Mammography provides a good example of how social, cultural, and political factors, in addition to experimental data, can influence the dissemination of medical technologies into clinical practice because even the best scientific information is subject to interpretation (reviewed by Lerner, 2001).

Although the use of X-ray imaging for the detection of breast cancer was first suggested in the early years of the 20th century, mammography did not begin to emerge as an accepted technology until the 1960s (see Figure 1-1). Between 1930 and 1960 a number of technical innovations were introduced to produce higher-quality images that were more reproducible and easier to interpret. Subsequently, the developers of the technology promoted its use, and some physicians began ordering mammograms to help with the diagnosis of complicated cases in which the physical examination was inconclusive.

The early reports of mammography's ability to detect small cancers coincided with increased public education efforts on the part of organizations like the American Cancer Society (ACS), which had launched a “war on breast cancer.” Before the introduction of mammography, ACS encouraged women to perform breast self-examinations and to seek medical attention for any breast lumps that they found. The advent of mammography was seen as a potentially powerful new weapon in this war. Even in the absence of clinical trials to test the value of breast self-examination or mammography, earlier detection was intuitively thought to be a good thing.

As the results of the first randomized controlled trial for the assessment of mammography as a screening tool were published over a number of years, the real potential of mammography to reduce breast cancer mortality seemed to have been realized (about 30 percent fewer deaths among screened women than among unscreened controls for women over age 50). The screening technology then began to diffuse more widely, in large part because of a demonstration project (a noncontrolled study) organized by the National Cancer Institute (NCI) and ACS. When preliminary results suggested that screening resulted in breast cancer detection at an earlier stage, the press and anticancer organizations like ACS enthusiastically spread the news. Anecdotal stories of women, both famous and unknown, whose cancers had been detected by mammography added to