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                                                                    Exhibit 99.1

[EXACT SCIENCES AND LABCORP LOGOS]               PRESS RELEASE
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FOR IMMEDIATE RELEASE
FOR FURTHER INFORMATION:
FOR EXACT SCIENCES:         INVESTOR RELATIONS AND            FOR LABCORP:
MEDIA:                      CORPORATE COMMUNICATIONS:
Amy Turner                  Amy Hedison                       Pam Sherry
Fleishman-Hillard           EXACT Sciences                    LabCorp
P: (617) 267-8223           P: (978) 897-2800, ext. 252       P: (336) 436-4855
E: turnera@fleishman.com    E: ahedison@exactsciences.com     E: sherryp@labcorp.com
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                     EXACT SCIENCES AND LABCORP(R) TO OFFER
                    PREGEN-PLUS(TM), CHANGING THE HEALTH CARE
                   LANDSCAPE WITH NON-INVASIVE, GENOMICS-BASED
                          COLORECTAL CANCER TECHNOLOGY

                EXCLUSIVE LICENSING AGREEMENT TO MAKE PREGEN-PLUS
     AVAILABLE TO A POTENTIAL MARKET OF 80 MILLION AMERICANS; WILL MARK THE
   FIRST DNA-BASED SCREENING METHOD FOR CANCER IN AN AVERAGE-RISK POPULATION

MAYNARD, MASS., AND BURLINGTON, N.C., - June 27, 2002 - EXACT Sciences
Corporation (NASDAQ: EXAS) and Laboratory Corporation of America(R) Holdings
(NYSE:LH) (LabCorp(R)) today announced the creation of an exclusive, long-term
strategic partnership to commercialize PreGen-Plus(TM), EXACT Sciences'
proprietary, non-invasive technology for the early detection of colorectal
cancer in the average-risk population. As part of the agreement, in addition to
certain royalty fees, LabCorp could pay EXACT Sciences as much as $75 million in
upfront, milestone and performance-based payments for a five-year exclusive
license, followed by a non-exclusive license for the life of the patents. The
introduction of PreGen-Plus, expected in the first half of 2003, will mark the
broadest commercial application of discoveries made about the human genome to
address a major healthcare problem such as colorectal cancer - the most deadly
cancer among non-smokers in the United States. There is no other DNA-based test
currently available for the early detection of cancer in an average-risk
population.

It is estimated that this year approximately 150,000 Americans will be diagnosed
with colorectal cancer and approximately 57,000 Americans will die from the
disease. The American Cancer Society recommends that the 80 million Americans
who are over the age of 50 be screened regularly for colorectal cancer, which,
if detected at an early stage, has a cure rate of more than 90 percent. A
majority of people, however, avoid screening because of the inconvenience and
discomfort associated with certain currently available screening methods, with
the result that most colorectal cancer cases are detected at a later stage when
the cure rate is less than 50 percent.


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EXACT SCIENCES AND LABCORP ANNOUNCE EXCLUSIVE PARTNERSHIP AGREEMENT / PAGE 2


LabCorp's first payment to EXACT Sciences of $15 million was made upon the
signing of the agreement, and the second payment of $15 million will be made
upon the commercial launch of PreGen-Plus, which is expected in the first half
of 2003. Of the remaining $45 million, milestone payments from LabCorp totaling
$30 million will be based upon EXACT Sciences deliverables related to scientific
acceptance, reimbursement approval and technology improvements and $15 million
will be based upon the achievement of significant revenue thresholds. In
addition to these payments, EXACT Sciences will receive a royalty fee for each
PreGen-Plus test performed by LabCorp. In conjunction with the partnership,
EXACT Sciences has issued to LabCorp a warrant to purchase 1,000,000 shares of
EXACT Sciences common stock, exercisable over the next three years at an
exercise price of $16.09.

 "The proprietary technology underlying the PreGen-Plus assay creates a very
accurate and patient-friendly test, and therefore represents a significant step
forward in the early detection of colorectal cancer in the average-risk
population," said Thomas P. Mac Mahon, LabCorp's Chairman and CEO. "We believe
PreGen-Plus could be the most important molecular test identified to date for
the millions of Americans who are candidates for colorectal cancer screening
annually."

Mr. Mac Mahon continued, "Our agreement with EXACT Sciences is another example
of LabCorp's pioneering leadership position in molecular diagnostics and our
ability to recognize the potential of DNA-based testing. EXACT Sciences brings
that same visionary approach in applying the discoveries of the human genome to
create novel DNA-based assays that address major healthcare problems. We are
excited about combining our skills with EXACT Sciences' to improve diagnostic
testing for cancer."

