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Date:  June 6, 2006
Contacts:  Christine Stencel, Media Relations Officer
Chris Dobbins, Media Relations Assistant
Office of News and Public Information
202-334-2138; e-mail <news@nas.edu>

FOR IMMEDIATE RELEASE

ASBESTOS EXPOSURE LINKED TO CANCER OF THE LARYNX;
EVIDENCE ABOUT LINKS TO CANCERS OF THE DIGESTIVE TRACT IS LESS CLEAR

WASHINGTON -- Sufficient scientific evidence indicates that asbestos exposure can cause cancer of the larynx, says a new report from the Institute of Medicine of the National Academies.  There is suggestive but ultimately insufficient evidence that asbestos exposure can cause cancers of the pharynx, stomach, colon, and rectum, added the committee that wrote the report.  The evidence is inadequate to draw any conclusions about esophageal cancer and exposure to this class of minerals.

The Institute of Medicine undertook the study to answer questions raised in congressional discussions about compensation for people with ailments associated with asbestos exposure.  The study committee assessed the quality, limitations, and applicability of 120 epidemiological studies of asbestos exposure and cancers of the throat and digestive tract.  It also considered information from approximately 200 experimental studies.  The committee classified the evidence as either sufficient to infer a cause-and-effect relationship; suggestive but insufficient to infer a link; indeterminate; or sufficient to infer that there is no connection.  

Cancer of the larynx -- the structure containing the vocal cords -- is relatively rare.  The American Cancer Society estimates that about 9,500 new cases of laryngeal cancer will occur this year and that about 3,740 people will die from it.  Smoking and heavy consumption of alcohol are the principal risk factors for this type of cancer.  The cumulative results of more than 50 epidemiological studies provided compelling evidence that asbestos exposure is associated with an increased incidence of laryngeal cancer and that the risk increases with the intensity and duration of exposure, the committee found.  Smoking alone or in combination with drinking may contribute to the accumulation of asbestos fibers in the lining of the larynx.

Some studies suggest that asbestos exposure is linked to a slightly increased risk of stomach, pharyngeal, and colorectal cancer, but in each case the cumulative results of the relevant studies were not strong enough to determine that there is a causal relationship.  The committee found the evidence suggestive, but still too uncertain.  In the case of esophageal cancer, there is not enough evidence to draw conclusions.

The study was sponsored by the National Institutes of Health at the request of Sen. Arlen Specter, R-Pa.  Established in 1970 under the charter of the National Academy of Sciences, the Institute of Medicine provides independent, objective, evidence-based advice to policymakers, health professionals, the private sector, and the public.  A committee roster follows.

Pre-publication copies of ASBESTOS: SELECTED CANCERS are available from the National Academies Press; tel. 202-334-3313 or 1-800-624-6242 or on the Internet at HTTP://WWW.NAP.EDU.  Reporters may obtain a copy from the Office of News and Public Information (contacts listed above).

[ THIS NEWS RELEASE AND REPORT ARE AVAILABLE AT HTTP://NATIONAL-ACADEMIES.ORG ]  

INSTITUTE OF MEDICINE
Board on Population Health and Public Health Practice

COMMITTEE ON ASBESTOS: SELECTED HEALTH EFFECTS
 
JONATHAN M. SAMET, M.D. (CHAIR)
Professor and Chairman
Department of Epidemiology
Bloomberg School of Public Health
Johns Hopkins University
Baltimore

LONNIE R. BRISTOW, M.D.
Consultant, and
Former President
American Medical Association
Walnut Creek, Calif.

HARVEY CHECKOWAY, PH.D., M.P.H.
Professor
Department of Environmental and Occupational Health Sciences
School of Public Health and Community Medicine
University of Washington
Seattle

PAUL DEMERS, PH.D.
Associate Professor
Department of Health Care and Epidemiology
University of British Columbia
Vancouver, British Columbia
Canada

ELLEN A. EISEN, SC.D.
Professor of Epidemiology
Harvard School of Public Health
Boston

GEORGE D. GUTHRIE JR., PH.D.
Scientist
Geology and Chemistry Group
Los Alamos National Laboratory
Los Alamos, N.M.

ROGENE F. HENDERSON, PH.D.
Senior Scientist
Lovelace Respiratory Research Institute
Albuquerque, N.M.

JOSEPH W. HOGAN, SC.D.
Associate Professor and Graduate Program Chair
Department of Community Health and Center for Statistical Sciences
Brown University
Providence, R.I.

AGNES B. KANE, M.D., PH.D.
Professor
Department of Pathology and Laboratory Medicine
Brown University
Providence, R.I.

FADLO R. KHURI, M.D.
Professor
Winship Cancer Institute
Emory University School of Medicine
Atlanta

ROBERTA B. NESS, M.D., M.P.H.
Professor and Chair
Department of Epidemiology
Graduate School of Public Health
University of Pittsburgh
Pittsburgh

MICHAEL J. THUN, M.D.
Vice President
Epidemiology and Surveillance Research
American Cancer Society
Atlanta

INSTITUTE STAFF

MARY PAXTON
Study Director