As many as three-quarters of all breast lesions that are biopsied as a result of suspicious findings on a mammogram, turn out to be benign; that is, the mammographic findings were falsely positive. (Many tissue biopsies performed on lumps found by physical examination are also benign, but the false-positive rate for physical examination has not been carefully studied.) “Overdiagnosis” is the labeling of small lesions as cancer or precancer when in fact the lesions may never have progressed to a life-threatening disease if they had been left undetected and untreated.
In such cases, some of the “cures” that occur after early detection may not be real, and thus, such women are unnecessarily “overtreated.” Technical improvements in breast imaging techniques have led to an increase in the rate of detection of these small abnormalities, such as carcinoma in situ, the biology of which is not well understood. Currently, the methods for classification of such lesions detected by mammography are based on the appearance of the tissue structure, and the ability to determine the lethal potential of breast abnormalities from this classification is crude at best.
The immense burden of breast cancer, combined with the inherent limitations of mammography and other detection modalities, have been the driving forces behind the enormous efforts that have been and that continue to be devoted to the development and refining of technologies for the early detection of breast cancer. The purpose of the study described in this report was to review the breast cancer detection technologies in development and to examine the many steps in medical technology development as they specifically apply to methods for the early detection of breast cancer.
The study committee was charged with surveying existing technologies and identifying promising new technologies for early detection, and assessing the technical and scientific opportunities. The committee was further charged with examining the policies that influence the development, adoption, and use of technologies. Funding for the study was provided by seven independent foundations and individuals, including 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.
Sharyl J. Nass, I. Craig Henderson, and Joyce C. Lashof
Committee on Technologies for the Early Detection of Breast Cancer
National Cancer Policy Board INSTITUTE OF MEDICINE and Division of Earth and Life Studies
NATIONAL RESEARCH COUNCIL