of early colorectal cancer screening. Specimen collection for guaiac-based fecal occult blood tests has proved awkward and embarrassing for patients in the past and has been an impediment to patient adherence.

The current rate of patient adherence with recommended colorectal cancer screening guidelines -- using any method -- is lower than for screening tests for breast, cervical or prostate cancers. It is estimated that only 33% of Americans over the age of 50 have been screened for colorectal cancer by fecal occult blood testing within the past two years(3) -- versus 84% of American women over the age of 45 who have been screened for cervical cancer by Pap testing within the past three years.(4) For the 80 million people over the age of 50 who are of average risk, the American Cancer Society recommends annual colorectal cancer screenings. If detected and treated at an early stage, the 5-year relative survival rate for colorectal cancer is 90%.

"We are confident that InSure will overcome the current challenge of patient non-compliance associated with traditional testing methods and improve the chances of detecting colorectal cancer in more patients at an early and treatable stage," said Dr. Schwartz.

Physicians and patients who are interested in learning more about InSure may call 800-531-3681, ext. 10, or may visit the InSure website at www.insurefobt.com.

About Quest Diagnostics

Quest Diagnostics Incorporated is the nation's leading provider of diagnostic testing, information and services, providing insights that enable healthcare professionals to make decisions that improve health. The company offers the broadest access to diagnostic testing services in the United States through its national network of laboratories and patient service centers, and provides interpretive consultation through its extensive medical and scientific staff. Quest Diagnostics is the leading provider of esoteric testing, including gene-based medical testing, and also empowers healthcare organizations and clinicians with state-of-the-art connectivity solutions that improve patient care. Additional company information is available at: www.questdiagnostics.com.

The statements in this press release which are not historical facts or information may be forward-looking statements. These forward-looking statements involve risks and uncertainties that could cause actual results and outcomes to be materially different. Certain of these risks and uncertainties may include, but are not limited to, unanticipated expenditures, changing relationships with customers, payers, suppliers and strategic partners, competitive environment, changes in government regulations, conditions of the economy and other factors described in the Quest Diagnostics Incorporated 2002 Form 10-K and subsequent filings.

  (1) The sensitivity of InSure Fecal Occult Blood Test was assessed in a
      study of a high-risk population.
  (2) CA Cancer J Clin 2003; 53:44-55.
  (3) National Health Interview Survey, 2000, National Center for Health
      Statistics, Centers for Disease Control and Prevention, 2002 -
      American Cancer Society, Surveillance Research.
  (4) Data from the Centers for Disease Control's (CDC) Behavioral Risk
      Factor Surveillance System (BRFSS) for 2000 and 2001.

SOURCE: Quest Diagnostics Incorporated

CONTACT: Laure Park (Investors), +1-201-393-5030, or Jennifer Somers
(Media), +1-201-393-5700, for Quest Diagnostics

Web site: http://www.questdiagnostics.com/