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Date: March 8, 2001
Contacts: Saira Moini, Media Relations Officer
Mark Chesnek, Media Relations Assistant
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New Technologies for Breast-Cancer Detection Demand More Study;
Film Mammography Remains Gold Standard

WASHINGTON -- Although several new technologies on the horizon show promise for improved capability to detect breast cancer, none have yet proved superior to traditional, X-ray film mammography in screening for breast cancer, says a new report from the Institute of Medicine (IOM) and National Research Council of the National Academies. More evaluation and development of new imaging tools and of promising molecular biological techniques is required and warranted.

"With all of its limitations, film mammography remains the gold standard against which new imaging technologies will be measured," said Joyce C. Lashof, chair of the committee that wrote the report and professor emerita, School of Public Health, University of California, Berkeley. "To date, no quantum leap has been made in this area. At the same time, many of the newer tools offer certain advantages and deserve to be studied further."

In fact, no single imaging technology is capable of accurately detecting all breast abnormalities, the report says. Ultimately, the best detection may come from using several different tools. For example, ultrasound and magnetic resonance imaging have shown potential as adjuncts to mammography in diagnosis and screening, especially in getting a clearer picture of dense breast tissue in certain women.

In addition to evaluating scientific evidence on the new technologies, the committee examined the process by which newer screening technologies work their way through the pipeline from testing to routine clinical usage. The report raises a concern that technologies approved for diagnosis could be prematurely adopted for screening, noting that diagnostic tools help determine the nature of a breast abnormality first detected through screening and may not be appropriate for both purposes. In evaluating a new technology's appropriateness for screening, the U.S. Food and Drug Administration (FDA) and the Health Care Financing Administration should base approval and coverage decisions on results of clinical trials that prove screening effectiveness, the committee said.

To accomplish this goal, a more systematic approach is needed for the assessment of screening tools, the committee said. Such an approach must involve clinical trials that are coordinated and designed with support and input from relevant federal agencies and breast-cancer advocacy organizations. Private insurers also should do their part by covering the costs of screening tests for women who participate in clinical trials but are not eligible for Medicare or Medicaid -- government programs that were created to cover health care costs for seniors and individuals with certain disabilities or limited incomes.

Because detection technologies and treatments are continually evolving, the National Cancer Institute (NCI) should sponsor clinical trials every 10 to 15 years to reassess the effectiveness of established screening tools, the report says. In addition, since age distribution in the United States is shifting toward an older population, the NCI should collaborate with other organizations in sponsoring further studies to assess the benefits and risk of mammography in women over age 70.

While imaging technologies indicate structural differences or changes in the breast, such as microcalcifications or new growths, some of the latest molecular biological technologies can provide information about the cellular characteristics of these abnormalities -- potentially leading to more accurate screening and diagnosis. Therefore, the committee also examined a number of tools such as growing breast cancer cells in the lab and identifying the genetic changes in particular kinds of tumors.

To increase understanding of the cellular characteristics of different tumors, researchers need specimens of breast tissue and fluids containing precancerous and cancerous cells. NCI should facilitate expansion of breast cancer specimen banks, both in number and resources, the committee said. This would aid identification of early-stage abnormalities that could become lethal. Women who contribute specimens for research should be assured confidentiality and protection against genetic discrimination.

Greater public access to current technologies is needed, particularly for women who lack health insurance, the report urges. Congress should expand the Centers for Disease Control and Prevention breast-cancer screening program to reach more women -- from the current 15 percent to 70 percent -- and state legislatures should provide Medicaid funds for treatment of women with breast cancer identified through this screening program. In addition, the Health Care Financing Administration and a panel of independent experts should analyze the current Medicare and Medicaid reimbursement rates for mammography and comparable radiologic techniques to determine whether the cost is adequately covered. Federal agencies and professional organizations should evaluate the current and future numbers of radiologic specialists and take measures to ensure an adequate supply of these experts.

The committee evaluated imaging tools currently available, examining film mammography and 17 other technologies. These included ones with FDA approval, such as full-field digital mammography, ultrasound, computer-aided detection systems, and magnetic resonance imaging, as well as those not yet approved, such as optical imaging. Many appear to offer varying degrees of potential for screening or diagnosis -- in some cases, both -- but more research is needed. No studies have shown a new technology to be a replacement for film mammography, for either screening or diagnosis. For instance, while digital mammography has been lauded as a major technical advance -- facilitating storage, retrieval, transmission and image adjustment for mammograms -- it has not shown greater accuracy than its nondigital counterpart.

There are multiple reasons for the push to develop new imaging and diagnostic technologies. Among women in the United States, the death rate from breast cancer has been decreasing by about 2 percent annually over the past decade, suggesting that early detection and improved therapy are having an impact on the disease, the report says. Despite these optimistic findings, the fact remains that film mammography does not detect all cancers, particularly among younger women, who often have denser breast tissue that is more difficult to view with X-ray technology.

