Two studies published in the Jan. 18 issue of Annals of Internal Medicine concluded that fecal occult blood tests in which the physician takes a single sample during a routine digital rectal exam (DRE) is not an acceptable way to screen for colorectal cancer. In an accompanying editorial, Harold Sox, M.D., editor of the journal, states: "Together, the 2 articles paint a disappointing picture of overreliance on an inaccurate test."

In one study, researchers compared results of a traditional fecal occult blood test (FOBT) using a single sample during a DRE versus results when a patient supplies six samples over the course of three days at home. The single-sample method detected less than five percent of advanced-stage cancerous tumors, compared with 24 percent with the multiple-sample method. (1) Testing a fecal sample taken during a single digital rectal exam appears to be a common practice. A second study found that almost one-third of physicians use this less reliable method as their only colon cancer screening test. (2)

"These findings reinforce that many patients think they are getting an accurate colon cancer screening test when they aren't," said Joyce G. Schwartz, M.D., Vice President and Chief Laboratory Officer at Quest Diagnostics. "This is extremely concerning because colon cancer is the nation's second most lethal cancer affecting both men and women.

"Physicians have found that some people are reluctant to do a fecal occult blood test at home because it can be difficult and messy to complete," continued Dr. Schwartz. "Patients must handle fecal matter and obtain six samples from three separate stools to complete the FOBT. In addition, they must refrain from eating certain foods, such as red meat, and taking certain medications, even aspirin, for a week prior to testing. However, the InSure colorectal screening test is more patient-friendly (3) than traditional fecal occult blood tests because of its patented brush-based collection system. InSure has no dietary or medicinal restrictions, and it is FDA-cleared at a level of 87 percent sensitivity." (4)

InSure is a fecal immunochemical test (FIT), which specifically detects trace amounts of human blood in the stool. InSure is more patient-friendly because it requires no fecal handling. A disposable long handled brush is swirled in toilet water and dabbed onto a card. These features have been shown to improve patient compliance with colorectal cancer screening by 66 percent versus the traditional fecal occult blood test. (5)

American Cancer Society guidelines include FITs, such as InSure, as an annual screening tool for the normal-risk population of people over the age of 50 or who are at high risk for colorectal cancer. InSure is available nationally to doctors and their patients through 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 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 provides advanced information technology solutions to improve patient care. Additional company information is available at: http://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, competitive environment, changes in government regulations, changing relationships with customers, payers, suppliers and strategic partners and other factors described in the Quest Diagnostics Incorporated 2003 Form 10-K and subsequent filings.

  (1) Collins JF et al. Accuracy of screening for fecal occult blood on a
     single stool sample obtained by digital rectal examination: a
     comparison with recommended sampling practice. Ann Intern Med.
     2005;142: 81-85.
  (2) Nadel MR et al. A national survey of primary care physicians' methods
     for screening for fecal occult blood. Ann Intern Med. 2005;142: 86-94.
  (3) Levin B et al. Emerging technologies in screening for colorectal
     cancer: CT colonography, immunochemical fecal occult blood tests, and
     stool screening using molecular markers. CA Cancer J Clin 2003;53:44-
     55.
  (4) U.S. Food and Drug Administration submission data; 2000.
  (5) Cole SR, Young GP, Esterman A, Cadd B, Morcom J.  A randomised trial
     of the impact of new faecal haemoglobin test technologies on
     population participation in screening for colorectal cancer.  J Med
     Screen 2003; 10:117-122.

SOURCE: Quest Diagnostics Incorporated

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

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