"As the first DNA-based test that will be used for population-based cancer
screening, PreGen-Plus truly changes the molecular diagnostics landscape," said
Don Hardison, EXACT Sciences' President and CEO. "The scope of this partnership
- - both in economic terms and, more importantly, in terms of lives saved -
highlights the power of applied genomics. As a leader in bringing the knowledge
of the human genome to reality, EXACT Sciences is delighted to be working with
LabCorp, given its unique scale, expertise and infrastructure, to make this
important test widely available. We are confident that the fruits of our
strategic relationship will result in greater numbers of


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EXACT SCIENCES AND LABCORP ANNOUNCE EXCLUSIVE PARTNERSHIP AGREEMENT / PAGE 3


Americans being screened for the disease and the prevention of many deaths from
colorectal cancer."

PreGen-Plus works by isolating human DNA that is shed in the colon everyday and
carried out of the body in stool, and analyzing that DNA for mutations
associated with colorectal cancer. PreGen-Plus is a completely non-invasive,
patient-friendly technology that requires no dietary modification or bowel
preparation. The simple process involves collecting a single stool sample in the
privacy of a patient's own home, and shipping the sample in a supplied container
and packaging materials to LabCorp's facilities for analysis. Following the
analysis, LabCorp will send the test results to the patient's physician for use
in connection with future monitoring and treatment.

INFORMATIONAL CONFERENCE CALL

EXACT Sciences, with LabCorp participating, will host a conference call to
discuss this partnership at 8:30 a.m. ET on Thursday, June 27, 2002. A live
Webcast of the conference call, and an archived version following the completion
of the call, will be available at www.exactsciencescom, www.labcorp.com and
www.companyboardroom.com. The conference call and Webcast are open to all
interested parties. Information for the call follows:

         Call in number for listen-only participants: 212-676-5273

A telephone replay of the conference call will be available beginning at 11:00
a.m. on June 27th through July 11th. Information for the replay is as follows:

         Domestic callers:        800-633-8284

         International callers:   858-812-6440

         PIN #: 07-20-461

ABOUT EXACT SCIENCES CORPORATION

EXACT Sciences Corporation is an applied genomics company that has developed
proprietary technologies that may be used for the early detection of several
common cancers. EXACT Sciences has selected colorectal cancer as the first
application of its technologies. Colorectal cancer is the most deadly cancer
among non-smokers, and is curable if detected early. Despite the availability of
colorectal cancer screening and diagnostic tests for more than 20 years, the
rate of early detection of colorectal cancer remains low. EXACT Sciences
believes its genomics-based technologies will enable early detection of
colorectal cancer so that more people can be effectively treated. Founded in
1995, EXACT Sciences is based in Maynard, Mass. Detailed information on EXACT
Sciences can be found on the World Wide Web at www.exactsciences.com.


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EXACT SCIENCES AND LABCORP ANNOUNCE EXCLUSIVE PARTNERSHIP AGREEMENT / PAGE 4


ABOUT LABORATORY CORPORATION OF AMERICA

The first national clinical laboratory to fully embrace genomic testing,
Laboratory Corporation of America(R) Holdings (LabCorp(R)) has been a pioneer in
commercializing new diagnostic technologies. As a national laboratory with
annual revenues of $2.2 billion in 2001 and over 19,000 employees, the company
offers more than 4,000 clinical tests ranging from routine blood analyses to
sophisticated molecular diagnostics. Serving more than 200,000 clients
nationwide, LabCorp combines its expertise in innovative clinical testing
technology with its Centers of Excellence. The Center for Molecular Biology and
Pathology, in Research Triangle Park, North Carolina, offers state-of-the-art
molecular gene-based testing in infectious disease, oncology and genetics. Its
National Genetics Institute in Los Angeles is an industry leader in developing
novel, highly sensitive polymerase chain reaction (PCR) methods for testing
hepatitis C and other blood borne infectious agents. LabCorp's Minneapolis-based
ViroMed offers molecular microbial testing using real time PCR platforms, while
its Center for Esoteric Testing in Burlington, North Carolina, performs the
largest volume of specialty testing in the network. LabCorp's clients include
physicians, state and federal government, managed care organizations, hospitals,
clinics, pharmaceutical and Fortune 1000 companies, and other clinical
laboratories.

This press release contains forward-looking statements within the meaning of
Section 27A of the Securities Act of 1933, as amended, and Section 21E of the
Securities Exchange Act of 1934, as amended. These statements are subject to a
variety of risks and uncertainties, many of which are beyond EXACT Sciences' and
LabCorp's control. These risks and uncertainties could cause actual results to
differ materially from those contemplated in these forward-looking statements.
Existing and prospective investors are cautioned not to place undue reliance on
these forward-looking statements, which speak only as of the date hereof. EXACT
Sciences and LabCorp undertake no obligation to update or revise the information
contained in this press release, whether as a result of new information, future
events or circumstances or otherwise. For additional information regarding the
risks faced by EXACT Sciences, see the disclosure contained in EXACT Sciences'
public filings with the Securities and Exchange Commission including, without
limitation, its Form 10-K for the year ended December 31, 2001 and subsequent
Forms 10-Q; for the risks faced by LabCorp, see the disclosure contained in
LabCorp's public filings with the Securities and Exchange Commission including,
without limitation, its Form 10-K for the year ended December 31, 2001 and
subsequent Forms 10-Q.

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