Film mammography also cannot prevent all deaths from breast cancer because it may not detect fast-growing malignancies early enough to effect a cure. Routine screening in clinical trials resulted in only a 25 percent to 30 percent decrease in breast-cancer mortality among women between the ages of 50 and 70, and a lesser benefit was seen among women aged 40 to 49.

As significant, of all breast lesions that are biopsied following suspicious findings on a mammogram, fully 75 percent turn out, in fact, to be benign. In addition to this high rate of "false positives," current screening methods also can lead to overdiagnosis and overtreatment of some women. Earlier identification of breast-tissue abnormalities will remain problematic, the report says, until a deeper understanding of the biology and genetics of such abnormalities makes it possible to distinguish those that are non-threatening from those that may become invasive and progress to full-blown, metastatic breast cancer.

The study was sponsored by the Breast Cancer Research Foundation, the Carl J. Herzog Foundation, Mr. John K. Castle, the Jewish Healthcare Foundation, the Josiah Macy Jr. Foundation, the Kansas Health Foundation, and the New York Community Trust. The National Research Council -- the principal operating arm of the National Academy of Sciences and National Academy of Engineering -- and Institute of Medicine are private, nonprofit institutions that provide science and health policy advice under a congressional charter. A committee roster follows.

Read the full text of Mammography and Beyond: Developing Technologies for the Early Detection of Breast Cancer for free on the Web, as well as more than 1,800 other publications from the National Academies. Printed copies are available for purchase from the National Academy Press Web site or at the mailing address in the letterhead; tel. (202) 334-3313 or 1-800-624-6242. Reporters may obtain a pre-publication copy from the Office of News and Public Information at the letterhead address (contacts listed above).

National Cancer Policy Board

Committee on Technologies for the Early Detection of Breast Cancer

Joyce C. Lashof, M.D., FACP* (chair)
Professor Emerita
School of Public Health
University of California

Craig Henderson, M.D. (vice chair)
Adjunct Professor of Medicine
School of Medicine
University of California
San Francisco

D. Craig Allred, M.D.
Professor of Pathology
Department of Pathology
Breast Cancer Center
Baylor College of Medicine

Derek Van Amerongen, M.D., M.S., FACOG
Chief Medical Officer
Humana Choice Care

Wade M. Aubry, M.D.
Vice President
The Lewin Group, and
Associate Clinical Professor of Medicine
Institute for Health Policy Studies
University of California
San Francisco

Janet K. Baum, M.D., FACR
Associate Professor of Radiology
Department of Radiology
Harvard Medical School, and
Director of Breast Imaging
Beth Israel Deaconess Medical Center

Suzanne W. Fletcher, M.D., M.Sc.*
Professor of Ambulatory Care and Prevention; and
Professor of Medicine
Brigham and Women's Hospital
Harvard Medical School; and
Professor of Epidemiology
Harvard School of Public Health

Marthe R. Gold, M.D., M.P.H.
Arthur C. Logan Professor and Chair
Department of Community Health and Social Medicine
City University of New York Medical School
New York City

Leon Gordis, M.D., M.P.H., Dr.P.H.*
Professor of Epidemiology
Department of Epidemiology
School of Hygiene and Public Health, and
Professor of Pediatrics
Department of Pediatrics
School of Medicine
Johns Hopkins University

Daniel F. Hayes, M.D.
Clinical Director
Breast Cancer Program
Lombardi Cancer Center
Georgetown University Medical Center
Washington, D.C.

M. Carolina Hinestrosa, M.A.
Co-Founder and Executive Director
Nueva Vida, Support Network for Latinas with Cancer
Silver Spring, Md.

Jean J. Latimer, Ph.D.
Magee-Womens Research Institute, and
Assistant Professor
Department of Obstetrics, Gynecology, and Reproductive Sciences
University of Pittsburgh

Richard R. Nelson, Ph.D.
George Blumenthal Professor of International and Public Affairs
School of Law, School of Business, and Graduate School of Arts and Sciences
Columbia University
New York City

Kenneth Offit, M.D., M.P.H.
Chief of Clinical Genetics Service
Department of Human Genetics
Memorial Sloan-Kettering Cancer Center, and
Associate Professor of Medicine
Weill Medical College of Cornell University
New York City

Faina Shtern, M.D.
Office of Research Affairs and Technology Transfer
Department of Radiology
Beth Israel Deaconess Medical Center
Harvard Medical School

Michael W. Vannier, M.D.
Professor and Head
Department of Radiology
University of Iowa College of Medicine
Iowa City


Sharyl J. Nass, Ph.D.
Study Director

* Member, Institute of Medicine